Back to Main Menu

Offshore Wind Power Pilot Projects Learning from International experience

Rajendra Kharul, Director and Head -
Siddharth Arora, Sr Research Associate -
Centre for Wind Power, World Institute of Sustainable Energy (WISE)

With India inching towards its first offshore wind power demonstration project, it can learn a great deal from international experience; especially from the European nations. The MNRE has set a target of putting up the project in the next few years, and the experience and learning from the mistakes of various European projects can help in avoiding any delays and addressing challenges in setting up of initial offshore wind power projects in India.

Horns Rev, Denmark

The Horns Rev project in Denmark was the first offshore wind farm built in the North Sea (Gerhard Gerdes, Albrecht Tiedemann, drs. Sjoerd Zeelenberg) established as part of Danish Offshore Action Plan, 1997. The project capacity is 160 MW with 80 turbines of Vestas V80 – 2 MW (4coffshore). The entire wind farm was commissioned in July 2003. There were no major delays in the project as Denmark had initiated the screening process for offshore wind farms in the early 1980s. The approval process consisting of EIA, public hearings, planning consent of local stakeholders, building permit, etc. for the offshore wind farm site was more or less covered by the early screening process. The complete approval process was organized by the Danish Energy Agency (DEA), a one-stopshop for all the approvals.

Horns Rev offshore wind project

In the framework of the approval process, environmental issues did not pose problems but approximately tourism issues did. The tourist organizations and the local municipality demanded that offshore wind farm be developed further out in the sea; from the planned 14 km from the coastline. However, DEA rejected their demands. Later on, the tourist organizations in fact took a positive view of the offshore wind project.

The commissioning of the Horns Rev offshore wind farm was planned for December 2002. Due to multiple problems after installing all the 80 turbines, the commissioning date was extended to July 2003. The main reason for the long commissioning period was the delay in assembling the turbines before shipment and installation. The selected wind turbine type, the offshore version of Vestas V80, was still at the prototype stage at the time of installing Horns Rev. Vestas had to make some improvements to the turbines during assembly and installation. These improvements led to a considerable delay in the wind farm installation.

During the operation of the wind farm, quality issues surfaced for a number of components such as rotor blades, gearboxes, transformers, and generators in the individual turbines. A significant number of individual turbine transformers failed in the autumn of 2003 and wind farm availability sank to 50%. It turned out that the transformer winding insulation did not meet the required standards, and the transformer windings failed due to highly corrosive operating environment. In December 2003, a decision was taken to replace all the turbine transformers with those made by Siemens. The replacement went on from December 2003 to February 2004.

Severe problems related to the generator arose in 2004. To solve those problems, as well as problems with the rotor blade coating and the lightning system, it was decided to dismantle the turbine rotors and nacelles and ship them onshore. The plan was to have at least 30 turbines running all the time, but in fact only 4 were operating in September 2004. Dismantling of the turbines went at a much faster pace than estimated while the erection was delayed. All the turbines were made operational again by mid-December 2004.

Scroby Sands, United Kingdom

Scroby Sands is one of the first offshore wind farms in the UK( It has been online since 2004. E.ON UK Renewables Offshore Wind Ltd (EROWL) owns the wind farm. The wind farm is 2.5 km offshore of Great Yarmouth on the east coast of Anglia (Gerhard Gerdes, Albrecht Tiedemann, drs. Sjoerd Zeelenberg), and comprises 30 turbines with an installed capacity of 60 MW ( The water depth is 3–12 m ( The project was planned through basic technical studies. The work started with site assessment in 1993/94. In 1995, an anemometry mast was installed to gather wind resource data. The site was chosen because of good port facilities at Great Yarmouth and good grid connection facilities.

Scroby Sands offshore wind project

The wind farm was one of the first projects in the UK territorial waters. In general, the Scroby Sands offshore wind farm was a success. The main obstacles in planning and realizing the project were lack of experience and underestimation of the time required to plan the project. The schedule was unrealistically short at the start of the project. The tendering period was only six weeks, and the process had to be repeated as a result. The sub-sea cabling proved time consuming, and diver operations were hampered by strong tidal currents. Commissioning was thus delayed by rough weather.

The planning and construction of offshore wind farms were quite different from those of onshore wind farms. New experiences were gained, and the planning of an offshore wind farm turned out to be nearly as complex as that of a conventional power plant. The combination of electrical power generation and offshore technology was quite new and challenging.

Egmond aan Zee, The Netherlands

Offshore wind farm Egmond aan Zee (OWEZ) was the first wind farm to be built in the Dutch North Sea and served as a pilot project (Gerhard Gerdes, Albrecht Tiedemann, drs. Sjoerd Zeelenberg). Formerly known as Near Shore Wind farm (NSW), OWEZ is located in the territorial waters near Egmond aan Zee. It has a total capacity of 108 MW with 36 Vestas V90, 3 MW turbines. After a preparation period of over five years, the final investment decisions were taken in May 2005. OWEZ is owned and financed by NoordzeeWind (a consortium of Shell Wind Energy and Nuon Renewable Energy) and developed by Bouwcombinatie Egmond (BCE) (a consortium of Ballast Nedam Infra and Vestas).

OWEZ dates back to 1997, when the Dutch government decided to start a Dutch pilot project. Extensive stakeholder participation and inter-governmental consultation was carried out by a Key Planning Decision (KPD) procedure. Out of six locations, possible an area off the coast of Egmond aan Zee was selected on the basis of EIA; which was completed in February 2000 and included environmental, technical, and economic considerations. Another EIA was done for the spatial configuration of selected location.

NoordzeeWind was selected as the developer on the basis of a tender in July 2002. This consortium was granted the sole right to commence consent procedures and apply for financial support regulations and execute a benchmark environmental research programme.

The final investment decisions by Shell Wind Energy and Nuon Renewable Energy were taken in May 2005. Bouwcombinatie Egmond was appointed at an earlier stage, based on a lump-sum, turnkey EPC contract. Construction work on onshore installations took place at the end of 2005. Offshore construction started in March 2006. The plant became fully operational in January 2007 and total investment for OWEZ is about ¤217 million.

The Dutch government has played a significant role in the progress of the OWEZ project. In addition to the decision to build a pilot project, the location and ancillary conditions of OWEZ were determined by various ministries. Interested market partners were permitted to join the process only after the site, capacity and research programmes had been determined. The KPD procedure and the first EIA encouraged thorough consultation and harmony amongst the relevant authorities at local, provincial, and national levels. Subsequently, decision-making and consent procedures could be undertaken in a broader framework of agreement and consensus.

Thornton Bank I, Belgium

Thornton Bank I is the first offshore wind farm project of Belgium. The site selection and project proposal were undertaken by a private company, C-Power. CPower is a joint enterprise, set up by various private Belgian companies (Interelectra, Ecotech Finance, Socofe & Dredging International) and a French company (SIIF Energies) (Gerhard Gerdes, Albrecht Tiedemann, drs. Sjoerd Zeelenberg). The proposal was accepted by the Belgian government and was promoted to demonstrate offshore wind energy utilization in Belgium. The originally planned location was close to the coastline. Due to environmental concerns, the government decided to shift the wind farm 30 km further out into the sea ( and to designate an area specifically for offshore wind farms.

The increased distance to shore had a huge impact on the economic viability of the project, and thus the government agreed to improve the situation by subsidizing the grid connection by 30% and offering a guaranteed energy sales price. The Belgian government cleared the pilot phase in order to analyse the impact of the wind farm on the environment before developing the remaining phases.

The pilot phase was of 30 MW with 6 turbines of 5 MW each ( All the approvals were obtained by 2005 but the project was delayed by one year owing to delays in setting up the financing scheme. The project was fully commissioned in 2009.

Thornton bank offshore wind project
(Google Fusion Tables)

The total cost for the pilot project was about ¤153 million (Gerhard Gerdes, Albrecht Tiedemann, drs. Sjoerd Zeelenberg). Three issues had a large impact on the viability of the project. The government's decision to shift the wind farm further out to the sea led to increased costs for the grid connection, as did the decision to request a pilot phase with fewer turbines. The third issue was of information on the soil conditions at the Thornton Bank. Earlier site investigation could have revealed the need to use stronger and hence expensive foundations at an earlier stage as unavoidable given government's decision to locate the wind farm farther. This unfavourable situation was the result of lack of experience with offshore wind farms and could not be foreseen. However, financial adjustments by the government helped to rectify this situation.

Thus the major lesson for C-Power was to conduct site investigation at an early stage and to do so in detail to obtain as much soil data as possible as a basis for the further engineering.


Borkum West, German Storage site for the Borkum West (Alpha Ventus) offshore
wind project

Borkum West (now Alpha Ventus) was the first offshore wind farm project in Germany. The initiators, PROKON Nord Energiesysteme GmbH, tried to find a location without any other competing demands and or without any conflicts with nature preserves. The result was an area between two main traffic routes in the German Bight. The Borkum West project was designed with a comparatively small pilot phase, consisting of 12 turbines of 5 MW each ( and was the first offshore wind farm in Germany to receive a building permit from the Bundesamt für Seeschiffahrt und Hydrographie (BSH), the federal maritime and hydrographic agency. However, due to problems in gaining approval for a grid connection for the sea cable, the project was delayed considerably.

The project was planned to be built in 2 phases: a pilot project with 12 turbines of 5 MW each and the second extension phase of 196 turbines. Initial planning of the wind farm began in 1998 and formal project planning in 1999 (Gerhard Gerdes, Albrecht Tiedemann, drs. Sjoerd Zeelenberg).

The developer, Prokon Nord, had set up an investigation programme to cover all items of an EIA and, in September 1999, submitted the first formal application for a building permit in the EEZ to the responsible agency, BSH.

The project site was outside the 12 nautical miles (approximately 22.2km) limit of territorial waters to avoid conflicts with such tourism-oriented East Frisian North Sea islands as Borkum, Juist, and Norderney. The area between the shipping routes of the German Bight was selected to ensure maximum distance from both the routes. From the experience of first pilot project, two standard investigation concepts were launched in 2003 (Gerhard Gerdes, Albrecht Tiedemann, drs. Sjoerd Zeelenberg).

China, First concession round

China's first round of concession bidding started in September 2010. Project developers were selected through an evaluation process that looked at the bid's tariff, construction design, technological capacity, and performance record, although low electricity price and high equipment localization appear to have been the prevailing factors in determining the winning bidder. Four projects totalling 1 GW were selected in four subsidiary counties of Yancheng city, Jiangsu. Two projects were offshore and two were intertidal (Jeff Beyer, Strategy Manager).

These projects were originally expected to be built within four years, but construction commenced for three of the projects only in September 2013. This delay was in part caused by conflict and poor coordination between various government departments, particularly the National Energy Administration (NEA) and the State Oceanic Administration (SOA). While the SOA wanted wind farms to be built as far away as possible from the shore, saving space for fishing, transport, and many other uses, the NEA wanted the exact opposite to reduce the costs and technical challenges of installing wind farms farther from the shore. Whereas the NEA is committed to developing offshore wind farms in China, the SOA has no such mandate. Poor coordination has led to certain areas being designated for both offshore wind development and other activities, with developers having to relocate after spending on planning the original farm's development. In order to resolve this conflict, the NEA and SOA jointly released a new set of regulations and frameworks for offshore wind projects in 2010, delegating the responsibility for selecting developer bids and for agreeing on the feed-in tariff (FIT) rates to the NEA, and that of site approval to the SOA.

The other major obstacle making developers unwilling to start construction is the overly low FIT. Prior to this first concession round, the government had removed the regulation stipulating that the highest and the lowest bids be eliminated from the tender, which had been used to good effect in the early onshore concession rounds. The danger of selecting bids based on price is that it tends to produce extremely low bids. In order to win the project, some bidders intentionally underestimated the operating costs to get a lower price than other bidders. This created a bottom-bidding war to win the projects, with developers entering bids with low and unprofitable FITs (Jeff Beyer, Strategy Manager).

The learning from all these projects can assist India in not repeating the mistakes and avoiding the pitfalls that can affect the financial viability of its pilot project. The final policy for offshore wind projects in India is being shaped at present and the learnings from these projects can help in identifying the areas that can impact the offshore wind project and need to be addressed in the final policy.

Major learning from these projects are listed below.


  1. 4coffshore. (n.d.). Retrieved Devember 03, 2014, from :
  2. Gerhard Gerdes, Albrecht Tiedemann, and drs. Sjoerd Zeelenberg, 2005,. European Offshore Wind Farms : A Survey for the analysis of the experiences and lessons learnt by developers of offshore wind farms.Varel, germany: Deutsche WindGuard. 148 pp.
  3. Jeff Beyer, Strategy Manager. Offshore Wind in China - Sharing the UK's policy experience. Carbon Trust.
  4. (n.d.). Retrieved December 03, 2014, from
  5. (n.d.). Retrieved December 03, 2014, from
  6. (n.d.). Retrieved December 03, 2014, from
  7. (n.d.). Retrieved December 03, 2014, from
  8. (n.d.). Retrieved December 03, 2014, from
Back to Main Menu