Wind Energy Magazine 2020 01

#1

Volume 7 March 2020

energy magazine

Rotor blades Optimisation for improved turbine performance

Interview Pure Energie

Rotor blade optimisation

Financing wind

The development of wind projects on land is much more an organic process than offshore. Renewable energy developer Pure Energie explains. u 06 - 09

Rotor blades have long been an undervalued part of a wind turbine.

Their quality, however, impacts the wind turbine performance. u 25 - 36

Rabobank - Project Finance shares their vision on subsidy-free tenders + how can citizens participate in wind? u 12 - 21

We know which way the wind blows.

ENVIR Advocaten is the expert if it comes to wind energy projects, whether it concerns permits or administrative proceedings. Together with our clients ENVIR Advocaten creates a fast, efficient and uncomplicated permit process.

We combine our expertise and experience for clear analyses and practical solutions, so together we achieve the best result.

ENVIR Advocaten The specialist in environmental law and administrative law

www.envir-advocaten.com

Editor’s note

The ‘weakest link’

W

hen you attend the many wind energy related networking events, you notice how thriving this Dutch industry is. It is therefore sometimes hard to imagine that with all our expertise in almost every aspect of wind energy development and in technology and innovations, the Netherlands is ranked last on the list of EU countries when it comes to the share of energy from renewables.

The Netherlands has a catching-up to do and it knows it by now. The 2019 Climate Agreement provides a clear strategy to combat climate change by reducing CO2 emissions with 49% by 2030 compared to 1990. Wind energy, both onshore and offshore, will contribute significantly in achieving this ambition. The production of electricity from offshore wind is set to increase to 48 TWh and onshore to 39 TWh by 2030.

34 Rotor blade inspection

The Regional Energy Strategies (RES) ensure that it is not just a playing field for commercial players. Required citizen participation must ensure that the local community also benefits directly from the renewable energy projects that are being built in their ‘backyards’. But when you are a developer, what is the best participation strategy for your project? Or for the politician who is responsible for the RES in his municipality? Wind Energy Magazine spoke to renewable energy developer Pure Energie and Leon Pulles, an advisor on this topic.

While onshore wind developers and local and regional politicians are dealing with this topic, offshore it seems to become less of a necessity as the future wind farms will be built further from the coast. The timeline and rules for offshore wind projects are quite clearly defined for the coming years and the cost of offshore wind energy is dropping beyond expectation, to the point that the last tenders resulted to be subsidy-free.

But, how long will this last? What if the steel and interest rates rise again? We asked the Project Finance department of Rabobank responsible for renewable energy financing.

A main part of this edition is focused on rotor blades, an essential but at the same time very sensitive component (or weakest link) of a wind turbine. We have invited a few Dutch players to share their view in the area of maintenance and inspection, blade to hub connection, and the afterlife of rotor blades, amongst others. These are just a few examples of Dutch expertise and innovative entrepreneurship in this area. While the focus here is on the quality of the rotor blades mainly, there are more activities related to rotor blades that remain undiscussed, such as the installation techniques.

This, we save for the next edition, out in September!

‘What is the best participation strategy?’

Sabine Lankhorst Editor in Chief Wind Energy Magazine presswem@vakbladen.com

01-2020 | 3

Contents

Interview Pure Energie

06

Rabobank - Project Finance

18

Theme: Rotor blades 26

We4Ce Root Bushing Solution Boltlife’s blade to hub flange connection methodology

28

Kader - Proper blade maintenance for optimal turbine performance

30

Alternatives on afterlife use of amortized rotor blades

34

Cross-sectoral collaboration for innovation & automation

36

Also in this edition: Citizen participation in the energy tranistion

12

Winner Offshore Wind Innovation Challenge 2019

38

Regular features:

Cover The rotor blades for Gemini OWF © Gemini

Onshore Wind Farm News

10

Wind Statistics

15

Column: ENVIR Advocaten

17

Offshore Wind Farm News

22

Column: ECN

25

General News

40

Agenda

42

24 -36

Theme: Rotor blades

Colofon

energy magazine

Editor in Chief: Sabine Lankhorst

Subscription service: Mijntijdschrift.com Curieweg 16 8013 RA Zwolle Tel. +31 (0)88 22 666 80 E-mail: abonnementen@vakbladen.com

Contributors to this edition: Peter Eecen, Benno Boeters, Mischa Brendel, Erick Vermeulen, Edo Kuipers Martijn Koelers, Iref Joeman

Subscription fees, annual: The Netherlands/Belgium: € 40 (incl. VAT) EU & ROW: € 60 (incl. VAT)

Cover image: The rotor blades for Gemini OWF © Gemini

Subscriptions may start at any moment and will be automatically renewed after a year. Subscriptions can be cancelled two months prior to the end of the subscription period.

Website: www.windenergie-magazine.nl www.windenergie-nieuws.nl

VOLUME 7 | MARCH 2020 | ISSUE 01 Wind Energy Magazine, a trade magazine for professionals who are involved or interested in onshore and offshore wind energy developments in the Netherlands.

Publication: Wind Energy Magazine is published twice a year.

Publisher: Rik Stuivenberg Publishing company: Vakbladen.com Enthovenplein 1 (5th floor), 2521 DA Den Haag, the Netherlands PO box 19949, 2500 CX Den Haag, the Netherlands

4 | 01-2020

Advertising: Archer Media B.V. Jos Raaphorst, account manager Tel. +31 (0)88 22 66 682 E-mail: j.raaphorst@archermedia.nl Artwork: Archer Media B.V. E-mail: traffic@archermedia.nl

ISSN 2352-7560 Copyright © 2020 Vakbladen.com The publisher does not necessarily agree with the views expressed by the contributors, nor does he accept any responsibility for any errors of translation in the subject matter of this publication.

No part of this publication may be reproduced and/

or published by means of print, photocopy, microfilm or any other medium, without the prior written consent of the publisher.

Personal data: Wind Energy Magazine records reader data for the purpose of distribution of the magazine. These data may be used to inform you about our other services or products.

Design: Content Innovators Printed by: Veldhuis Media, Raalte

12 Citizen participation in the energy tranistion Citizen participation is made a requirement in the Regional Energy Strategies.

It should help gain more social acceptance for future onshore wind projects. What are the best strategies?

06 18

The development of onshore wind projects is an organic process What started with a single turbine on a farmer’s grounds in Zeewolde, Flevoland, developed overtime into a mature company that currently owns and operates 70 wind turbines located all over the country, has another 60 granted, and now also develops solar energy. An interview with renewable energy developer Pure Energie.

Interview with Rabobank - Project Finance Rabobank has been a front runner in financing large wind farms. Pieter Plantinga and Marc Schmitz of Rabobank - Project Finance look back on their experience so far.

38 25-36 Rotor blades Rotor blades are a vital component of a wind turbine. The quality of a rotor blade has direct impact on the efficiency of the turbine output. Rotor blades are also one of the most sensitive components which come with many challenges.

Noise barrier with air bubbles for piling activities Marine Performance Systems develops a system with air bubbles that absorb and reduce noise. In December 2019, the company won with its concept the 2019 edition of the Offshore Wind Innovation Challenge.

01-2020 | 5

Interview

Sabine Lankhorst

Developing wind onshore is an organic process

In 1995, Dutch entrepreneur Alfons Wispels founded Raedthuys to develop onshore wind energy. What started with a single turbine on a farmer’s grounds in Zeewolde, Flevoland, developed overtime into a mature company that currently owns and operates 70 wind turbines located all over the country, has another 60 granted and now also develops solar energy. Last year, all business activities were united under one single brand; Pure Energie.

Pure Energie 6 | 01-2020

De Veenwieken Wind Farm, all photos, courtesy of Pure Energie

W

ind Energy Magazine spoke to Pure Energie’s director wind energy Arthur Vermeulen at the office in Enschede. In his role, Vermeulen is involved from the start, when a project is still an idea, up to the moment financial close is reached and construction can start.

He has been working in onshore wind for 27 years now, of which 16 years at Pure Energie and as such has witnessed from close-up how the onshore wind industry has developed ever since joining the company in 2004. Joining him at the table is communication officer Matthijs Oppenhuizen.

Back in 1995, the type of wind energy development depended on the policy by each municipality. In Zeewolde there was a favourable policy for solitary wind turbines on agricultural grounds, explains Vermeulen. The idea was to finance the wind turbine with capital from private individuals who would together own the wind turbine. For farmers this was not their core business therefore they asked parties like Raedthuys to manage the process and build the wind turbines. The first wind turbine was installed two years later, in 1997. In the eastern part of Flevoland, the policy was more favourable towards clustered wind turbines in line position and further away from residencies.

Vermeulen: “When the financial participation periods came to an end, the company started to take ownership of the turbines and exploit these themselves, thus becoming an utility also.” The produced power was sold at the energy market (APX). Eight years ago the company started selling electricity directly to end users also. This business unit was branded Pure Energie. In 2019 the decision was made to unite all business activities under this name.

Organic process Developing wind energy projects in the past was still a pioneering activity. Vermeulen elaborates: “At the start of this century there was no real local or provincial land-use planning. We just went out there and looked for possible locations and started talking to the local politicians to get their permission. In general we received more no’s than a yes.”

these requirements can change every four years when new elections take place.” Vermeulen agrees: “It is much more an organic process.”

Both men also agree that it is not always easy for local politicians.

Vermeulen: “They need to serve the local interest but at the same time decide on a project that serves a global interest.”

Oppenhuizen elaborates: “In the eyes of a local community, three wind turbines might already seem a large project but on a national or global scale this is just a tiny contribution to the sustainability targets. This brings along quite a dynamic.”

He provides the example of the wind farm De Veenwieken in the province of Overijssel where a height limitation of 150 metres was set to answer to the wishes of the community who wanted turbines without lights. As a consequence, it was not possible to use the full production potential for the location. “You are basically moving the problem to another location as the ‘lost’ capacity would still be

‘We should stop talking about megawatts. Metres, that of the hub height and rotor diameter, not megawatts determine the output’ installed somewhere”, he says. Vermeulen adds that in Emmen the company even withdrew a plan for a wind farm. Here the council also did not allow for wind turbines with tip heights above 150 metres. “With the decreasing trend of the SDE, unfortunately this meant that our business case would become unviable”, he explains.

Political clarity and consistency

At some point the objective by the national government was formulated for 1,500 megawatts of onshore wind energy by 2010.

Provinces slowly started to pay attention. However, it only really became part of their agenda in 2013, when the Energy Agreement was formulated, requiring 6,000 megawatts by 2020. The target was divided amongst the provinces who each started to formulate their land-use planning policies to facilitate this.

Vermeulen: “For a project to succeed it is very important that the responsible politician, like the alderman in the municipality, firmly supports the project and sends a clear message to its community as to the why. It is okay to take the time to properly prepare the environmental research before starting the formal process. It is also a good thing that citizens are given a formal saying, this is part of our democracy which we should treasure. However, there is too much time wasted on political bickering and this is in no one’s interest. It delays the project and creates unclarity.”

“Our search area became more defined now”, said Vermeulen, “we would either approach owners of parcels that were identified for potential wind energy development or the other way round; these landowners approached us to help them develop.” This does not mean that it is always easy to start developing projects.

Oppenhuizen explains: “Whereas offshore there is currently one policy for developing wind and a more clearly stipulated process to realise it, onshore this can vary with each municipality. Each can have different requirements with regards to tip height limitations, minimum distances from the built environment, the type of citizen involvement and requirements for financial participation. Also,

“The average lead time is ten years. This could also be four years”, he continues. He provides the example of the Drentse Monden en Oostermoer wind farm that has already been going on for twenty years. “The first ten years the initiative was put on hold due to lack of political will. Both province and the municipality were looking at each other”, he explains.

Oppenhuizen agrees: “There should be quicker decision making and when a decision is made then stick to it.” The Elzenburg-De Geer wind farm, near Oss, is a good example where the municipal council has, in his opinion, done everything well. “They were meticulous and clear and just set out to do it as initially planned.

01-2020 | 7

Interview

This provides more peace for everyone involved. And it worked, there were hardly any appeals.”

The discussion should also be more qualitative. Vermeulen: “We can see it with the RES (Regionale Energiestrategie). Often the ambition for the energy transition is there with the municipal councils. They set very ambitious targets but then don’t always know how to proceed. The frameworks in the RES are not always fitted. When it already goes wrong at the basis, then you are off to a poor start.”

“They often have never dealt with wind turbines before, and that’s no blame on them. Most people never dealt with wind turbines before. We on the other hand have been doing this for 25 years”, he says, “we know what we are talking about. Come and talk to us.”

Oppenhuizen agrees: “They are often hesitant because we are a commercial player but in practise sometimes the participating parties end up contacting us one by one with questions anyway.

Why not invite us at the start, even if it is just over coffee!”

Well-informed citizens Vermeulen and Oppenhuizen think that if politicians show more firm support to a project and are better informed then this could also help the local community to understand wind energy better and possibly take away some of the objections towards it.

Vermeulen: “It’s a shame that we cannot always use the full potential of a project location as it also means that the revenue is lower. Revenue that could have been used for the community.”

He refers to the general thought that bigger turbines mean more impact. “In practise it doesn’t really matter for your experience whether you see a wind turbine with a tip height of 150 or 200 metres. In fact, larger turbines are in general more modern and have less noise impact. For cast shadow the rules dictate a restriction of 6 hours per year. This remains the same however many turbines you place or how ever tall they are.”

Another misunderstanding, according to Oppenhuizen, is that one megawatt solar energy equals one megawatt wind energy. “We should stop talking about megawatts. In fact, metres, that of the hub height and rotor diameter, not megawatts determine the output. And it is the output that is the most important factor now that the SDE is getting lower!” he says. He illustrates this by referring to the Kloosterlanden and De Veenwieken projects. “In both locations we installed 2.35 MW turbines but at De Veenwieken they are 20 metres higher so the output is higher.”

Citizen participation Participation of citizens in a project is seen as a way to gain more social acceptance for the project. In the RES it has even become a requirement. The Kloosterlanden project in Deventer, consisting of two wind turbines which became operational in 2015, was Pure Energie’s first real project with an energy cooperative. Here the

8 | 01-2020

cooperative, Deventer Energie Coöperatie, owns 25% of the project. Since then, the company always works together with energy cooperatives when developing new projects. They have a strict policy on this; the risks should be evenly spread so participation should take place in all phases.

Having an energy cooperative on your side makes the meetings with the councils more easy and provides a higher chance of success, explains Oppenhuizen. “I don’t necessarily believe that involving an energy cooperative shortens the development process or makes the project less expensive. However, offering the local community the possibility to financially participate could, besides financial gain, lead to an increased feeling of involvement in the project. Also, as an outsider we have little to none understanding of the sentiments within the community so working with a local partner helps.”

The idea of working with other parties is not entirely new to the company so the switch to the participation model was a swift one.

Vermeulen: “When you look at it, the foundation for citizen participation was already laid with the first wind project in 1995.

Although, back then, the reason for participation was different, pure economical, and not yet per se as a means to engage the local community. The private investors were not yet organised and did not have to be from the local community.“ The real turn towards this model came when they won a tender for the development of one wind turbine in Den Bosch, he says. Here the council required that local citizens could participate financially and the generated electricity to be used locally. “We offered a wind bond, something we had already been thinking about for a while.

That was actually the birth of the wind bond in the Netherlands”, he explains. From that moment on this became the blue print for developing their wind energy projects and this was copied by the market also.

2020 activities In the next few years Pure Energie will add 60 more turbines to its portfolio. In 2020, the Deil Wind Farm along the A15 will become operational. Here, Pure Energie owns two of the eleven turbines.

Construction work will start in the wind farms Drentse Monden en Oostermoer (12 turbines), Weijerswold (2 turbines), Bijvanck (4 turbines) and Rietvelden (3 turbines), and possibly the company will receive the definite permit for the Koningspleij project in the first half of this year. Oppenhuizen: “At the moment we have a 250 GWh/y production volume. We received permits for 9 projects with a volume of 900 GWh/y, of which 400 GWh/y for the Windplan Groen wind farm, so we are multiplying our volume four times.”

Just before the end of 2019 the company announced a cooperation with an energy cooperative; ‘LochemEnergie’. “We will continue to look for new partnerships throughout 2020”, he adds.

Aerial view on the 2 turbines in Deventer 01-2020 | 9

Onshore

Wind Farm News

Haringvliet Zuid © Eneco

6

Nij Hiddum-Houw

1

1

Nij Hiddum-Houw Gooyum Houw BV and Vattenfall received green light for their repowering project near the Afsluitdijk, in the municipality of Súdwest-Fryslân.

The current wind farm Nij Hiddum-Houw has been operational since 1995. The 10 Vestas turbines (7 owned by Vattenfall and 3 by Brouwer Windturbines B.V.) with a total installed capacity of 5 MW, are being replaced by 9 larger, more powerful turbines. In addition, 6 nearby located solitary turbines are being dismantled. The new combined installed capacity is 42 MW.

2 Waardpolder All 6 wind turbines in Waardpolder Wind Farm, located in the municipality of Hollands Kroon, are operational. The wind farm is a project

by WP Energiek. It concerns a repowering project whereby the original 19 wind turbines were replaced by 6 modern, more powerful models. Until recently, the wind farm comprised of 19 Nedwind turbines with each a rated power of 250 KW/h. The construction of the six wind turbines was completed in November 2019.

The new turbines are from Nordex. These turbines, type N131, have a hub height of 120 m, a rotor diameter of 131 m, and a rated output of 3.6 MW.

10 | 01-2020

this future wind farm will be the company’s biggest onshore wind project. The wind farm will be built on top of a flood defence in the Maasvlakte 2 industrial area and will generate around 416 GWh of green power. Eneco expects to start the preparatory works for the construction in 2022 and complete the wind farm in 2023. Rijkswaterstaat will purchase the generated electricity under a 25-year PPA.

5 3 De Drentse Monden en Oostermoer The 175.5 MW De Drentse Monden en Oostermoer Wind Farm reached financial close at the start of 2020. The initiators are Duurzame Energieproductie Exloërmond BV, Windpark Oostermoer Exploitatie BV, Pure Energie and De Windvogel. The wind farm will feature 45 Nordex N131/3900 turbines, to be installed in 6 linear positions.

Each has a rated power of 3.9 MW, axis height of 145 m and a rotor diameter of 131 m.

Agreements have been made between the initiators and ASTRON, the owner of the nearby located LOFAR telescope, to reduce the amount of EMC radiation with 35 dB compared to the norm. A first turbine was installed in August 2019 to perform tests. The tests were successful. The project in the municipalities of Borger-Odoorn and Aa en Hunze will be completed in 2021.

4 Maasvlakte 2 Eneco won the tender for the Maasvlakte 2 wind farm. With a capacity of around 100 MW,

Westersepolder Construction activities are ongoing in the onshore wind farm Westersepolder, located near Numansdorp, in the municipality of Cromstrijen.

The 7 original turbines with a combined capacity of 3.5 MW are being replaced by 5 Enercon E-126 EP 3 turbines with each a capacity of 4.2 MW. Westersepolder wind farm has been operating for almost 20 years. The project is an initiative by Investment Engineering Projects and is expected to become operational this summer of 2020.

6 Energiepark Haringvliet Zuid Vattenfall is currently building a 54 MW energy parc in the Van Pallandtpolder in Haringvliet, near the town of Middelharnis. The energy project will feature 124,000 solar panels in an area of around 30 hectares and 6 wind turbines.

Also included are 6 batteries, combined the size of a sea container, for energy storage.

In the first half of February the installation of the first of 6 Nordex N117/3675 wind turbines was completed. Vattenfall reached financial close at the

end of 2018. The first preparatory work started early 2019.

Completion of the full project is planned for late 2020.

7 Piet de Wit Early February, De Plaet BV, a joint venture of Promill BV and Cooperatie Deltawind, received green light for the repowering of a wind farm near Ooltgensplaat in the municipality of Goeree-Overflakkee that has been operating since 2003. The 12 old Vestas V66 wind turbines will be replaced by 7 more powerful ones that can have a maximum height of 150 metres. The initiators are currently in the process of selecting the turbine supplier.

The wind farm is expected to become operational sometime in 2021. By replacing the old turbines, the capacity will rise from 24 to 30 MW.

8 Egchelse Heide At the end of January the wind farm Egchelse Heide, located in the municipality of Peel en Maas, received green light.

The wind farm is an initiative by energy cooperative Peel Energie and local farmers and will feature 5 wind turbines with a maximum height of 210 m. Financial close is expected in the summer. The turbines are likely to be installed early 2021 and will start generating power in Q2 of 2021.

Egchelse Heide© Pouderoyen.nl

1

3 2

4

5

6 7

8

Read the full news on www.windenergymagazine.com (EN) or www.windenergienieuws.nl (NL)

01-2020 | 11

Interview

Sabine Lankhorst

Citizen participation in the energy transition

Finding the right strategy for participation The Netherlands, albeit with a delay, is taking steps in the energy transition.

Wind, both onshore and offshore, is a large driver in the transition and many gigawatts of it will be needed. Especially onshore, social acceptance is vital in ensuring that these megawatts will be realised. So vital that local participation has been included as a requirement in the Regional Energy Strategies.

W

ind Energy Magazine spoke to Leon Pulles, managing partner of Energy Investment Management BV who advises sustainable energy developers in setting up participation strategies for

their projects.

Pulles: “The Netherlands has waited for a long time before starting the energy transition. People were in general not really engaged in energy matters.” As the pressure grew from the European Union, something had to be done. That’s when the government introduced the SDE subsidy scheme. Things started speeding up and the number of wind and solar farms were rising.

Not long after, the energy transition became a more frequent topic on the news and people were actually starting to look at their energy bills. People started to have an opinion on the subject, not always positive. In addition to the ‘Not in my backyard’ sentiment, there was also another sentiment growing, that our country was too small to make a difference. Is it worth spending that much money on the energy transition?, he explains.

‘With each project you will need to identify what type of participation is most suitable’ 12 | 01-2020

Topic at birthday parties “We all benefitted from the industrial revolution, we should now not walk away from our responsibilities in the energy transition”, Pulles says. Getting people involved could create broad support for the energy transition. He mentions Stephanie Platschorre from the Erasmus University who performed a research on what motivates people to financially participate in renewable energy projects through crowdfunding. [1] Her research showed that few people are really consciously involved.

It is therefore advisable for developers to engage the community in their project as soon as possible, especially when the project is planned in a challenging surrounding, he says, “go talk to the local people, explain them your plans and talk them through the different phases of the project. When possible, take them to a comparable project. Let them, within certain set boundaries, have a saying and ask them how they would like to participate.”

Getting citizens involved in an energy project is not entirely new.

He provides an example of a critical project that was handled adequately in his opinion. He refers to the case of waste disposal company HVC in the eighties. In the province of Noord Holland dioxin was encountered in the milk. The root was traced back to the waste disposal company of HVC. This was very much a major issue in those days. In the end, HVC wanted to build a new factory that would comply to the new regulations imposed. They went into a dialogue with the people in the neighbouring area in

Stephanie Platschorre, Leon Pulles and Noortje van Heijst

order for them to gain trust in the new factory. Small testing grounds were created for free to monitor and measure the dioxin level. These became the ambassadors for the project.

Pulles also provides an example of a wind energy project in Harderwijk in which he is currently involved. This project is being developed by the municipality itself. Here the municipality asked high school youngsters to share their thoughts on setting up a fund. In this so-called ‘Wind challenge’, three teams of each five youngsters created interesting concepts. Pulles: “They took their task very seriously and came up with some good ideas. During the development of the wind energy project some people actually stood up and became involved, including influential people in the community. These people should be involved in the entire process, as ambassadors!”

Informing and involving people will provide a clearer picture of a project. In the most positive case, people will get involved or otherwise become neutral. “Find ambassadors who will share the message”, he says, “it should become the topic during birthday parties!” Of course, you will always have people who remain negative, he adds.

Participation options Having the local community involved is not only advisable, since the introduction of the Regional Energy Strategies (RES) as part of the 2019 Climate Agreement, it is now also a requirement. The RES dictates that all new renewable projects require 50% local participation.

There are several options for developers to execute this, directly by offering shares or loans, or indirectly by setting up a sustainability fund whereby part of the revenue from the wind farm is reserved for green initiatives that improve the local community, or providing other local benefits.

People participate for different reasons. Pulles refers again to the study by Platschorre. Her research identifies several motivations for people to participate, one of them being financial return, of at least a 6, 7 % on the investment. Another motivation is to witness the social or sustainable impact of their financial participation. In addition, it is also often seen as a way to learn new things.

“Therefore, with each project you will need to identify what type of participation is most suitable. Is the project going to be located in a densely or sparsely populated area? What is the financial capacity of the local population? How strong is the sense of community identity?” he explains.

In the Harderwijk case, the community was initially provided four participation options; shares, loans, sustainability fund or discount on the energy bill. Here, the collective was given priority over individual benefits and the choice was made for green initiatives via the sustainability fund.

In the case of the onshore Krammer Wind Farm, in the province of Zeeland, participation took place through crowdfunding. This was a logical step as the initiators of the wind farm were citizen cooperatives. They already had a large support base through their members. Within a short period of time ten million Euro was raised.

Pulles was also involved in the Westermeerwind project. Here, the community participated for a total of more than nine million Euro

Opening Krammer Wind Farm 01-2020 | 13

in equity and loans. “We were expecting, based on questionnaires earlier on in the project, that there was much more interest in shares than loans. This demonstrates that people only really decide when the moment is there.”

Poster announcements for financial participation and sustainability fund

Financial participation With regards to financial participation, Pulles thinks the wind energy industry had to get used to this becoming part of the business case. “It seems like players in the solar energy industry are more entrepreneurial in this field. Perhaps it is because wind has been there for much longer. In solar, most players are relatively new and are used to this concept from day one.”

“In onshore wind energy development the main theme is social acceptance. That is already an important driver to make participation part of your project. Financial participation is a good way to do so. Of course you need to look at each individual project but in seventy percent of the cases, it works. The question then rises; what do you want, as a developer, to share from your business case point of view?”, he explains.

Participation generally takes place when financial close is reached, shortly before the construction starts. That is when the definite financial budget is determined and estimations can be made on the returns in participation. From a project developer point of view you would like it to be the sooner the better as the project development, the period up to financial close, could easily take between six to ten years for wind energy projects, says Pulles. “In the case of the Westermeerwind project, the initiators of the project wanted to have local participation to be introduced sooner in the project, however the banks involved required the project to become operational first. “This created a tension field”, he adds.

Participation in an early phase is possible, according to Pulles.

However, it is not possible to determine an interest rate because there is no definite budget available yet. There is also the risk factor. “People get their returns when the wind farm is operational, at an early stage you cannot set that moment in stone.

‘Financial participation should not be a stand-alone act’ 14 | 01-2020

It is however the right time to already start talking to the locals because financial participation should not be a stand-alone act”, he says.

There is also the discussion on the height of participation. Especially from the point of view of an Alderman of the municipality he would ideally wish for people that are less financially capable to be able to participate also. In that case, a sustainability fund in addition to financial participation via equity and loans would be the best option.

Future outlook Pulles is convinced that financial participation will occur more often, especially with the RES, and developers will be smart enough to do so. People will also get more used in participating in wind energy projects. Solar energy projects are less complex than their wind counter parts and are developed quicker. People tend to understand solar energy better and are more likely to accept and participate in these projects, he says. “However, they do not always understand that, for example, a four megawatt solar project is not the same as a four megawatt wind project. I also don’t think they quite realise how many solar fields will be realised in the next few years. The last SDE+ rounds showed more solar applications than wind applications, I wonder how they will feel about solar energy when all these projects are realised”, he explains.

We also have to wait and see how the SDE++ will develop and how the energy transition will take shape, he thinks. “With the SDE+ scheme, we were able to look ahead twelve to fifteen years.

In this scheme, banks are generally involved one or two years less than the SDE period. It is hard to say how this will be with the SDE++, and possible other future arrangements”, he explains.

And there is the human element, what will happen if people have been participating for a long period of time. What kind of returns will they expect? It is very important that the renewable energy sector tries to involve as many as possible citizens to create understanding and support for the Dutch energy transition.

1. Research was based on interviews and questionnaires among Oneplanetcrowd.com en Crowdfundmarkt.nl crowdfunding platforms.

Statistics 20 2005 2010 19

Sustainable development made easy Do you want to make an entry into the Dutch

Wind energy installed power in the Netherlands

wind market or are you simply interested in keeping up to date on what wind farms are being commissioned in the Netherlands?

! (

Commissioned in 2019

Subscribe to the WindStats database!

Call us for more information: +31 88 22 66 682

441 MW

or e-mail: presswem@vakbladen.com

197 MW

WIND ENERGY in the

! (

NETHERLANDS

!! ! ( ( ( ! ( ! (

2019 in review

! ( ! (! ! ! ! ( ( ( ! ( ! ( (

31 MW

! ( ! ( ( ! (

! ( ! ( ! ( ! (

ONSHORE 3.552 MW (+192 MW)

! ! ! ! ( ( ( (! ( 341 MW 1147 MW

! ( ! (

67 MW

OFFSHORE 957 MW

( !

34 MW

TOTAL 4.509 MW 2.307 wind turbines

! ( ! ( ! ( ( ! ( ! ! ( (

! ( ! ( ! (

87 MW

441 MW ! (

! ( ! ! ( (

! ( ! (

! ( ! (

239 MW

! ! ! ( ( (

516 MW Commissioned in 2019 MW wind turbines Drenthe 10 3 Flevoland 14 7 Gelderland 4 1 Noord-Brabant 27 7 Noord-Holland 91 38 Overijssel 30 13 Zeeland 14 6 Zuid-Holland 110 28

SOURCE: WWW.WINDSTATS.NL

WindStats

© WindStats.nl 2020

12 MW

�e increase in installed power in 2019 was higher than last year, even though 109 MW was decommissioned. �e largest new wind farms are Slufter 2 (Rotterdam, 50 MW), Waardpolder (Hollands Kroon, 22 MW), Spui (Hoeksche Waard, 21 MW) and Nieuwe Waterweg (Rotterdam, 21 MW). �e end of the year saw the start of construction of some large wind farms, notably Wieringermeer, Drentse Monden Oostermoer, Veenwieken and Deil). �ese will be commissioned in 2020 or 2021.

over windenergie in Nederland

01-2020 | 15

STAY UP TO DATE WITH THE DUTCH WIND ENERGY INDUSTRY energy magazine

• • • • • • • •

ON & OFFSHORE WIND LARGE-SCALE PROJECTS COMPANIES & ORGANISATIONS INNOVATIONS TENDERS & SUBSIDIES RULES & LEGISLATION INTERNATIONAL PRESENCE & COLLABORATION WEEKLY NEWSLETTER

WINDENERGY-MAGAZINE.COM

PREFER THE NEWS IN DUTCH? WIND ENERGIE NIEUWS • • • • •

ON & OFFSHORE WIND INTERNATIONAL NEWS LARGE & SMALL-SCALE PROJECTS COMPANY DIRECTORY WEEKLY NEWSLETTER

WINDENERGIE-NIEUWS.NL

SEND YOUR NEWS TO PRESSWEM@VAKBLADEN.COM

Column

Erwin Noordover Lawyer at ENVIR Advocates

Is financial participation the holy grail for public acceptance of wind farms?

N

ow that the spectre of negative interest rates on savings accounts is haunting us, we are looking for investment opportunities for our savings. The energy transition provides opportunities for this as various governments offer frameworks within which citizens must be given the opportunity to participate financially in wind farms.

One example is the province of Flevoland, which in its environmental regulations has set requirements for financial participation in wind farms. This includes offering the opportunity to participate financially in the project on a risk-bearing basis, based on a minimum of 2.5% of the initial total investment volume in the operational phase. However, this principle may be deviated from if the developer can demonstrate that there is insufficient interest in participation. These requirements for financial participation force developers to reach out to the public. At the same time, the government’s requirements for financial participation should not jeopardise the business case. Fortunately the Province of Flevoland has included an exception if insufficient money can be raised from the surrounding area.

A great deal is also expected of financial participation for the public acceptance of the energy transition for which the Regional Energy Strategies are now being drawn up. A guide for participation in sustainable energy projects has been published with guidelines for participation in wind projects. Participation is herein tailor-made and the competent authority checks whether the conditions for participation have been met.

Can the requirement to offer financial participation be taken into account when deciding on a zoning plan?

In view of the importance that local authorities attach to financial participation, the question arises as to whether this participation may be conditional for the cooperation with the development of a wind farm. Can the requirement to offer financial participation be taken into account when deciding on a zoning plan? It is doubtful that financial participation is a spatially relevant aspect, as it does not affect the environment.

But can the municipal council then state that the effects of a wind farm on the environment are only acceptable if the opportunity to participate financially was sufficient? This seems to be odd reasoning: the effects of a wind project are no different, but because there is a financial involvement of (part of) the surrounding area with the project, these consequences have become acceptable.

If offering sufficient financial participation becomes a criteria for cooperation with a wind farm, the risk arises that a developer with deeper pockets or a specific business case will be preferred over other initiatives, even if those other initiatives are a better option for the energy transition or the environment. Hopefully the focus on financial participation will not lead to an inappropriate balancing of interests and only helps with the public acceptance of the much needed development of wind farms.

01-2020 | 17

Interview

Sabine Lankhorst

Interview with Rabobank- Project Finance

‘Do you really want to risk companies supporting the industry to go bankrupt and lose thousands of jobs?’

Financing wind projects in rapidly changing times When the first offshore wind farm was built in Dutch waters, no one at that time would have been able to foresee how quickly the price per megawatt hour would drop. Neither did the Rabobank. A conversation with Marc Schmitz and Pieter Plantinga, managing director and executive director respectively at Rabobank’s project finance department, responsible for renewable energy financing.

18 | 01-2020

Marc Schmitz

Pieter Plantinga

Prinses Amaliawindpark © Eneco

D

uring the interview at their office in Utrecht it became instantly clear that both men have been working together for quite some time, ever since Plantinga joined the project finance team at Rabobank in 2009. Schmitz was at that time already working for the team since 1999. Prior to this, he worked for Vattenfall (back then Nuon).

refinancings. In the Netherlands, we were involved in the first offshore wind farm to be financed through project financing globally. In Belgium, we have been involved in all the offshore wind farms. Furthermore, we have also worked on a large number of German projects, the first French project, and on one in Taiwan. The latter, together with our team in India. Many of the companies involved in Taiwan are European so it made sense.”

Their project finance team handles all large renewable energy projects in Europe with a debt amount of at least 25 million Euro.

These projects include mainly solar, onshore wind and offshore wind. Other renewable energy projects, such as biomass, heat, and bio fermentation, are also dealt with within the team by separate specialists in this area of expertise.

Plantinga: “In the onshore sphere we worked or work on several large wind farms, including, NOP Agrowind, Krammer, Vermeer and Drentse Monden.”

How do you look back on your cooperation so far?

Schmitz: “Pieter and I built this department in Europe to what it is today. When he joined in 2009, our renewables team consisted of seven people, now we have a team of around twenty people. In addition, Rabobank has teams in India, covering renewable energy in Asia, and in the US.” Plantinga: “It was necessary to upscale and create the large, solid team as we have today. The wind energy market has matured, with more complicated structures. There is more market price risk involved now.”

Schmitz: “I remember the first wind project I worked on. These were 1.65 megawatt turbines near Muiden. Look at the sizes of the turbines now. We have in the meantime worked on around twenty offshore wind energy projects, almost thirty if you include the

Schmitz: “We are also active in Spain, the Nordic’s, recently the UK and Ireland again, and we are currently looking into the Polish market. Amongst these are more challenging markets due to newer structures with corporate PPA’s, including some market price risk.”

The Netherlands is also developing more large onshore wind farms. Is there a huge difference in the process between onshore and offshore?

Plantinga: “Although the type of financing is similar, the parties you work with are different. Offshore is very capital intensive and therefore there are larger and generally more professional sponsors in a single project. These sponsors tend to develop multiple similar projects, they know what we need from them. This market is more consolidated. Onshore, many of the old projects have been long term developments by farmers in the Netherlands. These have generally never developed a project before and will most likely not do this again. On average, only one out of three onshore projects being developed will be realised.”

01-2020 | 19

‘Onshore, you also have to deal with a legacy’

“Onshore, you also have to deal with a legacy. In the early days developers did not really involve the local communities. You can see the effect of it now in some parts of the Netherlands like Drenthe. This is something which needs to be addressed more and more consciously by developers in the early stages of project development. The Krammer project in the province of Zeeland is an example of how it should go, with the right set of shareholders and local participation.”

Plantinga agrees: “Another difference between us and the larger players is that they often use external advisors. We are more used in serving the entire market, especially in the Netherlands. Here we work together with the customer to set up the financial structure for their project, therefore each project is unique.”

Onshore there are already challenges in connecting new projects to the grid. Does this affect your business case?

Schmitz: “Project finance is quite straight forward, you finance a single asset with clear fund flows. With companies the money flows in all directions. With projects a technical advisor approves each drawdown based on actual progress of works. It is therefore easier to control. We have had an experience once where a project went way over budget. It then becomes a play between the banks and shareholders. In practise the shareholders will have to contribute more to the budget as they can’t risk losing the project to the bank.”

Plantinga: “Not in the sense that we simply don’t finance a project if the connection is not guaranteed. However, we now see private initiatives coming in who want to realise the grid connections.

We are following this development and are investigating if we could finance these.”

How is your team positioned in the international playing field of project financing wind energy?

Schmitz: “Rabobank is a niche player but definitely a front runner in our field. For a long time we were the largest project financer of renewable energy projects in the US. In offshore wind we were involved in one of the first offshore wind farms in 2006, Q7, now called Prinses Amaliawindpark. In 2007 we helped finance the first Belgian offshore wind farm C-Power. Keep in mind that offshore wind only really became popular in 2015, so we were almost ten years ahead of our time! In Scandinavia we were also one of the first to accept market price risk. We are involved in eight projects there.

The project finance department of Rabobank excels in financing projects with a value between 100 and 500-600 million Euro.

When it comes to project values of two, three billion Euro there are other players who are better equipped.”

20 | 01-2020

Have you ever experienced a situation where a project went too much over budget?

Plantinga: “In addition, each project has a contingency for unexpected costs. However, I once worked on a project that went way over budget. One of the suppliers went bankrupt and could, as a consequence, not deliver the components. This had a ripple effect on the entire construction schedule. It required a tremendous effort from all parties to restructure the project!”

How important is sustainability for Rabobank?

Plantinga: “Sustainability has come higher and higher on the agenda of the bank over the past years. And we are asked to do more in this sector.”

Schmitz: ”We actually already tried to push this many years ago but Project Finance remained under the radar for a while, amongst others due to the high capital requirements and long term debt in renewable projects.”

Westermeerwind Wind Farm. © Westermeerwind

The subsidy-free offshore wind tenders of lately are welcomed by many. Do you share this feeling?

Schmitz: “In 2011, Rabobank, together with Bloomberg, published a study titled ‘Reaching the ten cents per kilowatt hour’.

The target was 2020. We, and a group of 25 industry experts, were cautious whether this was possible. Look at the price now, 6 to 7 cents per KwH!” “However, I don’t think letting go of subsidies is per definition a good development. Let me put this right, I think the Dutch government is currently doing a very good job in managing the development of wind energy in our country, however, I think it would have been better to keep the subsidy system, albeit restricted to an acceptable level.”

“How many risks are developers willing to take? What if the projects will not be realised? Do you really want to risk companies supporting the industry to go bankrupt and lose thousands of jobs? That’s to nobodies interest. The problem is, nobody really knows what the situation is, say, in twenty years. The low interest rate and steel price have played a positive role in the lower cost of energy. What if the interest rate would go back to the level we have seen in 2011 or 2013,14?”

“If you want to move forward with the energy transition then you probably have to introduce the subsidy scheme again. In the past, the level of subsidy required was very high, over 100 Euro per megawatt hour. I personally think a limited subsidy, between 15 to 20 Euro per megawatt hour would be perfectly fine for a project.

Turbine sizes are increasing at a rapid speed and new technological innovations are introduced. As a bank, does this bring additional risks to the financing of wind projects?

Schmitz: “The increase in turbine sizes is a continuous natural process so it is not really a big risk.”

Plantinga: “Our technical advisers would probably say that further development of existing technologies sometimes pose more risks, due to things being overlooked. With new technologies, every tiny detail is tested and checked by certification bodies over and over again.”

Finally, do you have a favourite wind energy project?

Schmitz: “In general, the projects that were most challenging are the ones I look back on with most pride. For me these were the Westermeerwind, Belwind and NOP Agrowind projects. In these projects we had many challenges which we needed to overcome.

Plantinga: “I agree with Marc’s observation, these projects on which we worked together have been more challenging but very interesting to work on, even though they generally tend to take considerably more time to bring to a financial close. In these processes you also end up building strong relationships.”

Schmitz and Plantinga agree that this is something that makes them continue to enjoy this industry; the good relationships that they have built up over time which has resulted in a lot of friendships being established within the industry.

Plantinga: “Both the UK and France have indicated not to go entirely without subsidies. The strong focus on building offshore wind farms without subsidy remains a surprise to me anyway. One tends to forget that coal and gas plants have also been supported.”

01-2020 | 21

Offshore

Wind Farm News

IJmuiden Ver, © TenneT

3

1 Ten Noorden van de Waddeneilanden The Netherlands Enterprise Agency (RVO.nl) has granted Fugro a geotechnical site investigation contract for the 700 MW Ten Noorden van de Waddeneilanden Wind Farm Zone. The activities will take place from February to May this year.

The work comprises of a shallow subsurface investigation in Phase 1, followed by a borehole drilling programme, and standard and advanced laboratory testing, in Phase 2. The final deliverable will be a data package which can be used to prepare a detailed integrated geological and geotechnical soil model, on which wind farm developers will base future tenders.

2 Fryslân Several construction activities are currently taking place for the 382.7 MW Fryslân wind farm. The section of the cable route on the Afsluitdijk has been completed while work continues on the section of the cable route on land to the 110kV-station of TenneT in Bolsward. At the same time, work on the transformer station at Breezanddijk is stilll in progress and a start has been made on the realisation of the work island which will serve as a nature area after the wind farm has been built.

This area consists of 2 hectares above water level and a 25 hectares shallow water zone.

4 Hollandse Kust (Noord)

3 IJmuiden Ver TenneT has initiated a development process with HVDC suppliers to help design an innovative 2 GW 525 kV HVDC solution which can be used for the IJmuiden Ver Alpha and Beta connections (due in 2030) but also other future 2 GW high voltage connections like planned in Germany.

The partnership includes: ABB Power Grids, GE Renewable Energy’s Grid Solutions (Netherlands), a consortium of Global Energy Interconnection Research Institute Co. Ltd. (GEIRI) & C-EPRI Electric Power Engineering Co. Ltd. (C-EPRI) (China), Siemens (Germany), and Xian Electric Engineering Co., Ltd (China). These suppliers will provide specific information on this to IvOffshore&Energy b.v., which is carrying out the Front-End Engineering Design (FEED) study on behalf of TenneT. On this basis, a standardised platform design will be developed for all HVDC solutions.

The Ministry of Economic Affairs and Climate Policy published the Ministerial Order for permitting offshore wind energy Hollandse Kust (noord) Wind Farm Site V in December 2019. It is one of three offshore wind zones identified by the Dutch government to be developed by 2023. The tender to develop the Wind Farm Site V will run from 2 April 2020 till 30 April 2020, 17:00h CEST.

and Danish Bladt Industries.

The installation is performed

by DEME, using their heavy-lift vessel Innovation. According to Ørsted, the first turbine installation activities will start in April this year.

6 North Sea Agreement

5 Borssele 1 + 2 In January, foundation installation work started in the 752 MW Borssele 1 + 2 offshore wind farm, a project by Ørsted. The wind farm is planned to be fully operational by the end of this year. It will then be the largest Dutch offshore wind farm. In total, 94 Siemens Gamesa 8 MW wind turbines will be installed on monopile foundations some 22 kilometers off the coast of the Zeeland, at water depths varying from 14 to 39.7 meters.

The foundations are produced

by Sif, EEW SPC, EEW OSB

2

© Windpark Fryslân 22 | 01-2020

5

In February, the government, energy sector, fishery, nature organisations and port associations presented an agreement (Onderhandelaarsakkoord) on the use of the North Sea. The Agreement has the theme ‘additional miles for a healthy North Sea’.

The cabinet has now handed the Agreement to the parliament. A consultation period will take place till 31 March during which the participating parties can discuss the Agreement with their members.

The Agreement outlines the plans for the next ten years but also explores the period following. The government will sponsor 200 million Euro of which a large part (119 million Euro) is destined for the restructuring and greening of the cutter fleet. 12 million Euro will be made available for the safe passage of vessels during construction of the wind farms. Another 14 million Euro is reserved for enhanced supervision on the implementation of the Agreement and 55 million Euro is to go to additional monitoring, scientific research and nature conservation.

1

2

3 4

6

5

Read the full news on www.windenergymagazine.com (EN) or www.windenergienieuws.nl (NL)

01-2020 | 23

Donderdag

14 mei 2020 EVENT

Tot 15 maart: €100,-

ideas, intellectual property & innovation

Van idee naar innovatie op het 3i-Event 2020 Waar krijg je mee te maken bij het in de markt zetten van nieuwe technologie?

Tijdens het 3i-Event kom je in contact met IP-professionals die weten wat het nut is van een goede IP-strategie.

Voor wie: Start-ups, mkb-bedrijven uit food, techniek, chemie, life science en ICT.

Thema’s:

Meld je nu aan

•

De rol van patenten anno 2020

•

Hoe financier je de IP-strategie?

•

Octrooirecht vs Open Innovatie

•

IP in de chemie & life sciences

•

IP-bescherming bij digitale innovaties

•

De samenwerking tussen bedrijf en octrooigemachtigde

•

Kunstmatige intelligentie en autonome systemen

European Patent Office Den Haag

11:00 – 18:00

www.3i-event.com

Georganiseerd door:

Voor meer informatie over deelname en sponsormogelijkheden neem contact op met Frits Dufifie via f.dufifie@archermedia.nl of 088-22 666 52

Column

Peter Eecen, R&D manager wind energy at TNO

Sophisticated wind turbine blades

L

ooks can be misleading. Ever larger wind turbine blades seemingly look the same as their smaller predecessors, and not everyone understands the gigantic technical developments that are required to make these larger blades. Design and manufacturing of larger blades have to fight the laws of physics. Without innovations these blades would become too heavy and too expensive to be interesting. Only the fast innovations in development of design, materials, construction, and manufacturing have made the up-scaling possible.

New models in aero-elastics are required for the design of these very large blades. The tip speed of the rotor blades is usually between 80 and 100 m/s, which means that larger rotors, longer blades, rotate slower. Scaling up the aerodynamic profiles do however result in different performance compared to the smaller profiles. This is the reason that GE, LM Windpower and TNO perform an extensive aerodynamic measurement programme on the Haliade X turbine. The experiments provide the researchers the validation data to check whether improvements in design modelling are indeed correct.

‘Not everyone understands the gigantic technical developments that are required to make these larger blades’

To reduce the loading of the very large rotors on the support structure the large rotor blades become more slender than their smaller counterparts. This results in relatively thick aerodynamic profiles which have different aerodynamic characteristics than the presently applied thinner profiles. Reason for increasing the relative thickness of the profiles is that the height of the profile remains the same to accommodate the loads-carrying structure while the profile chord length becomes relatively smaller. These profiles are not commonly applied in other applications while the Reynold’s numbers become larger than in other applications.

That means that the performance becomes uncertain and elaborate airfoil testing is required.

To determine the performance under rotating conditions testing on full-scale wind turbines is required.

With the increasing rotor sizes, the hub on which the blades are attached becomes a more dominant weight and cost factor for the rotor. At the same time, the dynamic behaviour of the rotor is becoming dependent on the flexibility in the hub. The loads carried by the pitch drives that fix the blades to the hub require increasingly more attention. Within the Dutch innovation system, a project is carried out by GE, LM Windpower and TNO and addresses the forces and dynamics of the entire rotor assembly.

Finally, imagine the construction of 107m long blades where the root is 5.4m wide. Laying fibres along the entire span of the blade is challenging and requires automated and robotised solutions. Handling these blades requires innovative equipment, which everybody could have observed when the Haliade X turbine was installed at the Maasvlakte in Rotterdam.

01-2020 | 25

Rotor Blades

Edo Kuipers

We4Ce Root Bushing Solution for Rotor Blades

M.A.R.S.2020 For over 10 years, We4Ce has been providing technology to connect rotor blades to wind turbines – the We4Ce Root Bushing Solution. The adaptation of more stringent certification requirements, together with the demand for a reduction in the main mould occupation time, pushes the launch of the We4Ce M.A.R.S.2020 project. We4Ce’s vision and strategy is clear in this: a convenient, robust and costeffective blade root connection technology, following the latest DNVGL-ST-0376 ed. 2015 guidelines.

We4Ce was founded in 2008. Its main design offices are located in Almelo, the Netherlands. We4Ce also has agencies in China and Russia and a partner in India. Its core business is rotor blade design, from aerodynamic and structural design to technology implementation at our customer’s premises, next to accomplishment of the certification. Parallel to technology transfers which enables customers to manufacture the bushing connection in their own factory, We4Ce also provides prefab blade root parts as well as subcomponents since 2018.

We4Ce Root Bushing Solution Since its foundation, We4Ce is focused on the development of bushing solutions for the root part of rotor blades and becoming ‘the company’ in this field. This solution has been widely used with great success, especially in the Chinese market. Recently, the European market also showed increasing interest. At present, over 25,000 turbines worldwide are equipped with our bushing solution.

Our motto is ‘Simplicity is its strength!’. In the design office of ‘We4Ce-The Rotorblade Specialist’, our team is continuously working on further improvements and finetuning. The We4Ce Root Bushing Solution has the objective to fulfil at least the following criteria: easy to build/assemble, exchangeable with T-bolt-blade root connection, to be built as a prefab component, and to be strong enough for its application. Furthermore, only a minimum of activities may be required once the blades are demoulded.

The bushing of We4Ce follows the mechanical locking principle. It is a connection that finds its strength during the infusion moulding process of the blade root. The interfaces between the steel bushing and the surrounding laminate are of great importance. Since the assembly is done during the resin infusion process, this means that the connection is secured by the quality of the laminates. This leads to a higher strength than when using a bonded insert connection.

26 | 01-2020

In 2008, the development of the We4Ce Root Bushing Solution started with the M30, directly followed by the M36. In 2018, a smaller design, the M20, was introduced for the European market.

Having developed and tested these three different sizes, We4Ce gained valuable knowledge about the scale effect of bushings and the Critical to Quality (CTQ) effects to be considered.

The blade root bushing connection consists of an assembly of different sub-components, where the assembly tolerances are key to assuring quality. Although slight changes occur, a bushing connection involves the following sub-components: steel bushings, fibre material wrapped around the bushings, glass fibre elements between the bushings, core wedges to slope down the bushing thickness towards the rotor blade tip, and layers of laminate below and on top of the bushing assembly to integrate to the full rotor blade.

Sub-component Supply Since 2018, We4Ce also produces the sub-components of the bushing assembly in their own workshop. The aim is to provide the customers with a robust and cost-effective connection technology during proto building. For We4Ce, this means to have the QA/QC and material selection at a consistent level, raising the characteristic strength. As a result, our customers are able to concentrate fully on the assembly process in the main mould, which is their core business.

Prefabricated Root 180 Degrees To help blade manufacturers shortening their mould occupation time, We4Ce has started to supply 180 degrees prefabricated root parts. A few sets of relatively smaller roots have been manufactured and supplied from the east of the Netherlands to the southern European market. After a successful start-up and having finetuned the design for production, We4Ce transferred the technology to India for mass production.

The Launch of M.A.R.S. In the second half of 2019, We4Ce launched the M.A.R.S. project.

The acronym ‘MARS’ identifies the main characteristic features: being a Modular and Adaptive Root Solution, where Adaptive refers to the possibility to extend the number of bushings in a row, or to increase the loading level by shape adjustment.

Together with research institute TNO in Delft, the Critical to Quality items within a bushing-root are tackled more fundamentally, on an engineering level by analysis, as well as on a practical level by testing. Several material interfaces have been depicted as being critical for the strength of a bushing system.

Next to the default prescribed materials, it was also decided to include special pultrusion elements into the test programme to quantify the effect of material tolerances on the strength by means of testing.

Offering root segments (modular parts) to our customers as a hardware product, is the next ambitious goal of We4Ce. For this purpose, a close cooperation with a Chinese partner will be explored. The goal of the cooperation is an efficiency improvement for our customers in terms of main mould occupation time and a consistent and reliable quality level, taking an attractive cost-level in mind.

u Edo Kuipers With more than 22 year of experience in blade design, Edo Kuipers is one of the founders and co-owners of We4Ce. His main responsibility is running the engineering department from the aerodynamic rotor blade design, structural design, up to accomplishing the certification documentation. His special interest is to have the in-house developed bushing connection being applied in as many possible rotor blades as connection technology between the rotor blade and the turbine. Edo studied Aeronautical Engineering in the Netherlands and holds a Bachelor of Engineering degree.

Edo Kuipers, We4Ce - the Rotorblade Specialist www.we4ce.eu, e.kuipers@we4ce.eu

To impeccably execute the M.A.R.S. project, We4Ce works closely together with several European certification bodies in a step by step approach.

The M.A.R.S. project is expected to be accomplished by the end of 2020, however first results and findings will be applied earlier, i.e. by the mid of 2020.

For more information, please contact us at: info@we4ce.eu

01-2020 | 27

Rotor blades

Mischa Brendel

Boltlife’s blade to hub flange connection methodology

Safe upscaling of wind turbines Wind turbine generators get bigger and bigger each year. As a result, the dynamic forces on a rotor blade during its operation become immense. These tremendous forces are transferred through the blade-to-hub connection, which makes it imperative that this connection doesn’t have any weak points. This poses challenges for the designers of wind turbines. But those that can overcome these design challenges are looking at lower costs of quality and even better revenues.

B

oltlife specialises in creating high quality bolted flange connections in wind turbines, among them blade to hub connections. In 1996, a blade length of 20 meters was considered as state of the art; in 2003, 45 meters had become a standard and today we are working with blades of 107 meters long. In those days the T-bolt connection (IKEA connection) was the standard method to connect the rotor blade to the hub of the turbine. The last 15 to 20 years however, a root bushing connection is the most commonly chosen method for connecting the rotor blades.

One important advantage of a bushing solution over the T-bolt connection is the ability to apply more bolts on the same pitch circle diameter; about 30 % more bolts can be placed, which offers the opportunity to use longer rotor blades. An increase in size means an increase in power capacity and a reduction in maintenance costs. But it also means that we are reaching the limits of what our current standards can handle when it comes to design parameters.

High-quality flange connection An important aspect for the quality of the flange connection is

28 | 01-2020

the bolt preloading procedure. “Current bolt preloading procedures, like torque-angle or tensioning, have their flaws due to poorly manageable parameters like friction, lubrication issues and misalignment,” Joost Prieshof, CEO of Boltlife says.

“The reason is that only a small and unquantified portion of the applied torque will be converted into actual preload. This leads to a considerable scattered load throughout the bolted flange connection.”

Boltlife has developed a flange bolting methodology utilizing ultrasonic load measurement and custom sequencing methods, that create high-quality flange connections, where all loads are comfortably over the minimum required load, with very little scatter between the individual joints. The method used focusses on load-driventorque, as opposed to the conventional torque-drivenload. Furthermore, each Measuring WTG flange bolt in a flange will be measured and evaluated during the torqueing or tensioning load application. As a result, a fully traceable and repeatable load assessment is available at all times. Boltlife expects the method to be certified by DNV-GL very soon. The company is also developing an ultrasonic permanent remote measurement system.

Arnold Timmer, CEO of rotor blade specialist We4Ce, thinks that Boltlife is on the right track. “The Boltlife technology produces better connections, which potentially would allow us to design larger blades, and that enables a higher capacity wind turbine.”

We4Ce is a technology provider; it develops wind turbine rotor blades but does not build them. The company has over twenty years of experience, ranging from 50 kW to 14 MW wind turbines.

Timmer: “A rotor blade must be able to absorb the forces from wind gusts. But at the same time, it needs a certain level of rigidity. ” This means that a lot of force is exerted on the bolts and fringes, which connect the rotor blades to the turbines. That makes it imperative to tighten the bolts securely. It is of great importance to accurately control the bolt preloading procedure. If the design preload force is not valid on the actual turbine, this will result in bolt failures and unsafe situations. Variations (or scatter) on the prescribed preload force will always occur and for this reason, the We4Ce designers take the expected scatter into account in their designs. Controlling the preloading procedure in such a manner that the expected scatter is lowered, will result in more optimised blade root designs.

Reduction in maintenance costs Prieshof: “Current bolt preloading procedures have inaccuracies that can easily get to 30 to 40 % when it comes to torque to load.”

These are inaccuracies in which We4Ce has to make its calculations.” Boltlife closes the flange comfortably above the

“We are reaching the limits of what our current standards can handle”

Blade flange bushing

minimal required load. Together with the lower scatter, this creates a flange connection that is almost immune to fatigue damage.

Boltlife’s technology also reduces maintenance costs, Prieshof explains: “We take measurements with a probe, which can be done very quickly. Within ten seconds I have a re-measurement from within the blade connection and I can read out the load immediately.”

Currently, Boltlife is in the process of certifying its methodology with DNV-GL. “This certification will guarantee that bolted flanges meet the highest traceable quality standards and they can expect considerable improvements in their Maintenance Plan.”

Whether certification alone is enough, remains to be seen; the wind turbine market is a conservative one. Timmer: “I can imagine that the market is careful to release another approach. Companies are used to certain procedures and a new methodology could give some challenges, which need time to settle in.”

But when it does, the biggest advantage is clear: safe upscaling of wind turbines, which means more capacity and a big opex reduction.

01-2020 | 29

Rotor Blades

Sabine Lankhorst

Interview with Redak

Proper blade maintenance for optimal turbine performance Blades have been the so-called ‘underdog’ in wind energy for a long time. Its use was practical but not seen by definition as a vital element. Only later did the industry became aware of its importance in the energy production of a wind turbine. Dutch blade inspection and repair specialist Redak has witnessed this process from the start.

K

ader Benali is the owner of Redak, based in NoordScharwoude. His professional experience in wind energy dates back almost 30 years. After graduating from high school he worked on several jobs before joining Nedwind, a Dutch manufacturer of wind turbines. “At that time I didn’t know that much about wind turbines and actually thought they were built from wood, but as I have a passion for technique I decided to give it a try.” This decision would dictate his future career path.

International reach

Nedwind was at that time one of the main wind turbine manufacturers in the world with an international customer base.

At some point the company was split. Nedwind continued with the mechanical activities while the rotor blade manufacturing activities were placed under a new entity, Rotorline. This enabled Rotorline to also sell blades to other turbine manufacturers. Benali joined Rotorline. It didn’t take long before the management of Rotorline noticed his quality and asked him to specialise in maintenance and repair of blades. For Rotorline he worked in the Netherlands, the USA and Germany.

In the Netherlands he is involved in both onshore and offshore wind. Offshore, his company has performed inspection and repair activities on the Noordzeewind project, also known as Egmond aan Zee. Onshore, he is working for Vattenfall at their Haringvliet wind farm where 6 Nordex 117 turbines are currently being installed. Last year he signed a contract with Vattenfall for maintenance work on 36 wind turbines at the Prinses Alexia wind farm. His company is also performing inspections in the Deil wind farm which is currently being built in the province of Gelderland.

When Rotorline was sold in 1999 to LM Windpower, Benali joined this company. He worked for LM for two years before deciding to found his own company, Redak, in 2000, offering blade service and inspections.

Regular wind turbine blade inspections are nowadays part of the operation and maintenance budget for a wind farm. This was not always the case, explains Benali. For a long time, blades were not seen as important. The focus was more on the mechanical part of

30 | 01-2020

Even though a small company at first, he continued to work on international projects. In fact, his first assignment was in Curacao.

Having Vestas as a regular client certainly helped but he was also asked by other companies to perform blade inspection work on projects all over the world. Countries where Redak worked include South Africa, Australia, Jamaica, Thailand, Curacao, Chile, Uruguay and Costa Rica. Benali: “Half of the time during my career I spent abroad.”

Underestimated

Blade damage

Benali performing blade repair

‘When the leading edge starts to wear it affects the aerodynamics, resulting in a decrease in performance’

u Blade inspector requirements Full GWO VCA Blade B Repair and Inspection Course English in spoken and written Medical G41 test (for offshore) VOP Irata

01-2020 | 31

the turbine. The industry was not aware yet that the quality of the blades also has an influence on the production efficiency of the wind turbine. He elaborates: “When the leading edge starts to wear it affects the aerodynamics, resulting in a decrease in performance.”

Therefore in the early days, his job consisted mainly in repairing damaged blades and in the inspection of blades before transportation and before being installed on site. Blades often get damaged during transport. Not so much in the Netherlands, he stresses. Here the transportation companies are more experienced and transportation is bound to certain rules and regulations. In countries that are new to wind energy this can be different. He provides the example of South Africa where the government dictates that local input is used. “Transportation companies were not used to moving blades and often a lamp post or traffic light was hit when making a turn”, he says. It is therefore important to check the blades during transportation, for example when arriving in port.

Blades, and the leading edge in particular, are prone to several elements that can cause wear and tear like salt, lightning and the wind itself, he continues, “In several cases I was called out for an inspection overseas to find out that the blades were damaged beyond repair. This could have been prevented with regular maintenance.” He takes pride in his first project in Palm Springs, USA. Here he performed planned maintenance on twenty turbines over a period of 26 years. “In general, blade manufacturers provide a 20-year warranty but they can last longer when taken care for properly. In Palm Springs the turbines are now being replaced by more modern turbines, however, the blades were still in good shape”, he says.

It was only later on that the industry started to realise how the blade quality affects the turbine performance and regular maintenance was introduced. Benali: “Insurance companies also started to require maintenance to take place, in general once every two years.”

Inspection & Repair “On land, first we make a preliminary observation of the state of the blades from the ground, using a camera or sometimes drones.

Nowadays the cameras are of enough quality to do so. Based on the results we decide whether repair is needed”, Benali explains.

Repair work can be performed in 99% of the cases with the blade still connected. This is done by using rope access, a sky climber or boom truck. “It is only occasionally that a blade is damaged to such an extent that we need the blade to be dismantled and lifted down to perform the repair work on the ground. In those cases the damage is most of the time to the interior laminating. “To repair this we would need to do new laminating. The epoxy that is used needs to dry. This is done by means of a type of heat blanket which exposes the epoxy laminate to a temperature of 60 degrees Celsius during two hours”, he elaborates.

There are some limitations to doing repair work on site. When using epoxy it is important that the air humidity is below a certain level, less than 70 to 80%, says Benali. Ideally the temperature

32 | 01-2020

Roos and Cerri Ann of Redak during offshore inspections

should be above 15 degrees Celsius. New, modern blades now also require a vacuum system when performing repair work, he adds.

Offshore is a different story, both the inspection and repair are being performed using rope access. There are exceptions he says.

“Once I was asked to perform repair work offshore on a blade that was hit by lightning. In this case the damage was too big to repair using rope access. We had to rent a platform which could be installed on the transition piece and lifted up by cables.”

When asked whether he thinks drones will fully take over inspections of blades offshore in the future he is doubtful.

“Drones, currently being used, can only picture the external surface, they cannot provide a view on the internal layering of the blade so you won’t be able to see when delamination is taking place. The internal layering are the carriers of the blade. Do you really want to risk making decisions based purely on the results from drone images?”, he wonders.

Manpower Since the start of the company in 2000 his company witnessed a strong growth. He started to scale up a few years ago when he realised he was growing too quickly to manage every single detail himself. “I realised I had to transfer my knowledge and let others do some management tasks. I also started to use a software system for reporting and digitalising.”

Currently he has a fixed team of four people and around forty persons working for him on-call. He can look back on a very busy year in 2019, even to the point that he had to say no to a new project. This has mainly to do with limited manpower. “It is very hard to build an experienced, qualitative team”, he explains. “It really took me a lot of time and effort to get the team I have now.

There are simply not enough experts in the Netherlands so I had to attract people from other countries like Latvia and the UK. With this team I know that I can deliver quality.”

His team also includes two women. Not enough to his liking.

“These women are amazing, they are not afraid to go out there offshore and take on the activities that men have always done. In fact, they are actually more meticulous than men!”, he admits.

One of his wishes is to get more Dutch professionals interested but the fact that youngsters seem to prefer digital work rather than using their hands worries him.

Over 100,000 tons of quality heavy steel plates in stock AncoferWaldram Steelplates B.V. (AWS) is a stockholding wholesaler and steel service center, specializing in the supply of hot-rolled heavy carbon steel (quarto) plates, and profiled parts for more than 40 years now. Over the years, AWS has developed into a business that sets the standard for its industry.

Delivery program LR-A, LR-DH36, LR-EH36, VL-D36, VL-E36, VL-E36 / LR-EH36 (+Z35), VL-E36TM, VL-F36TM S235JR / S355J2+N / S355K2+N S355NL S355G10+M /S420G2+M / S460G2+M,

STRUCTURAL STRENGTH IN HEAVY STEEL PLATES

S355ML / S460ML, S460NL (Z35-US) Dillimax 690-1100 (+Z35) Dillidur 400/450/500/550 DicrestÂŽ5 (HIC resistant), SA 516 Gr. 60/65/70 P265GH / P295GH / P355GH, P355NH / P355NL2, P460NH / NL2

AncoferWaldram Steelplates B.V. is a company of Dillinger

T +31 (0)162 491500 | E sales@aws.dillinger.biz | I www.ancoferwaldram.com

AWS_A5_Windmolenpark 190x135.indd 1

19-02-20 14:15

Rotor blades

Iref Joeman

Alternatives on afterlife use of amortized rotor blades Despite the many advantages of wind energy, there are also several challenges this fast expanding industry is facing. One of these is the recycling of the turbines at the end of their life cycle. The rotor blades in particular are difficult to recycle. Much more research will need to be conducted on this topic.

u Iref Joeman

Superuse Studios considers reclaimend rotor blades as an excellent building material for urban furniture. ©Superuse Studios

34 | 01-2020

Iref Joeman completed his Bachelor in Mechanical Engineering on the topic Recycling PET-bottles in Suriname.

He came to the Netherlands in the summer of 2016 in pursuit of his Master degree. Initially at the Technical University of Delft, but later on at the University of Twente.

In September 2019 he successfully obtained his Master degree in Environmental and Energy Management. His thesis treated on the recycling of wind turbine rotor blades.

W

ind energy, together with solar energy, are the main drivers for reducing CO2 emissions globally. Their share in the energy production will rapidly grow as many countries have set ambitious targets to reach a reduction in emissions or even a carbon neutral energy industry.

But what happens when these turbines reach the end of their life cycle? Currently in the Netherlands, many of the first generation wind turbines are being dismantled, making place for the new much more powerful, improved generation turbines. This poses a problem that is the same for the solar industry; namely the recyclability.

Iref Joeman, while following a master in Environmental and Energy Management at the University of Twente, one day came across an article that discussed the challenges of recycling wind roto blades after their lifecycle. At that time he was not aware of this challenge and it aroused his curiosity. When it came to choosing a topic for his thesis, he did not have to think twice. His supervisor, who instantly approved his choice, got him in contact with a consultancy who offered him an internship. Over a period of five months he learned a lot from his colleagues and his company supervisor. Last year he successfully completed his master.

Main challenges Of the wind turbine components, the rotor blades are the most challenging to recycle as they are non-biodegradable. Normally, a blade has a life expectancy of approximately 25 years when it is kept in good conditions through adequate maintenance. This life expectancy of 25 years may seem like a long period, but with the growing size and number of rotor blades and wind turbines globally will lead to disposal challenges in the future.

In his research, Joeman discussed four methods for the afterlife treatment of rotor blades: pyrolysis, refurbishment, pavement application, and landfilling.

His research consisted of data acquisition from comparable research reports, articles and publications, complimented with data from interviews he conducted with several parties that are related to the topic of rotor blades. The interviewed parties varied from researchers, companies involved in dismantling, refurbishing and reselling end of life rotot blades, and parties active in landfilling and or recycling parts of wind turbines.

Research results With their robust size and weight and their non-biodegradable characteristics, it will become more of a problem to dispose of the rotor blades in landfills. Especially since many EU nations are phasing out landfills.

One of the conclusions Joeman drew was that, although challenging, recycling of rotor blades can be improved and realised. The current technical state of the art of the afterlife application of rotor blades is still in its development stage but

progress is already being made. Though limited, a few of the fore mentioned applications can be used currently.

One of these applications is pyrolysis in which the blade is decomposed in separate materials. Another application is shredding the rotor blades into granulates which can be used as a resource for pavements and other building applications or to manufacture furniture, skateboards, decorative lamps, amongst other things. This is done, for example, by Demacq in the Netherlands and is currently the most viable option. Yet another option is refurbishing end of life rotor blades in good conditions and reselling them. This is currently done in the Netherlands, around 20% of the amortized rotor blades are refurbished and resold to countries like Italy, Greece, Asia, eastern Europe and North Africa.

These options, however, pose their own challenges as the incineration and transportation produces quite a lot of CO2 emissions.

Replacing the thermoset epoxy material with the thermoplastic recyclable Elium is another viable option. Elium has been applied to and successfully tested on rotor blades with lengths of 8 m and 25 m recently. There is no certainty on the performance and application of rotor blades larger than 25 m regarding the use of Elium. Regardless of the infancy of this application, the application shows to have prominence in the near future.

The design and choice of material for the rotor blade is very crucial considering the rising trend of wind turbines being installed in the coming years. Rotor blades manufactured from recyclable material like thermoplastics and polyester can be a solution, but the mechanical and aerodynamic properties should not be compromised only because of their recyclability.

Next steps The reseach performed by Joeman and the outcome of his report is the first step of many to come as this topic is still in its early stage. Fortunately, technological research and development is still in progress. Time and public awareness may be an issue and has to be dealt with carefully.

Recommendation In order to improve the whole recycling process, the following should be further researched: the dismantling, transportation, and location of the refurbishing or recycling facility need to be improved to reduce transportation costs, CO2 emissions and the time delay in getting all the necessary permits. This can be done by either better planning and or technical innovation. Technical innovation can be designing and choosing better recyclable materials for the rotor blades, facilitating/improving the reverse engineering process.

There should also be more research into further development of available recycling methods. This can be achieved by making more funds available for NGO’s, researchers and universities.

01-2020 | 35

Martijn Koelers

Rotor blades

Cross-sectoral collaboration for innovation & automation in rotor blades Wind is a powerful renewable energy choice to sustain the planet we all know and enjoy.

Competition in the wind industry has never been fiercer. Reliable rotor blades are essential to bringing down the costs of wind energy.

T

echnology plays a central role in each wind turbine blade (WTB), taking factors such as materials, aerodynamics, blade profile, and structure into consideration.

These factors define the performance and reliability of the blade and require a high degree of precision. Excellent craftmanship, uniform processes, and flexible and responsive manufacturing set-up are needed to produce high-quality blades.

Innovation & automation To get ahead in the competitive wind industry, innovations are needed. Higher efficiency in current processes and introducing automation are key to ensure decreasing LCOE. But it is not only automation that will help. Along with these developments, material research is

36 | 01-2020

necessary as well as design, assembly and logistic innovations.

Key to these different topics is the need to collaborate with and learn from other industries. The composites industry will be one of the more prominent partners, they have experience in automation of production lines, albeit with smaller parts, but this kind of innovation involves more than simply implementing a new technique.

Simultaneously, innovation in one step of the value chain opens the door to further innovation in a linked process. Automation may lead to different ways of assembling the blade, which can lead to the use of different materials, and this then opens new ways of designing the blade or vice versa.

That said, all of this must not interfere with current processes. There can be no disruptive innovations in a live production line.

Official support These challenges can’t be solved by the separate industries, rather external and more formal nudging into the right direction is needed. Sector clusters and governments can pave the path into crosssectoral collaboration. Help is needed to facilitate these collaborations, the industries have their role, but governments could speed up the process by supporting or demanding cross-sectoral initiatives.

An important factor in this kind of support is the objective or the end result. Serious investments are needed for the implementation of new technologies on an operational scale and come with big risks.

It would be highly beneficial for crosssectoral collaborations if initiatives in this area would get official support beyond any technology readiness level and into a mature phase of manufacturing readiness.

CompositesNL.nl is the Dutch Composites Association

We4Ce_190x135.qxp_Opmaak 1 12-11-19 16:05 Pagina 1

THE ROTORBLADE SPECIALIST

Blade Root Technology

ut io n 2 0 2 0 ol S t oo R e iv t p a Ad r a M od ul

Wind turbine blade root technology: • Consistent quality • Low mould occupation time • High strength • Low cost of ownership Contact us: Arnold Timmer arnold.timmer@we4ce.eu Edo Kuipers e.kuipers@we4ce.eu

ode windnieuws

nr.3 | 2014

ode decentraal WindnieuWs

ode WindnieuWs

Duurzame energie voor en door iedereen

ode windnieuws odE windniEuws

nr.3 | 2017

nr.6 | 2014

nr.1 | 2015

nr.5 | 2014

Duurzame energie voor en door iedereen

Bent u geïnteresseerd in

ODE DECENTRAAL WINDNIEUWS Veiligheid als sluitstuk Ynso Suurendonk en Jesse Don

ontwerpstructuurVisie wind op Zee Ad. Littel

energiecoöperaties stomen door!

Siward Zomer

Duurzame energie voor en door iedereen

NR.4 | 2018

Duurzame energie voor en door iedereen

Duurzame energie voor en door iedereen

windpark noordoostpolder Frans A. van der Loo

www.duurzameenergie.org

windenergie? Wilt u meer lezen over de ontwikkeling van windenergie in een maatschappelijke context van voors en tegens?

Duurzame energie voor en door iedereen

EEn goEdE basis Wouter Pustjens

dE wind in drEnthE Mirjam Tielen

www.duurzameenergie.org

waardEvollE wind Frans A. van der Loo

Friesland in de Wind Mirjam Tielen

aanbEvEling wind op zEE van nii Linda Wes

reactie op essay pieter Boot Krispijn Beek

Windenergie is kinderspel Evert Kuiken

Windtur WindturBines en externe veiligheid Tom van der Linde en Jeroen Eskens

www.duurzameenergie.org

Zuid-Holland: Van woorden naar daden Mirjam Tielen

GedraGscode onder de juridiscHe loep Aaldert ten Veen en Derek Sietses

www.duurzameenergie.org

Windenergie. Hoe doe je dat met elkaar?

de waarde Van een onafHankelijk windrapport Erik Holtslag, Bob Schulte, Rolf de Vos

wind ind op land en de proVinciale staten erkieZinGen Verkie Ad. Littel

Klimaatverandering en wind interview richard Klatten Qurrent

airborne windenergiesystemen

lessen van houten h het proces en de betrokkenen

slimme smart grid in gotland

Oesters en windturbines VRIJDENKEN OVER HET ELEKTRICITEITSNET

VERMINDEREN VAN EFFECTEN VAN WINDTURBINES OP VLEERMUIZEN

PARTICIPATIE BIJ WIND OP ZEE

WINDDAGEN 2018 BEURS EN PRESENTATIES

www.duurzameenergie.org

www.duurzameenergie.org

Neem een abonnement op WindNieuws!

WindNieuws is hèt onafhankelijke Nederlandstalige vakblad voor de windsector, uitgegeven door ODE Decentraal. WindNieuws heeft een verdiepingsfunctie en biedt een platform om achtergrondkennis en -informatie te delen en te vinden.

WindNieuws verschijnt sinds 1983 zes keer per jaar.

Probeer WindNieuws nu vrijblijvend met een proefabonnement van twee nummers voor € 10,-

Meer weten of aanmelden? windnieuws@duurzameenergie.org www.windnieuws.nl

Event

Benno Boeters

Offshore Wind Innovation Challenge 2019

Noise barier with air bubbles for piling Marine Performance Systems (MPS) develops a system with air bubbles that absorb and reduce noise. On 9 December 2019, the company won with its concept the Offshore Wind Innovation Challenge, organised by Innovatielink and Offshore Wind Innovators.

D

riving wind turbine monopiles in the seafbed results in a large amount of noise underwater and in the seabed. The hammering by the pile driver can produce 170 to 180 dB of sound; that is comparable with the sound produced by a firing cannon. Should you swim nearby in the sea during the pile driving, you would turn instantly deaf. Moreover, in the future monopile diameters will increase, and therefore there is a growing demand for technological solutions that reduce the underwater noise. After all, authorities around the North Sea and elsewhere enforce strict limits in order to minimise damage to nature, fish and sea mammals.

enable the growth of oysters on the seabed near offshore wind farms in the North Sea. The fourth contestant was a company that uses sound to measure friction, tension and wear in jointed bolts and thus increases the efficiency of the maintenance management of wind turbines. (see Boxes) “We know a lot about bubbles”, says Pieter Kapteijn, Chief Technology Officer at MPS, in his presentation in the Oude Bibliotheek in Delft. He mentioned an additional reason for his evident selfconfidence; he found himself back on familiar territory because once in this building he was cramming to complete his study as civil engineer.

For this purpose, Marine Performance Systems (MPS) develops a system with air bubbles that absorb and reduce noise.

When the company won with its concept the Offshore Wind Innovation Challenge, Van Oord and other large offshore contractors responded immediately and already in January, a month later, meetings were planned to discuss cooperation and carry out experiments in Wageningen at the Marin (Maritime Research Institute Netherlands).

His company, with facilities in Rotterdam and Copenhagen, started in 2014 with the development of Air Lubrication, an air bubble drag reduction system for vessels.

By emitting air bubbles along a vessel’s hull, the drag of a vessel can be reduced with 30 to 40 percent. In that case it is of paramount importance that the air bubbles are emitted in the boundary layer between hull and water, that the bubble size is kept constant and that the bubbles can have their effect along the whole length of the vessel.

There were three other finalists in the Challenge. Two of them were focussed on the design of new oyster cages that must

Kapteijn’s colleagues and co-founders at MPS, Frode Lundsteen Hansen and Fulko Roos, made contact with Van Oord, and

38 | 01-2020

that company encouraged them to work out the idea of a noise barrier with air bubbles.

“Sound forces an air bubble to vibrate and that resonance supplies energy or heat to the bubble”, explains Kapteijn. “At the same time, that bubble spreads the sound pulses around to other bubbles, that will in turn absorb the vibration. It reflects in all directions. Thus, it is about absorbing – from vibration to heat – and scattering.

That results in noise reduction.”

During the piling of the tubular monopile in the seabed the hammering of the pile driver causes sound waves that propagate from up to down and back up through the pipe. A part of the noise is radiated to the surrounding water, and another part causes a low frequency vibration in the seabed, that will also be reflected upwards to the water surface.

“For the noisiest part of the sound spectrum, between 30 and 3000 hertz, we introduce air bubbles with a specific size, 7 to 0,3 millimetre diameter. It is essential that we continuously tune the diameter of the bubbles to the changing frequencies, because when the monopile is driven deeper into the seabed, the sound frequencies change”, explains Kapteijn.

“Noise mitigation is all about control.”

Monopile installation by Van Oord at Gemini OWF, © Gemini Windpark

“We are now working on an active system in which continuously performed measurements and feedback result in the oscillators producing air bubbles with the optimal diameter. For instance, when the strongest noise is around 400 Hz, the oscillator will create bubbles with a diameter of 1 to 2 millimetres.”

“We know how it works in theory, we are all in agreement about that. Now we have reached the engineering phase in which we continue the development with other partners, such as Van Oord, towards a practical, working system. We are confident that this approach will offer a solution and mitigate the underwater sound explosions”, according to Kapteijn.

u Oyster reefs Ecological values were the focus for two other contestants in the Innovation Challenge.

The British ARC Marine (not to be confused with the Dutch company of the same name, producer of teak shipping and yachting equipment) makes concrete reef cubes, that can be combined modularly to make every desired shape of oyster reef.

The two representatives of the Brixham, South East England based company, were wearing dark grey T-shirts advertising their goal: ‘accelerating reef creation’. Director Tom Birbeck showed the audience a map dated 1890 that depicted north of the Wadden Sea an area of 20,000 km2 that was covered by oyster beds. Those have disappeared by ‘destructive fishery’; bottom trawling with nets that are weighted with chains can wreak havoc on the seabed.

The hollow reef cubes, with sizes of 1, 0.5 or 0.25 m3, do not only offer an inviting habitat for oysters and other marine life, but can also offer protection to submarine cables and pipelines, Birback demonstrated. And the cubes can be used for coastal protection as well.

Annemiek Hermans of engineering and consultancy firm Witteveen+Bos demonstrated a different design to enable oysters to grow below wind farms, the O-float. This is a new type of oyster cage as well, but it does not rest on the seabed, as it floats thanks to a balloon above it and an anchor beneath it. That prevents the oyster bed getting covered by sand.

u Sound measures stress Tribosonics, a company in Sheffield, UK, reached the final of the Innovation Challenge with a technology that uses sound to determine the tension in already mounted bolts.

Pieter Kapteijn (L) and Frode Lundsteen Hansen (right), resp. CTO and CEO of Marine

A wind turbine contains thousands of bolted joints that are fastened with a precise force and lubrication. Determining the condition of the connections and the possible wear after an installation has been in operation for a while, is a very labour-intensive operation, especially in the case of offshore turbines. Christina King of Tribosonics (“We are very good at measurement systems”) showed how the tension in a bolt can be measured without turning the bolt or the nut. Tribosonics (tribology is the science of friction) sends a sound pulse through a bolt, along the entire length. The echo of the ultrasonic pulse forms an indication of the (surplus of) tension. The technology is also capable of evaluating the bearings in the gearbox of a turbine.

Performance Systems

01-2020 | 39

General news MOOI innovation scheme In February, a new 2020 subsidy scheme MOOI (stands for Missiondriven Research, Development and Innovation) was officially announced in the Goverment Gazette. The new scheme, with a budget of 65 million Euro, is offered by the Topsector Energie and TKI Wind op Zee organisations, together with RVO.nl (Netherlands Enterprise Agency).

The MOOI subsidy scheme supports integral solutions that contribute to the energy transition. It is based on the long-term mission-driven innovation programmes (MMIP’s) by the Topsector Energie and aims to speed up the process for innovations to market entry.

The scheme is intended for projects in the area of offshore wind (10.1 million Euro), onshore renewable energy (10.9 million Euro), built environment (27 million Euro), and industry (17 million Euro). The submission period is divided in two phases, a preliminary round and the final submission. All projects must first be submitted before 20 April 2020, 5 PM. The submitted applications are then evaluated by an advise committee. This has been introduced to provide applicants the opportunity to improve their applications. The deadline for the final submission is 8 September 2020, 5 PM. The projects need to meet certain criteria. More info can be found at rvo.nl/mooi.

SDE++ The tender round for the first SDE++ subsidy scheme will open on 29 September and close on 22 October 2020. There is 5 billion Euro available in this round.

SDE++ is the succesor of the SDE+ scheme.

It builds further on some of the features from the SDE+ but is expanding the categories of technologies that can apply for subsidies. A new principle in the SDE++ is the ranking based on expected subsidy per tonne of avoided CO2 emissions.

The Minister of Economic Affairs and Climate Policy, Wiebes, aims to publish the SDE amendment decision in April this year.

The publication of all underlying regulations concerning the opening of the SDE++ is expected this Spring. For the decision and regulations an approval from the European Commission is also required.

40 | 01-2020

KenzFigee launches new rope actuated knuckle boom subsea crane

© KenzFigee

Crane and lifting specialist KenzFigee launched their new knuckle boom subsea crane. This new generation rope actuated crane builds on proven technology but with improved features for optimized daily operations, safety and operability, without compromising to lifting capacity from approximately 400 tonnes up to 2,000 tonnes.

For the new design, KenzFigee incorporated their clients’ requirements.

These were mostly related to improvement of operational safety and workability.

The new knuckle boom subsea crane includes improvements including a high safe working load-up of up to 2,000 tonnes, a decreased hook weight and pendulum length, full deck coverage including reach at minimum radius and a lifting height and reach for tall objects.

Plan for further cost reduction in wind and solar on land

the eligibility of the projects, optimalisation of the production process by improved predictability and monotoring, and an optimalisation in grid connection.

The Dutch associations NVDE and Energie-Nederland have presented an action plan to further reduce the cost of electricity generated by wind and solar farms in the Netherlands. The associations worked together with companies from the wind sector, united in NWEA, the Dutch wind energy association, and the solar industry, united in Holland Solar.

When successful, these measures could achieve a cost reduction of several Euros per MWh. Additional reductions can be achieved by technological developments and other agreements stated in the Climate Agreement. These measures combined should make it possible to develop wind and solar on land without the aid of subsidies by 2025.

4 areas of improvement Several agreements have been made in the Climate Agreement to reduce the cost of electricity from solar and wind.

The plan focuses at measures that can be taken or already taken by the industry itself to lower the cost of electricity. The wind and solar sector have identified 4 areas of improvements, to be achieved by cooperation; more efficient management through standardisation, improvement in

General news

Haliade-X: World record holder on Maasvlakte II Recently, the world’s most powerful wind turbine, the Haliade-X of GE Renewable Energy, started operating on the most western point of Maasvlakte II. The blades, with a length of 107 metres, are good for a capacity of 12 MW and an estimated gross annual energy production of 67 GWh, enough energy to power 16,000 European households. During a festive inauguration on 17 December 2019, the wind turbine was deployed.

The owner of this world record holder is Future Wind, a consortium consisting of General Electric Renewable Energy, Pondera Consult, and Sif Netherlands.

The Haliade-X is built on the site of Sif, a producer of turbine foundations, bordering FutureLand, the information centre of Maasvlakte II. In the coming years, the owners and TNO will perform extensive testing on the 12 MW mega turbine for certification. To give an idea of the size: the 8 M turbines of Borssele I and II have a rotor diameter of 164 metres, whereas the rotor of the 12 MW turbine of GE has a diameter of 220 metres.

© Pondera

The Haliade-X could as easily have been built in Denmark or France, but thanks to a smooth issuing of permits and a logistically favourable location, Maasvlakte II was chosen. The location is just onshore, but enjoys a steady wind blowing in from the sea, and of course the turbine is intended for offshore wind farms. GE Managing Director Ward Gommeren expects that in 2022, Ørsted will install ten to fifteen 12 MW Haliade-X’s at the East Coast of the United States, the Skip Jack Project near Rhode Island. “Though for the tender procedure for the Hollandse Kust (Noord) Wind Farm Zone, the Haliade-X offer also an opportunity”, Gommeren says. The tender submission will be in April 2020, the construction phase is planned for 2023-2024.

LM Wind Power produces the hybrid carbon blades that exceed the length of a football field. Their flexibility and relatively low weight contribute to the power of 12 MW, allowing the Haliade-X to exceed a limit that a few years ago wind turbine constructors deemed unsurmountable.

The blade length also leads to higher energy production at low wind speeds.

They are made in the LM Wind Power production facility at Cherbourg, France.

The nacelle is produced in the GE factory

in Saint Nazaire (France). Contractor GRI in Seville, Spain builds the tower with a height of 135 metres. Two brand new 1350 tonnes Liebherr cranes (‘the biggest you can find’) were needed to build the Haliade-X. The tips of the blades reach a height of 244,4 metres; that is in accordance with regulations, higher is not allowed. Next to the Haliade-X will arise a measuring tower built by Extentruder in France. That tower will supply all desired information on wind, temperature and humidity.

TNO will play a major role in the tests that are planned during the next years. Sensors, strain gauges and accelerometers in and on the turbine components, already installed during the construction phase, will submit data on the performance of the construction in wind and weather.

According to TNO/ECN, this is the first time a wind turbine will be tested in such a manner.

The Haliade-X will also be equipped with instruments that ‘see’ approaching squalls and turbulences. Reflecting laser pulses of the ‘light radar’ will warn against all too heavy strains, so the blades can react in time and change their angles. The aeroelasticity, that is the extent of bending and twisting of the blades, and the prevention of resonation of the blades, are main issues during the tests. Also the yaw system (that steers the blades and the nacelle into the wind) can in the event of approaching strong winds be set to a larger resistance, thereby keeping the rotation speed and the temperature within the nacelle within limits.

At the inauguration, Ward Gommeren emphasized again that the 12 MW turbine will make it possible to take another step in reducing the Levelized Cost of Energy (LCoE), the price per MWh. The more power wind turbines produce, the less there are needed in a wind farm. That will reduce the costs of installing the monopiles, the nacelles and the blades, and later on the number of maintenance inspections at sea.

According to Gommeren, there are already five or six installation vessels in service that are capable to install the Haliade-X. He expects that ‘within a few years’ globally a large number of these heavy lift vessels will be available for the setting up of these mega turbines.

Benno Boeters

01-2020 | 41

Agenda

2020 Energy Storage Europe 11 & 12 MARCH, DUSSELDORF, DE www.eseexpo.com

NEXT EDITION IS OUT IN SEPTEMBER FOR WIND ENERGY HAMBURG READ WIND ENERGY MAGAZINE THE FIRST YEAR WITH 25% DISCOUNT

Belgian Offshore Days 18 & 19 MARCH, OSTEND, BE

Subscribe at

www.belgianoffshoredays.be

Windenergie-magazine.nl/abonneren

WINDFORCE Conference 12 & 13 MAY, BREMERHAVEN, DE www.windforce.info

3i-Event 14 MAY, THE HAGUE, NL 3i-event.com

DAILY REPORTING ON THE DUTCH WIND ENERGY INDUSTRY IN ENGLISH AND DUTCH!

Seanergy 9 -12 JUNE, SAINT-NAZAIRE, FR www.seanergy-forum.com

energy magazine

Global Offshore Wind 16 & 17 JUNE, LONDON, UK energy

events.renewableuk.com/gow20

magazine

nieuws

WindEnergy Hamburg 22 & 25 SEPTEMBER, HAMBURG, DE www.windenergyhamburg.com

Windenergie-nieuws.nl (NL) Ingenieurs in Energietransitie

Windenergy-magazine.com (EN)

17 NOVEMBER, TBC, NL www.vakbladen.com

42 | 01-2020

For advertising or content contribution go to www.windenergie-magazine.nl/contact

JOBS IN ENGINEERING, ICT, CHEMISTRY & LIFE SCIENCES Bètabanen is improved!

With a wider platform, more jobs, additional placement options and attractive pricing.

Visit the improved website today! www.betabanen.nl

MME GROUP • Non-destructive Testing • Metallurgical Laboratory • Marine Surveys • Rope Access • Playground and Recreational Safety • NDT Training Courses • Cathodic Protection (CP) • MGPS (ICAF) • Harbinger Boarding Equipment

A Longer Life

www.mme-group.com