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Models for European Digital Islands 5 FRAMEWORK PROGRAMME DG-INFSO EUROPEAN COMMISSION Objectives

• Providing an advanced picture of the state of the art about telecommunications and telematic infrastructures and services in European islands. • Facilitating the provision of community services and the use of telematics in different sectors and activities such as health, social exclusion, transport and business. • Defining and evaluating new models of telecommunications networks and telematic services for European islands and other isolated or geographically dispersed areas, where teleeducation, tele-training, tele-work and e-commerce will not be the final objective but a set of useful instruments used for the benefit of the local communities and local authorities. • Profiling alternative network telecom infrastructure and services in the European islands, isolated and less developed areas with potential for use in ISapplications. • Helping local authorities to shift public strategies from infrastructure conditioned to service oriented.

www.teleinsula.com Teleinsula is more than a portal, a common access point for a networtk of services and applications. Its origin was the Teleinsula project and now it is managed by the MEDIS project. Participants: INSULA (Co-ordinator) SILTANET Ud. - PROODOS S.A - ITER - CIES - ERIS@- ANClNET UNESCO (Sponsoring partner) - CEMR (Sponsoring partner)


./

editorial

by C!PRIANO

5

MARfN

oosser cric wacer-enerau

DlnomlaL

Research and Tecnological Applications in Solar Desalination by E.

/

DELYANNIS,

V.

BELESSIOTIS

13

Desalination systems using renewable energy sources in mediterranean countries

19

KONTONI,

THEOCHARIS TSOUTSOS

Brackish groundwater desalination. An alternative water supply strategy for seasonally-demand stressed mediterranean coastal regions by E. GEORGOPOULOU, A. KOTRONAROU, A. KOUSSIS, P.J. RESTREPO

23

Experiences of enewable energy desalination plants

29

by

RICHARD MORRIS,

PLATON BALTAS

Sustainable desalination, distribution, sewage and re-use in the Cape Verde archipelago by JOAN

by AHMED

by DIONYSIS

ASSIMACOPOULOS,

The annual regime and persistence of precipitation in Robinson Crusoe Island VICTORIA MARZOL,

ncurs =rorn ono coouc ISlondS \. rd 3 Workshop of the Alliance of Smalllsland States (AOSIS) on Climate Change, Energy and Preparations for the 9th Session of the Commission on Sustainable Development

InSUlo'S oooc RD&IS 2002, International conference and exhibition Sustainable Hotels for Sustainable Destinations unesco's

53

PILAR CERECED, JAVIER MARTfN VIDE

Energia e Acqua nelle Isole Minori Energy and Water in Smalllslands. International Conference. Alghero, 12-13 April2001, Sardinia-Italia ..1

47

EL-NASHAR

ist.cnocr-s oc worh by MO

I

41

ARTOHUROS ZERVOS

Small stand-alone solar MED and solar RO seawater desalination plants M.

37

MUHAIDAT

The cost of water RES powered desalination systems

by ALI

35

FAGES

Qatar - Producing drinkable water using reverse osmosis (RO) desalination system powered by solar energy

60 61 62 63

DOOL

Mab and islands: The new priorities Thirsty islands Developing renewable energies on small island Biosphere Reserves OOOh rcucius

70 70 71 72

orr-ounccmcr ce Island 2010, Towards 100% Res supply renewable energy sources for island sustainable development JOln ono SUDDort risu.o I

IU ..J

e o ,

'-'

Water: The absence of precious resources problems and solutions by l. P.GLEKAS, E. STYLlANOPOULOU by MARIA

/

7

en e

..J

75 77


rnsula International

ISS

Journal of Island AtTairs

1021 - 0814

January

2001

Year 10 N° 1

Editorial Board The last INSULA 's Board of Directors met in October 2000 and approved the inclusion of new members, as well as the re-organisation of tasks in the different fields and geographic areas. New vice-chairpersons have been

Editor:

Pier Giovanni d' Ayala

elected for the each geographical region: Northern Europe and Baltic (Reet Kokokvin - Estonia}, Southern Europe (Emmanuela Doussis - Greece), Central

Co-editor:

& Eastern Europe (Anamarija Margan - Croatia), East Asia & Pacijic (Hiroshi

Cipriano Marín

Kaka;u

- Japan}, Africa

(Nelson

Cabral - Cape Verde), Americas and Carib-

bean (Ronald Parris - Barbados). Franco Cavallaro (Sicily) and Chris Mavris

Scientific Advisory Committee:

(Cyprus} are the other new members

included in the Board.

Prof. Salvino Busuttil, Malta Dr. Ronald G. Parris, Barbados Prof. Nicolas Margaris,

Greece

Prof. Patrick Nunn, Fiji ProfG. Prakash Reddy, India Prof. Hiroshi Kakazu, Japan Dr. Henrique Pinto da Costa, Sáo Tomé e Principe Prof. Lino Briguglio, Malta

Production coordinator:

Giuseppe Orlando

Graphic designer:

Luis Mir Payá

Hiroshi

Kakazu

Anamarija

Nelson

Cabral

Ronald

Parris

Margen

Published by INSULA, the International Scientific Council for Island Development, with the support of UNESCO. Articles published in this journal do not necessarily retlect the opinions of INSULA or of UNESCO. Material appearing in this journal cannot be reproduced without the prior permission of the Editor.

•ínaula., the lnternational

Journal of lsland Affairs is distributed free to INSULA's individual and institutional members. For subscriptions and information, please write to:

•Irrs'ula c/oUNESCO l,rueMiollis 75732 París, FRANCE Tel.: +33 145.68.40.56, Fax.:+33 145.68.58.04 E-mail: insula@insula.org

Produced by: TENYOEA

4

International

Journal

S.L. Canary

Islands

of Island Affairs

Peter Bridgewater {Australia¡

is the

neIV UNESCOMAB representative in the lnsula 's Board of Directors.

Traditional fishing in the coastal isLands of Oman

Photo: INSULA


Water and Energy Keys lo eradicale Ihirsl on islands by

Nw

island specialisations

in the 1", decades and the evolution of their popula-

tion have a c1ear reflection in their water resource availability and their increase in energy

consumption. Increasing water shortage is generating new risks such as competition with traditional agricultural activities or removal of resources from fragile, valuable and unique ecosystems. Enormous economical and territorial distortions are therefore generated, situations that should be foreseen on time to avoid irreversible outcomes. Water and energy are now two sides of the same problem, c1early defining one of the key development dilemmas of the forthcoming years. lslands increasingly fall back on seawater desalination, almost always powered by conventional energy sources, encumbering even

~

more their economies and increasing their extreme energy dependence. The solution ofthis paradigm cannot be based only on planning policies and efficient use of water resources. The water-energy

equation can and should be resolved by joining new

c1ean energy technologies and the possibilities offered by seawater desalination. We have becn able to verify in a few years that new RES-powered desalination methods reached an acceptable state of technological

maturity that allows to design scenarios where energy

dependency is progressively reduced and traditional water resources are allowed to recuperate, preserving islands against further depletion. This is one of the key ideas on which the lsland 2010 (Towards 100% Renewable Energy Sources Supply) initiative, developed with the EC's Altener programme support, is based. This Dossier on Water and Renewable Energies tries to bring new ideas for this technological alliance with a high strategic value for island regions. With the help of Prof. Arthouros Zervos and the RENES (Renewable Energy Source Unir) ofthe National Technical University of Athens, we included in this issue some of the most outstanding results presented on the occasion of the Conference "Policies and Strategies for Desalination and Renewable Energies" he Id on the island of Santorini in the last month of June. Within the same context initiatives such as the Forum "Sustainable Hotels for Sustainable Destinations" bring original solutions in favour of a responsible tourism in island realities with their distinctive factors. A tourism where the sun and the wind would actually contribute to their improvement and not to their depletion and, at least, avoid islands increasing thirst or importing more energy than they can pay.

C!PRIANO

!O

e

o o

..J

U

MARĂ­N


International

Objectives of the Conference:

Conference

Renewable Energies for Islands Towards 100% RES Supply,~

NTUA-RENES,

tive in island areas and small and medium sized islands. • Oisserninate the 100% RES integrated technological

systems.

• Identify feasible 100% RES opportu-

-c

Chania-Crete, Greece 14-16 June 2001 Organised by:

• Pro mote the 100% renewable objec-

nities in islands. • Binornial Water-Energy.ldentification of appropriate technologies, barriers for RES - Oesalination applications in small and medium-sized islands.

~ .OPEII

~

,s"aau

National

Technical University of Athens

RENES

• Promote inter-island and international co-operation

in favour of develop-

ing renewable energies on islands. • Indicate legal frameworks and regulatory solutions that facilitate their integration.

Co-organisers: Insula, Iter, Ademe

• Promote effective alliances and marThe European

Commission's

White

Paper "Energy for the Future: Renew-

ket strategies. Reinforce dedicated renewable en-

acteristics. • The environmental impact of con ven-

ergy information systems for islands.

munity Strategy and Action Plan to in-

tional sources and technologies are

• Training andoeducation in renewable

crease RES market penetration, to im-

greater than on the mainland because

able Energy Sources" sets out a Com-

energy in islands. • Identify necessary awareness actions

prove security of energy supply, to re-

of the fragile and vulnerable nature

duce energy dependency, and to reduce

of island territories.

that help to consolidate the essential

greenhouse gas emissions in order to meet the Kyoto objectives.

On the other hand, the Barbados

role of renewable energies in energy

Conference on islands and small island

supply, quality of life and the environ mental protection of islands.

In order to foster the implementation

states, he Id in 1994 under the auspices

process ofthe Community Strategy and

of the United Nations, established that

Action Plan, the European Commission has launched "The Campaign forTake-

one ofthe basic de'termining factors for ~. sustainable and equitable development

Participant.: - Government decision-makers.

Off' that runs from year 2000 to year

of islands lies in energy aspects. Sub-

- International agencies and programs

2003. One of the key sectors of "The

sequently, the Island Solar Summit, held

- Responsible

Campaign for Take-Off" is the "100

in Tenerife in 1999 confirmed that most

Communities Aimed at 100% RES Sup-

islands

realized

that

the energy

ply". Islands constitute an ideal field

sustainability strategy is one ofthe big-

for implementing the Community's key

gest development

action to strive for 100% RES supply:

moment. This strategy has been shaped

• Islands have a very rich RES poten-

in the Island Solar Agenda.

challenges

of this

tial most of which is not exploited yet.

Today, the maturity ofRES technologies offers the opportunity for islands to succeed energy independence,

ent on outside energy.

the large-scale

exploitation

s of islands'

management. - Energy agencies that deal with islands. - Island Universities, research centers and technical institutes.

by

- Industrial associations and operators. - Technology

providers and service

suppliers.

of their

Contact:

ten times higher than in other re-

abundant RES potential. An idea c1early

gions.

expressed in the agreements stemmed

Prof. Arthouros

Zervos

• Local economies are very often de-

from the 1st European Conference on

NTUA-RENES,

National

pendent on tourism and the related

Sustainable Island Development (1997):

industry is developing fast. As a re-

"Energy sources other than renewable

sult, energy problems (due to high

must be considered as provisional so-

Tel.: +30-1

7721030

seasonal differences in demand and

lutions unsuitable to solve in the long

Fax: +30-1

7721047

to power load peaks) and environ-

term the energy problem in islands."

E-mail: Zervos@fluid.mech.ntua.gr

Tnternational

Journal

of lsland

Affairs

energy

- Inter-island co-operation networks.

• Most islands are extremely depend• Electricity generating costs can be

6

mental problems are common char-

Technical University of Athens 9, Heroon Polytechniou GR-15780

Str.

Zografu-Athens.

GREECE


Research and Tecnological Applications in Solar Desalinalio··

")

~ L lJ l

U iJ 10

:3

lJ

r

L

lJ

(f) (f)

O

O by

W,c<oun,,,;n

the south

tems the benefit

can be doubled:

E.

V.

DELYANNIS*,

technical, construction and operation,

part of the Greek mainland and most of

desalted water and thermal or electri-

procedure. The second type, the "indi-

the small islands in the Aegean sea ar-

cal energy supply.

rect method" involves two separa te

chipelagos have more or less restricted

Around Mediterranean

basin there

systems: the collection of solar energy,

water resources to totall y lack of water.

exist many coastal and inland arid or

In mainland small rivers carry very lit-

serni-arid regions, e.g., the north Africa

system,

tle or no water at summer time and dur-

coast from Suez canal up to Algeria is

desalination method. Both systems re-

arid characterized by very small rain-

quire a higher degree oftechnical skil!.

fall, abundant solar intensity and high

The direct solar energy method uses

ing winter

they turn to torrential

streams rushing all water to the sea. In

by a conventional coupled

solar converting to a conventional

these places drinking and good water

salinity sea water but no sufficiently

a variety of simple stills, indirect meth-

shortage is often very acute prevent-

fresh water resources. Almost all is-

ods use thermal or electrical energy

~.

ing even exploitation of natural goods.

lands in Mediterranean

In many islands rain still is collected in

prus, Malta and the numerous smaller

basin, as Cy-

individual residential cisterns or it is

islands suffer more or less from water

transported

shortage. Large cities have install large

in non affordable

high

capacity

pnces, from mainland.

conventional

desalination

and can c1assified as follow: • distillation methods using solar collectors • electrodialysis:

using high concen-

tration solar collectors, photovoltaic

It is important to remember that wa-

plants but small communities can be

ter supply is a strategic commodity and

satisfied with solar desalination plants,

has to be as possible of good quality and low cost.

solar distillation or small capacity solar

• reverse osmosis: using photovoltaic

plants (or alternative energy powered),

or wind energy power generation

Low humidity and intensive solar ra-

if water is needed for agricultural pur-

diation, almost 300 days per year, run solar

energy,

geothermal

but also

wind

poses or other use.

energy a very attracti ve

Solar energy is obviously the old-

eration

Solar distillation is a very old procedure known from the antiquity as con-

and

application for desalination purposes.

and/or wind energy for power gen-

SOLAR DESALlNATION METHODS

ception, but though the first practical,

Solar desalination

years ago, no important or sophisti-

processes

can be

large scale, application was about 125

devised in two rnain types: The "direct

cated

mano It is inexhaustible but dilute and

method", which involves the creation

achieved since because this type of

this creates few problems that can be

of a single unit incorporating both so-

est and most popular energy used by

improvements

have

on the other

lar energy and energy collection in one

hand is a very intensive energy indus-

device. They have a simple structure

Solar & Other Energy Systems

trial process. Coupling the two sys-

and does not require a sophisticated

Laboratory

solved.

Desalination

* NCSR "DEMOKRITOS", - GREECE

been

BELESSIOTlS*


plants

offer little design

future improvements ertheless

freedom

are limited. Nev-

they are almost

solution

and

the perfect

for poor very small comrnuni-

can be classified

in two main catego-

ries: the single

effect

basin

There is a big variety ofboth

portant,

fering

lacking financing desalination

a very recent Started

means. methods

historical

over

background.

the last three

when desalination

ha ve

decades were ma-

methods

ture and solar energy plants, due to the oil crisis, were in intensive

experimen-

Remote

coastal areas in the Medi-

01'

terranean

good qual-

basin are lacking

ity fresh

water

but having

abundant

seawater

or brackish water. Small corn-

munities

up to 1000 people can be sat-

isfied with small units say lOto 100 m' d-I which may be more reliable many

mainly

cases

and in

more cost effective

water transport However,

than

from long distance.

solar energy

increase

uncontrollable

and can not managed

by man, thus for solar desalination

the

devices

efficiency.

to technical simultaneously

tillation

an efficient

devise

may not be economic

lar devise for solar distillation For small communities ble water, design

must be as simple as human factors

must be taken in consideration.

important

factor affecting

water. Construction

als must be not expensive as possible available

sup-

may be also unsteady

cal application

Greek

any practi-

referred.

so me references

There

exist

on solar distillation

during

the mediaeval

period,

mostly experimental.

and as much

and renaissance The first

with

raisins

wood,

Figure

l presents

the Kimolos

lation plant of total surface m2, now out of operation, and totally

nance.

plant

build in Porto

Chile, of 22.5 m3 d-I capacity.

concrete

alurninum

operation

to

impregnated

resistance

was in 1872 when a solar in Las

can be, according

\

seawater

application

was erected

The figure

distil-

area 2508

due to wrong

the plant

Madeira,

same pattern as the Kimolos

in the

plant, to-

tal surface area of 1200 m2â&#x20AC;˘ Is the only

mental studies

one still in operation

but no any large instal-

USA and the Academy Turkmenia,

solar distillation for potable for seepage

of ex SSR in

started programs to pro mote

a single

within Europe.

the operation

efficiency

basin green-house

of

type solar

still is low, about 35 %. For this reason

in arid places,

either

many attempts

water

crease still output. Sharma (1993) gives

(Delyannis

& Belessiotis,

a model

have been made to in-

that predicts

the hourly

put, by using an approximate

The next decades numerous

Normally

water or for drinking

19%)

distillation

were developed devices

which

on the inside

tation procedure

SUf-

as soon as they are formed

in

the still air space and are condensed

at

( Hussain

& Rabin,

1995). They claim thermal efficiencies 60 %. The factors that

70 and overall influence

the performance

fect solar

stills

of single ef-

are analyzed

by EI-

(1993). There exist numerous but still no large

plant erected

according

to

these findings.

suitable

The activities of the Solar Laboratory In the Solar and Other Energy Systems Lab.

lack of mainte-

presents

Santo,

and alloy.

Since then where reported many experilation until the 60th when OSW in the

tracted

Bassouni

differ-

are not

labor. Material

availability

distillation Salinas,

materi-

in local market.ln

and operation

local market

by many ancient

to condense

or medium

of construction

but without

allowed

vapors

face of the glass cover but they are ex-

papers on the subject

Solar distillation

is a very old concep-

cline solar still where

rable as there exist considerable

Solar distillation

philosophers

the price of

ences in material cost as well as in con-

source.

COII-

tugal

many cases cost is not totally compa-

struction

tion expressed

and

is another

produced

is to find the

energy, which

plan!

Germany, and LREC, Por-

low temperatures

of construction

demands

water and electricity

A low

for operation

is necessary.

Materials

by Gn,

plants.

lacking pota-

To be reliable

ski lIed personnel

The Porto Santo solar distĂ­llation structed

the most popu-

strategy

ply with a any renewable

Thus

"green house" type, sin-

the simplified

energy

desalinated

and

solar dis-

water produced.

gle effect unit remains

possible.

due

increase

cost of installation

cost of operation,

most important

for

uses in-

details

which

way

to match

to feed the still with

hot water. A novel technique

parts to

01'

Nevertheless,

reasons,

maintenance

is inherently

flat -plate collectors,

to

types dif-

in construction

and in combining

for the potable

tal stage.

type of still coupled

fect stills found the larger application.

ties having lack of water and more im-

Indirect

type and

effect stills. The single ef-

the multiple

ied the same

out-

compu-

for most sin-

gle effect solar stills. Yadav (1993) stud-

of NSCR

progress

"Demokritos"

are in

studies on asymmetric,

green-

house type solar stills. The purpose to study the best operating

conditions

suitable for the Greek environrnent, is insolation

is

that

around

the year, affect of

wind, and efficiency

coupled with a low

cost fresh water production.

The results

of the experimental

work, on a real-size

solar still include,

models

performance,

applicable

that predict

to all types sin-

gle effect, green-house solar stills, The models take in consideration and

constructi

(Belessiotis

ng

operating parameters

et al., 1996, Voropoulos

et

al., 1996,2000, Mathioulakis et al., 1999). The aim of these extensive to combine

solar distillation

time and sensible

studies

is

during day

heat storage,

in one


device, for night operation.

Further

more to combine f1at-plate collectors for efficiency increase and if necessary for hot water supply, especially in cases where

there exist

brackish

water

sources. Such systems can be useful eitheras individual unitsorforsmall

to

medium size solar plants.

Mulliple effecl solar slills There is a big variety of this type of solar stills but until to day no any solar

water (Delyannis 1989, Block, 1989).

The plant in La-Luz, of 15.1 m-d-I

disti lIation plant has been erected.

There exist numerous

solar driven

capacity using brackish water as feed

They are all either experimental devices

desalination plants of small or medium

water. Energy is provided by a pho-

or units field tested. Hamad et al. (1993)

capacities. A rather detail tabulation is

give an analysis of so me of the numer-

referred in CRES (1998). A selected

2 The plant in Oshima island, Japan,

number of the most important solar

erected in 1988. It has a capacity of

desalination

6.5 m'd-I and is powered by a 25 kW-

ous multiple effect solar stills.

Solar driven desalinalion

plants that have been

erected from the 80ths up to day are

tovoltaic field of S kW out put

peak photovoltaic array

given informatively in this paper. Most

Solar driven desalination may be ap-

of them are demonstration plants. Fig-

Solar powered RO

plied for larger communities

ure 3 gives

the first solar driven

Reverse osmosis is the most widely

good quality water, as is the case of

desalination

MSF plant of 7.0 rn''d-l

many countries across Mediterranean

capacity, constructed in 1979.

lacking

solar driven desalination process. Has the advantage that can be installed in modules the number of which can be

basin in the African and Middle East The distillation plants

increased according

these places made the water problem

1 The MEB evaporation plant at Abu-

capacity. The modules are compact, but

very acute. Almost all countries around

Dhabi, UAE, erected in 1984 and is

there is the disadvantage of the short

Mediterranean Sea are situated in the

still in operation. Has a maximum ca-

membrane life which by now is ex-

so called "sunny belt". Thus coupling

pacity of 120 m'd-I. The solar field

tended up to 6 years. Reverse osmosis

a solar energy conversion system, ther-

consists of evacuated

mal or electrical power, with small ea-

torso Three storage tower provide 24

conversion

hour operation.

photovoltaics

coasts. The demographic

growth in

pacity conventional desalination plant may be the solution to the problem, The

t be collec-

2 in Safat, Kuwait a field of220 rn-Iine concentrating

parabolic

to the required

desalination units require solar energy plants,

wind energy or

to supply the system

with electrical or mechanical energy to

past 30 years were installed many solar

focus

driven desalination plants the majority

troughs provides with thermal en-

of which were erected to provide water

ergya 12-stage, self regulating MSF

and electricity and in the same time as

plant. The plant was built in 1985.

cial system producing 5.7 m'd-I powered by a photovoltaic array of l 1.2

prototypes to study operational

con-

3 The 10-stage MSF plant in La-Paz,

ditions for further improvement

and

Baja California, Mexico. Thermal en-

cost reduction. Solar driven desalination ths

about the 70

started

and despite the numer-

run the RO units and the pumps. l. At Doha, Qatar, a prototype commer-

kW-peak

ergy is provided by a field of double

2. The Jeddah, Saudi Arabia, SWRO

tube f1at-plate collectors of total ef-

plant which operates on 12 hour ba-

fective surface area S 18.4 m",

sis producing 3.2 m3. It is powered

ous studies and projects proposed so-

4 At El-Paso, USA, aMEB desalination

by a 8 kW photovoltaic array to sup-

lar driven plants consist only about

plant of 19 m-d-I uses as heat source

ply energy to the RO units and to the

0.02% of conventional

fuel driven,

a solar pond. The solar pond of 3355

pumps.

desalination plants. Studies found prac-

m2 total surface area provides ther-

tical applications

mal energy and electricity.

started by an US-

Saudi Arabia agreement about the 80ths to promote solar driven desalination.

Electrodialysis plants

The project called "SOLERAS" had ca-

Electrodialysis

pacities 100 to 400 m'd-I desalinated

application:

found not wide solar

COMPARISON OF SOLAR DESALlNATION PROCESSES Up to day RO is the most successful system and the most in practical appli-


~

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v.,

10

Voropoulos K., Delyannis E.,

Experimental and theoretical method lor the determination 01 the daily output 01 a solar

still:impute

-output

method,

Desalination 100,99-104,1996 Belessiotis

V., Delyannis

E.,

Solar

desalination. Is it effective?, part 11,Solar

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small communities, Brace Research lnsti-

periment, Desalination, 100,27-34,1995

tute, Tech. Rep., No MT-6, August 1968

Delyannis

E., Status

01 solar assisted

Mathioulakis M., Voropoulos K., Belessiotis

desalination. A review, Desalination, 67,3-

v.,

19,1987

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Abdel-Monem

A. EI-Basuni, Factors inllu-

encing the performance 01 basin-type so-

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lar desalination units, Desalination 93, 625-

lorced condensing technique in a moving

ter Reuse, 5, (No 1), 28-33,1996

632,1993

lilm

Block D. L., Solardesalination 01 water, Florida

Hamed O. A., Eisa E. t.. Abdalla W. E., Over-

Solar Energy Center, Cape Canaveral, Res.

view 01 solar desalination, Desalination, 93,

Rep., FSEC-RR-89, 1989

563-579,1993

CRES, Desalination guide using renewable

solar

desalination

still,

Hoffman D., The application 01 solar energy lor large-scale

seawater

desalination,

1998

Desalination44, 153-165, 1992

e

o :::Jl

o U

e

u L u

L)

Desalination 101,255-262, 1995 Sharma, V. B., Mullick S. C., Calculation 01 hourly output 01 a solar still, Tras. ASME,

energies, European Communities, 94 pp.,

O

L

122,85-03,1999

inclined

t;

JSEE, 115,231-236,1993 Voropoulos K, Delyannis E., Belessiotis V., Thermo-hydraulic simulation 01 a solar dis-

10

3 u

e L) L

Lawand T. A., Systems tor solar distillation,

tillation system under pseudo steady-state

U

Proc. Appropriate technologies tor semi-

conditions, Desalination, 107,54-51, 1996

(J) (J)

Mediterranean Conlerence on "Renewable

arid areas: Wind and solar energy lor water

Yadav Y. P.,Transierlt performance 01 a high

Energies lor Water Production" 13-19,1996

supply, 201-225, 19751bid:Engineering and

temperature

economic evaluation 01 solar distillation lor

Desalination, 91 , 145-153, 1993

Delyannis E., Belessiotis overview 01 renewable

Delyannis E., Belessiotis

v.,

An historical

energies,

v.,

Proc.,

Solar applica-

solar distillation

system,

Hybrid Syslems Wind, Powered Desalinalion Hybrid systems based on wind power offer multiple possibilities and great versatility. Modularity is one of their most attractive characters. In the image, some of the projects developed by ITER.

PRODESAL - Pro Desalination ENERCON-30 Wind Turbine 200 kW Power Energy Consumption 3,5 kwh/rrr'Hourly Production LO,5rrr' Modular Desalination ENERCON-12 Wind Turbine 30kW Power Energy Consumption 3,5 kWh/m3 Hourly Production 3,75 m3

o o


Economic Viability of Aegean Desalinalion Planls SCHEMATIC

PRESENTATION

AND WATER Upper ~

••••

OF AN INTERGRADED

PRODUCTION

SYSTEM

ELECTRICITY

For the vast majority of Aegean

ISLANDS

Archipelago islands the water re-

FOR REMOTE

sources are quite restricted, limit-

Reservoir

ing the economic development of

(h,)

the local societies. J.K., Kaldellis, K. Kavadias and D. Vlachou of the Lab. of Soft Energy & Environmental

Applications

Protection - TEI Piraeus, examined the economic viability of several

- - -- -

desalination plant configurations, using an integrated cost-benefit analysis. All the governing parameters of the problem have been taken into account, including the

Proposed Solution for Electricity & Water Demand Problem Concernlng Remote Islands

first

installation

desalination

cost

of the

plant, the annual

maintenance & operation cost, the energy consumption cost, the loANNUAL

ENERGY

COST FOR CLEAN

WATER

PRODUCTION

IN SMALL

ISLANDS

cal economy capital cost and the corresponding

140000 -.:- 120000

••

!:!:!.

•..

80000

~

••

•..

60000

[

40000

tion, not only the electricity de-

~

mand problem is sol ved but also I-

r-r-

1----

< r-

8 >. e'••

~

r-e-

~ 100000 :::J o

inflation rateo By

adopting the suggested formula-

~

-

20000

r

o

1--

~n-

-

l

1-

,---

the c1ean water can be produced -

at a minimal costo

-

-

r---

r---

-

-

f-

-

c:

W

dw days of autonomy Vo = 1OOOm3/day Cw - Clean Water CLEAN

WATER

ISLAND

PRODUCTION

INCLUDING

,'.',. l

COST FOR A MEDIUM

MAXIMUM

,.-1

ELECTRICITY ,·~,,,"'-05

3,00

- ---+---&·~max

____

2,40

U

2.00

:; W --;

--

----.-

1,80

U

•••

.•. .. .. ..

- -----------_._--...--

--.---~-~

1,40

---

1,20

t---------

1,00 000

0,01

0,02

0,03

0,04

-_

I

---JI

••••.•

0,06

2.50

International

Journal

of Island Affairs

COST

ISLAND

[ _________ * - .••

2,OO¡

m ••>max 'm··:>mk1

____

0,07

-..... 0.06

...•

..,_

t-

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m··~.,HIl 11011/\-,,300

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PRODUCTION

Very Sm<llll$land

~'

~

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WATER

FOR A VERY SMALL

-

....-.--.--~.-.-1i ------....--.--.-

1,60

CLEAN

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SIZED

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0,02

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0,06

0,07

0,08

0,09

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Water: 'he Absence o, Precious Resources Problems and Solutions

)

,J '~ r:

L l

l)

-1 tU

e L

tU

(J) (J)

o o by

e

YP'"'. in the past 10 years has experienced tremendous water

DESCRIPTION Physical characteristics

1. P.

E.

GLEKAS*,

STYLlANOPOULOU*

on the central plain and 27°C on the Troodos mountains while in January the

shortage problems, experiencing a de-

Cyprus is situated at the northeast-

average minimum temperature is 5°C and

crease in precipitation levels ofthe or-

ern part of the Mediterranean

basin,

OOCrespectively. Due to the aridity of

der of 18% compared with the period

33° east of Greenwich and 35° north

the climate, evapotranspiration is high,

1916/17-1976/77. A1so during the years

of the Equator. It is the third largest

which, on an annual basis, corresponds

island in the Mediterranean

to 80% of the rainfall.'

through overpumping

occurred

un-

with an

km2 out ofwhich 47% is

derground water depletion. The con-

areaof9251

sequences from the "absence of wa-

arable land, 19% is forest land and

ter" were the inadequate

34% is uncultivated land.'

water sup-

Demographic characteristics

\

ply to the residential sector leading to

There are two mountain ranges, the

periodic interruptions in the supp1y. It

Troodos range in the central part of

administrative

also led to significant cuts in the wa-

the island with a height of 1952 me-

Limassol, Larnaca, Paphos, Farnagusta

ter supply of the agricultural

tres and the Pentadactylos

and Kyrenia. The capital is Nicosia.

sector.

range in

The island of Cyprus is divided into 6 districts,

Nicosia,

New more expensive ways of water

the north of the island, rising to a

Kyrenia

provision

heightof 1085 metres. Most oftheriv-

Nicosia and Farnagusta are under Turk-

desa1ination and sewage water reuse.

ers, which flow only in winter, have

ish occupation, since 1974.

Additionally water beca me a signifi-

their sources in the Troodos moun-

were

sought

such

as

cant limiting factor in the future de-

tains and only one significant river

velopment of economic sectors (par-

has its source in Pentadactylos.

ticularly hotel s and industry). Actions

The climate is typical

which could alleviate this situation are

Mediterranean with rni1d

proposed

winters,

such as accurate

estima-

and

ignificant

FAM

parts

of

GUSTA

long, hot dry

tions of water balance, the creation of

summers and short au-

a Unified Water Entity, changes in wa-

tumn and spring seasons.

ter costing (the tariffs representing the

Sunshine is abundant during

real water cost) and changes in the ag-

the whole year, with an average du-

ricultural sector. The absence of a re-

ration of sunshine of 11,5 hours per

source such as water needs solutions

day in sumrner and 5,5 hours in winter.

which are basically enwrapped in the

The average maximum temperature in

concept of effective management.

July and August ranges between 36°C

LlMASSOL

Map 1: The administrative

* Environmental Consultants

districts of Cyprus

Management Ud - CYPRUS


The total population ofthe island according to 1992 Census reaches 774,5 thousand inhabitants.

Nicosia is the

Figure 1: Water Demand in Cyprus

Waler

Demand

Dem"nd

Analysls

39% ofthe total population.' The population per administrative

district

is

Table 1: The population

Permanent

Population:

155.944

Seaso",,1

Popul"tion:

16.719

01 Cyprus.

POPULATION

Public

Tot'"

PERCENTAGE %

r'"

300973

39,0

Limassol

172827

22,3

Famagusta

110139

14,2

Larnaca

103964

13,4

Kyrenia

33828

4,3

Pafos

52854

6,8

Industrial

uses:

Source:

774585 Census 01 Population,

.. ,'

lO6m3/year

Arables:

Veget..bles:

T rees: Gr"Pes: Total

irigation

demand:

--------:-

125.06

184.962 1275.907

J1 0.897

(396.827

-

Industries:

12.639 12.376

breeding:

10.1 79

T ot ••• industrial

demand:

15"195

Display Monthly . distributions. and other gr"Phs

Gr"Pm

Display paramelers used lo estímate Water Resources

P",ameters

View

Close

Thematic

M"P

MI'P

I I I

I

4

·100 /992.2

both for its domestic and its irrigation

435 mm, 7,4% lower than the average

needs. This is due to its serni-arid cli-

annual precipitation for the period 1968/

The main characteristics of the Cyprus

mate, the low average annual rainfall.

69 - 1997/98.5

economyare the small size of the inter-

Regional variations in rainfall are con-

nal market, of the business units and

siderable, with the two mountainranges

tion had as a result the insufficient col-

labour market as well as its openness.'

receiving "more abundant rainfall than

lection in the dams of the necessary

Economic

activities

The tertiary sector, that of services,

the two easternplains.

plays the most important role in the economy, in that way reflecting

The all declining levels of precipita-

water quantities to satisfy the needs of

In the past years there have been

the country. Although many dams have

the

observed declining levels of precipita-

been constructed after Independence

transition ofthe Cyprus economy from

tion leading in that way to decreased

in 1960 totaling to high storage capaci-

exports of minerals and agricultural

water supply. While the average annual

ties, the water quantities collected cov-

products, particularly copper, asbestos,

precipitation levels for the period 1916/

ered only 35% of that capacity. The

'l.t 530 mm, the respec-

possibility of exploring groundwater re-

tive average for the period 1916/17-

sources was basically inexistent. The

center

1997/98 showed a decline of 3% reach-

downstream aquifers depend more and

duringthe decades of 1980 and 1990.3

ing 515 mm. The 30 year average of the

more on artificial groundwater recharge

period 1968/69 -1997/98"at475 mm was

due tú the fact the groundwater regime

citrus and manufactured

products to

an international tourist center and a regional information

provision

17-1976/77 was

,"

WATERSUPPLY ANO OEMANO IN CYPRUS

15% lower than the respective average

in most are as has been rnodified from

ofthe period 1918/19 - 1947/48 at 556

Water

mm

the building of high dams not far from the coast.

Oemand

The figure shown belowdemonstrates

Finally, the 10 year average for

5.

the period 1988!89~ i997/98 declined at

the total water demand for the island of It can be observed that the' agricul-

The prolonged "absence of water" " has caused a shift from conventional

Average Precipitatiori

Cyprus, totaling to 455,44 MCM. 600

" 530

water resources to the employment of non-conventional

515

methods such as

tural sector has the highest water de-

500

mand reaching 82% of the total demando

400

one desalination plant, which is located

The demand for the permanent popu-

300

in Dekhelia in the Southeast part of the

lation follows with 12% ofthe total and

200

island and has been in operation since

the non-perrnanent population (mainly

100

435

16/17 76/77

Water

o mm

Supply

Cyprus has always been confronted with the problem of inadequate water

International

Journal

of Island

Affairs

Figure

desalination. In the island there is only

] 997. The technology employed in the

tourists) consists of 1%.4

14

,1

Details

Production:

Med-CoDesa/

..

f'"--W~~ D~~

Demand

- Poultry

Cattle

Al data are Pfes-ented in

: ,l.':

15.594 13.412 171.67

dem.-nd:

Water

Electric

Source:

Total

domestic

Single

Nicosia

11

1473.692

Demand:

Le"k"ges:

DISTRICT

3,~,

r-OomesticWate,Demand

shown below:

El

Reglon.

1774585

Population:

Tot"IW"ter

Demand

1 Main

Type: Permanent

e

19196 sq km

Area:

most populated district concentrating

for

IC

Region:

16/17 97/98

68/6997/98

88/8997/98

Time series 2: The average precipitation the years

prus th roughout

Dekhelia desalination plant is Reverse Osmosis with a capacity of 40,000 tons/ year and production of 13 MCM per

in Cy-

year. A second desalination unit is being constructed in the area of Lamaca


with a capacity of 14 MCM per year and

(overall depletion of 1500 MCM 5) and

hydrochemical charts has been initiated.

will enter operation in 200 l. Conceming

with inadequate

A lot of effort has been exerted for

the water produced from sewage treat-

sources (lack of adequate precipitation

groundwater protection and rehabilita-

O

ment, the 2 MCM produced annually

to fill the dams).

tion, the most recent being the Order for

o

surface

water re-

a

t;

e

:::J

in

the Protection of Underground Waters.?

in hotels. There are plans to increase

the country especially

in the last 10

AII sources of water supplied for do-

o

the treated water quantities for both

years is the problern of limited supply

mestic use are regularly monitored for

U

watering of specific cultures as well as

both to the domestic and the agricul-

the chemical and bacteriological char-

for enriching groundwater aquifers.

tural sector. Additionally

One of the major consequences

are utilized mainly for watering gardens

Water

Balance

The continuous

the lack of

acteristics of water. Quality of drinking

water has put restrictions to the devel-

water supplies is in full compliance with

opment of economic sectors such as

WHO guidelines and EU standards."

e

u L

U ....J 10

:3

u

However, the last years of drought,

the tourism and industry.

drought during the

L

Concerning the domes tic sector se-

as aforementioned, have been charac-

e ....J

the

vere water saving measures ha ve been

terized by the periodic interruption of

L

have been more

implemented mainly through the peri-

water supply in the main cities of

acute in so me areas. Taking into ac-

odie interruption of water supply to the

Nicosia,

and

(J) (J)

count the overall water shortages in

households, which has been restricted

Larnaca. The absence of water in the

o

each district it can be observed that all

to three times a week 12 hours each

distribution system has created prob-

years has created water shortages in the country . As aforementioned drought

problems

Famagusta,

Limassol

the non-occupied districts apart from

time. The limited water supply has been

lems including not enough water to tlush

Paphos have been experiencing water

causing the dissatisfaction of the pub-

toilets, wash dishes and c1othes, or pro-

shortages. When it comes to the do-

lic due to the consequent

mestic sector, the situation changes for

ience and the additional provisions for

Limassol at least, however significant

storing water.

supply problerns remain for Nicosia, Larnaca and Famagusta. Table 1: Water shortages

of the domestic

sector in the various districts

Area

Water Demand

Water Shortage

(M CM)

(MCM)

o

ing water," The interruption of water supply has

The agricultural sector has also been

led to the installation of storage tanks

suffering from signi ficant cuts in the wa-

in residences and buildings. The clean-

ter supply, reaching 56% cuts in the sup-

liness and sanitation of individual stor-

ply of the sector for the year 1998. The

age tanks is unknown and could be

limited supply in the sector has caused

source of problems in the future.

a

Interrupting the tlow of potable water in the distribution system allows the

gated and the change of land use.

Nicosia

24.772

21.465

It is irnportant to highlight here that

pipes to fill with water, empty and then

Limassol

15.146

0.806

the inadequate and inter annually per-

refilJ. This creates a conditions called

l.arnaca

9.419

8.950

sistent drought has caused a shift frorn

cavitation which scours the pipes and

Farnaqusta

7.532

7.155

relatively cheap conventional water re-

creates a cloudy water which is full of

sources, underground and surface, to

suspended material: This is unaccept-

non-conventional

more expensi ve

able from an aesthetic standpoint and

methods such as desalination and sew-

places the potability of the water sup-

o

ter balance are rather pessimistic. Low

ply in question.?

precipitation levels are highly proba?le . age water reuse. o

that will persist, with the groundwater Although <inincrease in supply for 2020

Qualitative Corisequer'lces

EXISTING MANAGEMENT FRAMEWORK

is predicted due to the production of

Although groundwater is generally of

After describing

reserves continuing to be unavailable.

the water shortage

water from non-conventional resources

good quality, in sorne parts of the river

problems and its consequences

(40MCM frorn desalination and 25MCM

deposit and coastal plain aquifers there

the country is facing, it is important to

from treated wastewater reuse) a 100

are increased nitrate concentrations due

examine further the decision making

MCM of water shortage will still exist.'

to the agricultural and urban develop-

process and the general management

ment and increased salinity because of

environment in order to see the situa-

CONSEQUENCES FROM WATER SHORTAGE

over pumping. In some rural areas, ni-

tion in a holistic way and at the same

trates and phosphates from agriculture,

time find possible solutions.

Quantitative

animal husbandry and industrial activi-

changes

Institutional

that

Framework

The absence of water in the last dec-

ti es present

ades has found the island of Cyprus

Groundwater is regularly monitored and

The statutory and common law rights

with depleted groundwater

a programme

relating to water resources and water

resources

O

vide a continuous safe supply of drink-

inconven-

a decrease in the total afea being irri-

The future trends conceming the wa-

U

a pollution

problem.

for the preparation

of

o


supply in Cyprus are covered by 25

The Water Development Department

members from each municipal area sup-

laws. All these laws were enacted dur-

is responsible for implementing the wa-

plied by the Board. The Boards manage

ing the colonial era and still rernain in

ter policy of the Ministry of Agricul-

their own fmances and produce a bal-

force. The main points outlined in these

ture, Natural Resources and Environ-

ance sheet annually and fix their charges

laws are the following 1:

ment with the objective of the rational

and future budgets accordingly. All do-

• AII surface and groundwater , incIud-

development and management of the

mestic water supplies are metered.

ing wastewater is vested to the Government.

water resources in Cyprus. In this context, the responsibilities of the depart-

• The government has power to con-

ment cover a wide and di verse spec-

struct waterworks and sell water at a

trum, which incIude:

price fixed by the Government and

• Collecting,

the House of Representatives. • Existing water rights are protected

and

The pricing policy of water is differentiated among the various economic

processing,

archiving

hydrogeological,

Pricing policy framework

cIassifying

hydrological, geotechnicaJ

and

sectors due to the existence of subsidies and other non-stable factors. Water from government waterworks that

and ab antiguo rights are vested to

other data necessary for the study,

is used for municipal use (incIuding in-

those who can prove ownership of

maintenance and safety of the water

dustrial, commercial and tourist pur-

development works.

poses) is sold at full cost. The full cost

such rights. • Individuals

may sink or construct

wells for groundwater

abstraction,

after obtaining a permit from the District Officer. • Individuals may forrn Irrigation Divisions or Associations irrigation works.

to construct

• Villages and towns may form their

• Studying, designing, operating

constructing,

and maintaining

works,

such as dams, ponds, irrigation, do-

treatment

and di s-

posal of sewage effluent.

debt service

or depreciation

and

charges on working capital. This is in

mestic water supply and sewerage

accord with the provisions of the loan

schemes, water treatrnent works, sew-

agreements with the World Bank. Con-

age treatment and desalination plants.

cerning potable water, the Government

• Protecting the water resources from

sells water at a stable price of33,5 centl m3 to the Water Boards, while for agri-

pollution.

own Sewage and Drainage Boards for the collection,

covers the annual operating expenses,

culture, water is so Id at a price of 6-7 The Town Water Boards (TWB) dis-

Ecent/rn? (subsidy of 67%) to farmers.

tributing water to the domestic and in-

The water cost from the Dekhelia

• Environmental issues are covered only

dustrial consumers derive their bulk sup-

desalination unit is at 55 Ecent/rrr'.

indirectly by the existing legislation.

plies from groundwater and partly from

According to Water Supply (Munici-

treated water delivered to storage reser-

pal & Other Areas) Law - Cap350 Water

voirs by the WDD's trunk main system

Boards have power to impose water rates

Administrative framework

from surface water~upplies.The TWB are

or charges for the supply of water. AII

The policy control of the Water Indus-

made up of three members nominated by

domestic supplies are metered. Boards'

try in Cyprus is divided between the

the Government. These are the District

sources of water may be developed by

Ministry of the lnterior, the Ministry of

Officer, the Accountant General and the

themselves or be bulk supplies from the

Agriculture, Natural Resources and En-

Director of the WDD and up to three

Water Development Department.

vironment, the Ministry of Finance, the Table 2: Water rates of the Town Water Boards.

Ministry of Commerce and lndustry and the Planning Bureau. At the executive level, the industry is mainly in the hands

Quantity (m3)

of the Water Development Department

A 1-20

30

15

6

of the Ministry of Agriculture but which

A 21-40

45

35

11

A 41-50

70

55

22

A 51-60

90

75

22

A 61-80

110

90

40

A 81-

110

90

56

B 1-200

45

35

18

B201-400

65

40

18

usually acts only in an advisory capacity. Legal power lies within the district officers of the Ministry of the Interior. The Departrnent of Agriculture is cIosely concerned with irrigation matters, the

Larnaca (CVE cent)

Geological Department with the devel-

B 401-

75

60

opment of boreholes, the Land Surveys

C 1-1000

45

40

Department with the registration of wa-

C 1001-2000

45

55

ter rights, the Accountant General with

C 2001-4000

65

55

75

55

finance, loans and tenders and the Planning Bureau with budgets.

16

Nicosia (CVE cent)

International

Journal

of Island Affairs

C 4001 Sources.Planning

Bureau,

/999.

Limassol (CVE cent)


Three tariffs have been employed by the Water Boards: Tarriff"A": Private residences Tarriff"B": Hotels, clinics, government

schools,

and other

public buildings Tarriff "e": Factories

and industrial

units It is important to note that the Water

1997. Factors which contributed to the

be redefined bearing in mind that the

~

al! increasing importance include the

drought conditions occurring in the last

t;

water shortage, the division of agricul-

10 years are likely to persist.

for touristic activities.

Additionally,

agricultural

O

e

o

tural land into smal!er pieces and its transformation

10

::Jl

The creation of a Unified Water Entity

o

originating from Cyprus have faced in-

The Government Waterworks Law is

U

tense competition from products origi-

the most legal instrument for the man-

products

L

e

u u L

nating from the European Un ion coun-

agement of the water resources of the

Boards have varying rates presenting

tries which gained generous financial

country. Nevertheless,

great differences as shown in the table

aid within the EU Agricultural Policy.

pose since it does not explicitly define

ACTIONS

effective overall responsibility for the

e LJ L

below:

it fails its pur-

a single administrative

TO BE TAKEN

authority for

THE ROLE OF THE AGRICULTURAL SECTOR

AII the above show that current water

water resources and waterworks man-

management is heavily dependent on

agement. The law instead bears the frag-

It was considered appropriate to explain

precipitation. AII current government

mentary nature of responsibility which

in more detail the role of the agricul-

efforts are directed towards the oppo-

is a great impediment to the effective

tural sector in the water management

site direction through the development

resources management. The creation of

system ofthe country since agriculture

of non-conventional

water resources

a Unified Water Entity will have a sig-

has the greatest

mainly desalination.

It is important

nificant contribution to the more effec-

consumption.

As

aforementioned the agricultural sector

however, in this effort to take into con-

tive decision making process and con-

consists of 82% of water demand and

sideration al! the relevant factors related

sequently to better coordinated man-

around 75% of current water consump-

to an effective water management sys-

agement of the water system. It is sug-

tion. Although with high irrigation effi-

temoSome important actions to be taken

gested that the Unified Water Entity

ciency (85-90 %), is characterized by

are the fol!owing:

be responsible for four sectors of the

water consuming cultures, such as oranges, grapefruit, lemons and grapes, as wel! as winter potatoes.

hydrologic Accurate estimations

potable

cycle such as irrigation,

water provision,

wel!s and

of water balance:

boreholes

Additionally the water tariff of the

A revision of the hydrology of Cyprus

purpose of this Entity will be the de-

sector is heavily subsidized at 67% of

needs to be conducted for accurate es-

velopment, management and rational

its price at Euro 0,112/m

permits and sewage. The

timations of the remaining water re-

exploitation of the limited and valuable

One could question the effectĂ­ve-

sources in the island. Additi .'nal!y both

water resources of Cyprus.

ness of the government support meas-

water demand and supply need to be

3â&#x20AC;˘

ures for the agricultural sector if we take

re-estimated to formulate a new water

Changes in water costing.

into account the fact that the contribu-

balance. Parameters which play an im-

As it was seen from the above sections

tion of the agricultural sector to the GDP

portant role in the water balance such

of this study, some of the current water

ot the country

as evapotranspiration

levels, under-

tariffs such as that of agriculture is heav-

trend throughout the years, from 10%

ground water levels, losses from sur-

ily subsidized while there are great dif-

in 1980, to 7% in 1990 and to 4% in

face and underground waters need to

ferences among the tariffs for the do-

shows a decreasing

mes tic and the industrial sectors among the various Town Water Boards. In or-

Figure 3: The contribution of GOP in the economic sectors

100%

der to implement a costing system which

90%

corresponds to real water costs, it is nec-

80%

essary to re-estĂ­mate water production

70% 60%

o Tertiary

50%

.Secondary

40%

.Primary

30%

costs from the various projects and uses. Redistribution

of water resources

among and wihin the economic sectors.

20%

The significance of the economic sec-

10%

tors in the country

has changed

throughout the years, through a shift

0% 1950 1961 1973 1975 1978 1995 1996 1997 1998 Source: Economic

Outlook,

1997.

from the primary (agricultural) and secondary to the tertiary sector that of

LJ

10

:3 u

u (J) (J)

O

o


sary within a unified, well coordinated

Resourees

ter managernent systern as described

adrnnistration

Countries in the frame 01 the Centennial of

above seems to show "preference" to

representing the actual needs and eco-

the agricultural sector, the sector with

nornic activities of the country.

services and tourisrn. The current wa-

the least irnportance in the econorny.

and a costing systern

the National Agronomie Institute of Tuni-

Census of Population, General and De-

2

veloprnent

ferent actions could lead to different

sources mainly through desalination.

of non-conventional

Although,

that action is concerned. This is par-

coupled with the persisting drought of

the needs of the country

ticularly applicable to the agricultural

the last 10 years rnake the desalination

sector and the type of cultures planted

option cornpelling,

(water consurning or not).

"absence

of water"

solutions

mographie Charaeteristies, Department of

re-

treatrnent as far as water availability for

Statisties and Researeh, Ministry 01 Finanee, 1992. 3

Planning Bureau, Eeonomie Outlook, The

4

Glekas

Republie of Cyprus,. 1997.

tion tor Water Desalination Policies in the Perspeetive of a Sustainable Development.,

In this paper, the consequences of the

tive management system to be able to

"absence of water" have been identi-

face unpredictable and cornplex situa-

fied. It was shown that inadequate sup-

tions which usually characterize

plies of a valuable resource, has sig-

handling of this precious resource.

1997 -2000, Contraet ERB -IC18-CT97-0142 5

pect of demand and supply is neces-

Georgiou A.P., The Water Shortage in the non-oeeupied areas of Cyprus, Arehiteets and Engineers, 1999.

B

the

Geologists and Mineralogist Association of Cyprus, The Water problem: Water Resourees, Water Poliey and Management, July 1998.

nificant negative effects on the welfare

an integrated as-

Stylianopoulou,

of the

of a flexible and at the sarne time effec-

possible solutions,

E.

rnust have as

CONCLUSIONS

on its econorny. In order to identify

I.P,

MEDCODESAL, Mediterranean Co-opera-

epicenter and prirnary goal the creation

of the people of the country as well as

Southern

sia, 10-12 November, Tunis 1997.

Cyprus is heading towards the de-

Additionally even within a sector dif-

in Mediterranean

7

References 1

laeovides I.S., The Water Resourees Management in Cyprus, International Seminar on Sustainable

Management

of Natural

Conway J.B., Water Problems in Cyprus and the Promotion of Desalination as a Solution to Potable Water Shortage, Prepared for the Republie of Cyprus. August 1999.

Sdawes Proiect (SellVlaler Desalinalion Wilh an , Aulonomous Wind Energy Syslem) The SDAWES project makes use of a natu-

by the European Cornrnission, (Joule

Gel/eral

ral renewable resource, wind, to produce a

III Prograrn); it began in February

natural scarce resource, water. The rnain

1996 and finalised in 2000.

Pumping Station. (2) Product water tank. (3) Brackish water tanks. (4) Desalinauon

objectives ofthe project are to identify the best desalination systerns to connect to an off grid wind farrn and to assess the influence of the variations of the wind energy on the behaviour of the desalination plants elernents and on the quality of the produced water. To pursue these objectives, three kinds of desalination systerns, Reverse Osmosis (RO), Vacuum Vapour Compression (VVC) and Electrodialysis Reversal (EDR), have been connected to an off grid wind farm to produce fresh water on a significant scale. The project is located on the island of Gran Canaria (Spain) and was co-financed

18

International

Journal

of Island

Affairs

view o/ th e i nst all ati ons. (1)

dome. (5) Flywh eel building. (6) Wind Turbines. (7) Feed water pipe circuito


Desalinalion Systems Using Renewable Energy Sources in Medilerranean Counlries

.-J

10

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e

o :::Jl o L Qj

e Qj L Qj

G

e

:3 Qj

e

o L Qj (f) (f)

O

o by

1

n water-deficient

countries,

ile with consequent impacts on popu-

among which the countries of the Medi-

lation, environment and development".

terranean

Demographic

region

are encountered,

growth, increased per

MAR/A

KONTON/*,

THEOCHAR/S

RENEWABLE ENERGY SOURCES IN DESALlNATION

desalination of sea and/or brackish wa-

capita consumption, extension of wa-

Water scarcity

ter is considered a sustainable method

ter distribution

among others, through mobilization of

networks,

increased

could be alleviated,

to alleviate water scarcity. Furthermore,

use of irrigation

the use of renewable energy technolo-

creased industrial development and al-

such as the reuse of wastewater or the

gies in providing the power to support

leviated levels of potable water needs

desalination of sea or brackish water.

the energy intensive desalination sys-

due to the development of tourism, are

Desalination

tems, represents a elean alternative to

some of the factors that put severe

ergy input, so an increase in the provi-

the use of conventional fuels. The pro-

strain on water resources.

sion of water supplies, will invariably

in agriculture,

in-

~.

the non-conventional

water resources,

requires significant en-

mean an increase in energy dernand".

motion of the RE-driven desalination

In the Mediterranean, the two major

systems is elosely related to an overall

specificities related to water use are ir-

scheme for integrated water resource

rigation and tourism. Irrigation con-

ricultural,

management. Prerequisites for the use

sumes about 80% of the water re-

needs becomes expensive and energy

ot such systems is the formulation of

sources in the Southern and Eastern

intensive,

the appropriate framework of legisla-

parts of the region 7. On the other hand,

desalination is needed. Since, the pro-

tive, institutional, financial and social

the water demand in the Mediterranean

vision of new facilities for water pro-

issues to address both water and en-

is increasing considerably due to the

duction can put severe strain on the

ergy management through the devel-

250 mili ion domestic and foreign tour-

existing electrical power supplies their

opment of capacity building and the

ists per year.

installation may signify the creation of

dissemination of successfully operated projects.

Thus, the production of water for agindustrial

and domestic

particularly

where

Thus, the demand made on those lim-

more generating capacity. This can in-

ited resources threatens both the quan-

elude new generating capacity some-

tity and quality of a commodity that is

where in the electrical network, new, lo-

essential to social and economic activi-

cal but grid connected generation fa-

Countries, is one of the regions that

ties and to human life and health. Water,

cilities or totally autonomous generat-

considered as water-deficient.

being critical for social and economic

ing capacity where grid does not exist.

The Mediterranean Region, and especially the Southern Mediterranean Water

consumption has increased by 60% in

activity, regarded

the area during the last twenty-five

everybody should have access to it, has

as something

that

years and continues to do so. Avail-

been used in an unregulated manner and

able water resources are becoming in-

the charges made were well below op-

creasingly scarce, threatened and frag-

eration and maintenance costs.

In countries where energy costs are high, as it is the case of developing

* Centre tor Renewable Energy Sources CRES - GREECE

TSOUTSOS*


sources are available. Moreover, the

and geothermal

volatility of international energy prices

reached cornmercial maturity. The devel-

PROMOTION OF RE·POWEREO PLANTS ANO INTEGRATEO WATER RESOURCE MANAGEMENT

and the increasing concern to regional

opment of integrated RE desalination

Despite the fact that reliable technolo-

countries,

desalination

of seawater

from which new desalination plants will

would be economical!y prohibitive un-

draw their power. New electricitydemands

less abundant

can be satisfied with RE whereas wind

indigenous

energy

technologies

have

and global pol!ution problems has in-

systems is reasonable, for example, in less

gies exist to produce abundant water from

tensified an interest in the application

developed areas, where water is a more

sea or brackish water, still the problem of

of clean renewable energy sources for

fundamental requirement than power and

water scarcity has not been solved. Ba-

al! energy uses, including desalination.

an electrical grid connection may not ex-

sicalIy,there are two main reasons for that:

The period from 1960 to 1980 witnessed

an explosive

growth

of

ist, or in the case where the existing elec-

a) the cost of equipment, which is signifi-

trical grid is inadequate to cope with the

cant, and b) the cost of energy for the

desalination plants most of which were

large added demand of new desalination

production of water in significant quan-

developed in the Middle East area. It is

plants. Furthermore, with the growing

tities, and at economic rates, which are

remarkable since the area is rich in fos-

trend for deregulation and privatization

extremely high for the majority of the

sil fuel reserves (oil and gas), which

of utilitymarkets, self-generation of power

water deficient countries. While the cost

are used to provide power to the plants.

from a water utility may be more attrac-

of equipment, a once-incurred cost, could

However, taking into account the envi-

tive than purchasing it from the local elec-

be possibly covered, this is not the case

ronmental implications from the com-

tricity company. At small scale, stand-

for the cost of energy used for the

bustion of oil and gas for power pro-

alone packages can be cornmercially at-

desalination process as a whole

duction for desalination, and not only,

tractive to potential investors.

there is a need for utilizing the alternative, non-polluting

In addition to the obvious economic parameters/obstacles mentioned above,

Despite the diversity of renewable

energy sources,

such as Renewables''.

energy forms, it seems likely that mainly

there are also other discriminatory barri-

wind, geothermal,

ers that hinder the exploitation of the avail-

active solar and pros-

able potential for renewable technologies

doubtedly may have a major role to play

pects of producing commercially viable

and consequentIy the penetration of RE-

in expanding the capacity of main grids

renewable driven desalination systems.

powered desalination plants 4:

Renewable energy sources (RES) un-

photovoltaics

have short-term

Table 1. Potential requirements

Constitutional • authorizing

function

implementing

the necessary

steps to secure

• encouragement

and con-

of

private sector

partici-

pation ..

-¡¡; c:

:Si

.=-..

• effective

.~ C;

• regulating decision-making

CI..

constitution

and development

of

• encouraging stakeholders • authorizing

the

• provision

G>

all

ers by users/clients and the IWRM platform

• provision of reliable information

effective control

of violations

of quantitative

for effluents

• provision

of effective

countability

wa-

in use of water at

• development

of an effective and

transparent

accountability

• power to control

• power at the service provider to con-

and sanction

violations

and qualitative

• a clear

regulatory

and qualitative

decision

framework

and standards

for

• cost recovery by the service provider • negotiations agency

making

and transparent

• sufficient capable people to meet the IWRM of policy rnakinq, adapting

lation and all other activities

:::¡:

InternationaJ

and its cli-

and recovery of its associated

ac-

costs

legis-

• sufficient capable people to meet

• sufficient

participation

use of water of private sector

capable people to meet the

the IWRM demands on planning

IWRM demands.

and management.

ment and management

development

JournaJ of IsJand Affairs

of market incentives to

most economic

through

Ec:>C>I

the managing

provider

mechanisms

'"c:

G>C: ~"'''' a:'"

between

/service

ents on the level of service it provides

¡¡:

demands

of water (quantitative

and qualitative)

make

e

at

• assessment of the demands, actual use

• development

CQ5CL1

interests

agency

trol and sanction violations

basin level

·u '" c:

G>G> C:<'>E

of clients

and by the managing and availability

• analysis of several scenarios for

with norms

of quantitative

standard

and ground

• representation

mechanism

for use

• provision

a>

of

making

and regulating

and sanctioning

...•

participation

In decision

• effective control of the service provid-

which reflects the interests of dif-

interventions based on inter-

ests of all stakeholders

-¡¡;

capacity

ters

relevant institutions

standard

Ooerational function

function

making

ferent uses and users

ity of surface

and implementation

of laws and regulations.

~

• a decision

on the availability, use and qual-

• effective development

.s

at the various levels of IWRM

Oraanisational

agencies to take

serve the resource

20

6.

control

and

provided

planning.

develop-

of services


Barriers:

There is a set of requirements that

market without a demonstration phase".

concerning mainly the lack of clear

should be fulfilled for the successful

Technologies need to be demonstrated

policy-Iong-terrn policy - to new en-

implementation of the IWRM scheme.

in order to ensure that all initial objec-

ergy technologies and the improve-

This set of requirements

tives have been achieved and to identify

ment of public acceptance

• Political and Legislative

address the

three functions of IWRM, namely:

further issues that must be resolved.

• Institutional and Infrastructure: barri-

• the constitutional, i.e. the creation of an

These may include specific component

ers that are closely related to the ex-

enabling environrnent with the appro-

design, operational systems and scaling

isting - traditional energy/transport

priate legal an policy framework for the

up to a larger size. Thus, the demonstra-

supply infrastructure, the inflexibility

effective implementation ofthe organi-

tion phase is an important step in the

of the system to respond to changes

sational and operational functions;

development of the technology from "the

-.J

10

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e o :JI

o L Q)

e Q) L Q)

U 10

in demand or technology availability,

• the organisational, i.e. the integrated

laboratory to the end-user'l.It is also very

:3

focusing more on supply-side rather

water resource management itself, in-

important to demonstrate the system in

Q)

than demand-side solutions, the role

volving resource assessments, plan-

which a technology is to work, rather than

u

played by conventional fuels, etc.

ning, decision making, implementation

demonstrate all kinds of developed tech-

L

• Economic, financial, fiscal: barriers,

and policies on allocation and use of

nologies. It is necessary, therefore, to go

where under the existing fiscal regimes

water resources with the/ and based

through the defnonstration phase in or-

Q) (f) (f)

the new energy technologies cannot

on the interests of all stakeholders, and

der to minimize the risk before entering

o

compete in a fair and open market with

• the operational/functional,

i.e. the

the market. Often, and this is more impor-

conventional energy sources, espe-

effective provision of water services

tant, that when a technology is being dem-

cially, since the latter are "inexpen-

responding to social needs.

onstrated, there are parties involved that

sive". Access to economies of scale

These requirements are described in

are willing to develop the technology

Table P.

further to the commercialization phase ket. In this case the demonstration is

guidelines, lack of information, level

RES- DESALlNATION TECHNOLOGIES: FROM RESEARCH TO THE MARKET

of education

The introduction of renewable energy

user, it is often of greater interest to dem-

is also a barrier. Socio-economic bar-

and to disseminate the results to the mar-

riers are also important, e.g. consumer attitudes, acceptability, etc. • Environmental

and other barriers:

which are related to the planning and training, lack of

driven by the market needs. Although the demonstration of a technology is mostly of interest to the end-

standards and norms, and more spe-

technologies

in the world market is

onstrate the whole system in which the

cifically for the desalination plants,

prompted by three main reasons / cor-

technology will perform. In this way, it

the disposal of the brine.

nerstones of the current energy policy:

will be possible, at this stage, to identify

All those barriers are inter-linked and

security of supply, protectiop' of the en-

and evaluate

\.

all those issues that

result in some difficulties for the new

vironment and free market. Although a

should be addressed before this tech-

energy technologies in achieving the

di verse range of energy sources and

.nology can be introduced into the mar-

potential offered.

technologies can meet world energy de-

ket. The demonstration of a technology

mand, renewable energy sources can of-

within a complete system under market

de alination, and especially RE-pow-

fer undoubted benefits in terms of envi-

conditions is particular important for its

ered systems, is closely associated to

economic viability. The economic as-

the overall promotion of the use of non-

ronmental protection and coping with global warming. Furthermore, renewable

conventional

energy is more suitable for regional or

tion, are being tested and proven at this

of the integrated management of water

local applications and especially in coun-

phase. In the case that the end user gets

resources (IWRM).

tries with few indigenous resources.

a positive cash flow the maturity of the

However,

the

promotion

of

water resources as part

An integrated water resource manage-

In recent years a number of desalination

sumptions made during project defini-

technology is shown and the financial

ment scheme provides a platform 3:

technologies

• for weighing all relevant interests

some of which can be considered as com-

able investment, accelerating this way

and decision making on use of water

mercially viable in their basic process

the market penetration process.

and water systems in the river basin;

has been demonstrated

institutions are willing to finance a reli-

engineering. Initially, a demonstration of

The dissemination of the results of

the interests of all

individual innovative technologies took

the demonstration phase is of particular

stakeholders and be under govern-

place which eventually developed to the

importance for the success of a given

ment power to protect the interest of

demonstration of different systems into

technology. Dissemination

• that represents

society at large; • that should have decision, control and sanctioning powers.

of energy

which renewable energy could fit. It has

technologies is the process by which a

been proven that it is impossible for a

successfully demonstrated technology

new technology to penetrate the energy

is supported further in order to reduce

.c

O


its overal! costs and make it more com-

and customary

petitive, so that it can become commer-

establish rational legal regime and en-

cial. Newly developed technologies are

forcement mechanisms; c1early defined

and communications

(serninars and

much more expensive that the "stand-

roles and responsibilities; involvement

events in promoting

the concept of

practices

Inforrnation, education and comrnu-

in order to

nication issues: Awareness-building

ard commercial ones", due to new com-

of all stakeholders; decentralization of

water as a valuable resource; social

ponents, processes or materials, and

responsibilities; partnerships with pri-

mobilization

often the first demonstration

vate sector; capacity building, etc.

plant is

estimated to be 50-100% more costly than the standard

technology

one".

Thus, even if an innovative technology

Social issues: the building of partici-

all types of

stakeholders, al! sectors and at all levels of adrninistration; educational cam-

and gender equity

paigns; use of mass media; exchange

(establishment of user groups, farmer

of experience, and best practice arnong

patory structures

is successful!y demonstrated, the tech-

associations, etc. to participate in re-

mangers and operators; production of

nology cannot normally compete in the

source managementat locallevel; fund-

communication aids, advertising).

energy market due to the comparatively

ing; gender -awareness

training for

The incorporation of the above men-

very high cost. It may need 7 or 10 such

personnel at all levels; basic education

tioned measures would contribute to

demonstration plants before it becomes

and technical

"standard commercial technology".

stakeholder level; surveys of local in-

desalination

digenous

The developed dissemination

strat-

egies playa particular role in the promotion of new technologies,

training at the lowest

promotion

of

RE-powered

systems in water scarce

tech-

areas, with significant benefits on environrnent, social and economic sectors and local/regional development.

water management

as they

ties to identify the needs of the poorest users, ensuring the opportunity to

able the interested groups to benefit

express their views and have equitable

from the results of similarly developed

access to service providers, etc.),

projects assisting, thus the technolo-

Economic and financial issues: de-

gies in question to break the market

mand management and pricing (advo-

barriers and become commercial.

cacy and awareness-raising

In

the

niques and enterprises, research activi-

intent to raise the awareness and en-

addition to the difficulties encountered

References , "Desalination Guide Using Renewable Energies", C.R.E.S., E.C., Directorate General for Energy, 1998 2

EURORED, Project report, Universidad de

principie of water as an econornic good

for a new technology to enter the mar-

that should be subject to equitable and

ket, renewable powered desalination

adequate pricing for all uses to be ac-

plants presenting, more or less, a new

cepted; pricing of RE-desalination -pro-

technology, have also to face the fact

duced water; support for the introduc-

that the existing applications lasted for

tion oftariff reform and appropriate pric-

a long period of time, and might have

ing regimes; establishment of regula-

to change. Tntroducing something new

tory framework to monitor prices set

"Experience on Desalination with Renewable Energy Sources", APAS-RENA-CT94-0063,

so that the

las Palmas de Gran Canaria, E.C. Directorate General for Science, Research and Development, 1996 3

Hofwegen, P.J.M.van, and F.GW. Jaspers, Analytical Framework for Integrated Water Resources Management, Guidelines for assessment of Institutional Frameworks, IHE

'.

monograph 2, AA Balkema, NL(1999) 4

"Improving

Market Penetration for New

means that something has to change,

by service providers; promotion of en-

Energy Technologies: Prospects for Pre-

something that has existed for so me

vironmental economic analysis to en-

competitive Support", Proceedings of the

time, and this is not an easy task.

sure that the criteria offinancial viabil-

Conference, E.C. Directorate General for Energy, October 1996

ity reflect true values of the resource

MEASURES ANO ACTIONS TO BE TAKEN The measures to be taken, on one hand

and its amenity; introducing water and

5

Energy Sources for Water Production", Pro-

energy saving technologies, etc. Environmental

"Mediterranean Conference on Renewable

ceedings of the International Conference,

issues: natural re-

Santorini, 10-12 June 1996, C.R.E.S., 1996

to implement the various prerequisites

source management (advocacy on be-

â&#x20AC;˘ "New Technologies for the Use of Renew-

and on the other to minimize the effects

half of water as an essential resource of

able Energy Sources in Water Desalination",

of the barriers mentioned previously -

economic value, particularly in areas of

addressing both water and energy is-

scarcity; investments in environmental

sues- and to support the wide scale ap-

protection of vulnerable areas; support

plication of RE-desalination

for rneasures which reduce environmen-

systems,

should take into consideration,

Proceedings of the Conference, Athens 2628 September 1991, C.R.E.S., E.C. Directorate General for Energy, 1991 7

"Research and Development Needs for Decentralised Integration of Renewable Energy

in ad-

tal pollution; environmental impact as-

with Desalination Technology", APAS-RENA-

dition to technological issues, the following 8.3:

sessments to measure the potential of

CT94-0063,

actual effects of water related projects

C.R.E.S., E.C. Directorate General for Sci-

Institutional and management issues:

on the ecosystem, especially concern-

EURORED, Project report,

ence, Research and Development, 1996 8

"Towards Sustainable

Water Resources

policy review and reformulation to meet

ing the effect of brine disposal into

requirements

brackish / estuarine waters; monitoring

sources, development, co-operation", E.C.,

of environmental changes; etc.

Directorate General for Development, 1999

for integrated resource

management; review of existing laws

22

involving

International

Journal of Island Affairs

Management:

Guidelines

for water re-


.-J

Brackish grounclwater desalination

10

~

o e

An alternative Water supply strategy for seasonally-demand slressed mediterranean coastal regions

o :=Jl o L ilJ

e ilJ L ilJ

L)

10

:3 ilJ

.c L)

L

ilJ (J) (J)

o

o

by

INTRODUCTION

E.

A.

GEORGOPOULOU*,

A solution to the above-mentioned

There is a growing tendency to imple-

problem could be the utilisation

A.

KOTRONAROU*,

of

KOUSSIS*,

P. J.

RESTREPO**

vestigated through an integrated and consistent

approach.

In that regard,

ment desalination of sea water, typically

desalinated brackish groundwater, in-

decision-makers favor the use of user-

through reverse osmosis, in many re-

stead of sea water, coupled with an ef-

friendly integrated

gions of the Mediterranean

fective

tools , which alIow easy access to the

that face

serious water shortage problems. How-

strategy

for

controlling

seawater intrusion and the enhance-

decision-support

information, as welI as the investiga-

of

ment of the hydrologic budget through

tion of alternative schemes using dif-

desalination technologies, this method

reuse of wastewater. This strátegy may

ferent values for specific parameters.

of production of potable water is still

lead to a sustainable management ap-

rather expensive, in particular for islands

proach

that are geographicaIly isolated from the

growth can be attained without undue

a Decision Aid Framework for the in-

mainland power grid and where the cost

environmental

degradation. Tt can be

vestigation of the feasibility and appli-

ot scarce electric energy is high.

particularly suited for arid areas of the

cability ofthe proposed altemative wa-

Mediterranean

ter supply strategy. The purpose of this

ever,

despite

the

evolution

Brackish water, of l ,000-1 0,000 ppm

\.

through

which

economic

basin, where there is

From these general considerations, the necessity arises for the development of

TDS, can be desalinated at a signifi-

scarcity of water and the water demand

framework should be to combine the dif-

cantly lower cost, i.e., at about one third

has substantial temporal variations, ris-

ferent elements

of that of sea-water. Several brackish

ing during the summer many times over

groundwater

water desalination plants are currently

the annual average.

treatment and recharge, desalination

(surface hydrology,

dynamics,

wastewater

In order to investigate the feasibility

etc.) in an integrated environment, in

and sufficient data are now available

and applicability of such an alternative

order to facilitate the investigation for

to alIow (i) the determination ofthe de-

water supply strategy, several aspects

an optimal scheme that will promote sus-

ciding factors influencing process se-

must be examined, incIuding legal, ad-

tainable and economically viable water resources exploitation.

in operation (e.g. in the Canary Tslands),

lection and (ii) rather accurate cost pro-

ministrative, environmental and finan-

jections for a new plant. However, fur-

cial considerations. Furthermore, vari-

ther pumping of brackish water from

ous scientific

issues

must be ad-

• National Nymfon,

Observatory 11810

of Athens

Thissio,

Lofos

Athens-

groundwater aquifers may worsen sig-

dressed in order to describe the dynam-

nificantly the existing situation in re-

ics and feedback of the natural system,

gions that already face salinity prob-

subject to human control. Last, but not

ration. 1002 Walnut SI. Suite 200, Boul-

lems.

least, all these elements have to be in-

der, CO 80302, USA

GREECE •• Optimal

Decision

Engineering

Corpo-


GENERAL CONCEPT OF PROPOSED ALTERNATIVE WATER SUPPLY STRATEGY

groundwater

• Lower water treatment costs, which result from desalinating

It is well known that several arid coastal

water, from coastal aquifers, with sa-

consideration

linity le veis much lower than that of

tation by treated wastewater.

of recharge augmen-

• Assessment of desalination technol-

sea water (-3.5%).

Mediterranean areas face severe water

dynamics in terms of

quantity and quality, with explicit

brackish

ogy and encapsulation

• Avoidance of sharp saltwater intru-

of techno-

supply problems. A typical practice for

sion incidents, due to the aquifer's

economic plant operation features.

dealing with this problem is through

damping of the impact of seasonal

• Assessment of wastewater treatment

pumping of groundwater. However, in

demand stresses, giving the system

technology and treated wastewater

many cases, the non-enforcement

time to recover.

recharge

of

appropriate regulations or the lack of an appropriate administrative

percolation

• Increased defence against salt water

author-

intrusion

from

aquifer

ity results in uncontrolled water pump-

through recharge augmentation treated wastewater,

or deep injection) and

encapsulation

mining,

ing that threatens the regional water

options (namely surface of techno-economic

plant operation features.

by

• Economic evaluation of the overall

with enhance-

balance. The situation is even worse in

ment of the hydrologic

budget, as

scheme, on the basis of the informa-

cases where there is also a significant

treated wastewater is reused, instead

tion derived from the analysis of sur-

seasonal

of being lost to the sea.

face hydrology, groundwater dynam-

variation

needs, usually

of water supply

because

ics, wastewater treatment - recharge

of tourism.

is severe enough - prohibits the fur-

BASIC ELEMENTS THE DECISION-AID FRAMEWORK

ther exploitation of affected pumping

In order to come up with conclusions

of the alternative water supply strat-

These two elements usually provoke sea intrusion in the aquifer, which - if it

OF

and desalination,

taking al so into

account environmental

aspects.

Regarding the economic evaluation

wells. The response of the aquifer to

regarding the feasibility and applica-

egy under investigation, a very large

human interventions may vary in terms

bil ity of the proposed strategy, a Deci-

number of variations exist regarding

of time and degree of significance, de-

sion-Aid Framework must address in

the design parameters of the concept

pending on the type of these interven-

particular the following elements:

to be applied. Each of them has differ-

tions, the natural recharge (i.e. precipi-

• Simulation of potable water demand

ent consequences for the evolution of

tation, inflows through the boundary),

and demand projections for the plan-

salinity of the aquifer and for the cost

as well as on the particular characteris-

ning horizon investigated, based on

of the whole scheme. For example, the

tics of the aquifer in question.

regional

total amount of wastewater recharge,

The concept of the proposed alternative water supply strategy

characteristics

and past

the wastewater

trends.

recharge method, as

well as the recharge location affect sig-

is de-

• Establishment of hydrologic budget

picted in Fig. 1. The main advantages

(using measured data and hydrologic

nificantly the capital and the operationJ

of the approach are:

modelling) and stochastic analysis of

maintenance cost, while all these ele-

~.

Fig. 1: Concept

DESALIN"ATION PLANT

r------

.rt,

..6.C'.Ji'.I

of the alternative

WATER DEMAND good qualitv water

Households Tourism Agriculture Industrv

water supply

I Ootlon 2: I s1ll'face .. .. I I

GROUNDWATER

t,

ET

1Oetíen 1: 1

tlf brtrekish

f!rowtdwater

under investigation

WASTEWATER TREATMENT wastewater PLANT

Other

Punwint?

strategy

WATERSHED

dired I

. ..

Rain

I

T

Infiltration

Artificial f!roundwa1er recharge

SEA

with treated wastewaier (resh -sea water inkrfoce

24

International

Journal

of Island Affairs

Runoff


wastewater treatment - recharge and

Fig. 2: Data on existing pumping wells

water desalination).

The need for

from the fact that, given the nature

o

4uO

su •• opedo Su•• opedo

'res Yes

No

No

No

No

AgVMVaUJ

Yes

No

No

Ye. Ye, Yes

OEYAA OEYAA 7 LAK<Hkinou5625

liIes T$art-Gefi&

No

No

No

No

Pnv&te

o

'res

No

No

'res

OEYAA

6

equations), in order to identify feasi-

U

ble solutions rapidly the number of

u L u

o

.217

IrdJunaluse MocedusefpollJljeLirigatJOn)

e_

.117A

·¡m~33 .""l!" aleO

ellA -:1: .212 Oll2A·:~•.m ei\70A .31

O:~~~270 011-..288

Fig. 3: Cost functions F

possible . • A stage of detailed economic analy-

20

sis, which allows the refinement of

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el.

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e3.

ContJacl

Analyllcal Iunctiens '01 capital eeet ln m2 x No $kicb +

r••E•• o). engin.

C4. W

.oduIe,

C5. Ven.

flft

14 4 E••o/rnl

&. hPÑng

(in EUfO).

[In

High ••••••••

CS.

O......,... E..

_r r••

Euro) -

SOEt.roIm3

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Cl0.0dotc_r

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CI2. R••••• od

el3. Che.icaI feed

15.852 X

r•• EUfO)' SftI~s

(in

SO

C17. A..-..,

__

~r

framework, deci-

X ( rnlleedlday)

X (

the same time, allow decision-makers to "intervene" in the different steps of

l000x

the decision framework, by modifying

U7S) X ElI'oIskid

X

Noskids

certain parameters and by examining

X

m3Ploduc:tlsec l 0.8

the consequences of these changes on

O EU'o

r••E••o)•

the results. In addition, decision-mak-

144 E•• o/rnl X rnl blnoIday

(in EUfO)•

0E ••o

x(MWlD.85 5

••E •• o)·

usually require a user-

ements of the problem at hand and, at

X

m3 feedl day ) X

inawence &: boncb (in E•• o).

C18. M•••••

~St

43311

dNning (in E,"o)-

C16. 8ñno b_

rnl PlodueUday + 3766)

lCOOlstocage+

$) -

C14. Cartñdge filler•. fin Ewo) C15.•••••.•••

As mentioned above, apart from the

(DAT), should integrate the various el-

x IrnlPloduc:tlday) U6)x

3209

fin E•.•o).

piping

o

5181 E•.•o/skid X Noskid$

6024E ••o X (HPll00lP"'l'effiOaenc¡>

•• Eulo). o)'

X

• X

+

°

ers should be able to examine more than

E •••

one solutions. Furthermore, the DAT

Oiectcoot ICl·Cl7) Di"'''''''

jC1·Cl7)

should be applicable to different case

•••

studies and allow the updating of the various databases incJuded in it. The

ments, together with the seasonal pro-

to concentrate on the most interesting

latter fact safeguards against the even-

file of wastewater recharge, may affect

variations from an economic point of

tuality that the concJusions drawn by

of

view. In order to reduce the number of

using the DAT are "static", in the sense

that is pumped and, if

possible alternatives to be finally ex-

that they do not reflect the most recent

amined, the decision-aid procedure can

developments regarding cost figures of

be split in two stages 2:

the various technologies applied, gen-

significantly groundwater needed,

the

desalinated,

salinity

and, con se-

quently, the relevant cost figures. Given the complexity of the problem

• A screening stage, which identifies

eral cost elements (e.g. financing char-

and of its analysis, some of the choices

the most promising alternatives on

acteristics, water and electricity prices

made at the beginning of the analysis

the basis of cost minimisation. In this

etc.), regional trends regarding perma-

will be arbitrary and may leave out some

leve! of analysis,

nent population, tourists, agricultural

an optimisation

promising variations of the water sup-

model is applied, which uses simpli-

ply strategy

fied versions of the various project

investigated.

Thus,

a

"guidance" should be provided during

components

the initial stage of the analysis in order

charge,

(i.e. natural water re-

groundwater

dynamics,

u

ponents are used.

friendly tool. This Decision-Aid Tool

x (m3 prod.Jctlday) 0.65

u

as well as detailed other project com-

sion-makers

X No membfenes

&47&E•.•o +

conlrob (in Ewo) -

cs.

C11. Ptee •••

1200 EaoImembr.

:3

(f) (f)

grated decision-aid

2(D) ElA'oMmeI X No v e;sets

e6. EIectñcaI Nialation &.

x m3IPloduc:t+blendl1day

10

L

need to develop a concise and inte-

600 ElI'o/m2

LJ

by the screening procedure. In this

lf»X) El.fo

(in Euro) •

EwoJ -

C1.IMtr~ation

Ei 50 m2 adJnin $paCe) x

e

e LJ

PRESENTATION OF THE DECISION-AID TOOl

H

•••üesehnenon

L

most promising solutions, determined stage, complete simulation models,

and data for desalination

=:JI

o

of functions

variables should be kept as small as • Potab6eute .11f~use

e

and

namic character 500 88.0 2761

t; O

ofthe problem (i.e. non-linear and dy-

143.92

10

at this stage stems

simplifications

21A 21 281 393 22

-.J

and industrial activity etc. Thus, an effort has been made to develop such as DAT within the framework of the ongoing WASSER project

O


2,

which represents one of the project's

final deliverables.

It should be men-

such as zooming-in and -out, working

put data regarding permanent and sea-

on specific sections/elements

sonal population, agriculture and in-

of the

greater region, arranging layers, modi-

dustry. The user has the possibility to

a tool is not to produce a tool for com-

fying layers' characteristics,

either define the rates of change that

mercial purposes, but to show how the

specific

tioned that the aim of developing such

topographical

getting

information

for the

(e.g., area of a selected region or length

planning horizon, or to select the type

be integrated within a single software

of a river segment) etc. In the future,

of expected future change on the basis

environment. In addition, maximum ef-

the coupling of DATwith GIS may also

of past trends (i.e. linear, exponential

fort has gone into the incorporation on-

allow the incorporation of data regard-

or logarithmic growth). Moreover, re-

line of the different project parts. How-

ing renewable energy sources, which

garding potable water demand, projec-

ever, given the complexity of the prob-

are site-specific, in order to explore dif-

tions can be performed

lem and especially thecomplexity ofthe

ferent possibilities for electricity sup-

rately for each town of the region or for

issue

ply for the desalination plant. It should

the region as a whole (FigA). Water

groundwater dynamics, complete on-

be noted that such composite

demand projections serve as input data

line integration is outside the scope of

have already been developed and can

for the estirnation of the volume of

be of great assistance to decision-mak-

wastewater that can be made available

ers

If digitised maps for a particular

for aquifer recharge (after suitable treat-

Input data

case-study do not exist, the tool has

ment).Next, the water demand projec-

DAT includes, first of all, data that are

of stochasticity

related

to

our current work.

3.

tools

either sepa-

been designed such that the user has

tions, and the raw wastewater volumes,

related to the geographical character-

the possibility either to work without

together with simple cost functions and

istics ofthe application area, in particu-

GIS or to use the available maps.

other

data

for

desalination

and

use,

A second broad category of input

wastewater treatment and recharge, ba-

and surface water re-

data comprises technological and eco-

sic general econornic data (e.g. electric-

sources. In addition, DAT includes data

nomic

on

ity price), and data on surface hydrol-

on perrnanent and seasonal population,

desalination (Fig.3), wastewater treat-

ogy are fed into the screening part of

agriculture

and industry, i.e. on the

ment and recharge, as well as water

DAT. A user-friendly interface allows

water consumers. Moreover, it includes

pumping. Furthermore, input data com-

the user to enter the data required for

data on the existing pumping wells (i.e.

prise also cost data for the alternative

the simulation of the aquifer (the USGS

well code, state of ownership, type of

water supply sources (if any) for the

SUTRA model is used"; an interface has

use, pumping rate, water level, water

particular area. Finally, this category

been prepared to facilitate data input

qualityetc.).

also includes general econornic data for

and model runs). At the end of the

a particular case \.study, such as water

screening procedure (which basically

and electricity

consists of an optimization model

lar

information

geomorphology

on

land

An additional characteristic of DAT, regarding the above mentioned infor-

functions

and

data

prices, currency

ex-

US-

ing dynamic programming), the most

mation and data categories, is that it

change rates (in case that some cost

has been coupled to a GIS (Fig.2) in

figures are not provided in the local

promising - in terms of cost - alterna-

currency), inflation rate etc.

tives of the general water supply strat-

order to provide the possibility to: â&#x20AC;˘ Visualise certain important character-

It should be mentioned that although

egy are derived. Environmental consid-

istics of the case study under inves-

DAT has built-in default values for the

erations are included in the form of

tigation (a fact which increases the

various elements, the user has the pos-

user-defined constraints, with respect

user-friendly character of the tool).

sibility

â&#x20AC;˘ Use information regarding location of existing pumping wells, location of demand centres, type of land uses

to change

these values

as

to the quality of the aquifer at a specific point at the end of the planning

needed. A third category of input data refers

horizon.

(e.g. hy-

The next step involves a more de-

aquifer's width

tailed design of the basic elements of

to the aquifer characteristics

etc., if such info is considered an im-

draulic conductivity,

portant issue to be exploited further

etc.), as well as to surface hydrology

the system (desalination,

wastewater

(e.g. regarding the issue of transpor-

(e.g. precipitation,

treatment

for the se-

tation cost).

groundwater etc.).

lected alternatives. ent technologies,

case study area, DAT can show all this

Data processing and results

information to the user, either separately

Data processing within DAT includes

profile of each alternative. For the de-

or overlaid. In addition, it offers so me

first of all the projection of water de-

sign of the desalination

of the most common capabilities of GIS,

mando This is done on the basis of in-

provides two options: automatic de-

infiltration

to

International

Journal

of Island Affairs

and recharge)

Simple design

rules, together with data for the differ-

Thus, ifthematic maps in digital form (thematic layers) exist for a particular

26

he/she considers appropriate

various elements presented above can

are used in combi-

nation with the pumping and recharge plant, DAT


Fig. 4: Water demand

cases where there is a favourable po-

projections

tential. However, RES have also par••• Rhodes

Island - Waler

demand

ticularities (e.g. potential mismatch in-

13

(projechonlJ

compatibility between the power outI

To.m. Ag;cWt".llndu,tJ)Il

A_'I

spocific~r,,~ '99'~I_doyt

put from RES and the load of the sysSpocific""""""",ioolo, 1268100001 . (1)1 2Il2O~_doyl

ill

~

tem) that should be also taken into ac-

'YId..et demand

52610

crcrecucn for íhe year

2020

A typical output of the detailed eco-

450>0

I---'.,;c.¡~d--;! FEB I---'.,;c.¡~d--;! MAR I---'d----,d-....,j

JAN

29960 22410 14860

APR

7310

:: 50

70

60

so

BO

00 10 o Proected popoIation

• P est population

20

¡......;~-;~-~ ¡......;~----.:;:;¡.-~

I---'d-":d--;! ~~ f--='-=I----,d-....,j

JUL

~~ ¡......:~-~--;!

;:::~==::=~ 8." 1)01 1~

~==.:.;=....:.::::=::J_!2.:.=:.:....::=:::..::=::.J

rates and for the various sensitivity analyses (if the user decided to per-

L

all alternatives are compared with respect to economic viability. Since the

•• Deseñnetion planl . Capital

,-- __ 2001

-=""""~;=c""Uf_,e..,..nc_,--,

C_o._'

BuOJino'l Memb, ene, V."els

357.600IIEUA (E•••o)

I

~!.:::~

561.60011EUAIE••o) '56000 IEUA{E o)

% ~t~::~n

.:J ~

31.B491IEUAIE",0]

InsWnent.oiooondcont'o1~:::::::;1::::4';':':;;.1""a~2IEUAIEU<O)

S¡.WOJkt

Cooooct..,..,...¡,g·uoining

(mobiIz"",,,-•••••ance. cont;,gencie, TOTAl:

!·I=tematks:

)

~_-

---,2',,¡,'.36,.,.,°IIEUAIEUJO) 62040 IEUAIElAol 144.000 IEUA(E •• o) 10.000 IEUA(E•••o) '84.124 IEUAIE",o) I

L-

••••...

I1l:l

Plojedl.MicJosoftVi···1

the alternative

.:J

to be not economically

NPV<ü), it is of interest to know how

2._22_.9'--.94--.J31IEUA IE•••o)

I

.:J .:J

c:::Do

:::J

Iii"lo

c:::D

~

1'"

.:J

:::J

~00

~

.:J .:J .:J

.:J

.:J .:J .:J .:J

t$)COJetPHOTO-PAINT 811 ~ De se lin •••• n plan...

more

1'$1

l1st I

scheme proves to be

expensive

than

sea

water

desalination. On the other hand, even when the alternative scheme turns out

~

[IJ 1'''

Capitalcost has: beencalcUated on the bese 01:a) conflgwalion design and b) des.alination CO$tft.ncóoos Hoeeve. res"'s can be changed drectly by the Use! n this screen

~s,.,'IIIl!YMicJoooItwOJd·

advanced

~ .:J .:J .:J .:J .:J

1'"

11-__

as

!1st 1

ge.w ••",

Ploc."""""O Rest",edpi¡>ing

such

wastewater treatment, wastewater re-

.:J

l1st

EiedJie.!I""aI""""'l

vestments

p"

1'"

Brinou_

O!heJ

Con~~~~tíon

charge etc., there can be cases where ~O:

M"OO' ••••• cIeOJwlg eq<.iomont -~

der investigation involves additional in-

c:::D ~

:::J :::J [IJ ~

Chen-icoI leed ",si... c..uódslerol •• ,

al.ternative water supply strategy un-

I!lIilD

col!

viable (i.e.

this compares to seawater desalination (which, for instance, could be even more expensive).

calcUated

Final @l ~nm:il(~ 8:36

••

Remarks

In arid, seasonally-demand Mediterraneancoastal

stressed

regions, there

sidies etc.), as well as a water price. The

may be other water supply solutions

ment-by-element analysis" or user-de-

data entered here are used for the eco-

apart from seawater desalination that

fined designo Following the design of

nomic analysis of all the alternatives,

merit investigation.

sign of the facility on the basis of ele-

The alternative

each unitlfacility, the capital cost as

but the user has the option to carry out

strategy pro posed by this work, namely

well as the operation and maintenance

a sensitivity analysis for these param-

the desalination

cost for the planning horizon used are

eters, as well as for other parameters

pumped from aquifers coupled to ad-

calculated (Fig. S).

such as the cost of electricity. It should

vanced wastewater treatment and re-

of brackish

water

The final part of DAT consists of the

be noted at this point that the electric-

charge, needs to be tested through the

detailed economic analysis of the vari-

ity cost represents one of the most im-

development of an appropriate and in-

ous alternatives on the basis of their

portant factors that affect the economic

tegrated methodology and its applica-

Net Present Value (NPV). In this step,

viability of a desalination

plant and

tion to specific case studies that have

the user must enter certain data regard-

thus it is worth investigating the, pos-

the general features stated above (arid,

ing the financing of the whole scheme

sibility of electricity

seasonally-water-stressed,

(i.e. loan characteristics, possible sub-

renewable energy sources (RES), in

supply through

L

e .i.J

economic viabilities.

plant

e tU

of the alternative for different discount

Sea water desalination is considered

of capital cost for the desalination

:JI

o L

3

as a "baseline scenario", against which Fig. 5: Estimation

e o

tive is shown in Fig. 6. The graph gives

ferent alternatives on the basis of their

..1I tl. Ahodesisland- \IIate ...

O

an overview of the economic viability

form any). The user can compare dif-

OEC YEAAI

t;

tU U 10

nomic analysis for a specific alterna-

375'0

10

tU

count.'

60'60

-.J

already fac-

ing groundwater salinity problems).

tU

tU

en en

o o


The purpose of the work presented

Fig. 6: Output

of the detailed

economic

analysis

in this paper is to demonstrate how the various elements

of the problem at _ 1:1

hand can be combined consistently and

x

integrated in a user-friendly environ2.GOO.1XXl

ment in order to assist a decision-rnaker

2.'00.1XXl

to handle questions such as, e.g. "Is it

e Bese case .SMSl ·20~ .Sens2: ·lOD:(

2200.1XXl 21XXl.1XXl

worth investing in the desalination of

1.800.1XXl

the aquifer

treated wastewater?"

•.10O:C

• Sens4

•.20 0%

1 GOOIXXl

brackish water instead of sea water, while recharging

oSens3-

1 ,001XXl

with

1.200.1XXl llXXl.1XXl

In order to an-

8OO1XXl

swer this question, economic, as well

GOO.1XXl

as en viron mental considerations must

2OO.1XXl

be taken into account. A decision-aid

·200.000

4oo.1XXl

tool can facilitate significantly the in-

°rw.Y.~v.:-&~~~~~~~~~~~~~~~~lP.~·~~~;~~:

·4oo.1XXl ·600.000

vestigation of this issue, by providing decision-makers

with all the informa-

tion that is needed in order to have a c1ear and complete picture of the consequences of the application of different water supply alternatives.

References I

Acknowledgement:

RENES (1997-98), "Mediterranean eo-operation lor water desalination polieies in the

ergies", prepared by the Centre lor Renew-

perspeetive 01 a sustainable development

European

Commission/DG

This work has been partly funded under

able Energy Sourees (CRES) within the

(MEDCODESAL)", INCO Programme Con-

theENVIRONMENT & CLIMA1EPRO-

Iramework 01 the Thermie Programme.

traet No. INCO IC18-CT97-0142.

GRAMME of the European Commission, IXi Environment,CONlRACTNo ENV4-

2

groundwater desalination & Wastewater

International Journal of Island Affairs

01 Athens (2000),

4

3

United States Department 01 the Interior/ Bureau

01 Groundwater

01 Reelamation

(1998),

Water Treatment

"The

Desalination & Wastewater Reuse in the Wa-

Desalting

ter Supply 01Seasonally-Stressed Regions",

Manual: A Guide to Membranes lor Munici-

Environment & Climate Programme Con-

stressed regions", Co-ordinator: National

Reverse Osmosis (RO) Plan!

Utilisation

2nd Progress Report, Annexes-Volume 111,

reuse in the water supply of seasonallyObservatory of Athens.

National Observatory "WASSER:

CT97-0459, "WASSER: Utilisation of

28

XVII (1998),

"Desalination Guide Using Renewable En-

Membrane

pal Water Treatment (2nd Edition)". 5

Voss, C.1. (1984), "Saturated-Unsaturated

traet No. ENV4-CT97-0459.

Transport", U.S. Geologieal Survey Water-

National Teehnieal University 01 Athens/

Resourees Investigations Report 84-4369.

,

Photo:

TEMAK


Experiences o. Renewable Energy

~

O

re r

:) )

Desalinalion Planls 1()

:3

u (

L by

RICHARD MORRIS·,

PLATON

BALTAS**

D

he provision of fresh water

is becorning an increasingly important issue in many areas in the world. Areas

more, whereas, system reliability has

visit was performed for three of these

considerably

plants in:

A number

increased. of successful

do exist.

• Cran Canaria Wind powered VC SO m3/ day

Desalination

these in which demand for fresh water

These applications prove that the cou-

is expected to increase within the com-

pling of the two technologies has ap-

ing years. Access to potable water is

proached technical maturity and is ea-

• Siros -Wind powered RO 900 m3/day

an inherent human right for all. As with

pable of providing fresh water at a rea-

The conclusions of this work are pre-

energy, it is necessary to actively pro-

sonable cost. However, cost reduction

sented in this paper.

mote policies leading to effective man-

and technological maturity is not suffi-

agement of water supplies in the Medi-

cient for large-scale application. A re-

terranean.

newable energy driven desalination

Desalination

applications

RES

around the Mediterranean are between

• Lampedusa- PV powered RO 120 m3/ day

RE DESALlNATION COMBINATIONS IN EXISTING APPLlCATIONS

using Renewable En-

system provides a vital product to a

ergy does offer the potential of provid-

local community and thus social inte-

ing a sustainable source of potable wa-

gration is very important. Although the

Renewable energy sources are by their

ter for some communities, particularly

number of RES-desalination

nature characterised

\.

applica-

by intermittent

those in arid areas where there are no

tions is relatively limited, it is very im-

and variable intensity. Desalination

indigenous sources of fossil fuels.

portant to learn all lessons frorn these

pracesses are designed for continuous

applications.

The lessons are not al-

steady state operation. This appears

ways of a technical nature. They also

to be the main problem concerning the

onventional desalination

technol-

ogy is fairly well developed and so me processes considered quite mature al-

have to do with the availability of ex-

interfacing the two technologies.

though there is still considerable scope

perienced personnel for the operation

Two approaches to solving this prob-

for improvement and innovation. Re-

and maintenance of the plants, the eco-

lem have been identified. These are

newable energy sources offer a sus-

nomic subsidies for water production,

modulating the process to cope with

tainable route forward with minimal en-

or even the public confidence on the

variable energy input, or by including

vironmental damage. Considerable ad-

dependability of a new technology.

an energy storage buffer to even out

vances have been made in the devel-

UNESCO has addressed these issues

opment of renewable energy sources,

and launched a project for the review

This has been the approach in most of

in particular

in wind energy

of existing RES desalination

the 79 renewable energy desalination

photovoltaics.

The cost of electricity

by wind

turbines

and has

dropped significantly over the last 15

plants.

plants identified in this study. The ma-

authors performed a literature survey

jority are pilot/demonstration

and contacted

Out of these plants:

existing

desalination

plant operators where possible. A da-

machines

tabas e on existing

has

been

increased.

cost has dropped even

the energy supply.

Under a contract from UNESCO the

years and the size and reliability of the Photovoltaics

(f) (f)

o

T

produced

U

RE desalination

plants was created. Finally, an on site

*Richard **Sunlight

Morris & Associates - Germanos

plants.

- UK

S.A. - GREECE


Figure 1. RE desalination

plant capacity

for the 79 identified

This consumption

plants

is increased by

the operation time: increment of 50%

30%

,....-

after 2.5 operation years

1--

25% 20%

distribution

-

• For VC systems: 8.5-16 kwh/m-, depending on size

-

~ r==

15%

--

plants --

.~

At the moment there are no large-

-

==

scale applications of renewable energy

,---.,

10%

such as solar

,---.,

~

.......

5%

or wind energy

to

desalination plants. The majority ofthe plants use photovoltaics to power the

".~.~

0%

0--·

desalination process. As shown in Figure 3, the great majority of plants utilise solar energy.

Plant Capacity

(m3/day)

• 2/3 desalinate sea water

energy costs are the most important el-

SDAWES - WIND POWERED VAPOUR COMPRESSION PLANT IN GRAN CANARIA

The capacity of these plants is rela-

ement in determining water costs where

The SDA WES project was designed to

tively small. The capacity distribution

the water is produced from desalination

produce water from wind energy in

is shown in the following figure.

plants. Some energy consumption data

combination with a variety of different

• 1/3 desalinate brackish water, and

In many reports it has been stated that

for traditional desalination plants using

desalination systems:

10 - 40 m3/day, which by desalination

different desalination

• Reverse Osmosis

The average plant size was around

techniques

are

standards is very small. Ttis not known

given below. These data refer to con-

• Vapour Compression

how many of these plants still exist but

ventional operated plants in operation

it is likely that only a few remain in op-

at their nominal power consumption and

• Electrodialysis The main objectives of the project are:

eration. The lessons learnt have hope-

production.

• to identify the best desalination sys-

fully been passed on and are reflected

• For RO systems:

tem to be connected to an off grid

5.9 kWhlm3 without energy recovery

in the plants currently being built and tested.

wind farm, and,

(large production plants)

The processes best suited for inter-

• to assess the influence of the varia-

4.3 kWh/m" with energy recovery

tions of the wind energy in the be-

mittent operation are the membrane

(using a turbine)

haviour of the desalination system

processes. It is hardly surprising there-

• For EDR systems:

~.

and the quality of the water

3

fore that most of the plants built have

1.22 kWh/m (for feed water salinity

The project is located on the island

used a membrane process - reverse os-

of 3000 ppm and product salinity of

of Gran Canaria (Spain). It consists of

mosis. This is show in Fig 2.

500ppm)

the following elements:

Figure 2. Desalination conjunction

processes

with renewable

used in

Figure 3. Renewable

energy

Other 4%

Hybrid 10%

MED 14% Wind 20% MSF 10%

RO 62%

Solar Thermal 27% 30

International

Journal

of Island Affairs

energy sources used

in RES desalination

plants.


• The off-grid wind farm with two wind turbines of230 kW each.

10

t; O e

to a 100 kVA synchronous machine (see

• Three desalination system with two pumping groups Eight identical

-.J

temo The 1500 rpm flywheel is coupled Picture 2.).

o

In terms of budget, the SDA WES reverse

osmosis

plants, producing 25 m3/d each • A vapour compression unit (50 m3/ day)

project projects

is one of the biggest in Europe.

R&D

.:::JI

The VC plant

L

o QJ

started up in July'98.

e QJ

Part of the project involved the crea3

• An electrodialysis unit (190 m /day)

tion of a mathematical model of the plant.

• A control system with two PC's and

CIEA-ITC, SA performed a set of tests

L

QJ .u 10

a PLC's network.

were performed in the installed plant

3

Vapour compression desalination is

(February'99) in order to collect data to

a thermal process. The equipment takes

validate the model (developed by NEL).

QJ .c .u

time to warm up and if left without en-

The plant was working normally un-

L

ergy input will cool down. Because of

QJ

til March'99, when scaling problems Picture 3. Vapour Compression

(f) (f)

plant

scaling problems on the heat transfer

were detected. Scaling problems are not

surfaces, the process has to be oper-

un usual in desalination plants and this

ated at less than 700C. This means op-

was to be expected. After several con-

erating under vacuum. This also takes

tacts with the supplier, they gave the

time to draw down and will degrade

instructions to sol ve the problerns; the

PHOTOVOLTAIC - R.O. PLANT IN LAMPEDUSA ITALY

through inevitable in-Ieakage of air if

plant was cleaned up (November 1999)

Lampedusa is a small island belonging

the vacuum system is switched off.

and restarted up in January 2000. New

to Italy situated between Sicily and the

o

o

difficulties appeared with new delays,

Libyan Coast. The island is some 10 km

and the plant began to work normally

long by 2 km at its widest point. For most

in May'2000.

of the year the population

Most of the time to date has been

is around

5,500. In summer this is swollen to nearly

spent in procurement, erection, com-

20,000 by an influx of tourists, mainly

missioning and trouble shooting. As a

from Italy. Fishing and tourism are the

result only a limited amount of experi-

most important activities. Annual rain-

ence has been gained in the operation

fal! averages 300 mm and occurs during

of the plant. However enough experi-

the winter periodo Water resources are

- wind farm and

ence of the plant has been~~ained to

poor. There are some brackish wells but

show that the combination works but

theses do not provide drinkable water. The potable water supply is from three

Thus the process has an amount of in-

not enough to draw any concrete conclusions.

ertia. These problems can be reduced

A major shortcoming of this plant is

supply 800 m3/day of very good quality

Picture J. SDA WES project desalination domes

vapour compression plants, which can

through good insulation and well de-

that the wind energy capacity greatly

water. This is blended with brackish

signed sealing systems.

exceeds the demand of the desalination

water prior to passing into the munici-

In this instance the vapour compres-

processes. This makes matching sup-

pal distribution

sion plant has been coupled to a wind

ply and demand difficult. Either incor-

45,000 m' ofwater is imported by tanker

farm as the energy source. Temporary

porating larger desalination plants or

from Naples to supplement the system.

energy storage is thus essential and a

smaller wind turbines can solve this.

flywheel has been added to the sys-

Vapour compression

desalination

tion is being given to installing further

verse osmosis. The seawater requires

desalination

less pretreatment

seasonality of demand makes it difficult

and the process is

more robusto However

to justify

plants but the extreme further

investment

in

the energy consumption of reverse os-

desalination equipment which would he

mosis is much lower than VC and this

idle for most of the year.

can be an important

consideration.

The plant was designed and erected

of VC can

by Italsolar (now ANIT) in the premises

be lowered but much more research is

of SOFIP. SOFIP is a utilities company

needed.

based in Palermo. The company owns

The energy consumption machine

This is an expensive method of supplementing the water supply. Considera-

has a number of attractions over re-

fundamentally

Pie/u re 2. Flywheel and Synchronous

system. In summer


and manages water utilities in South-

The R.O. plant consists of two RO

the first washing without monthly re-

ern Italy. On Lampedusa, the company

units (3 m3/hr and 2 m3/hr). More re-

freshing. This caused damaged to one

owns and operates the electricity sys-

cently the large unit has had its three

permeator.

tem and sells power to the island

high-pressure pumps replaced by two

A second stop in summer 1993, for

high-pressure pumps of a more reliable

substitution of the inverter of the aux-

The company also has the contraer to

make. The energy recovery system,

iliary service did not cause any prob-

manage

which was giving trouble, has been re-

1em. Since 1995 the plant is operating

moved. Energy consumption

24 hours per day.

population

through the grid system.

the three VC desalination

plants that the municipality

owns.

of the

The fact that the PV-R.O. plant is 10-

Power to run the VC plants is drawn

large unit is currently 6 kWh/m'. Con-

from the island grid. The municipal

sideration is being given to fitting more

cated and operates within the SOFIP

water supply system is not metered and

efficient pressure exchangers,

which

premises, which comprise the diesel

the water costs are incorporated

have become available in the last two

power generators supplying power to

into

the general taxation system. The Lampedusa seawater

autonomous

RO system

PV-

was commis-

years. The membranes, which were 10

the grid and the VC desalination unit,

years old, have been replaced with new

has been very favourable, since opera-

membranes. The membranes of the small

tion and maintenance are performed by

sioned in 1990. The project cost was

unit have also been replaced, but not

skilled personnel.

1.38 million ECU and was partly funded

the pumps or energy recovery system.

Additionally advantages from locat-

by the European Commission.

The small unit has an energy consump-

ing and operating such RES - driven

tion of around 4.5 kwh/rn'.

desalination plants by the local Water

The system was sized to provide 5 m31hr of desalinated

Utilities stem from the fact that:

water for three

From initial commissioning in 1990

days of 8 hours operation on three con-

until 1995, the plant operated in autono-

• operation by part time employees is

secutive non-sunny days. It consists

mous mode. Having satisfactorily dem-

possible (lower operational costs);

of a 100 kW PV, a battery storage ea-

onstrated autonomous operation it was

• experts are available for purchasing

pacity of2 x 2,000 Ah at 220 VDU (Pie-

decided to incorporate the system into

spare parts, for planning and manag-

ture 4. and Picture 5.).

the grid network in order to operate the

ing O&M, for dealing with local au-

RO plants continuously

thorities for permits and licensing,

Picture 4. Par! o/ the photovoltaic Lamp edus a

array a/

"

Picture

5. Battery

room a/ LampedLlsa

and increase

output. Since then it has operated on a

etc.;

24 hours per day basis with network

• there is direct interest of management

back-up when battery power is insufficient.

to produce and sell desalted water with profit

The plant was subject to a long stop

The cost of personnel will remain el-

in 1992 due to a s rious damage in the

evated if the plant does not coexist with

seawater aspirating system. The stop

an organisation capable to operate it

went on for many months and the

with part time of its own personnel.

membranes were left in the water of

Special attention should be also paid to the following: • plant has to be fully automatic, reducing the staff requirements and increasing system reliability • daily inspection of the plant is necessary • the specifications of the membrane manufacturer has to be exhaustively observed The Lampedusa PV-R.O. plant has had a successful operation for more than five years, proving that with an improved sizing and without any incentive, it is feasible to produce and sell water at prices definitely lower than from other water sources, like water transportation.

Yet, improvements of

some specific parts are always possi-

32

InternationaI

JournaI

of Island Affairs


.-J O

ble (e.g. pumps with lower maintenance requirements,

lower energy require-

~ O

ments, improved mechanical transmis-

e

o =:JI o L

sion motor/pumps, etc.).

WINO POWEREO REVERSE OSMOSIS SYSTEM IN SIROS, GREECE

QJ

e

QJ

L QJ

LJ

The project at Siros was part funded

O

by DO XII as part of the Joule III pro-

:3

gramme. The objective of the project

QJ

e LJ

was to develop the concept of a family of modular

sea-water

desalination

L

QJ

plants making use of the locally avail-

(f) (f)

able wind energy resources.

O

o

The design involves a number of new ideas to reduce the energy consump-

Picture 6. Interior of the RO container for the pilot plant on Si ros.

tion of the process, to increase the reliability of the process and to reduce the

sumption of the desalination plant is

est plants recently built providing po-

overall cost of water. The family con-

200 kW and the nominal power of the

table water from a renewable energy

cept was to be based on a limited

WEC is 500 kW this allows the balance

source. This is important as it demon-

number of standardised modules. The

to be fed into the island's electrical grid.

strates the potential of being able to

project involved building two wind

This is very beneficial since all com-

supply entire communities. While no

energy desalination plants of different

munities requiring water also require

water cost figures are available for this

sizes - one was located on Tenerife and

electric power.

project, the scale of the project cou-

the other on Siros. The plant on Ten-

The RO unit is installed in 5-40 ft con-

pled with the fact that a very competi-

erife was the first to be built and con-

tainers. The number of RO modules al-

tive wind turbine is being used sug-

sisted of a 30kW Enercon E-12 coupled

lows the output of the plant to be var-

gest that water costs should be at the

to 2-RO modules. The plant on Siros is

ied dependent on the amount of en-

based on a 500kW Enercon E-40 and 8-

ergy available. Each RO module incor-

low end of the spectrum for this type of planto

RO modules with an output of between

porates a novel energy recovery sys-

60 - 900m3/day fresh water. The smaller

tem, which is based on a piston accu-

project, developing the concepts fur-

unit on Tenerife was used to test some

mulator principie.

ther, is currently

of the concepts prior to the construction of the larger plant on Siros.

~.

There is provision for both drinking

Work on a second

phase of this

underway

100%

funded by Enercon.

water storage tank and seawater stor-

CJnSiros, the wind turbine and the

age tanks. The sea water storage tank

RO plant are installed on two different

also acts as an energy buffer, in that

CONCLUSIONS ANO SUGGESTIONS

sites some 1.5 km aparto The RO plant

operation of the sea-water pump is re-

One major conclusion of this work is

is situated by the sea. The wind tur-

stricted to periods when high wind

that there are relatively few real appli-

bine is erected on a hilltop to get maxi-

power is available. A similar philosophy

cations of renewable

mum wind power and is connected to

is applied to the drinking water storage

desalination

the RO plant via a medium voltage

tank. Water is only pumped during peri-

plants or demonstration

transmission line. The electricity from

ods of high wind power availability.

energy driven

systems. Most are pilot systems.

We need more "real" systems.

the WEC is buffered in the energy stor-

The company has developed a pat-

age system. This includes a diesel gen-

ented energy recovery system to re-

erator, batteries and a flywheel genera-

cover the pressure energy from the di s-

Most work is focused on the success-

tor. The output is fed into the RO unit

charging brine. Various other systems

fui interface of the various components

and the electric grid.

are used to keep the energy consump-

and improvements in energy consump-

tion to a minimum. Tt is believed that

tion.

The RO unit contains 8 identical RO

While technology is relatively mature there is still ground for improvements.

modules, which allows the capacity of

the energy consumption

the system to be varied from 60-900 m3/

kWh/m3, which is exceptionally good.

desalination combination. However, the

day. Since the maximum power con-

The plant on Siros is one of the larg-

cost of wind has dropped to a level

is around 3

PV - RO is clearly

the favoured


where it is competitive to utility grid electricity. Energy storage is a major issue and is almost always required for these type of systems. Fly wheels are possible in certain ap-

While most attention is devoted to

Governments need to be persuaded

improving the energy part of the sys-

of the potential and importance of sus-

tems, there is scope for improvement

tainable water desalination and support

in the performance of all items of equip-

applications.

ment, to make them more efficient, reliable and to reduce the capital cost.

Acknowledgements

plications and can be used to smooth

In the near future, PV - RO looks as

out the energy output in short termo

to continue to be the most popular corn-

Batteries are almost always required for

bination for small to medium sized ap-

thanks to UNESeO

PV to smooth out the daily production

plications. Wind may be more impor-

study. They would also like to thank

of energy. Diesel is required for backup

tant for larger ones. ve is possible but

the owners of the plants surveyed for

and as demand grows systems even-

will have to improve energy efficiency.

their co-operation and help in arrang-

tually become hybrid.

Other thermal processes similar to ve

ing the plant visits. Finally they would

are under development

like to thank the relevant staff at the

It is also important to notice that few sites require water only. Local development invariably requires both water and electricity. ln cases where a local grid does not ex-

and may be-

It is al so very important to understand what drives

the demand

for

in Santorini at which the results of the work were presented.

water in Mediterranean

ist, a mini grid will be established with die-

countries as this guides the technol-

sel back-up. If a local grid exists then the

ogy development needs. To our opin-

RES desalination system will eventually

ion this is tourism and the trinomial is:

References Renewable Energy Powered Desalination Systems in the Mediterranean Region. By

be connected to the grid and the renew-

Tourism, Water and Energy.

Richard Morris & Associates. Report lor

able energy will become a fuel substitute.

Finally, most important,

UNESCO, July 2000

Prototype

solar thermal

desalination

system

/oeated near Muscat (Su/tan-

ate of Oman}. This plant was designed by So/Desalo 2000 in co-operation eolleetor funded

Solar Water Desalination using Pervaporation Membrane

34

for funding this

NTUA for organising the conference

come viable.

desalinated

The authors would like to express their

Module

lnternational

Journal of lsland Affairs

company

It was set up in Mareh

with Sultan Qaboos Uruversity of aman and the solar thermovSolar/Germany.

by the Middle

East Desalination

The projeet Researeh

is commendably

Center (MEDRC).


Sustainable desalinalion, distribulion, sewage and re-use in Ihe Cape Verde archipelago

"5 r

t

º

e )l

O

e

U

e

u u L

L)

o

-3

L

U (J) (J)

by

M,oy

areas of outstand-

The negative consequences

are:

JOAN

o o

FAGES*

• re-use, through a dedicated network

ing tourist interest are often beautiful

• Depletion of age old aquifers.

of non-drinkable water.

islands with sun, sea and sand. Unfor-

• Pollution of the shoreline with waste

The problem with this system is that

tunately, many ofthem have little or no

it consumes large amounts of energy,

waters.

drinking water, an essential basic re-

• Squandering of water as it is not re-

as it can require some 10 kWh per m3 of

source. Solving this problem becomes

used for other purposes that do not

desalinated water, including pumping,

top priority if one pursues the develop-

require drinking water.

treatment and re-use.

ment of tourism, farming and industry. The initial solution that is often applied is to desalinate water from a brackish well, using energy generated by diesel fired

of energy as the re-

If this energy had to be generated by

sidual heat of the electric generators

a diesel-fired generator, we would con-

is not used.

sume about 2 litres per m' and, there-

• Squandering

• Squandering of resources as non-re-

generators, which is either not sufficiently

newable, polluting and expensive to

treated later on, or is not treated at all.

transport fossil fuels are used.

~.

This unfortunately common practise can have serious ecological and also

This scheme, which is naturally unsustainable, should be replaced with:

fore, it should be ruled out as a basic energy production system. We mentioned earlier on that one essential resource for a tourist destination is the sun. Moreover, wind is also

economic consequences in the medium

• sea-water desalination

an abundant

and long termo In the short term, how-

• distribution of drinking water

coastal

ever, it is the answer that usually in-

• collection of waste waters

should, therefore, give serious consid-

vol ves the least investment.

• water treatment

eration to using these natural resources

resource

tourist

in nearly all

destinations.

We

as sources of energy. Wind energy is now a technologically Drinkable water reservoír

Irrigaríon water reservoir

mature energy for producing electricity, and, moreover, at a reasonable investment cost. It should, therefore, be used as a basic energy source, even if it requires the back up of a con ventional source of energy. The conventional

source could be

an electric generator that consumes a bio-fuel, like vegetable oil (rape seed, sun flower, "jatrofa", etc.) or bio-gas * -Agua de Ponta Preta" project Sal island (Cape Verde)

President EREF (European Energies

Renewable

Federation)

* Managing Director of HIDROWATT, SA


from fennenting organic waste (sewage

the use of some not very widely used

treatment sludge, solid organic waste),

technologies, but it also entails lower

or so me other renewable biomass, in-

operating costs and less environmental

stead of diesel.

impact. Environmental impacts have a

·"gl.llldttl'om ••••.• Ia·¡l<oject Saii$land(c.paVe<<M)

Solar energy for electricity genera-

cost, although, as they are difficult to

tion, either with photovoltaic panels or

evaluate, they are not included in prices.

with high temperature technology, is

For all these motives, this altemative is

still in the development stage with re-

econornically viable in the medium tenn

tem made up of an aero generator and a

gard to full comrnercial application, ex-

and, of course, it is the only possible

generating set.

cept for certain specific cases.

altemative for sustainable development.

limited water resources available, as

To produce hot sanitation water, we

for commercial application. Solar panels

DESCRIPTION OF AN ACTUAL CASE IN CAPE VERDE

can use low temperature solar thermal energy, which can be considered mature

The system will allow the area to have

also have the added advantage that they

The Ponta Preta urbanization, on the is-

can be installed as stand-alone facilities

land of Sal (Cape Verde) is constituted

in each consumer centre building.

by several hotel establishment localised

well as provide drinkable water and sewerage systems by using a non-polluting renewable energy source. Basic parameters which define installations are:

Should a central hot sanitation water

in the southem part of the island of Sal,

DESALlNATING

network be available, it could be advis-

in the Cape Verde Republic. The project

• Sea water collection: Pit on the beach

able to use suitable heat exchangers to

is located in an area rich in large, golden

harness the remaining heat from the

sand beaches but poor in water resources.

• Total production capacity: 2,000 m3/d

waste waters at the treatment plant in-

The service system proposed for the

• Treatment technology: Reverse os-

let and the heat of the exhaust gasses

Ponta Petra urbanization includes pro-

and the cooling water from the auxil-

duction and supply of drinkable water

iary electricity generators.

through sea water desalination, sewage

PLANT

with a capacity of 5,000 m3/d

mosis with energy recuperation • Configuration of installations: 4lines of 500 m3/d each. • Depósito de almacenamiento de agua

method

of urban waste water and its reuse for

of exhausting ancestral resources and

plant watering. Mud produced during

polluting, and not renewable, energy

the sewage process will be used as an

• Total power installed: 500 kW

consumption has been substituted by

organic corrector for soil improvement.

• Specific consumption ofthe system:

In short, the unsustainable

The project in its entirety has been

a process that: • Uses sea water, it distributes

and

heats it

potable: 1,700 m'

5.1 kWh/m3

thought with the aim to achieve an integral water cycle' management, start-

SEWAGE

~.

PLANT

and re-uses

ing from desalination to obtain drink-

• Water purification and irrigating wa-

them to recharge traditional aquifers

able water from sea, to return it to soil

ter production capacity: 2,000 m3/d

• Consumes c1ean, native and renew-

through irrigation. Wind power will be

• Water purification technology: Acti-

• Treats

waste waters

the main energy source of installations.

able energy. This system obviously

involves a

higher initial investment and requires

The energy supply of the installations will be achieved through a mixed sys-

vated muds • Treatment for water reuse: Filtration and disinfection • Configuration of installations: 21ines of 1,000 m3/d

AtlantlcOcean

• Water reservoir for irrigation: 1,700 m' • Total power installed: 100 kW

-Well

• Specific consumption of the system: 1.2 kWhJm3

~

.Aero:generators

Technical plot~; Reservoirs

/

ENERGY

SUPPLY

• Generating sets: 2 sets of350 kVA + 1 reserve set of 350 kVA • Aero generators: 2 units of 280 kW • Height: 50 m • Rotor diameter del rotor: 30 m -Agua de Ponta Preta" project Sal island (Cape Verde)

• Interconnection

with the local elec-

tric energy supply grid

36

International

Journal

of Island Affairs


Qa.ar - Producing Drinkable Wa'er Using Reverse Osmosis (RO) Desalina.ion 5ystem Powered by Solar Energy L

lJ

(f) (f)

o o by

INTROOUCTION

and have a high potential of solar ra-

The lack of water for human needs and

diation and brackish water.

irrigation is of increasing importance for the Mediterranean countries. Miss-

AHMED

MUHAIDAT*

• Use of solar energy as a clean and free source of power supply.

This paper presents the conclusion of the scientific, socio-econornic

as-

• Sustainable management of natural resources (water).

ing water hinders the development and

pects of a small-scale reverse osmosis

• Studying the feasibility of the RO-

influences the economical

desalination units powered by solar

these countries. 'Water does not know

(RO) desalination plant powered by PYs to pump about (50 m3/day) brackish

political borders'. This is the reason for

water from desert well in Qatar village

power of

the troubled political situation in the near East.

energy. • Transfer the RO-desalination

tech-

in Jordan. This brackish water will be

nology (small -scale units) powered by solar energy to the region.

Fresh water in Jordan is rare. The fast

desalinated using RO to produce (40 m3/day) of drinkable water and to sup-

population growth and the rising wa-

ply the inhabitants of this village and

ter consumption aggravates this situa-

their cattle with fresh water. The site of

tion per capita. The Government of Jor-

the project was chosen depending on

dan gives a lot of attention to provide

the site selection criteria, where the

SECURING FUTURE WATER SUPPLY ANO BRACKISH WATER SUPPLY IN JOROAN

every inhabitant of the country with

potential of solar energy and brackish

The agricultural sector is the main con-

fresh water and makes big efforts to

water is available. Also, this village is

sumer of water in Jordan, using 650 Mio.

solve the shortage of fresh water in the

far away from the electrical grid.

M3 of water in the year 1994 mainly for

The study was prepared according

irrigation purposes. Agriculture thus

to the sub-grant agreement singed on

accounts for 75% of the national water

contribute towards the alleviation of the

Aug. 1, 1998 between the Royal Scien-

demand, although it is only producing

water scarcity problem, due to high

tific (RSS) and the EcoPeace Organiza-

7% ofthe GDP. On the other hand, the

potential of brackish water in Jordan.

tion for the Middle East Solar Energy

industrial water demand in 1994 was

Zone Project.

in this

only 45 Mio. M3.It is, however, expected

import of fossil fuels, it becomes irn-

project are Jordan, the Palestinian Au-

that the industrial water demand will

portant to investigate the technical and

thority, Israel, and Egypt, and it is initi-

have tripled by 2015. Domestic water

economical prospects of the srnall-scale

ated and financed by the Mertz-Gilmore

consumption per capita is considerably

desalination technology

Foundation (JM-GF) in USA through

lower than in other countries of region

country. Desalination of brackish water can

Since Jordan depends mainly on the

powered by

Participating

renewable energy.It is especially inter-

the EcoPeace.

esting with regards to the supply of

The main objectives of the study are:

drinkable water in remote areas, which

• Solving the shortage ofthe drinkable

are not connected to the electric grid

water.

• National

Energy Research Center

(NERC) P.O.Box 1945 Al Jubaiha. Amman

11941 - JORDAN


(851/capitalday

compared

130 l/capital

Consumption

values varyfrom (4.35 -7.18) kwb/rrrday'

than 300 1/capitalday in the Gulf States).

The monthly variation on a tilted surface

The domestic

water demand

will, how-

is lower than on a horizontal surface. For

ever, increase

rapidly

in the future due

example, a minimum of (5kWh/m2day) cor-

to both a rapid population

growth

responds to maximum

rate

m-day).

sumption

project, Qatar, the annual average solar

The water supply the population, grading

grid covers but needs

major

and the available

water

There

mated to be 30% or more A comparison

are esti-

1.

leads to the conclusion

the current

water supply

not be sufficient

that

sources

to cover

are five main

being

desalination.

They

on two technological

ap-

used in commercial

will

are based

the future

proaches,

being distillation

demand

for water. A study on the water

brane

balance

in Jordan

stage flash distillation

it determined

was conducted,

and

separation

ple-effect distillation

a water supply deficit for

and mern-

processes.

BWRO

0.5 - 2.5

ED

0.7 - 2.5

MSF

10.0 - 14.5

MED

6.0 - 9.0 7.0 - 15.0

VC

processes

Multiple-

SWRO

4.0 - 8.0

MED/SWRO

3.2 - 3.6

It is obvious

with membrane

processes

lower

than

This scientific

heat source.

ing main elements:

Table (1) shows the brackish groundwater resources, termined

in different

sins of Jordan

operated

groundwater

and c1early

there are huge reservoirs

typically

ba-

They are most efficiently

with power available

of brackish

water that could be used for water supply after desalination:

and are of

for MED and up to

Solar irradiation

with an average of (5.6kWh/m2day) horizontal southern

surface

trodialysis

in

areas of more than (5.8 kWh/

process,

for small unit capacities,

is

cur-

and January,

membrane

proc-

(RO) and elec-

(ED). AII three processes as single purpose

to their modular

The estimated

but still monthly

means of above (4.20 kwh/m-day)

operated

he

osmosis

structure,

are

plants. Due RO and ED

to any plant size

and can be found in all capacity ranges.'

tion is 9.4h. The weakest months are December

as do

can be easily adapted

m'day) and the average of the sun dura-

( KWh/m3)

can

are based on the

availability

energy

consumption

today of the different

in the site. Also, other factors

nomic, ecological), and distances

the size whether

GW-Basin

Aquifer

Resourees (MCM)

in Jordan

Potential

of the systems

Extraetian (MCM)

Field visits were performed

54

Dead Sea

AB, K

3200

67

K-D

1000

8

B,S,SS

Azraq

V,AB, R

1680

29

B,S,SS

Sirhan

AB, K-D

50

5

B S SS

4000

13

B,M,S,SS

Qatar village,

Journal

of Island

Affairs

situated

that

in the southern

would fit this category

of Ihe project consist

â&#x20AC;˘ Brackish

water

stores

the following

by PVs

brackish

to operate S

S,SS

pumping

an average

sys-

system

that pumps of 50m3/day

and of

water. This system consist

a photovoltaic

Comments: AB Ajlun Aquifers and Berqa Aquifers K Kurnub Group V Basalt Aquifers D Disi Group Z Zerqa Group B,M Groundwater extraction S Groundwater partially saline SS Groundwater is brackish

International

for sev-

eral sites in Jordan and concluded

powered

2800

V, AB;Z;D

to be used

or not.

tems: Camments

AB K

Hammad

grid. Also

is needed to determine

it is feasible

Syslems

Jardan Vallev

Wadi Araba

eco-

proc-

in 1987

Annual

(social,

the need for water,

from national

this information

part of Jordan,

esses is shown in Table (2).

Water Resources

role , like the situa-

tion of the inhabitance

The project Table 1: Brackish

criteria

of brackish water, and solar

play an important

esses, reverse

and peak values

Site selection

radiation

electricity

on a

crileria

sion (VC), also a distillation available

in Jordan is very high

Sile selection

60,000 m3/day for MSF. Vapour compres-

rently up to only 2,400 m3/day. VC uses

POTENTIAL OF SOLAR ENERGY IN JORDAN

study covers the follow-

plants in coplants

in unit capacities

5000-20.000)m3/day

indicates

use an external

as dual purpose

generation

which have been de-

for saltwater

STUDY

supply of heating steam as the primary

situation

1.

which

SCIENTIFIC

numbers

water supply

(RO) is con-

(MED) are distilla-

tion processes,

indicate the dramatic

con-

desalination.

the year 2000 of 1.031 Mio m '. These

of Jordan's

38

that the energy

sumption for brackish water desalination

siderably

(MSF) and multi-

Energy

Sea Water

up-

future

losses

Electrical

Braekish

4.

ofthe estimated

water

water demand

irradiation is (5.69kWh/m2day)

97% of

Process

(kWh/m3)

site for the

CURRENT STATUS OF DESALlNATION TECHNOLOGY

since

quantities

population.

For the proposed

Energy

by Desalination

Process

values of (8 kWh/

and an increase of per capita water conby an urbanized

Table 2: Estimated

be measured. On a tilted surface the mean

day in Syria, Egypt and Iraq and more

power supply system

the brackish

water pump-

ing system (Fig. 1). â&#x20AC;˘ Reverse osmosis desalination powered

system

by PVs were it was chosen

to desalinate

an average of 40m3/day


Fig. 1: Block diagram of brackish

water pumping

Fig. 2: Block diagram of RO-desalination

system powered by PVs

-.J 10

system

t::

powered by PVs

O

e

o

PV

::J\

o L

U

e u

L Well

V

Brin. Waste Tank

V

:3

of fresh water. This system consist a

4 Hydrological

data of the brackish

buildings

and

surroundings

of the

t.; r--

.lo-

photovoltaic

power supply system (to

operate the RO-desalination to electrify

the

unit and

buildings

of the

praject) and the RO-desalination

unit

(Fig.2).

water well to be utilized

(static wa-

project

ter level (18m), dynamic

water level

of the following

(7m), pumping head (30m), casing diameter

of the well (13inch),

(30m/h),

• Measurementand control system were this ineludes

sensors to measure

and

record the weather data as well as the different

inputs

and outputs

of the

praject systems (electrical parameters,

total depth (40m),

yield salinity

site. The system

is composed

components':

- PY-generator

L

to convert the sun light

into electricity

(DC-current)

with a

Two identical DClDC-converters

and water ternperature.

380VDC/220VDC,

on the above

formation

mentioned

the following

tems were designed

project

insys-

regulate

weather data, water flow etc.).

(each

20KW, effic.9O%) to

age of the PY-generator

and the volt-

battery

charge and discharge

Brackish water pumping

block(by

process)

Two identical DC/AC-inverters

(each

Design and sizing of the project systems

system powered by PVs

the main goal of system design and siz-

to pump

ing is to achieve

brackish water fram the well to the stor-

A storage

age tank. The systern

of:

effic.85%, DOD 75%) with a total stor-

the su n-

age capacity of I76KWh energy. This

the right balance

tween daily needs of electrical consumed

by the loads and daily pro-

duced electrical achieve

energy by PY array. To

this, we should

start with the

loads. The daily consumed energy

electrical

by the loads has to be identi-

fied at the beginning procedure, needed

be-

energy

of system

so as to calculate

PY electrical

sizing

the daily

energy

and total

peak power of PY array Climatic

features

are very important

an average

• A PY- generator

site

is composed

to convert

light into electricity

• An inverter

and sized

of 50 m'/day

of

(DC current) with

a peek power of 3 KW p. to convert

rent into AC -current

the

block

is sufficient

(220YDC,

to operate

the

day.

RO-desalination

unir

ity of 5m3/h, effic.80%) to desalinate 50m3/

by the brackish water pumping system to produce 40m3/day of fresh water".

water.

in any PYs sizing;

Reverse osmosis desalination

In order to size PYs components

powered by PV s

effec-

tively, monthly worst case e1imatic fea-

This

tures must be taken into consideration.

desalinate

The following data are used for design-

system

wi 11 be used

to

to achieve prelimi nary information about

of 50 m'/day

of

the design and sizing of the systems and

brackish water (pumped

by the brackish

average of 40m3/day fresh water, and then

ter (40m /day) daily solar radiation

in the

system)

to produce

an

of brackish

pumped (50m3/day)

during the operation

be-

The sirnulation of the systems was accomplished using the computer, along with

The system

specifies software (pY-Design

is composed

of:

PRO, and

MS Excel) and performed for a typical day

PVs-power supply system water to be

their behavior

fore baying and installing these systems.

to store it in fresh water storage tanks.

site ofthe project (worst case in Dec. 4,35 KWh/M2/day)

is

(Fig.2)

1 The inhabitants'

needs for fresh wa-

of the simulation

an average

system

water pumping

3

Simulation ofthe systems The main purpose

ing and sizing of the project systems:

3 The amount

energy

battery

day of brackish water, which is pumped

(55 m ') to store

they differ frorn one month to another.

2 Average

into AC-current.

This unit (Fíg.2) designed (with a capac220YAC,

2.2KW, effc.55%)

brackish

10KYA,

to convert the DC-current

the DC cur-

(3ph, 220YAC,

set (3ph,

tanks

3ph, 220/380YAC,

effic.80%)

load one and half non-sunny

\.

3KYA,effc.85%). • A motor-purnp

• Storage

of the selected

220YDC/

This system (Fig. 1) designed

O

and control the output volt-

age of the storage

and sized:

(f) (f)

o

total peek of 34KW

of brackish water (3000-1 0000) PPM

Based

U

This

system

(Fig.2)

power the RO-unit

will be used

and to electrify

in each month of the year. The main reto the

sults of the simulation of the project systems are shown in Figures(3,4,5).

39


Table 3: Economic

Political Systems Powered by:

evaluation

Costs of the Project Systems ($) Investment O&M Costs Costs 560385 43359

Solar Energy System

results

Water Production Costs ($/m3)

NPV

2.97

IRR

negative

negative

Diesel Generator

271810

55912

3.83

negative

negative

National Electr. Grid

567000

46366

3.17

neaative

neaative

Fig. 3: Solar data of Qatar Village for the period 1995-1998 applied

in the Simulation

process

Fig. 4: Simulation

of brackish

water pumping system

powered by PVs For a typical day in each month

14.00

12.00

1000

&00

600

,.

~ ~

!"

~

~

'JJJ

200

oMonthlyAverage

Daily Radialion on PV Array Surface

(WJhIm2.d)

SOCIO- ECONOMIC FEASIBILITY STUDY

â&#x20AC;˘ Sunshine Ouration (h)

The main conclusion

rameters of the financial analysis are

tions, the suggested project would help

The main objective of this study is to provide a detailed economic evaluation

CONCLUSION

for the project and to present a cost ben-

The main conclusion of the cost ben-

efit analysis for the different options re-

efit analysis of the project was that

improving these situations

7.8.

garding the power supply systems to

using PVs to produce the necessary

power the project systems. A financial

power to operate the desalination unit

analysis has been carried out to deter-

is more feasible on the long run al-

gramme for Producing Water from Brack-

mine the fmancial feasibility of the project.

though the higher investments

ish Water resources with Reverse Osmosis

But it should be c1ear that pure financial

compared to the other two alternatives

Supplied by a Renewable Energy Hybrid

(Diesel and National grid). \,

System", RWTH, SIJ, RSS, Nov. 1997.

analysis is not the only criterion to deter-

References: 1

cost

2

Project: "Research an Development Pro-

Desalination Technology "Survey and Pros-

mine the feasibility of such projects, so-

According to the water production

cial factors playa great role in this proc-

cost per cubic meter using PVs as a

ess. Therefore in the final evaluation, the

power supply system found to be the

cost benefit analysis is the more suitable

cheapest compared with the other two

ergy systems in the Jordanian-Iraqi scien-

criterion to meet our purpose.

alternatives as shown in Table (3).

tific cooperation project" A. Muhaidat, R.

The results of the economic evalua-

The financial analysis upon using the

tion of the project such as the criterion

net present value, internal rate of re-

of the cost benefit analysis and the pa-

turn criteria, found that both criterion

Fig.5: Yearly simulation and electrification

results of RO-system powered

by PVs

for a typical day in each month

pects" Ribeiro, Jacqueline , EC Joint Research Center IPTS, Aug.1996 3

tional Solar Energy Conference, Nov.2025,1993, Amman-Jordan. 4

ble (3), which mean that the project from

tional Solar Energy Conference,

the financial point of view is rejected.

ber 20 - 25, 1993, Amman-Jordan 5

The socio-economic study for Qatar

lnternational

Journal

of Island Affairs

Novem-

"Photovoltaic Application in Jordan" Ahmed Muhaidat, The National Energy Research

6

''Technical consultaion Caterpiller company-

7

"Wadi Araba, Status & Prospects", Ministry

Diesel generators" Amman-Jordan.

of Social Development, Amman- Jordan,

Village covers the main socio-economic

1998.

indicators such as: family size, education, income, infrastructures, obstacles

M. Audi Forth Arab Interna-

Center, March, 1997 Amman-Jordan

taken into consideration.

"

chracteristcs in Jordan"

M. Alsaad,

and other scientific benefits ha ve to be

.

"Solar radiation

have negative values as shown in Ta-

But this is not the only criterion to judge

.

"Design procedure of the renewable en-

Taani, M. Mahmoud Fourth Arab Interna-

such project, where social dimension

40

was that the

people of Qatar lives in very bad situa-

shown in Table (3).

8

"Development Needs and Opportunities in Wadi Araba and Disi Area", Near East Foun-

facing development of the region, and

dation in cooperation

living conditions.

FICE Amman 1994.

with UNICEF OF-


'he cost 01 water RES powered Desalination Systems

iO [ O

e (l

~

o

'vc: Q..., L

u

u o :3 u

e lJ

L

U (J) (J)

O

o by

Th'

DIONYSIS

ASSIMACOPOULOS*,

ARTOHUROS

selection o, the optimum combination of RES and desalination

combinations, and compare them on the

straints such as site characteristics and

basis of the economic results of the

financial requirements and compared in

technologies

in a specific region is

associated investments. In the present

order to select the optimum solution.

based on resource availability, techni-

work, a method is proposed for the pre-

The overall design algorithm is pre-

cal compatibility of processes and tech-

liminary plant design and evaluation of

sented in Figure l. The first step of the

nological maturity. Numerous RES -

economic indicators. The Profitability

proposed approach involves the defini-

desalination combinations

tion of a list of altemative technology

identified and tested in the framework

Index, proposed in the assessment of wind or PV power investments, 16-17 is

arrangements, which can satisfy the tar-

of the ongoing research for innovative

used in the estimation of the' â&#x20AC;˘.. expected

geted water demando In the next step, a

water-selling price on the basis of the

detail design of the each candidate op-

overall discounted water cost.

tion is made to determine the plant ea-

desalination processes

1-9.

have been

Detailed as-

sessments of available and exploitable water resources and water needs have

pacity, the structure of the power unit,

been carried out in the framework of research programmes 10-12 taking into ac-

THE DESIGN APPROACH There is no straightforward way to se-

final step pursues a financial analysis

count current and future trends on eco-

lect the appropriate RES - desalination

of the investment associated with the

and the operational characteristics. The

nomic development, environmental and

technology for a specific case. Rather

selected RES desalination combination.

socio-economic factors. Moreover the

an iterative approach is most probable

The investment and operational costs

market potential for RES desalination in

to be followed, involving careful as-

are analytically estimated and the ex-

specific regions has been identified,

sessment of available options in meet-

pected water-selling price is evaluated

based on the combined evaluation of

ing the regional water demand and the

on the basis of the overall discounted

water shortage problems and RES po-

economic viability of the selected so-

water cost. The expected water-selling

tential with the objective to determine

lution. The decision maker handles in-

price is used for comparison among al-

economically competitive options for

formation such as feed water quality

temative RES desalination options as

RES powered desalination

13-15.

Although various methods to assess the economic

viability

of specific

desalination plants powered by RES

and quantity, desalinated water speci-

well as different schemes to cover water

fications, type and size ofthe available

shortage such as transportation of wa-

RES potential and commercial maturity

ter, construction of dams or conventional

of the technology in order to decide on

desalination systems.

have been presented, there is still the

operational characteristics of each can-

need for a unified approach, which can

didate solution. Furthermore,

assess alternative

date options are screened through con-

RES desalination

candi-

* National GREECE

Technical University of Athens-

ZERVOS*


The type of RES to be used with a particular

desalination

process

de-

case. The energy balance between energy production from RES and auxil-

process. For

iary energy sources and the energy demand of desalination

processes is

tovoltaic cells can be used. For medium

used for determining the capacity of

and large-scale plants, the use of PV is

the energy unit. The algorithm for the

not yet an economically

VES

can point

ity and the specific energy consumpsmall size plants, both wind and pho-

Define Alternative RES - Desalination combination

combinations

pends on RES availability, plant capaction of the desalination

NO

desalination

out the optimum solution for a specific

competitive

analysis of the energy flows for the

option due to high PV costs, low effi-

entire unit and the determination

of

ciency of PY cells and the large area

auxiliary energy supply needs is out-

requirements. Storage may be applied

lined in Figure 2.

only for very small capacities and for

The RES potential and the available

autonomous systems since its high in-

area for the installation of the RES unit

vestment cost prohibits the develop-

determine the maximum capacity ofthe

ment for larger units.

power unit and the energy production. The energy produced from the RES unit

Design of the Desalination Unit The capacity

Figure

l. RES - Desatina/ion

design algorithm

The identification powered

of candidate RES-

desalination

processes

is

and

of the desalination

when

it reaches

the

plant and the daily and seasonal op-

is supplied to the desalination plant. The energy produced in periods of low

by the water process is

RES availability and the fraction ofthe

selected taking into account the capac-

RES energy that is not needed for the

ity of the plant, the feed water quality

desaJination plant are dumped or sold

and the product water requirements.

to the grid. The fraction of desalination

The energy

of each

plant energy needs that is not covered

desalination process are estimated on

by the RES unit is provided by auxil-

requirements

based on an overall assessment of the

the basis of the plant capacity, the feed

iary energy sources (grid, diesel gen-

available water and energy sources in

salinity as well as operating character-

erators, energy storage).

both quantity and quality terrns. The

istics of the plant using the simplified

selection of the appropriate desalination

models presented \.in Appendix l.

Ifthe energy supplied by RES meets the energy

requirements

of the

desalination unit, then there will be no

technique differs according to the type and potential of the local RES, remote-

Design of the RES Unit

energy

from the auxiliary

energy

ness, feed water salinity, required prod-

The most challenging problem asso-

sources. An auxiliary energy supply

uct water quality, and the water demand

ciated with the implementation ofRES

system can be used, in this case, to

that determines the plant capacity.

powered desalination plants is the op-

make up for periods of low RES avail-

timum matching ofthe intermitted RES

ability.ln the case, where the maximum

processes considered are Reverse Os-

power output with the steady energy

available RES energy is not adequate

mosis, Vapour Compression and Elec-

demand for the desalination

to cover the energy needs, a grid con-

trodialysis. Both Electrodialysis

(EO)

Power management and demand side

nection or diesel generator is neces-

and Reverse Osmosis (RO) are used for

management are the two options avail-

sary. The size of the diesel generator

able to solve this problem. In the first

and the energy flows to and from the

controlled hy-

grid are deterrnined in order to cover

In the present work the desalination

the production

42

only

desalination plant power requirements

eration are determined

demando The desalination

Identification of alternative combinations

varies according to the RES potential

of potable

water

process.

whereas Vapour Compression (VC) can

case, an appropriately

be used for the production of distillate

brid RES unit that is able to provide a

water- Electrodialysis is mainly used for

steady energy output is used and it is

the power shortage. The energy production from RES as

brackish water desalination since en-

sized at the nominal power demand of

well as the energy flows from the RES

ergy requirements

the desalination

unit to the desalination plant are esti-

increase substan-

process. In the sec-

tially with high salinity. On the oppo-

ond case, the desalination process op-

mated by simplified models. In the case

site, vapour compression is mainly re-

erates only when the energy output of

of wind energy powered desalination

served for seawater desalination

and

the RES unit is able to cover the en-

plants, the mea n annual wind speed

for medium or large units. Reverse Os-

ergy demando The cost analysis and

and the k-Weibull distribution are the

mosis can be applied in all cases.

comparison among alternative RES -

main site-specific inputs necessary for

InternationaJ

JournaJ

of IsJand

Affairs


the evaluation of energy production.

ability margin, which determines the

Both the desalination unit and the RES

The main technology related inputs are

difference of discounted cost and sell-

unit costs are taken into account in the

the height and the power curve of the

ing price, is measured by the profitabil-

estimation of the water production cost.

selected wind turbines. In the case of

ity index. Positive values of the profit-

In the case that the plant is grid con-

PY powered desalination

plants the

ability index indicate that the invest-

nected, the potential

solar radiation in the specific region as

ment is viable while negative values

power sales have to be exc\uded from

well as the efficiency ofthe PY cells are

indicate that the overall discounted

the analysis because a fraction of the

the main necessary

costs are higher than the expected wa-

plant costs is covered by those rev-

ter-selling price.

enues and does not influence the wa-

inputs for the

evaluation of energy flows to and from the grids. Details on the modelling of

PI = NPV

(1)

e,

the Renewable Energy converters are

and NPY, the net present value of the

Financial

Evaluation

investment, which is given by:

The financial analysis of the pro-

(3)

Dew= Discounted water cost L

The profitability index is used to calcu-

posed investment involves the capital

NPV = SJ~J * Q" + sP¡,: * Q". R

and operational costs, the estimation

SPw= Water selling price

of the overall discounted costs and the

Qw

evaluation of the expected water sell-

SPE

ing into account equations

ing price. Operational and maintenance

QE

water-selling

= Desalination

el * R -

ter cost (equation 3). _CI*R+CO&M-SPr:*Qr: DC wQw

el = Initial investment cost

given in Appendix 2

revenues from

CO&M

(2)

cific costs for each component of the

= Electricity selling price = Excess power sold to the grid R = Capital recovery factor eO&M = Annual operation and mainte-

desalination and the RES unit.

nance cost

costs are defined by the user, as spe-

The Profitability Index (PI) is defined

price

(f) (f)

based on the overall discounted cost

O

late the expected water-selling

of the RES - desalination system. Tak-

plant capacity

1-3, the

price can be estimated

from equation 4. Sp¡v =

c * R * PI + DCw

(4)

l

Qw

The overall discounted water cost is a

The comparison among alternative RES

as the net present value of the invest-

function of the initial investment and

- Desalination schemes is based on the

ment per unit of initial capital invest-

the operational and maintenance costs

estimated

ment (equation 1). The minimum profit-

of the RES powered desalination plant.

overall discounted estimated

ERES' Energy

produced

water-selling

price or the

costs. Moreover,

water prices can be corn-

pared to the actual water selling prices

ERES~DES: Energy given by RES to Desal

in order to specify whether the pro-

by RES

posed investment

is competitive

to-

wards conventional methods of water EDES Energy needs of desalination unit

Plant Structu re Desal, RES

supply. The change of water-selling price with profitability index helps the

No

No

decision maker to identify the selling price that best matches the economic requirements from the investment. The

No

graph of the water-selling price versus

Yes ..,

the profitability index is a straight line,

Give (ERES-EDES)

in accordance to equation 4. The slope

to Grid

of the line depends on the initial in-

Get Yes

(EDES-ERES~DES) from grid

.-

No

Calculate energ y needed from auxiliary sources

~ Give ERES-ERES~DES to grid

I

Plant Structure Desal, RES, Grid

I

vestment, the financing parameters of the investment (lifetime, discount rate) and the plant capacity. Higher slopes represent more attractive investments since a small increase of the selling price leads to a substantial increase of the profitability

EAUX = EDES-ERES~DES

index and con se-

quently to the net present value. Higher

••

PI values lead to high revenues and

Plant Structure Desal, RES, Diesel Unit

consequently

more profitable invest-

ments. On the other hand, lower PI valFigure 2. Algorithm

[or estimating

annual energy flows

and plan! size

QJ

ues lead to lower consumer water prices

O


making the proposed investment competitive

with alternative

options

to

cover water demand.

Table 1. Energy balance for the 1000 m3/d RES-Desalination RES

Desalination

Desalination

Nominal

RESenergy

Gridenergy

RES

energy

energy

installed

usedby

usedby

energy

needs

production

power

desalination

desalination

toGrid

(MWh/y)

(MWh/y)

(kW)

(MWh/y)

(MWh/y)

(MWh/y)

Combination

CASE STUDY The case study identifies

and de-

signs the most appropriate RES powered desalination plant for a water demand of 1000 mvd. The mean annual wind speed, considered

for the case

study, is 6.4 mis and the annual solar

Units

RES

RO-WT-G

2866

3301

920

1697

1169

1604

RO-WT-NG

2866

3301

920

1697

O

O

VC-WT-G

5641

5777

1610

3235

2406

2542

VC-WT-NG

5641

5777

1610

3235

O

O

RO-PV-G

2866

2809

1968

2809

57

O

RO-PV-NG

2866

2809

1968

2809

O

O

radiation on a tilted surface is 1680 kWh/m2â&#x20AC;˘

tion while excess energy produced during high wind energy production is re-

grid and non-grid connected option.

Design of alternative RES-Desalination options

jected.ln the case of PV powered plants,

This is due to the selected PV unit ea-

Six alternative

combinations

of

the capacity of the power unit has been

pacity, which exactly matches the en-

selected to meet the energy require-

ergy requirements

of the reverse os-

desalination process and renewable en-

ments of the desalination process. This

mosis plant, and consequently the en-

ergy technologies have been evaluated.

option implies that the desalination

ergy flow from the PV unit to the grid

The desalination processes that can be

plant operates only when adequate so-

does not substantially affect the plant

used for seawater are reverse osmosis

lar energy is available.

economics.

trodialysis (EO) is not used for seawater desalination and is excluded from further analysis. The RES technologies that

In most Aegean lslands,

which face severe water shortage prob-

(RO) and vapourcompression (VC). Elec-

Water production cost estimation

lems, the only available alternative to cover water demand is water transpor-

The overall discounted water cost for

tation by ships. The cost of this option

have been evaluated are wind turbines

each of the selected RES desalination

ranges from 2.9 - 3.5 EURO/m3 but is

(WT) and photovoltaics (PV) either grid

combinations is estimated according to

subsidised resulting to water prices in

connected or stand-alone. The high en-

the investment and operational costs

the range of 1.5 to 1.7 EURO/m3. Com-

ergy needs of vapour compression and

ofTable 2, l. A lifetime

the high PV costs indicate that this com-

of 15 years and a dis-

bination is not expected to be economi-

count rate of 8% are

cally competitive with the rest of the

assumed.

available options and is excluded from

presents

Table

~

3

the

esti-

overall

dis-

further analysis. The operating pressure

mated

of the RO plant is 90 bar and the recov-

counted cost for each

ery ratio is 0.32. The recovery ratio for

of the selected RES-

the VC plant is 0.55 and the salinity of

desalination combina-

the feed and product streams are 35000

tions

and 200 ppm respectively. In the cases

desalination

and

Table 2. Investment

Reverse Osmosis

pacity of 1000 m /d.

ensures the stability of the grid.

Initial investment

1600

Consumables

0.25

Labour Maintenance Vapour compression

Initial investment Consumables Labour

3

The

plants

Desalination processes (EURO/m3)

a

of grid connected desalination plants the

and operational

costs of RES - Desalination

unit ea-

installed capacity of RES units does not exceed the maximum allowable limit that Table I presents the energy balance

44

no substantial difference between the

0.05 2500 0.15 0.2

Maintenance

0.08

Electrodialysis

Initial investment

328

counted water cost is

(Costs refer to

Consumables

lower in the case of the

brackish water

Labour

desalination)

Maintenance

overall

dis-

grid connected

wind

for the selected RES-desalination com-

powered RO plant due

Renewable energy technologies (EURO/kW) Wind Turbines

binations. The existence ofthe grid con-

to the revenues from

nection provides the option to direct the

power

excess energy to the grid during high

grid. The PV powered

wind energy availability and to get the

RO

required energy during low wind energy

scheme

availability.

higher

For non-grid connected

0.2

sales plant

to the is

with

the the

discounted

0.2 0.01

Equipment

750

Installation

500

Maintenance Photovoltaics

0.13

32

Equipment

4000

Installation

153

Maintenance

10

plants a diesel generator covers the en-

costs due to the high

Grid electricity price (EUR/kWh)

0.063

ergy demand during low energy produc-

PV costs and there is

Electricity selling price (EUR/kWh)

0.044

lnternational

Journal

of lsland Affairs


Table 3: Water production

RES Desalination Combination

cost

Figure 3. Water selling

Estimated Discounted Water Cost (EURO/m3)

RO-WT-G

1.50

RO-WT-NG

1.69

VC-WT-G

2.13

VC-WT-NG

2.44

RO-PV-G

3.15

RO-PV-NG

3.14

price for various

combinations

e

o

)( Q)

:!:

.o

:::JI

2

e >.

WT, RO, G WT, RO, NG

1,5

~ ¡¡:

- - - - - .WT, -

1 -

o•.. a,

-WT,

ve, ve,

e L

j~1

2

3

4

5

those for which, an

energy powered reverse osmosis plant

increase of the prof-

is economically competitive when the

itability index pro-

comparison is based on the subsidised

duces

water price.

crease

L

a small

(J) (J)

Table 5. Expected water selling price of RE-desalination

in-

to the ex-

pected water-selling

RO-WT-G

e o

duction cost for different wind, taking

price (the slope of

into account the investment and op-

the lines is a func-

~s

erational costs of the RES unit. For a

tion of the energy

en .Q).D

mean annual wind speed of 6 mis the

production

electricity production

RES unit and the to-

Expected water price

selling Internal Rate

(EURO/m3)

of Return(%)

1.68

13.8

RO-WT-NG

1.87

10.6

VC-WT-G

2.42

13.8

VC-WT-NG

2.74

10.6

RO-PV-G

3.78

10.6

RO-PV-NG

3.76

10.6

Subsidized water prices

1.5-1.7

c:;:;

= re re e O

by the

O D

options

E

(j)0 UJÜ

a:

Euro/kWh, is higher than the grid elec-

tal investment

tricity price of 0.063 Euro/kWh. In this

of the plant). Grid

case, the RO plant capacity should be

connected wind en-

the higher possible because it is more

ergy powered RO is again considered

profitable to use the wind power for

the best option since, compared to PV-

price to the price that consumers al-

water production than to sell it directly

powered RO unit, presents higher en-

ready pay. Water prices are dictated by

cost

to compare the expected water-selling

to the grid at a price lower than the

ergy production and lower investment

the high costs of water transportation

power production

cost. For a wind

cost. Compared to the wind powered

by ships, which is the main option used

speed of 8.5 mis the electricity produc-

VC plant, the RO is much more attrac-

to cover the water demand in these re-

tion cost is lower than the power-sell-

tive due to its lower energy require-

gions. Taking into account the water

ing price (and the grid electricity price).

ments.

In this case the RO plant capacity

price in these regions the option that

Table 5 presents the estimated wa-

best matches the conditions of the se-

should be as low as possible in order

ter-selling price and the internal rate of

to maximize the power sales to the grid.

return for each investment. The water-

lected region is wind energy powered ROplant.

selling price has been estimated assuming a profitability index ofO.2, which is

CONCLUSIONS

considered adequate for an investment

The proposed method focuses on the

with very low operating and mainte-

selection of the most applicable RES

price as a function of the profitability

nance costs. One of the criteria to se-

and desalination technology combina-

index for the selected RES-desalination

lect the most applicable combination

tion for a specific region. The tool pro-

combinations.

for the region under consideration

Expected water selling price Figure 3 presents the water-selling

The best options are

is

vides an insight to the design of the RES desalination

Table 4: Electricity production cost for the grid connected wind RO plant

Wind speed (rn/s) Electricity production

cost (EUR/kWh)

:3

4J

tive on economic terms. Only the wind

cost of 0.057

4J D 10

D )

desalination alternatives are competi-

Table 4 presents the electricity pro-

4J

4J .c

6

3

Water Selling Price (EURlm

of the RE-

4J

NG

--PV,RO,G

O

o

L

G

--pv, RO, NG

0,5

with the non-subsidised cost of water most

10

O

2,5 'O

-1

t;

3

paring the RE-desalination water cost transportation,

of RES and desalination

system and power

matching of the intermitted RES sup-

6.0

7.0

8.0

8.5

0.057

0.046

0.044

0.040

ply and the steady energy demand by the desalination

process. The plant

Grid electricity price (EUR/kWh)

0.063

design algorithm focuses on the energy

Electricity selling price (EUR/kWh)

0.044

balance between the desalination plant,


the energy production

unit and the

auxiliary energy sources.

References 1

The use of the profitability

index

method provides the tool for compar2

ing the expected water-selling price to the current water consumption

Wind Energy - A review 01 options", Proc.

guide using renewable energies", Eurapean

01 the Mediterranean Conlerence on Re-

Commission, 1998.

newable Energy Sources lor Water Produc-

Hanali , "Desalination using renewable en-

tion, Santorini, Greece, pp 118-123, June 1996.

ergy sources" Desalination, 97, pp. 339-

rates.

This comparison represents one of the

JOULE-THERMIE Programme, "Desalination

352,1994.

10

REDES, "Decision support system lor the

Rodriguez-Girones, M. Rodriguez, J. Perez,

integration 01 renewable energies into wa-

possible criteria in order to select the

J. Veza,

ter desalination

best option to cover the water needs

desalination powered by solar, wind and

3

operational

of investment

costs

approach

to

geothermal energy sources", Mediterranean

of a specific region. The estimation

"A systematic

for

both

and the

desalination and the renewable energy

11

PRODESAL, ''Towards the large scale de-

Conlerence on Renewable Energy Sources

velopment

lor Water Desalination, Santorini, Greece,

desalination", Final Report, EEC, DG XII,

J. Rheinlander,

01

decentralized

water

APAS RENA CT94-0005, 1996.

1996. 4

systems, Final Report,

EEC, DG XII, APAS RENA CT94-0058, 1996

F. Lippke,

M. Schrnitz-

12

MEDCODESAL, "Mediterranean cooperation lor water desalination policies in the

plants allows for the evaluation of the

Goeb, G. F. Tusel, "Electricity and potable

expected economic outcome of the in-

water Irom a solar power plant", Renew-

perspective 01 sustainable development",

able Energy, Vol. 14, No 1-4, pp.23-28, 1998.

Task 2, Interim Report, EEC, DG XII, INCO

vestment. The tool provides the option 5

to test different scenarios and identify

CT

G. Caruso, Naviglio, "A desalination plant using solar heat as a heat supply, not el-

13

D. Voivontas, K. Yannopoulos, K. Rados,

the optimum combination of RES and

lecting the environment with chemicals",

Zervos, D. Assimacopoulos,

desalination based on a detailed finan-

Desalination, Vol. 122, pp. 225-234, 1999.

tential

E. Zarza, M. Blanco, "Advanced MED solar

desalination

cial analysis.

The relative

costs of

6

ence at the Platalorma Solar de Almeria",

well as the RES potential represents parameters that can be analysed with

7

Prepared

in the framework

able Energy, 18, pp.331-347, 1999. 15

sea water multiple effect distillation plant -

ment on the islands 01 the county 01 Split

10 years 01 operating performance", Prac.

and Dalmatia", Renewable Energy, 19, pp.

newable Energy Sources lor Water Produc-

of the

"MedCoDesal - Mediterranean Coop-

8

R. Vujcic, M. Krneta, 'Wind driven seawater desalination plant lor agricultural develop-

M. EI-Nashar, M. Samad, "A solar - assisted

173-183,2000.

01 the Mediterranean Conlerence on Re-

Acknowledgements

1999.

BenJemaa, 1. Houcine, M.H. Chahbani,

"Potential 01 renewable energy development

1996.

desalination energy demando

Greece",

lor water desalination in Tunisia", Renew-

duction, Santorini, Greece, pp 45-53, June

and

14.

powered

in

Renewable Energy Sources lor Water Pro-

option

RES supply

systems

Proc. 01 the Mediterranean Conlerence on

the tool in order to identify the best to match

"Market po-

energy

Desalination, 121,pp.159-172,

desalination plant seven years 01 experi-

desalination and RES technologies as

01 renewable

16

B. Chabot, "From Costs to Prices: How to

tion, Santorini, Greece, pp 62-72, June 1996.

determine tariffs to secure a private devel-

L. Sardi, "RO desalinators powered by PV

opment 01 wind power", European Wind

eration for Water Desalination Policies

systems lor small/medium Italian islands",

Energy Conlerence, "Wind Energy lor the

in the Perspective of a Sustainable De-

Proc. 01 the Mediterranean Conlerence on

Next Millenium", Nice - France, March 1999.

'.

Renewable Energy Sources lor Water Pro-

velopment" project, partially financed by the EUROPEA N COMMISSION DG xn, INCO-OC

9

17

B. Chabot, "From Costs to Prices: Eco-

duction, Santorini, Greece, pp 36-44, June

nomic evaluation 01 photovoltaic energy

1996.

and services", Progress in Photovoltaics:

M. McCourt,

R. Hunter,

J. Mugnai,

"Desalination by Reverse Osmosis Using

Research and Applications, 6, pp. 55-68, 1998.

A pila/ plan/ for desatina/ion pond as heat source.

coupled

Developed

/0

a solar

by University

of Rome "La Sapienra"> DINCE and University of Ancona - Energy Department,

46

International

Journal of Island Affairs


Small Sland-alone Solar MED and Solar RO Seawaler Desalinalion Planls

~

o

~ O

e o J

o L Q)

e Q) L Q)

u

o

:3 Q)

.c

u

L by

AL!

M.

EL-NASHAR*

Q) (f) (f)

O

o

Moy

rernote areas of the

considerable attention has been given

and substances will increasingly need

world such as coastal desert areas in

to the use of solar energy as an energy

to be based on growing reliance on re-

the Middle East or some Mediterranean

source for desalination because of the

newable sources of energy.

and Caribbean

high cost of fossi I fuel in remote areas,

islands are suffering

In this paper, the economics of two

from an acute shortage of drinking wa-

difficulties in obtaining it, interest in

stand-alone solar desalination technolo-

ter. Drinking water for these locations

reducing air pollution.

gies are compared: a solar stand-alone

can be hauled in by tankers or barges,

Desalination of seawater and brack-

multiple-effect distillation (Solar -MED)

or produced by smaJl desalination units

ish water is one of the ways for meet-

system and solar stand-alone sea water

using the available saline water. The

ing future fresh water demando Con ven-

reverse osmosis system (Solar-RO). The

transportation of water by tankers or

tional desalination technology is fairly

capacity of the plants is assumed to fall

barges involves a lot of expenses and

well establ ished and some of the proc-

in the range 100 - 1000 m3/day. The com-

is fraught

esses may be considered quite mature

parison is based on the economic and

with logistical

problems

\.

which can make fresh water not only

although

very expensive when available but its

scope for improvement and innovation.

supply is susceptible

to being fre-

there is still considerable

Unfortunately

meteorological environments prevailing in Abu Dhabi, UAE.

it is energy intensive

erating expenses of any conventional

SYSTEM CONFIGURATIONS

utilize fossil fuel, such as diesel oil, as

desalination

Two system configurations are consid-

the energy supply can also suffer from

Thus, one of the main concerns about

ered for the current economic study:

the same procurement

using desalination as a means of sup-

â&#x20AC;˘ A solar stand-alone system consist-

quently interrupted. The use of small

and one of the major cost items in op-

conventional

desalination

are encountered

units that

problems that

with transporting

fresh water, namely transportation expenses and supply reliability.

plant is the energy cost.

plying fresh water to remote communi-

ing of seawater MED evaporator sup-

ties is the cost of energy.

plied by thermal energy in the form of

Apart from energy cost implications,

hot water from either high-efficiency

there are environmental concerns with

flat plate collectors or evacuated tube

blessed with abundant solar radiation

regard to the effects of using con ven-

collectors with pumping power sup-

that can be used as an energy source

tional energy sources. In recent years,

plied by an array ofPV cells, see Fig-

So me of these remote

areas are

for small desalination units to provide

it has become clear that environmental

ure l. The system, referred to as con-

a reliable drinking water source for the

pollution

figuration # 1, is designed for 24 hours

inhabitants of these areas. Recently,

green house gases resulting from burn-

caused

by the release

of

ing fossil fuels is responsible for ozone warming.

ing of a seawater RO unit supplied

The need to control atmospheric emis-

by electricity from a PV array which

sions of greenhouse

is designed to supply electric energy

depletion and atmospheric *Water & Electricity Abu Dhabi, UAE

Authority

per day operation. â&#x20AC;˘ A solar stand-alone system consist-

and other gases


to the RO plant throughout 24 hours

Figure 1 Stand-alone

solar MED seawater

desalination

plant, (Configuration

#1)

per day, see Figure 2. This is referred to as configuration #2.

1_

O-------j·---~--~-~~---¡----,

ID

For the solar-MED system, several

+.~1'''

.".,.."

Batt<oy SIO<Oge

pumps are required to force the differheliilting water punp

ent streams to flow through the system and also to inject different chemicals into these streams to ensure safe and reliable

operation.

The major

pumps required by the evaporator are SWin

the seawater intake pump, feed water pump, distillate (product water) pump, brine blowdown pump, drain pump, antiscalant dosing pump (for feedwater stream),

NaClo dosing

pumps (for

seawater

sw pump

seawater intake and distillate streams), NaHC03

DistHlate

Rri~

tank

dosing pump (for distillate

stream) and CaCl2 dosing pump (for dis-

Figure 2 Stand-alone

solar RO seawater

desalination

plant, (Configuration

#2)

tillate stream). P>JlIITay

Double glazed, well designed flat

jj ----:--0 .

plate collectors can produce hot water at about 80°C with reasonable

a ••• ery "or09"

effi-

ciency while evacuated tube collectors

Olnrwtrttr

N:;power

r--~--'-------T-------r------~----------' ., ., .,.,

can easily produce water at more than 95°C with good efficiency albeit higher

.

.,

2-'st¡oe RO

collector cost. The pumping power for this system is more for the conventional system because at least three additional pumps should be incorporated:

me-

chanical vacuum pump, heat collecting

Fudpl.K1lp

pump and heating water pump. The mechanical vacuum pump is to replace the steam ejector in the conventional system since no steam is available in water treatment and product water stor-

commercially available configurations

ing pump is used to circulate the col-

age tank. The seawater intake can be

such as hollow-fine-fiber, spiral-wound,

lector fluid (water) through the collec-

of an open type or a beach well de-

tubular or stacked-plate

tor field to enhance solar heat collec-

pending on the raw water quality and

treatment of the product water usually

tion. The heating water pump is used

the site conditions.

involves degassing (removal of CO2),

to draw hot water from the heat accu-

having a course filter and a feed pump

mulator and supply it to the first effect

is shown in the figure. Depending on

of the MES evaporator

the quality of raw water, pretreatment

the RO system for pumping the differ-

can be carried out by a number of pos-

ent fluids and injecting chemicals is

sible processes

supplied by a PY system similar to the

the current system. The heat-collect-

to initiate

seawater boiling in that effect The electrical

energy required for

such as: dual-media

pumping is produced by a PY system

filteration, chlorination or UV light ap-

system used for the solar MED plant.

plication,

antiscalant, de-chlorination and micron

The desalination part of the Solar-

filtration. The HP pump is connected

OESIGN ANO SIZING CONSIOERATION

to the energy recovery device on the

Thermal Energy Requirement of the

seawater intake, raw water storage tank,

same shaft as shown in the figure. The

solar MED system

raw water pretreatment equipment, HP

RO modules which incapsulate the RO

pump, 2 stage RO modules, product

membranes

Tnternational

Journal

of lsland Affairs

addition

All the electrical power required by

which consists of PV cells, battery stor-

consists of a

acidification,

chlorination and pH adjustment.

age and an inverter (power conditioning). RO system shown in

48

An open intake

type. Post-

of

can have one of several

The thermal energy requirement of the MES evaporator, Qev, depends es-


sentially

on its rated capacity

as its performance

ratio. The perform-

ance ratio, PR, for MED depends

mainly

evaporators

on the number

fects, N, according lation

as well

of ef-

to the following

re-

Pumping Energy Requirement of the Solar RO Plant The energy requirement ess is essentially energy

1.2:

PR= - 0.809 + 0.932N - 0,0091 N2 (1)

to ensure

º

d

ev -

~

(2)

PR

(defined

where M" is the rated (design) capacity

product

whether energy recovery of the

of the sum-

mation of the rated motor capacity the different

electric

of

motors which are

operating

available

plant concepts,

plant.

1 shows

brine

blowdown

pump,

pump, the chemical heat collecting

vac

pump and

requirement

(3)

d

of the

(

RO

from Bucher

Thermal Collector Performance

m' day'.

tube collectors

to be the collector

are assumed

l.

water temperatures,

is determined

defined

of a col-

by its efficiency

as the ratio of the amount

heatcollected

the wa-

the solar collectors.

Based

from Abu Dhabi solar

plant, the heat collecting

flow rate per

meter square of collector

absorber

rated power collecting

of 70 per cent, the

consumption

pump

of the heat

(in kW) can be ob-

tercepted

by the collectorfluid

by the absorber

collector. This efficiency, he, is essentially

e

where A is the collector e

of (wain-

plates of the referred to as

dependent

on a pa-

Table 1 Typical specific

Sizing Thermal Collector Area computer

simulation

"SOLDES"

was used.

field, a called

This program

the operation

of solar MED

is described

in detail in reference", The main input to

ture, site latitude and longitude,

collec-

tor tilt angles, monthly average seawater temperature,

specification

and perform-

ance data for the collectors, mulator

and the MED

the accu-

unit and the

pumps. The main output results are the daily distillate production, ofkWh's

consumed

amount

of heat

daily amount

by the pumps, daily collected

of seawater

and daily

RO plants of small capacíty-,

Process

Specific energy demand

Seawater

0.15 - 0.5

Energy demand depends on seawater level and filter oressure droo

intake Pretreatment

Remarks

kWh/m3

0.1 - 0.2

Depends on chemical and bacteriological

e

program

sign process. The program

energy requirement

tained from the equation P =2.691·(l0-2)·(0_04SA

(8)

study.

drop per collector

panel of about 1 mH20, and assuming a pump efficiency

the collector

to be

area

is about 45 kg h:' m? which is assumed for the current

is assumed

solar radiation and ambient air tempera-

ter) to the amount of solar radiation

to be maintained

efficiency

the program are hourly or daily average

the power required

Based on a pressure

For flat plate collectors,

in ex-

flat plate collectors

)1.13

area in m".

(5)

High-pressure

7.5-18.5

Recovery turbine

anaívsis of seawater

Depends on pump type (centrifugal orpiston type) and on speed and pressure control

pumping 4.5 - 7.5

:::JI

o L Q)

e V

L

Q) .u

/O

:3 e .u L

For lower

qui ements given above we have to add

on data obtained

(7)

eration and can be used also in the de-

of choice when col-

cess of 80°C are required

lector power re-

to circulate

- 2.6 x - 1.92 x2

plants similar to the one under consid-

can be used. The performance

ter through

3.

e

Q)

formula

\.

where the power is in kW and Md is in

In addition to the pumping

the

can be expressed

FOr sizing the thermal collector

specific

of seawater

lector outlet water temperatures (4)

= 0.84

simulates

Evacuated

P =4.36+0.096SM,-2.2(1O·S)Md2 ev

typical

plants of small capacity

the

efficiency

11e =0.76-4.36x

the distillate

recirculation

=1.42+0.039SMI.03

Table

pump, the

the heating water pump. P

on

is being used.

demand

energy

dosing pumps,

collector

by Sanyo),

lead to different

pump, the

sea water pump, the feedwater

(manufactured

where x is in units of °Ch m-2 kcal' .

which in turn influence

pumps.

are: the vacuum

tube col-

of the type used at the solar

by the following

ties and the various types of equipment commercially

energy

used in the

and

area. For evacuated

on the

The wide range of raw water quali-

the specific

evaporator

en-

as the ratio

pressure,

used in the plant to drive the different The main pumps

lectors plant

flow and feedwater

flow),

consists

opera-

requirement

ratio (defined

Pumping Energy Requirements The electrical power requirements

absorber

water) depends

of Solar-MED Planto MES evaporator

required

mainly on the salinity of the feedwater,

between

T2 is the outlet water tempera-

ture and 1 is the solar radiation

lev-

~ O

o

pressure

as the kWh's of electrical

the recovery

(6)

1

11c

and L is the latent heat of vaporization.

T;

perature,

energy

ergy per m3 of product

) -

the different

safe and trouble-free

tion. The specific

-M

O.5(~ + T

2 = -----'--=---"-

where TI is the collector inlet water tem-

in the form of electrical

used for pumping

els and for injecting chernicals

from (2)

Q" can be obtained

x

of the RO proc-

streams to the operational

....J /O

rameter x defined as

Energy saving by expansion turbine

Q) (f) (f)

O

o


amount of heat supplied to the evapo-

needs that go beyond the daily energy

rator. The program has been validated

requirements.

ing to zero with the resulting optimum

against the actual operating data from

The nominal battery capacity, Q con-

array area, Aopt, and optimum battery

the Abu Dhabi solar plant and the com-

sists of two quantities: the long-term

storage capacity, Qopt, were obtained.

parison was found to be satisfactory.

battery capacity QI and the short-term

Using the weather data for Abu Dhabi.

battery capacity Q2' The first represents the amount of energy needed to sat-

Sizing the PV System

isfy the load during the eloudy days of

Sizing of the PV array and battery stor-

the month and the second corresponds

age capacity was carried out using the

to to the daily peak demand that can-

procedure given by Groumpos et al.'

not be met by the daily array output,

which is used for minimizing the cost of

(11)

the PV system. In optimizing the PV system, two major features are considered: the lifecyele cost of the system should be as small as possible and an acceptable performance figure for the loss-ofmined. The LOLP value used in sizing the system is 0.01 which is identical to the value used in by Groumpos et a1.5. The array area required

for each

month is determined by (9) A= DL/['I1 (J - M

(12)

Q2 = (CF)

(13)

(9)

A

DL is the daily electrical demand (kWh), ratio of the night load to the total daily

= 0.08)

1

is the average daily insolation is the standard deviation in the daily insolation (k'Wh/rn? per day) for a month

M

is the fractional monthly average insolation difference and is equal to

Where ID is the insolation, which is required to exactly meet the load demando The amount of battery capacity Q (kWh) needed depends on the load demand, parameter characteristics of components and on weather patterns at the site. Clearly for applications where energy is required throughout a 24-hour period, such as this one, the need cannot be met through the PV array power output alone. In addition, there is a need for energy storage to meet energy

Journal

of lsland

Affairs

100 ::;;M

d

::;;

1000

(16)

[C

+ (NSR)](DL)

where Cev = evaporator capital cost,

$ (1999 price)

(14)

PR Tb

= performance ratio = design maximum brine temperature, 0C.

The performance

and can be expressed as:

evaporator

+bQ]+Xpv +Rpv

f3 (M)Q

(15)

=a (M)A +

where a = PV array unit cost, $/m2,

b e

= battery unit cost, $/kWh, = power conditioning unit cost, $/m2,

d = ratio of engineering cost to total hardware cost, e

= ratio

of installation cost to total

hardware cost,

I

= ratio of management cost to total hardware cost,

XPV

= present

worth of annual O&M

costs, RPV

= present

ratio (PR) of the

(defined as the distillate

output in kg per 1055 kJ of heat input)

\.

TLC=(l +d+e+j)[(a+c)A

(10)

International

temperature according to the correlation given by Fosselard et a1.6:

owning and operating the PV system

(kwh/rn? per day) during a month S

number of effects and maximum brine

PV system is the total present worth of

kWh/day the system system efficiency (assumed

facturers and on cost information avail-

Md= rated (design) capacity, m' day'

The totallife-cyele cost (TLC) for the

electrical demand for a month, '11

on budget offers from different manu-

the load, CF is a factor which depends

PV system, m? DL is the estimated average daily

The cost of MES evaporator is based

on the allowable depth of discharge,

Q = (CF)

is the array area of the

Evaporator

Where C is the number of days dur-

load. Thus Q can be expressed as

where

01 MES

Cost

ing which the battery is able to supply

and NSR is the no sun defined as the

x S)]

Capital

Cost

cost depends on the design capacity,

Q,=(CF)C(DL) (DL) (NSR)

ECONOMIC GROUND RULES Capital Equipment

able in the open literature. The capital

QI and Q2 can be expressed by

load-probability (LOLP) should be deter-

50

equation with respect to M, and equat-

worth of battery

replacement costs.

the following equation 1: PR

= - 0.809 + 0.932N

Capital Thermal

Cost

- 0.0091Nl

(17)

01 Solar

Collectors

Solar collectors used for this application should be capable of producing hot water at a temperature ranging between 70 and 90째C. Evacuated tu be collectors and high-efficiency flat plate collectors can be used to produce hot water at a temperature in excess of 80째C. The specific cost of the solar collectors are assumed to range between 200400 $ m-2 (flat plate and evacuated tube

a (M), f3 (M) = parameters depending on M The minimum life-cyele cost was obtained by differentiating

is related to the number of effects by

the above

collectors). The cost is assumed to inelude both the solar collector proper as well as the support structure, piping, val ves, etc.


Capital Cost of PV Electricity

The present worth of annual fuel and

ing steam at 10 bar and having an effi-

O&M costs are calculated from the fol-

of the photo-

ciency (LHV) of 86 per cent is consid-

lowing expressions'

Generating System The main components

A fire tube packaged boiler produc-

voltaic (PY) system are a PY array, a

ered appropriate. The capital cost of

bank ofbatteries and an inverter (power

such a boiler, Ch

conditioner). The cost per peak watt

and adjusted to the 1999 cost level us-

( fWp) ofthe PY array, e - including rv support structure - was obtained from

ing the Marshall and Swift Equipment Cost lndex. The resulting correlation is

where

the paper of Bucher' and was corre-

shown below:

Fo = fuel cost in the first year

lated to the array peak power, P in kW

c'.~= 1O.824(Ms)o.87+6.973

according to the following equation e

pv

=

7.1 + 2.8p·024

(18)

(

)

is obtained from

0.15 'S,S 'S, 15

j'W(OM)

Csg = cost of boiler, $

The heat accumulator is assumed to be

Ms = steam generating capacity,

(23)

_ OMo( 1+ gom )[1_( 1+ gom )'] k - g"m 1 +k

of operation, $ OMo = O&M cost in the first year (20)

where,

a vertical cylindrical tank made of mild

T

of operation, $

= annual

gr

Capital Cost of Heat Accumulator

1 (T 1+ u = j.;)(-"_.I )[1-(-"'-' )") k g, I +k

I'W(F)

7

fuel escalation rate

(assumed 0.03)

L

gOIll= annual O&M cost escalation rate (assurned 0.03)

ton h'

= interest

k

steel with a thick layer of fiber glass in-

N = plant lifetime, years

Capital Cost of Diesel Generator

designed to operate at atmospheric pres-

for Conventional Systems

The cost of water, c", ($/m3) was calcu-

sure and is provided with a pressure re-

A diesel generator whose capacity will

lated as follows

liefvalve as a safety measure. Hot water

obviously depend on the capacity of the plant itself can supply the electri-

tank at the top via a special water distri-

cal demand of the desalination plant.

bution grid that ensures that hot water

The capital cost of the diesel generator

where

diffuses slowly through the surround-

is obtained from the following relation,

Md

ing water with causing too much turbu-

which is based on recent commercial

PF

lence in order to enhance thermal strati-

bids:

e = 50

fication through the tank.

is obtained from the following relation e = 456.6(

MSI

(19)

where eSI

3

It should be noted that all water costs

800(~)O.5494 40

given in this section do not include

where Cdg is the cost in $ and P is the

of land. These additional costs are very

di:

seawater intake and outfall costs or cost rnuch site dependent

rated capacity in kW.

)-0.46

100 ~M,,~ 600

= plant rated capacity, m /day = plant factor (assumed 0.85)

and has to be

added to the cost estimates given here.

300

SI

(24)

MA365)N(PF)

(21)

The capital cost of the heat accumulator as obtained from manufacturer's data

TLC e"

= specific cost of storage capacity, $ rn' (1999 price)

Mst= storage capacity, m3

Capital Cost of Steam Generator

RESULTS

Figure 3 shows the required coUectorarea

The estimates of the cost of water that

and PY array area for Solar-MED plants

are given below are based on the Iife-

with capacity varying from 100-1000 m31

cycle cost analysis of the plant which

day. The collector areas shown here are

includes capital, O&M and fuel costs

specific to the weather conditions of Abu

(for conventional plants). The totallife-

Dhabi, UAE and are based on PY system

cycle cost, TLC, equals

efficiency of 8 percent and col lector effi-

TLC = C¡o¡+PW (F) + PW( OM)

for Conventional Systems

(22)

ciency parameters given above. The cost of water produced by the

Low pressure and low capacity steam

Where

Solar-MED plant for two different spe-

generators are required to supply the

C¡o¡=total capital cost including

cific collector costs of200 $/m2 and 400 $/m2 is shown in .

MES evaporator with the low-temperature thermal energy necessary to drive

engineering, installation and management costs,

Figure 4. The lower specific cost figure is representative of good flat plate

the unit. The capacity of the steam

PW (F) = present worth of all annual

generator depends on the capacity of

fuel costs incurred through

collectors while the higherfigure is typi-

the MES unit as well as its perform-

out the lifetime of the plant

cal of evacuated-tube collectors. lt can

(for conventional plants),

be seen from this figure that the cost of

ance ratio. For a unit having a PR

=

13

and producing 200 m3 day' at design

PW (OM) = present worth of all annual

(f) (f)

O O

rate (assumed 0.08)

sulation to reduce heat loss. The tank is

from the collector field is supplied to the

U

water varies in the range between 3.8

conditions, requires only 0.6 ton h' of

O&M expenses incurred

$/m3 and 6.8 1m3 with the lower cost

low-pressure steam.

throughout plant lifetime

figures applicable to plants with capaci-


Figure 3 Collector requirement

and PV array area

by Solar-MED

plants.

Area m2 18000 16000 14000

12000 10000 8000

- - -- - - --

6000 4000 2000

PVarea

o~----~----~----~------~--~ o 200 400 600 800 Plant

Figure 4 Cost of water Cost

01

8

Water,

collector

plants

200$/m2 __

1>00

m3/day

system is more economical than the

33 percent of the total capital cost of

Solar-RO system under the present

the plant with the remaining capital

economic and ground rules used.

cost distributed between the PV sys-

• The cost of water from the SolarMED and Solar-RO

creases with the plant capacity and

by Solar-MED

and

this cost approaches that for con ven-

Solar-RO plants of different capacities

tional plants when the fuel cost be-

Solar-MED plants are more economi-

ered competitive

tional RO system for a crude oil price

the upper range (700-1000 m3/day) both

of 10 $/OJ or higher and for capaci-

technologies appear to produce water

ties in excess of 700 m3/day.

fossil-fueled

MED

plants with different crude oil costs is used in the steam generator of the fossil-fired MED system are assumed to

-.

--

-

take the values 3, 5 and 10 $/OJ while

--

- --

-

the cost of the diesel fuel used in the diesel generator is assumed to be three

Plant

m3/day

Capacity,

Figure 6 Cost of water conventional different of water,

by Solar-MED

MED plants

crude

oil costs,

and

--

ct ea

$fGJ

-

~.

accounts for the cost of refining and

velopment Cooperation on Solar Energy

cf.

the cost of fossil fuel becomes high cr s

$/GJ

e

,,,.c,,,

. -_o

- - -- - . - - - - ..•.

, ENAA and WED (1986)," Research and De-

transportation.

-

....

~

It\. can be seen that as

1000

Plant Capacity,

m3/day

Figure 7 Cost of water from conventional system

RO

water from fossil fuel plants approaches

(cf is cost of crude

--el = 3 $/GJ el = 5/GJ _______ •• ·el=10$/J Solar-RO

20

Cost of

ater,$!m3

200

400 Plant

International

Capacity,

Journal

800

--ROO

m3/day

of Island Affairs

Solar Energy Contributions to

of the

Performance

of a Solar

Desalination Plant". Solar Energy 44(4). 5

can be seen to decrease sharply as the

Groumpos, PP and Papageorgiou, G., "An Optimal Sizing Method for Stand-Alone

plant capacity increases. This is due to

Photovoltaic Power Systems", Solar Energy,

the decrease in the specific cost of the

Vol. 38, No. 5, pp.341-351 , 1987 6

Fosselard G and Wangnick K (1989)," Comprehensive Study on Capital and Operational Expenditures ter Different Types of

decrease in the specific cost of the RO

Seawater Desalting Plants (RO, MVC, ME,

plant with the increase in its capacity.

ME-TVC, MSF) Rated between 200 m3 d:

The increase in fuel cost in conventional

3,000 m3 d",

RO plants results in a corresponding in-

Congress on Desalination and Water Re-

oil cost of$ lO/OJ, it can be seen that the

Proceedings, Fourth Warld

use, Volume IV, Kuwait. 7

1000

w.,"

EI-Nashar A M (1990)," Computer Simulation

Solar-RO one is shown in Figure 7. The

crease in the cost of water. For a crude

.•• ==

Bucher,

FAO-SREN-Seminar, Freising, 1996 4

15

10

T (1995)

Potable Water Supply in Arid Regions",

with the capacity and is also due to the

oil)

W T and Hodgkies

Porthan Ud. 3

The results of a similar comparison between fossil-fueled RO system and the

Hanbury

Desalination Technology 95, Glasgow, UK:

that from the Solar-MED system.

PV array as the array power increases

and the Solar-RO

Desalination Plant", Final Report. 2

such as in remote locations, the cost of

cost of water from the Solar-RO system 500

References

times as much as the crude oil which

for

$/m3

.•..•..•.

52

with the conven-

shown in Figure 6. The crude oil costs

15

7

comes high. • The Solar-RO system can be consid-

cal than the Solar-RO counterpart. In

a conventional,

20

Cost

systems de-

between the cost of

ter produced by Solar-MED plants and

plants.

rl.------.-S-oI-a-r--M-E-D--------------Soi-a-r--R-O-,1

10

cause collectors represent only about

A comparison between the cost of wa-

$/m3

of Water,

• For small capacities, the solar MED

at about the same cost.

by Solar-MED

and Solar-RO 25 Cost

400 $lm2

1000

Figure 5 Cost of water

drawn from this study:

ties (100-600 m3/day), it can be seen that

---

can be

increase of no more than about 25 per-

is shown in Figure 5. For small capaci-

"--- - .•. --- - ~

conclusions

cent in the cost of water. This is be-

water produced

costs.

,

Plant Capacity,

The following

A comparison

$/mJ

500

CONCLUSIONS

bling of the collector costs incurs an

tem and the MED evaporator.

by Solar-MED

with two different

1000

m3/day

Capacity,

ties in the higher range. Notice that dou-

Peters M S and Timmerhaus K D (1981) Plant Design and Economics for Chemical

Solar-RO system can be competitive

Engineers, Third Edition. McGraw-Hill In-

with the conventional RO system.

ternational.


:.c L

o

:3

u 10 (j)

L

U

D

e

53 (j)

by

Th'

MO

MARZOL *, PILAR CERECED**,

VICTORIA

JAVIER MARTíN

fundamental interest of the studies in Climatology, that have a

and spatial location or specific behav-

be surpassed

iour, is of interest to decision makers

quency of the rainy days in relation to

clear retrospective basis, paradoxically,

responsible of the territorial planning,

its intensity. This is important due to

is its predictive value used for social

mainly because they are a li~iting fac-

the immediate effects in the environ-

and economical issues in the medium

tors of great importance.

ment and for the conservation of the

and which is the fre-

and short time. The detailed knowledge

With this purpose, we have consid-

fragile ecosystems of remarkable inter-

of atmospheric phenomena, in relation

ered necessary to know the probabili-

est, such as the case of Robi nson

to its intensity, temporal distribution

ties that certain quantities of rain can

Crusoe island in Chile (Fig. 1). The island of Robinson Crusoe is part of the archipelago of Juan Fernández. It is located 670 km from the Chilean coast (33°37'S - 78°54'W). Its surface is almost

CHILE

48 km". This island is not only known by

6ah¡'E!~

the history of the famous shipwrecked sailor Robinson Crusoe, it is also well known because it has been a National Park since 1935 and in 1977 was declared by UNESCO, a Reserve ofthe Biosphere

l-t

• Opto. de Geografía. Universidad

AERO~MO

"Instituto Universidad

de

Bay in the island of Robinson Crusoe (33°37'S;78 53'W), U

Chile

Geografía.

Pontificia

Católica de Chile-CHILE

,•• Departamento Fig. 1: Loca/ion of Cumberland

de La

Laguna (Islas Canarias)-SPAIN

B•• I.P~.

de Geografía

Física y

A.G.R. Universidad de Barcelona-SPAIN

VIDE***


Great part of the island is considered autumn

1,5 km to a bay, BahĂ­a del Padre; this

winter

volcanic mountain range of steep slopes

road al so suffers the constant nega-

44%

with peak s over 500 m of altitude, prin-

tive effects of rain. From that bay, it is

30%

summer

9%

spring

Fig. 2 Seasonal Juan FernĂĄnde;

scend an abrupt cliff by a mud road of

a fragile zone. It is structured along a

17%

distribution oJ the rain in (Chile). 111 percentages.

cipally composed of basaltic rocks. A

necessary to sail for one hour and a

numerousjuvenile

halfto arrive to the village. AII this trav-

basins are formed in

this mountains; their sources show well

elling depend on the meteorological

formed riverbeds where the water tlow

and oceanographic

conditions.

strongly during the rainy events. Their power, especially where the vegetation

OBJECTIVES ANO METHOOOLOGY

due to its Biogeographical interest. Nev-

has a low coverage. The steep slopes

A particular characteristic of the elimatic

ertheless, it is an island strongly threat-

are more susceptible to be deteriorated

variables is that their values have a cer-

ened in more than a third of its surface by

by the effects of rain. The intense use

tain dependence on what has occurred

short distance give them high erosive

erosion and the effects of rain and the

done by the cattle and the low quality

before (Arlery et al., 1973).This depend-

scarce cover of vegetation in some ar-

of the soils have caused that great ex-

ence augments according the time in-

eas. The invasion of exotic species are

tensions have very scarce vegetation

terval between both values is reduced.

causing the destruction of the endemic

and nude soils.

In this way, it is higher between two con-

subtropical forest mainly composed of canelo

(Drimys

cofertifolia),

luma

The knowledge of rain behaviour in the island is vital for the conservation

secutive days than between two consecutive

years. This dependence

is

(Amomy/1us fuma), peralillo (Coprosma

of the Fernandezian forest and the pro-

higher in climatic continuous variables

pyrifolium) and mayo (Fajarcunayui.

tection and management of the eroded

such as temperature and atmospheric

in

areas. AIso it is important for the con-

pressure than in precipitation. This prop-

Cumberland Bay, around 600 persons

In San Juan Bautista,

located

trol of the risk zones of mass move-

erty is known as persistence.

live dedicated to the capture of lobsters

ments, especially where the population

and fishing activities. This is the only

live. AIso, this information is essential

Iyse the frequency

The objective of this study is to anaand mean daily

village and it is located in the piedmont

for the accessibility of the island and

quantities of precipitation in the Juan

of the El Yunque, the highest mountain

its communication

FernĂĄndez meteorological station, the

of the island. The most irnportant ex-

The most important way of reaching

only one in the island,

treme natural events that affect that vil-

the island is by airplane, highly deter-

Cumberland Bay. The aim is to charac-

with the continent.

located

in

lage are the mass movements: currents

mined by the meteorological

condi-

terise the persistence of the rainy peri-

and tluxes oftorrential materials (tloods)

tions. The access is very difficult not

ods in relation to their intensity, using

and landslides.

Events of this nature

only because it is necessary to have

the persistence coefficient of Besson.

haveoccurred in the years 1972 and 1980

good conditions of visibility, but be-

It has been considered that the more

and the area has been considered as a

cause the small runway is partially

certain temporal resolution to charac-

risk zone of this type of catastrophes

paved, and it is only for small planes.

terise the precipitation of rain is in a

(Castro et al., 1995).

After landing it is necessary

daily scale, for this reason it has been

\.

The principal

street of San Juan Bautista

to de-

worked out with the daily values of 35 years (1960-1994), which make a total of 12,783 days. It has been qualified as a rainy day, the one that register a minimum ofO.1 mrn. The method used in a daily base, quantify the following parameters: a

umber of days with rain in each month and year

b Number of days according intensity intervals e Number of rainy sequences according its duration, between l and 25 consecutive

days.

d Number oftimes and quantity ofrain in each of the days of the year 1960-

54

lnternational

Journal

of lsland

Affairs


1994. For example,

in January

rained in four occasions

L

1"

I

es

and a total

:3

2

of76I!m •

;.)

10 For example

on January

only in fouroccasions

(f)

1" it rained

L

ofthe period stud-

ied with a total of76I!m2.

U

O

e

evertheless,

S (f)

in June 25 of the same period, 29 times rained and a total of2,733l/m2

was reg-

istered. This mean that there is a probability of lI % that it will rain the first day ofthe

year and 83% in June 25.

The first hypothesis cipitation more

persistent

the intensity proved

is that the pre-

in Cumberland

Bay has to be

according

augments

of the rain. lt has been

that this relationship

many environments

ofthe

is true in world and is

these

of the frontal

latitudes.

type of rain in

With the objective

relate the quantity

to

have

been distinguished: a Days with weak

precipitation

(W):

between 0.1 and 4.9 mm. b Days

with

moderate

precipitation

(M): between 5.0 and 14.9 mm. e Days with strong between

precipitation

(S):

In this way, the hypothesis

less than 5.0

mm in one day. character

of the is-

land does not allow that the results of this study be considered

as a principie we

THE PRECIPITATION REGIME OF CUMBERLAND BAY The annual average precipitation Juan Fernández Rain is registered station

every

in the meteorological

month

of the year, spe-

cially from the beginning

because

the last days of August.

the meteorological

station

is

ofthe

station is 1023,7 mm.

think that they will be of great interest,

ofMay

until

In this winter

located in the only inhabited zone ofthe

season almost 60 % of the total annual

island, in Cumberland

Bay, that is the

precipitation

place where a number of landslides have

is produced

occurred

with 169,7 mm and a similar

and it is in the area of influ-

ence of six runoff that descend

sol id materials

from the

of

can be transpórted,

during

falls in May, slightly

the month of July, quantity

less than in June

(Table 1). In this period of the year the rain is five times and halfmore summer.

'.

is present. The maximum

The precipitation,

than in

c1early cy-

can be

as: PW < PM < PS < PYS,

that is, the probability

rainy days with intensity

in a steep slope, and big quantities

precipitation

(YS): equal or more than 50.0 mm.

formulated

as weak, that is

summit ofEI Yunque (915 m) to the coast

15.0 and 49.9 mm.

d Days with very strong

qualified

to all the sectors of it; nevertheless,

and the frequency

of days with rain, four intervals

one interval

The mountainous

logic that it occur in this case, specially because

The volcanic origin of the island is shown in the crater of el Padre Bay.

TABLE

I Monthly values of precipitation

of a rainy day

after a day with weak precipitation

in the Meteorological

is

less than the probability

of a rainy day

after a day with moderate

precipitation,

Average Precipitation

and number of rainy and dry days

Station Juan Fernánez

Mean value for rainy day

(1960-1994)

Nº of rainy days

Nº of dry days

%

%

rainy days

dry days

3.3

325

760

30.0

70.0

January

30.4

a rainy day after a day with strong pre-

February

30.8

2.9

361

628

36.5

63.5

cipitation

March

62.6

4.8

454

631

41.8

58.2

this will be less than the probability

and inferior

of

to the probabil-

ity of a rainy day after a day with very

April

88.7

5.8

518

532

49.3

50.7

strong

May

166.7

8.4

722

363

66.5

33.5

June

155.5

8.2

653

432

60.2

39.8

July

169.7

8.1

716

334

68.2

31.8

114.6

6.4

625

460

57.6

42.4

85.9

5.5

550

500

52.4

47.6 58.6 66.9

precipitation.

In a first moment convenient

it was considered

to differentiate

with precipitation

the days

equal or inferior

1.0 mm, corresponding

to the days with

drizzle - very light rain typical coasts or deserts

to

of arid

- but since these are

August September October

51.5

4.0

449

636

41.4

November

35.5

3.5

347

703

33.0

31.7

3.0

359

726

33.1

66.9

1023.7

5.9

6079

6705

47.5

52.5

only the 7.7% ofthe days with rain less

December

than 5.0 mm and only the 2.9% of the

YEAR

rainy days, it was decided

to use only

Ref.: Dirección

Meteorológica

de Chile.


clonic type, is produced by the fronts

The winter is the most rainy season of

of temperate perturbations, associated

the year (44% ofthe precipitation falls in

to the Polar Front. It has general direc-

winter, 30% in autumn, 17% in spring and

tion SW-NE and are frequent in this part

9% in summer). A more detailed analysis

of the Chilean coast.

show that the months of May and No-

In the contrary, the minimum of annual

vember are clearly winter and summer

precipitation is registered from Novem-

respectively, in relation to the rain be-

ber to February, with only 12% of the

haviour. For this reason, we consider more

annual rain. lt coincides with a higher

appropriate to mention two contrast sea-

number of dry days, over 66% from No-

sons: a rainy one, from May to August,

vember to January; it is necessary to make

and other "dry", from November to Feb-

a more soft qualification of summer dry

ruary; the months ofMarch andApril are

months because in each of them there is

a relatively abrupt transit to the winter,

a precipitation of more than 30 mm.

while the months of September and Oc-

The quantity of dry and rainy days

tober are a more soft transition to the

in the year is very similar, with a differ-

summer(Marzol,etal.,1996).

ence of only 5% in favour of the dry

Looking fora similar place in theNorth-

days. Certainly in Cumberland there are

ern Hemisphere (in latitude, island, dis-

many rainy days in the year and they

tance to the continent and situation in

have a daily average of rain about 8.0

relation to the Equator) we found that

mm of water in winter and about 3.0 rnrn

Lnfraestructure and management 10 stop erosion in t h e runoff [rom th e surnmit o/ El

Funchal in the south of the island of

In summer.

Yunque to Cumberland

Madeira, has the same characteristics.

lrnport ant losses 01 soil are produced the trees.

after intense

Bay.

rain with consequences

on the roots o/

When comparing the data of both meteorological stations, each in one hemisphere, Juan Fernández is 3°C colder than Madeira, almostdouble in rain (1023.7rnm and 638.5 mm respectively) and almost duplicate the number of days of rain (174 and 90 days). It is almost sure that the higher displacement toward the Equator of the fronts in the Southern hemisphere There is a great cliff o/ 300 m in the northweSI oj the island.

The Yunque is ¡he highesl

56

International

Journal

moun¡ain

o/ Robinson

of Island Affairs

Crusoe /sland

(9/5 m.a.s.!.)


than in the North one, originates a difference in a way that the characteristic

of the precipitation

ROBINSON

CRUSOE

L

ISLAND (1960-1994)

L

30

O

of

Cumberland are more similar to the Northern coast of

:3

2Of-------.--rt\rt\-c

the Atlantic island than the Southern one. This is not

U 10

extensive to the temperature.

(j)

L

The annual regime, in a daily resolution of the

QJ

D

e .rs

precipitation of Robinson Crusoe is presented in figures 3 and 4, where the frequency or number of

I

J

M --

times in which each day of the year was rainy is shown. Also the quantity of mean precipitation of

Fig.3 Calendar

Rainyda)'$

of the [requency

o

A

--

Mobile

me.n

of 21

D

'"

(j)

dlys

o] rainy days in the year in Juan Fernáruiez

( 1960-1994)

each day in the period analyzed is shown. In both figures, the mobile average of 2\ in 21 days has been overlapped, this has softened the curve eliminating the spurious irregularities. A regular behavior

ROBINSON

CRUSOE

ISLAND (1960-1994)

140 ~, ---

"

120 100

is shown with a remarkabJe difference between sea-

u...

80

sons. The regime of the frequency show a progressive evolution between the summer minimum and the winter maximum, with some singularities in February-March, August-September

60

lb 11'I1 IV

40

.•..

'

I J

The regime ofthe mean value has a "plateau shape" higher values and a singularity in September.

PERSISTENCE OF RAINY DAYS ACCORDING TO THE INTENSITY OF PRECIPITATION It has been proved that in so me regions of the Mediterranean

there are more

'1'lIln1.

.I~

,

11

I

~U1IIII~

111

20

and December.

with a winter period, from May to July-August, with

, IIL.II 11

,~ ~ M

--~ -"-A

--

-

Mean quantity

of raín in each day

Fig,4 Calendar of the mean quantity Juan Fernánde : (1960-1994)

.a

1"

-

"

o

M --

Mobile

of precipita/ion

.Al

D

365

mea n of 21 days

in each day o/ the year in

tion behaviour has a great value be-

lation to the meteorological prediction,

cause it not only help to predict, but

it is important to show that in June and

also to prevent the consequences of a

in July, there is 60% ofprobability ofa

heavy rain in a region.

rainy day, and 78% that a rainy day is

In Robinson Crusoe, the probability

preceded by another of equal qualifi-

of a rainy day in winter is over 60%,

cation. The highest differences of prob-

probabilities that it will rain in one day,

while in summer it will only rain one of

abilities are in spring time, from Sep-

if it is preceded by a rainy one (Clavero,

three days, near 30% (Table Il). In other

tember to November.

1981; Martín Vide, 1979). Moreover, the

way, if one has in account what hap-

persistence of a rainy day after a day

pened the day before, the probability

with rain seems to be higher in relation

of a day with rain after a rainy day, aug-

\.

to the amount of water fallen in the

ments cJearly with respect to the sim-

precedent day. To know the precipita-

ple possibility of a day with rain.ln re-

TABLE

11:Monthly and annual

probabilities

of days with rain (p)*

and of a day with rain after a rainy day (p')**

in Juan Fernández

(1960-1994)

Rainy Davs

(p)*

January

325

0.30

0.44

February

361

0.37

0.49

March

454

0.42

0.51

April

518

0.49

0.58

May

653

0.60

0.69

June

716

0.68

0.74

July

722

0.67

0.73

August

625

0.58

0.67

September

550

0.52

0.67

October

449

0.41

0.56

November

347

0.33

0.48

December

359

0.33

0.45

6079

0.47

0.61

YEAR

(p')**

* Number 01 days with rainl number of days observed

San Juan Bautista

is the only village of Robinson

Bay. Six hundred persons

live there, dedicated

Crusoe lsland. 11 is located in Cumberland

lo the capture of lobsters.

** Number of days with rain after a rainy day / number of days with rain


In the last 100 years, 100.0 mrn in a day have been surpassed in seven occasions, all of them happened in autumn and winter. Some episodes, like the occurred the 12 of May 1980, produced landslides that flooded the village of San Juan Bautista due to the great quantity of material that flowed from the runoffs ofEI Yunque (Marzol, et al., 1996). According

to the c1assification

of

the daily values of rain in Cumberland in relation to the 4 intervals of intensity (weak, moderate, strong and very strong), it is shown, in first place, that

In this forest

tree-ferns

are abundant

the number of rainy days augment from January until June or July, no matter what intensity have had the rain; this is a characteristic

of the 4 intervals

used (Table lll). In second place, the rainy days of less intensity are more frequent than the ones with high intensity. June is the month with more frequency

of days with very strong

rain more than 50 rnm), even though they do not reach 2%, while from November to February, the rainy days with low intensity are predominant. In this period, more than 82% of the days with rain did not reach the 5.0 mrn in 24 hours. In the winter months, this

The access

value is reduced to something

planes

TABLE

more

to the island is very difficult

because

there is only one small rllnway for small

and with pool- conditions. \,

111:Number of days with weak, moderate, strong and very strong

precipitation.

Percentages

in relation to the number of days with rain in

Juan Fernรกndez Days with rain

Days with weak rain

(1960-1994)

Days with moderate rain

%'

0/01

Days with strong rain

0/01

Days with very strong rain

%1

January

325

272

83.7

41

12.6

10

3.1

2 0.6

The scarce cover of vegetation in some areas

February

361

301

83.4

47

13.0

13

3.6

O 0.0

[acilitate

March

454

347

76.4

69

April

518

358

69.1

116

15.2 22.4

34

7.5

4 0.9

39

7.5

5 1.0 9 1.4

May

653

368

56.3

185

28.3

91 13.9

June

716

385

53.8

220

30.7

99 13.8

July

722

365

50.6

240

33.2

114 15.8

12 1.7 3 0.4

August

625

387

61.9

170

27.2

66 10.6

2 0.3

September

550

378

68.7

126

22.9

45

8.2

1 0.2

October

449

345

76.8

74

30

6.7

O 0.0

November

347

287

43

16

4.6

1 0.3

December

359

304

82.7 84.7

16.7 12.4

43

12.0

12

O 0.0

6079

4097

67.4

1374

22.6

569

3.3 9.4

Year

the erosive eJJects of rain, specially

in the mouruain

slopes.

39 0.6 The erosion is one of the major worries of the

(1) Percentage

58

International

in relation

Journal

to the monthly

number

of Island Affairs

al days with rain.

authorities

of the islands.


than 50% toward

the days with inten-

is confirmed.

sity of moderate

to strong.

confirmed

When the amount to what occurred

of rain is related

the day before,

found that the probability

The cited hypothesis

is

(TableIY).

in Cumberland

Bay are the

This affirmation

the number

be-

being rainy the next rain, only

of rainy

days,

approxi-

the volume

characteristic

was true in 56% of the days. The an-

clear

nual values of PW, PM, PS and PYS are

maximum

the following:

minimum in summer.

seasonal

distribution:

with one

0.561

Ps

423 = 0.74-," = --------

dry; this confirm

if the day

the persistence probability

If the amount

of precipitation

of a

in relation

of days with rain

alter a day with weak rain and the number of days with weak day. The calculation other three probabilities

of the

are similar mutatis

It can be said that in Cumberland

Bay,

rain (equal

is continued another

rnrn), there is a high probability will continue

raining

MARTíN VIDE, J. (1979) Relación entre la cantidad de la precipitación y la persistencia

to 50 mm

in an 85% of the cases by

PPM, strong

sobre

de las se-

en Barcelona (período 1911-70). Estudios Geográficos, XLVI (181), 473-483. MARZOL,

V.,

CERECEDA,

P,

97) Caracterización de la pluviosidad de

of the heavy

Bahía Cumberland

In the pre-

(isla de Robinson

Crusoe, Chile). Cuadernos de Investigación, 22-23,97-114.

01 days with rain after a day with weak rain PPD, moderate

PPs and very strong

01 each intensity

that it

Notas

SCHEMENAUER, R y CASTRO, C. (1996-

rainy day. This high probabil-

TABLE IV Number

VIDE, J. (1985)

cuencias lluviosas y secas en el año medio

In this way a

rains have to be considered

vador Llobet. Departamento de Geografía,

variaciones de la distribución

to how high was the inten-

ity of the continuation

or more than 50.0

persistencia de días de precipitación en

Universidad de Barcelona, 143-148.

vention ofthe effects that they can pro-

every time there is a day with very

en San Crusoe,

comuna de Juan Fernández, V Región,

MARTíN

\

mutandis.

strong

of the

the probabil-

daily value equal or superior of the number

Isla Robinson

de los días de precipitación en Barcelona.

ity that it will rain the next day augment

sity in the day before.

quotient

áreas con riesgo morfodinámico Juan Bautista,

Aportacions en Homenatge al Geóqrat Sal-

day before is considered,

The value of Pw has been obtained as the

L. y

n días. Notes de Geografía Física, 4, 31-39.

of the

0.61

39

BRIGNARDELLO,

valencia. Probabilidades de secuencias de

day with rain after a rainy day is high:

961 PM = -------- = 0.699 1374 ~ 3J Pvs= -------- = 0.846

C.,

CERECEDA, P. 81995) Determinación de

Australis, 40, 43-61.

rain days. The annual

569

CASTRO,

CLAVERO PARICIO, P. (1981) Estudio de la

was a rainy day, than if it was

before =

(1973) Climatologie. Méthodes et pratiques.

Chile. Revista Geográfica de Chile Terra

Bay, the probability

of a day with rain is higher

2300

has a

in winter and one "softened"

In Cumberland

-;:Ú)9-7-

is that

of the precipitation

V r:

ARLERY, R., GRISOLLET, H. et GUILMET, B.

Gauthier-Villars, París.

mately half of the days of the year. Another remarkable

PPW

the next day in

PPVS and the correspondent

(PW, PM, PS y PVS) in Juan Fernández Probability*

PPM

Probability*

PPS

probabilities (1960-1994)

Probability*

PPVS

Probability

85%. That is, there are more probabili-

January

118

0.43

21

0.51

3

0.30

O

-

ties of good shot in the prediction

Februarv

145

0.48

23

0.49

8

0.62

O

-

March

117

0.34

37

0.54

16

0.47

3

0.75

Aoril

197

0.55

69

0.59

29

0.74

4

0.80

the next day, if it is

what wiU happen considered fore rained,

of

not only that the day bebut with the intensity

it

happened. In summary, if it is compared the annual probability

of a day with rain

after a rainy day (p') (Table I1) with the correspondent

probabilities

of a day

with rain after a rainy day with a determined intensity,

it can be observed

Mav

237

0.64

141

0.76

65

0.71

8

0.89

June

264

0.37

168

0.76

86

0.87

11

0.92

Julv

252

0.35

182

0.76

91

0.80

3

1.00

Auqust

244

0.39

122

0.72

49

0.74

2

1.00

September

226

0.41

101

0.80

38

0.84

1

1.00

October

178

0.52

49

0.66

23

0.77

O

-

that

November

130

0.45

27

0.63

7

0.44

1

1.00

PM, PS and PYS are higher than p, and

December

132

0.43

21

0.49

8

0.67

O

-

then the hypothesis

YEAR

2300

0.38

961

0.70

423

0.74

33

0.85

PW<PM<Ps<PYS,

3

:1..1

References

amount, more than 1.000 mm ayear, and

is demonstrated

e

C. ofthe

rainy day after a day with weak rain. cause 84% of the days with more than

L

([)

precipitation

of a

.:c::

-.J 'O

Conclusions

rain is higher than the probability

=

and

scarce cover of vegetation.

The most relevant characteristics

Pw

in places

near them, or in the steep slopes

in the majority ofthe months

rain after a rainy day with very strong

50.0 mm continued

in the runoffs,

it is

of a day with

day, while in the case ofweak

duce, specially

''O


3rd Workshop 01 the Alliance 01 Small Island States (AOSIS) on Climate Change, Energy and Preparations lor the 9th Session 01 the Commission on Sustainable Development

The

third workshop ofthe Al-

liance of Small Island States (AOSIS) on

look at the full range of efficiency

exist opportunities for the improvement

means, with due consideration to the

and more efficient use of materials".

el imate change negotiations, energy and

special situations of SIDS. lmproving

preparations for the 9th session of the

the efficiency

Commission on Sustainable Develop-

distribution and utilization will lead to

"... Renewable

ment took place in Nicosia, Cyprus, from

a reduction of the energy consumption

forms is a priority. However, in total, it

of energy production,

Energy energy in its modem

15 to 19 January, 200 1, under the aus-

per unit of energy service, but many

plays a relatively minor role in the total

pices of the Government of the Repub-

SIDS have been relatively

energy balance at present. The general

slow at

lic of Cyprus. It was organized by the

adopting energy efficiency

Alliance of Small Island States (AOSIS)

and designs. This stems from lack of

in cooperation with the Division for Sus-

appropriate policy, lack of information,

implementation

tainable Development

of the United

awareness and education, and the fact

schemes for smoothing initial capital

Nations Department of Economic and

that there has been a reticence of con-

costs, improved system efficiency, and

Social Affairs (UNDESA).

sumers and energy suppliers (power

well? structured

practices

need is for increased development and utilisation of renewable energy sources, of better fi nancial

demonstration

and

Insula was invited to participate in

utilities) to rnake the higher initial in-

training activities and programs. Such

this crucial meeting that will have strong

vestment to achieve future savings. It

demonstration projects should be a full

has been well demonstrated

repercussions

on the future energy

policies of Small Island States. The par-

and rec-

package of equipment and training and

ognised that making energy systems

installation. Some past projects in SIDS fai led to take a comprehensi ve approach

'. contributes

ticipation of INSULA, represented by

more efficient

the Vice Secretary-general Mr Cipriano

costs, (thereby

to reducing

MarĂ­n, allowed to introduce to the par-

energy), reducing the volume and costs

".. .In considering renewable energy

ticipants the RES promotion strategy

of imported fossil fuels, reducing de-

technologies at the regional and national

improving

access to

and were therefore not successful.

in European islands and the ambitious

mand, improving local air quality and

levels the following main strategies and

objectives

the reduction of greenhouse gases."

recommendations have been identified:

outlined

in the Towards

100% RES campaign (Altener project).

"... Many technological options ex-

a Establishing regional networks and

The workshop report also ineludes the

ist for improving energy efficiency in

centers of excellence for the exchange

advances made by small island states

residential and commercial buildings,

of experience in the development and

with regard to their wager on energy

the tourism sector, industry, transpor-

application of renewable energy, re-

sustainability and maximum development

tation, agriculture and forestry. While

search and development

of renewable energy sources. A few out-

numerous technologies to improve en-

tion, including joint development

standing paragraphs of the report:

ergy efficiency

projects, the sharing of testing and

and manage energy

demand more effectively

Energy

60

Renewable

Efficiency

are readily

available, new developments

can en-

coopera-

training facilities and South? South cooperation for capacity-building.

"... Energy efficiency improvement has

hance the potential of this option fur-

b Disseminating technology options at

been identified as the most practical

ther. A major part of industrial energy

the national, regional, and intemational

measure that can be taken at this stage,

is utilised by the light manufacturing

levels for mature solar, wind, biomass,

since most SrDS are unable to make

industries. Although the scale is rela-

hydro

radical shifts in their energy mix over

tively small from an economic basis, for

geothermal, ocean (wave, tidal and

the medium termo There is a need to

SIDS as a group or by region there does

ocean thermal energy conversion), and

International

Journal

of Island

Affairs

incIuding

mini-hydro,


hydrogen from renewable sources, and

sumption in SIDS could be seen as quite

tional levels the following main strate-

other renewable energy technologies.

large if mari ne and aviation bunker fuels

gies and recommendations

e Learning from past experience and

are counted. The linkages to the tourism

identified:

establish closer links between re-

sector are evident. lt will continue to be

search, development, demonstration

difficult for SIDS to address and improve

a Promoting efforts to manage growth

projects and industry.

the situation, since most of the technol-

in demand for transportation in the

d Promoting trade in renewable energy

ogy is imported. Still heavily dependent

devices and systems and facilitate the

of petroleum, the options are constrained.

wider context of sustainable development.

creation of an enabling environment

The issue is also intimately linked to life-

b Promoting, as appropriate alternative

for rapid market growth Supporting

style. It is widely recognized that some

fuels ensuring that technologies are

have been

national efforts to build organisational

sros

have taken very strong measures,

proven, the costs are affordable, train-

such as restricting vehicle sizes to better

ing and public awareness is provided,

production and diffusion of renewable

suit local conditions. Ttwas also recog-

and the necessary infrastructure to

energy technologies, as well as for

nized that large SIOS delegates would

establish these is available.

require some dispensation for this restric-

e Improving energy efficiency within

tion. These examples along with the im-

each transportation mode, including

Energy-related Issues in Tranportation

Targeting the youth to get the public

d Ensuring the importation and supply

"... The transportation sector is a pre-

awareness started early was also high-

of c1eaner and better quality fuels,

dominant consumer of imported energy

lighted as an important measure".

and the improvement of maintenance

pacts need to be shared among SIDS.

and this is of growing concern to SIDS.

sea transport.

system.

and concerns for SIDS, especially in the

Strategies and Recommendations

multi-island countries and for the more

In considering energy-related issues in

effectiveness and availability of pub-

isolated islands. Energy per capita con-

transportation at the regional and na-

lic transport systems.

Transportation creates special problems

e Oeveloping transportation rnanagement policies that would improve the

Energia e Acqua nelle lsole Minori Energy and Water in Small Islands,~.

Besides gathering the best practices, experiences

and technologies

of this

sector in Europe, taking into account deveIopment and occupational opportunities that can be developed locally, the meeting will also favour research

International Conference

institutes and the interested companies

Alghero, 12-13 April 2001, Sardinia-Italia

the best technology for an appropri-

to carry out a thorough study to find ately dimensioned small desalinating

TI e Conference is organised by the Ital-

be satisfied, in the next future, by the

ian Federal Association of Scientific

new alliance between desalination and

and Technical Organisations-FAST, the

renewable energy sources This would

National Association of Small Italian Is-

allow to close, through the purification

land Municipalities-ANCIM

plant, as a solution that will allow tourist resorts and small islands to achieve partial or total water autonomy.

and the

and the introduction of saving meas-

Conference

Sassari Province Energy Point (Sar-

ures, the c1ean and efficient circle of

Antonio Giovanni Rassu

dinia).

water use and production.

Director

The action is inserted

within the

framework of the cooperation between

This initiative relies on the support of INSULA (International

Scientific

the European Island OPET and OPET

Council

of Islands

Cronos, as an international action airn-

Agence

de l'Environnement

ing at the objective Islands 100% RES.

Maitrise de I'Energie (ADEME - France),

The Conference

approaches one of

the Catalonian

Oevelopment),

Energy

et de Institute

the most burning island issues: the bi-

(ICAEN - Spain), the Intersolar Center

nomial water-renewable energies. The

(Moscow) and the collaboration of the

increase in water demand, particularly

Institute of Technology

on small islands, seems that can only

able Energies - !TER (Canary Islands).

and Renew-

Organization

Punto Energia Provincia di Sassari Multiss S.p.A. S. p. La Crucca, 5. 1-07100 - Sassari Tel./Fax: +39 079 3026092 E-mail: energyss@tin.it Contact

European

Franco Cavallaro ANCIM Tel.:+39 090 361867 Fax:+39

C-

o c')

and manufacturing capacity for the

education and public awareness.

cn

O

090 343828

E-mail: frcavall@tin.it

Island

OPET</