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Intelligent sustainable home system A modulary system designed to decrease energy consumption in an eco-friendly manner

Group 1

Thijs Baltes s1127144 Mieke van den Belt s1098497 Berber Bijlsma s1109650 Marijs Bults s1234862 Job van Dongen s1225766 Jurrit Heerink s1254413 Lisette Heerink s1218824 Liza Hodenius s1211765 Reinout Holtrup s1106678 Nynke Lof s1232452 Olivier Maas s1128205 Ivor Muijlwijk s0209023 Rianne van der Pol s1125435 Jop van Roosmalen s1113534

Problem description



Since 1990, use of electricity is increased by 51%. People become more concerned about the environment and they tend to do something about it. Besides, energy sources are not inexhaustible. Hence a system must be developed for houses to make them more energy efficient. Such a system is elaborated in this project.


Type of house Owner-occupied or private corner houses, terraced houses and semidetached houses are types of houses that are included within this definition. Owneroccupied houses are in general equipped with more luxury, isolation, a garden, and provide a larger market.

The goal is to design an energy efficient and comfortable home

System description The system consists of different modules, all focusing on reducing water, gas and electricity consumption. A total of six subsystems ensures a maximization of energy recycling and efficiency. One of the subsystems is the interface, which allows the user to control the other subsystems. All modules can be purchased individually. This way the user can choose which modules to purchase and which kind of energy to reduce.

// Is usable for multiple rooms // Is connectable to existing energy network // Is connected to main system // Is modular User // Overrules autonomous system // Surveys subsystem energy consumption Interface // Gives feedback // Saves behavioral patterns // Is Wi-Fi compatible // Controls subsystems // Triggers energy reduction Sensors // Detect user // Detect statuses of devices Price

// Is affordable for Average Joe // Is recouped within 10 years


// Reduced by 30% per year

Users The system will be designed for the average Dutch households under four persons. This way, more than 80% of the Dutch occupants is taken into account. Statistics show the average disposable income is around 33.000 Euros a year. Most people spend a third of this money on their house, including mortgage and energy bill. The investment should not rise above this consumer’s budget.

topology diagram

Alternative energy

Autonomic smart system

Actuators/ Sensors

This subsystem is about creating green energy. By inspecting efficiency, costs, and suitability, the choice for the best method(s) can be investigated and therefore implemented in the system.

To reduce energy consumptions, devices will be controlled in a more efficient way. An autonomous smart system will adjust the actions of the system to the habits of the user.

This smart and interactive system uses Wi-Fi tracking, which automatically regulates electricity and central heating to personalize the system. The system keeps track of the user’s behavior, so the house will minimize energy consumption.

Recycle water

Thermal energy

User based interface

Drinking water is rather valuable, thus using this water for all kind of goals is considered waste. A system that recycles water as much as possible will be developed, which minimizes spilled water. The development of this system will consist of three investigation subjects: 1. The possibilities for generating energy from (flowing) water 2. Ways to recycle as much water as possible 3. Opportunities to exchange heat from one subsystem to another.

About 65% of the total energy consumption of an average household consists of using thermal based systems. Therefore it is of significant importance to save and use energy as efficient as possible. This will be achieved by fulfilling four main goals: 1. Minimize usage of thermal energy by analyzing the behaviors and needs of the user. 2. Using the released wasted thermal energy as a heat source. 3. Minimizing heat loss through isolation and efficient ventilation. 4. Minimizing the required energy for heating up water.

An interface will be created to inform the user about the actions of the system and to allow him to influence the system. The interface will consist of two elements: a device, which is set on a central point in the house, and an app for smartphones and tablets. The device will be leading, but to give the user the convenience of controlling at a distance, an app will be added.




System Engineering



The NRG is a modulair system consisting of one basic system and three seperately purchasable modules, respectively the Thermal Energy, Water Reduction and Alternative Energy modules.

7 Different keydrivers have been identified: • Create a more energy efficient home • Retain comfort while reducing energy • Create awareness with the user • Provide user insight in the energy consumption • Fit the device to user needs • Ensure a simple installation proces • Reduce system costs to improve affordability

The basic system can be seperated in three parts. The autonomic system is a computer that regulates information and controls the devices. A combination of Wi-Fi based actuators and sensors ensure the (de)activation of devices and pass on information to the autonomic system. The user is able to adjust any type of data through the User Interface, which is also accessible via a mobile app.

System and environment

Each aforementioned module will be available at a different price range and with a different energy reduction/production percentage. Hence users can decide what type of energy to reduce and the size of their investment.

= User Interface = Wi-Fi (W), Actuators(A) & Sensors(S)


A selection of the requirements will be treated for most requirements were met during the project. (For the full list of requirements see the extra information) \

= Autonomic system

• The target: The initial plan was to bring the NRG available for the semidetached, corner- or terraced, owner-occupied or private houses. The conclusion was made that the system can be implemented in any house, taking into account a variety in possible energy reduction. This makes the target a lot bigger, resulting in an increase of potential sales. • The user interface: This part of the system will not be delivered with every module as stated at first. Instead it will be a part of the basic system that is compatible with separately purchasable modules. • The price: The entire system costs roughly €5000,-. This equals the amount of money determined at first for the simplest version of the system. Hence the price for the system is reduced drastically. • Water reducing: This subsystem ended up being highly inefficient for an existing house. However for a new building it can be considered to implement this subsystem for a further reduction of energy consumption.

= Thermal Energy Module

Test plan

Topology diagram

Costs & savings

= Alternative Energy Module

= Water Reduction Module = External source of input

The ensure synergy in the system, it is necessary to test and monitor the NRG in different phases of the implementation, starting at the production and working up to sales and installation. At first the entire system must be tested in practice, to correct teething trouble and major flaws. Testing must occur in extreme environments. Also the installation process must be thoroughly tested at forehand by the target audience.

In the topology diagram the autonomic system including all modules is displayed. Every module comes with its own set of actuators and sensors (all depicted in the diagram with a triangle icon). Thus the actual amount can very.


The consumer must at least purchase the basic system, after which he can add one or more of the three modules. Each module has its (dis)advantages, depending on the type of house and the amount of money the user wants to invest. Module Basic System Water Reduction Thermal Energy Alternative Energy Total System


Solar panels

Water collector


Costs [€] €575,€2750,€760,€3760,€7755,-

Reduction [%]* 24% 2.9% 9% 38.5% 54%

* The reduction is the percentage of the energybill per year that is being reduced when installing this module.


On a €2114,- bill, the average user will save €1132,- per year when purchasing all modules. i.e. The payback is less then 7 years. However the Water Reduction module has a very low reduction percentage. When leaving out this module the total system costs €5095,- and will ensure a reduction of 50.7%, €1071,- a year. In this case the payback is less than 5 years.

Conclusion = Wi-Fi signal (out) = Wi-Fi signal (in) = Electric current = Mechanical signal = Thermal signal = Natural source = Ultrasonal signal


User Interface

Meter Cupboard


Groep 1 Thijs Baltes (s1127144 ) & Rianne van der pol (s1125435)


= CO2 [ppm]

= Wi-Fi Tracker

= window

= User

= Devices

= System component

= Radiator

= Actuator

= Device using water

= Sensor

The system creates awareness through the interface showing the user collected data on the energy reduction and savings. The NRG is a smart system that adapts to every user, forming a personal pattern to ensure that ultimately no user/device interaction is required. To ensured the highest possible energy reduction, while keeping the investment as profitable as possible, the best option is the purchase every module aside from the Water Reduction module. With the extra costs this module brings it will become profitable solely when the user is building a new house and installment will not imply renovations.


user interface



The user interface is the connection between the user and the NRG. It consists of a device, placed at a central place in the house, and an app for smartphones and tablets. The user interface receives its data from the -level


Also, it provides insight into energy consumption and collected energy. NRG

13:00 21°C NRG







generated energy

collected water



explanation displays Home screen

screen shows the most essential options for controlling the system. On the left, buttons can be found for ‘menu’, ‘edit’, ‘schedule’ and switching between -level are 2 shown. At last, a pause button is displayed, to temporarily shut down all the devices when the last person leaves the house. By clicking on a room, only this room will be shown. NRG

13:00 19°C

editing a room shown. A grid will be added, representing 2 . The placement of devices can be edited by dragging it to the preferred place. When pressing the plusbutton, one can choose which device has to be added.


electricity of several years are displayed, as is the consumption of the average Dutch household. Lines in the graph can be switched on or off by clicking in the legend. The user can choose whether he wants the consumption to be shown per year, month, week or day. Likewise, the y-axis of the graph can be set to kilowatt-hour or euros.


Schedule NRG



menu ‘Insight’ refers to the screen displayed in 1

be viewed and new assignments for the schedule can be added.




recent notifications

living room

recent changes



working room



13:00 KWH

Electricity Amount of consumed energy per month kWh

bedroom #1



Average Dutch household 2010


2011 300









working room



12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 00:00

00:00 01:00

15°C 15°C 15°C 15°C 15°C 21°C 21°C 21°C 21°C 21°C 15°C 15°C

THU 15-05 15°C









0 apr


2014 (current)








consumption and proposals for possible schedule changes are displayed. ‘Recent changes’ show changes that have been made to the schedule. At last, general settings for the system are available, such as time, language,


costs & savings The costs that will be made for the user interface, are only development costs for programming. Other costs, such as those for the screen, will be included in the costs of the autonomic system. By making the user aware of the energy consumption and its corresponding ways of reduction, both energy and money can be saved. However, these savings are not directly caused by the user interface, but by awareness of for instance thermal energy consumption. Therefore, these savings will be allocated to the corresponding subsystems.



To investigate the convenience of the user interface, a test can be performed. By performing this test, subjects run through the user interface and share their

To provide the user the convenience of remote control, an app will be added. Nearly every function can be executed in the app, except for editing rooms and devices. It will be possible to change device statuses and check energy consumption at any time. If the user wants to change a device status, a pop-up

conclusion The user interface does indeed provide insight and give the user the Because of the clear interface, reducing energy consumption is made approachable for everyone.

Groep 1 berber bijlsma (s1109650) & mieke van den belt (s1098497)



sensors & actuators


In order for the NRG system to function properly, there is need of sensors and actuators, which are the eyes, ears and hands of the system. Every change in the home environment needs to be traced and adjusted for use efficiency.



The rate of CO2 is measured by a CO2 sensor, which defines the quality of the air, using infrared light. When this rate is exceeded by a certain value (in parts per million), a Wi-Fi signal will be sent to the autonomic system. Thereafter, the autonomic system will communicate to the user, through the user interface, that fresh air is needed. The user decides whether or not to open a window.

Wi-Fi-Track is a system that detects users in their homes, without the need for the user to carry a tracking device. Wi-Fi-Track senses moving objects, without interference of walls or other objects. It works on a low power consuming Wi-Fi signal, using only 75mW. Wi-Fi-Track sends raw data (x, y and z coordinates) to the main computer which transformes this data into a position. After determining the position of the user, the autonomic system decides which action to undertake, using different sensors and actuators.



autonomic system electricity

electronical devices

To control electronical devices, a device which is placed in between the electronical device and the power socket is designed. The device contains a Wi-Fi-microcontroller, current meter, kilowatt-hour meter and a mechanical switch. Using this device, the autonomic system is able to control all electronical devices through Wi-Fi and thus wireless. Each type of electronical device has it’s own frequency, so the autonomic system knows which device it is communicating with. The current meter determines whether a device is already turned on or off, so the mechanical switch knows which way to switch. The kilowatt-hour meter keeps track of the used power, for communication with the user, through the user interface.

water quality and flow sensor

In order to be able to recycle rain water, a water quality sensor is applied in the water tanks. If the quality is not high enough, the water is purified again or deposed in the sewage as waste water. If it is high enough, the water is used for laundry or toilets. A flow sensor is placed after the water recycle system, so the user is informed about the amount of water that has been saved.


• Save energy • Be self recoupable* • Be controlable using Wi-Fi • Be wireless • Have components with a maximum size of 10x10x10cm • Function autonomically *In 10 years, in combination with other systems

Groep 1 Job van Dongen (s1225766) & Marijn bults (s1234862)



Conventional radiator knobs are substituted by electrical knobs. These contain Wi-Fi microcontrollers to communicatie with the autonomic system, so the temperature can be regulated at room level. When the user opens a window, a distance sensor will send a Wi-Fi-signal to the autonomic system stating the opened window. To save energy, the system will tell the radiator in that specific room to turn off.

meter cupboard

The energy meter in the meter cupboard needs to be a smart meter, to be able to measure the generated solar energy. The smart meter will be subsidized by the Dutch Government. Next to the amount of generated solar energy and the amount of energy returned to the energy company, it needs to know what the energy, water and gas consumption is. To measure the real-time energy generated by the solar panels, an electric power measurer is used, specifically designed for solar panels.

costs & savings

€ 100,• Wi-Fi-Track: 2 times (2 floors) € 18,• Energy meter in cupboard € 135,• Water quality sensor € 20,• Flow sensor € 8,• Temperature sensor € 50,- + • Electricity control devices: 10 times It is unclear how much energy will be saved due to Total € 331, the sensors and actuators, for they just help function Roughly € 330, the NRG system properly, instead of reducing certain waste or saving energy directly.



Autonomic System


The subsystem autonomic system is about the controller hardware and software. It stores and collects data and generates actions. The goal of the autonomic system is to control energy consumption in a smart way. It consists of 3 parts: 1. Hardware 2. Software 3. Interaction: self-learning and control

Requirements • • • • • • • • • • • • • • •

Have network connectivity Receive sensor information Collect information on energy consumption Recognize patterns of use Make decisions Store data Dedicate tasks Provide user interface of status info Receive commands from user interface Encrypt database and connect with user interface Work fast (input should be processed within 5 seconds) Endure at least 10 years Have production costs of a maximum of 30 euro Easy to install (30 min.) Control a 7 inch touch screen. Wi-Fi Tracking

Hardware 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

Printed circuit board (PCB) Wi-Fi transponder Network interface controller (NIC) Central processing unit (CPU) Memory (Dram) Hard drive (HD) Wi-Fi Modem Wires Power supply Housing Touch screen of 7”

Interaction: self-learning and control

The self learning process is based on statistic analysis of the time changing variables stored in the database. These variables are categorised into 4 levels, which enable analizing in 4 dimensions. “Week number”, “day”, “time period” and “room number”. The system uses the variable values to make predictions about user behavior and energy consumption. For example, to calculate the propability of the presence of a person, the system considers these four dimensions. With these dimensions the system draws a conclusion in the form of a propability value. After this conclusion it performs an action.


Some variables are programmed factory based and therefore they have to be tweaked experimentally with computer based models by forehand. At a later stadium the AS will have to be tested at several houses before the AS is ready for introduction to the consumers.

User Interface Subsystem Actual and history of power consumption of lightning and devices, heating system and water, Send status of windows, CO2 levels and device power status.

Signal with change in frequency, intensity, phase shift

Intepretation of Wi-Fi Tracking signal

Overrule control of devices pause Deliver timetable

Deliver data


Software (Controller & Database)


Log all input and output parameters and actions Data request

Amount of people, Velocity of people and limbs, XYZ-coordinates of bodies,


Boundary conditions needed to calculate system controlls and energy consumptions Set the timetable variables Request the timetable

Room temperature Window status, and CO2 level

Heating system

1. Is able to control the user interface Water Actual value of water 2. Controls the devices which are connected to Arbitrary set heating consumption and the system power of specific rain water 3. Provides database information to the user Meter cupboard radiators interface All external data Actual value of total conTurn on and 4. Displays the user interface exchange is done sumed gas, and electricity off devices 5. Encrypts and decrypts data over Wi-Fi Devices Solar system 6. Generates time based history of actions Actual amount Action and light 7. Logs parameters of produced Send power Value power 8. Logs power consumptions status 9. Logs user activity 10. Stores boundary conditions The diagram above shows the integration plan and the interfaces 11. Handles the variables user set, factory set and between the controller, database and the sensors and actuators. time dependent 12. Interprets Wi-Fi tracking signal

Cost And Savings

Rebuilding costs

Autonomic system +/- €50,- (based on production price of Raspberry Pi €25,- + 7” Touch screen €20,-+housing €2,- +other costs €3,-) +/- €0,-

Energy costs

+/- €6,- annually

Maximum saving

€300,- (15%) (dependent on user behavior and the performance of the related subsystems )1 +/- Dependent on costs of other necessary subsystems. Payback time can’t be calcutated for just this specific subsystem.

Production costs

Payback time

Group 1 Reinout Holtrup S1106678 & Olivier Maas S1128205


At the moment the Autonomic System (AS) is workable but could be detailed with more exceptions and more specific controls to make the AS even better. The self-learning part of the AS makes the system more efficient in time as more precise predictions are possible with the data earned through time.

1. G. Wood, M. Newborough, Dynamic energy-consumption indicators for domestic appliances: (



Autonomic System


Controller Software

It shows: • How the information is stored in the database • How the controller software works • How the self-learning principle works

The process of action calculation is illustrated on the diagrams on the next page. Action parameters are calculated by evaluating values and by applying conditions. The diagrams show that actions are calculated in a mathematical form: For the thermal system for example: (How big should the action be)*(should the action be performed)

Database Storage

By designing the software in this way it is very easy to expand the software by adding more conditions.

On these pages, some more detailed information about how the autonomic system works is given.

The database is accessed by the software by pushing and pulling variable values. There are 3 types of variables: 1. Time changing 2. Ajustable 3. Factory set Time changing variables are about behavior. For the self-learning system it is needed to find patterns in user-behavior. This requires that the information is stored in a way that data manipulations can be done easily. Ajustable variables have values that are set by the user. They contain user preferences and user specific settings, like the geometry of the house. Factory set variables have values that are set at the moment of production. These values do not change, they are definitions.

The software interprets sensor information and calculates which actions should be provided by the actuators.

Some values don’t exist directly in the database. The database doesn’t contain fixed values of chances that a person is at home at a given time. However, it does contain logged information. Values for chances about presence at a certain time can be obtained in the following way: The chance that a person is present in a specific room, is determined by multiplying the average presency at that specific time with the average precency of that specific day.

Patmoment = Ppresencyattime ⋅ Pprecencyatday Ppresencyattime = Pprecencyatday =

∑ presentattime(time,room) numberofvalues

∑ presentattime(day,room) numberofvalues

The diagram below shows a simplified map of the database. Time changing variables have 5 attributes: (week number, day, time period, room number and value) Values can be boolean expressions or numbers.

Note: In this diagram the variable “Time period” can have only 4 values to illustrate it more clear. In the real system, this variable should be able to contain values for every second. This can make the system more accurate.



Autonomic System

Temperature Control WIFI Tracking(n)

User Interface

User Interface



Measured temperature(n) Tm


Requested temperature(n) Tr (room and time dependent)


Detects Person DP in room(n) DP=1 | True DP=0 | False (when DP changes, reset timer)

Detection time DT. (default value=10 min.)


UH=1 | chance that the user will be present in 10 minutes and will stay longer then 10 minutes. >80% UH=0 | else

Person stays(n) PS PS=1 | DP=1 && timer>DT PS=1 | UH=1 PS=0 | DP=0 && timer>DT (default value PS=0) PS=1 | set to 1 by user interface overrule PS=0 | set to 0 by user interface overrule

Window status(n) WS=0 | open WS=1 | closed




(Tr − Tm )⋅(WS)⋅(PS) = HeatControlParameter

The HeatControlParameter is the action that should be send to the radiator controller. it is an arbitrary value.

Device Control User Interface


Turn on/off device(n) TOOD=1 | TimeScheduleMachineValue(n)=1 TOOD=0 | TimeScheduleMachineValue(n)=1 TOOD=1 | set to 0 by user overrule TOOD=0 | set to 1 by user overrule

The DeviceSwitchOnOff is the action that should be send to the specific device. It is an boolean value (on/off)

TOOD = DeviceSwitchOnOff WIFI Tracking(n)

Light Control

User Interface

Detects Person DP in room(n) DP=1 | True DP=0 | False (when DP changes, reset timer)


Requested light status(n): RLS=0 | requested light database value(n)=0 RLS=0 | requested light database value(n)=0 RLS=0 | set to 0 by user overrule RLS=1 | set to 1 by user overrule

User Interface

Person in room(n) PIR PIR=1 | DP=1 PIR=0 | DP=0 PIR=1 | set to 1 by user interface overrule PIR=0 | set to 0 by user interface overrule *(PIR)

RLS ⋅ PIR = LightStatus

The LightStatus is the action that should be send to the specific light. It is an boolean value (on/off)



Thermal Energy


Within the subsystem thermal energy, the main goal is to decrease the consumption of thermal energy. After research, we concluded that two of the four drafted goals stated in the first poster could not be fulfilled profitable. Remaining are the two following goals: 1. Increasing the efficiency of the use of thermal energy by analyzing the behavior and needs of the user. 2. Minimizing heat loss through efficient ventilation. The first goal is fulfilled by a mechatronic system that makes use of centrally controlled radiators. By combining this system with a ventilation system, the second goal will be fulfilled.

Requirements • • • • • •

Have purchase price of maximally €1.000 Have profitability of minimally 30 percent Reduce gas consumption with a minimum of 30 percent Provoke the user to make use of the available thermal energy more efficiently Be able to function autonomously Provide the opportunity for the user to modify the thermal heating system to increase the efficiency

Heating system

X is the standard minimum temperature. Depending on the degree of insulation, temperature X varies from 15 °C to 18 °C. The preferred temperature set by the user is called Y. This maximum temperature can be set per floor or per room. Four methods of determining the temperature are checked every 30 seconds, to check if data are available on the temperature for that moment in time for every room. If data are available, the first method will be used, overriding every subsequent method. 1. Modified by user 2. Detection 3. Use of autonomic patterns 4. Standardize Every frequently used room contains at least one thermostat knob, placed on the radiator. The knob contains temperature sensors. Data on the temperature are transferred with the use of LAN communication from the knobs to the user interface and the other way around. The user interface executes the control system, as described in diagram 1. The thermostat knobs function as actuators, and control the flow of thermal energy transferred to the radiators. Diagram 1: Control system

Ventilation system




There are numerous mechanical ventilation systems available to control air supply and exhaust automatically. However, purchasing can cost up to 7000 euros. To save energy, rooms should be adequately ventilated, but not more than required. By using two CO2 sensors, users are getting aware of the air quality in a particular room. Based on the measured CO2 level, the user interface provides the user with advise about closing or opening windows in a specific room to improve air quality or to save energy. By opening a window in this room (WS = 0), thermostat knobs receives a signal to turn off. When the windows are closed again, the heating system restarts automatically. As a result, energy losses are minimized.

Product Thermostat knob Window sensor CO2 sensor Overhead Total

Costs (€/n) 25 20 150 100 295

Minimum costs (€) 125 (5n) 100 (5n) 300 (2n) 100 625

Expected costs (€) 200 (8n) 160 (8n) 300 (2n) 100 760

1. Milieu Centraal, Bespaartips verwarming,’s/thema-1/energie-besparen/energiezuinig-verwarmen-en-warm-water/bespaartips-verwarming/, 28 februari 2014.

Groep 1 Jurrit heerink (s1254413) & Lisette Heerink (s1218824)

Whether or not this system will function in practice, depends on whether or not other subsystems operate in practice. The Wi-Fi tracking system that will be used, will be tested by the subsystem ‘Actuators and Sensors’. The control system will be tested by the subsystem ‘Autonomic Smart System’. Testing of the user interface is covered by the subsystem ‘User Interface’. The total heating and ventilation system, showed in diagram 1, merely combines the used methods mentioned above and can only be tested in the final test phase.  

Product Heating system Ventilation system Total


Maximum savings (€/year) 5101 30 540

Estimated Expected efficiency (%) savings (€/year) 50 255 100 30 285

The amount of thermal energy comsumption can be reduced significantly when this module is purchased. The heating system can reduce gas consumption by 25 percent. Financially, it is also viable. The efficiency of this subsystem at normal usage can be up to 37,5 percent. This seems very high, but this is necessary for compensating the costs made within other subsystems.



Alternative energy Installation


Throughout the Netherlands, the solar radiation is almost the same. To properly make use of this energy, the solar panels should be positioned correctly. The influence of the angle and direction of incidence are displayed in the info graphic (figure 2) below. The values represent the used percentage of the solar panels under that condition. Shadows on the panels should be avoided. A shadow on one panel influences all solar panels, because solar panels are linked in series.

This sub-system examines the best way to reduce the energy bill by generating alternative energy. Solar panels are the most lucrative manner. The payback time is between 5 and 15 years and the investment is relatively small. Wind, bio-waste and geothermal energy demand a larger investment or are not profitable on this scale.

A few assumptions are made: • Price of electricity: €0,23 per kWh Both flat and sloping roofs are suitable for solar panels. On flat roofs, the solar • Average electricity usage of our target group: 4733 kWh per year • Efficiency solar panels in The Netherlands: 70 to 90 kWh per 100Wp (Watt-peak: panels should be mounted on steep stand. To avoid the shadow cast by this stands, panels on flat roofs take up twice the surface. power of one solar panel) • Interest for a 10 year saving account: 3,35%

Requirements • • • • • • •

Have a maximum total price of 4000 euro Have a maximum payback time of 10 year Be able to fed back excess electricity into the power grid Be adaptable to different houses within the target group Prevent to be the cause of a fire Be able to measure generated and excess energy Have maintance maximal once a year


Alternative Energy is connected to the sub-system Autonomic System. The connection is a digital signal consisting the generated and excess kilowatthours. The energy meter sends this signal via Wi-Fi to the Autonomic System. The Autonomic System manipulates the information and delivers it to the User Interface, where it is shown to the user as feedback.

Solar panels

Figure 2: Power usage (


If the converter delivers more than 2,25 Ampere, it should be connected to a separate group in the meter box. Also the main connection of the house should be checked at capacity when installing this sub-system.

Maintenance Converter

Solar panels have a durability of 25 years. It is advised to clean the solar panels every year to maintain the efficiency. To prevent overheat, the converter should also be cleaned every year. The converter has a durability of 8 to 12 years.

Costs & Savings

Power usage

In worst circumstances, a solar panel delivers 182 kWh or €41,86 per year. In the best circumstances, this is 234 kWh or €53,82 per year. To fulfill the requirements about the payback time, 10 panels are needed in the worst case and 5 panels in the best scenario. This means a gain of 1820 kWh and €418,6 per year in the worst case and a gain of 1170 kWh and €269,1 per year in the best. Underneath, a calculation of the costs in both cases can be found. The solar panel Yingli 260Wp mono-crystalline and converter Soladin 600 are choosen because of there low cost and high efficiency.

Power grid

10 panels Solar panels (Yingli 260Wp mono2200 crystalline) Converter (Soladin 600 ) 335 Materials for installation 350 Installation panels 875 Total costs €3760

AC-cable Energy meter Meter box


Figure 1: Architecture

Figure 1 shows the architecture of our subsystem. Solar panels on the roof convert solar energy in direct current. This DC is conducted via cables to the converter. The converter converts the signal to an alternating current. This is being transported to the meter box. It depends on the power usage at that moment if the electricity is used or is fed back into the power grid. The energy meter keeps track of the amount of generated energy and excess electricity. As stated under ‘Interface’ this information is sent to the Autonomic System and so on. The converter has an MPP tracker (Maximum Power Point). The MPP tracker searches for the point where the product of the voltage and current of the solar panels is at its maximum. Group 1 Ivor Muijlwijk (s0209023) & jop van Roosmalen ( s1113534)


5 panels 1100 335 350 615 + €2400total

The parts used in this subsystem are purchased and tested by its own manufacturers. Therefore, we expect no big errors when installing this subsystem. The strength of the Wi-Fi link with the Autonomic System should be tested, but should also not be that big a problem as Wi-Fi is a known technology.


The best way to generate private energy is buying solar panels. This technology is suitable throughout the Netherlands. The amount of energy generated depends on the angle and direction of the panels. A 10 year payback time is possible regardless the circumstances. An investment is needed of minimal €2400 and in the worst case €3670. The customer can choose to alternate the amount of solar panels for a bigger profit and smaller payback time. The results are calculated with a constant electricity price. We expect that the price will rise further in the future so we think the profit will get higher.




Water reduction

The subsystem water reduction firstly looks at the possibilities of reducing water costs. Secondly the system investigates the opportunities of reducing the usage of clean drinking water. The water has to be recycled or other sources have to be utilized. Three options are available for a water recycle system: 1. Rainwater system 2. Grey water system 3. Combination of those two

Requirements • • • • •

Reduce the water bill with 25% Recycle no toilet water Must be refilled automatically with clean drinking water Provide no water shortage Guarantee the quality of water

water use

The three most water consuming devices in an average household are: the shower, the toilet and the washing machine. Only those three were taken into account.



Volume (L/year)







Washing machine 33,73





Figure 1: Rainwater system

Water recycle systems

1. Rainwater system (figure 1) • Rainfall: 34.500 – 45.000L p/year • Water consumption toilet: 40.887L p/year • Water consumption washing machine: 22.484L p/year The toilet will be exclusively provided with rainwater, using the separate rainwater system. 2. Grey water system (figure 2) • Grey water storage: shower + sink + bath 82.000L p/year • Water consumption toilet: 40.887L p/year • Water consumption washing machine: 22.484L p/year Using the grey water system, the combined total water needs are satisfied. Testing: The parts used in these subsystems are purchased and tested by its own manufacturers. Therefore, we expect no big errors when installing this subsystem.

Costs & Savings Rainwater system

Grey water system

Material costs

From +/- €2.250,-

From +/- €5.000,-

Rebuilding costs

From +/- €500,-

More than €500,-

Energy costs

From +/- €2,-

From +/- €10,-

Maximum saving

€61,33 (23%)

€95,06 (36%)

Payback time

+/- 45 years

More than 53 years

3.The costs of the combined system are not elaborated, because the costs will be significantly higher then the other two systems. The grey water system provides the total water needs. The combined system will not provide additional savings.


Figure 2: Grey water system Group 1 Nynke Lof s1232452 & Liza Hodenius s1211765

We may conclude that the three systems are not profitable for an average household (e.q. 4 persons) in terms of costs.The elaborated systems are more suitable for companies like hotels or apartment complexes. For those who don’t care about the costs, but do care about the environment, these systems provide a decent solution.

Project DMS - An Intelligent System to Reduce Energy Consumption For Homes  

In project DMS diende een ontwerp gemaakt te worden voor een systeem dat het energieverbruik in een huis op een intelligente manier weet te...

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