One hundred megawatt offshore

Google Translate

Dutch plans for large scale offshore wind farms are poised to come off the drawing board following environmental agency Novem's thumbs up to a proposed 100 turbine, 100 MW near-shore experimental wind plant off the North Sea coast. Commissioned by the Dutch economic affairs ministry, Novem's feasibility study reckons the experimental plant could be up and running in the North Sea by 2001 and will provide valuable pointers regarding the functioning, maintenance and ecological impact of offshore wind projects.

Wind development offshore is regarded as a necessity in the Netherlands if the government is to realise its target of a 10% reduction in fossil fuel consumption by 2020 through the use of renewable energy sources. Under these plans, wind energy is to account for some 20% of renewable power production, and planners believe the Netherlands simply lacks the space to set up the necessary wind plant on land. "The generation of wind energy at sea must make a major contribution to the government's targeted savings on fossil fuels," Novem says.

According to Novem's report, presented to economic affairs minister Hans Wijers in late November, there are no "unsurpassable obstacles to the realisation of a near shore wind energy plant of circa 100 MW." From an ecological, technical, and planning perspective the project is viable, asserts the supervisory committee's chairman, Jan van der Vlist.

With costs of the project estimated at some NLG 450 million, however, financing may well prove a major hurdle. The study points out that existing tax breaks aimed at promoting renewable energy sources would not be enough to boost the project's profits to a level attractive to investors. Consequently some form of government subsidy will be needed, the study cautions.

This recommendation has already been taken up by government, despite the liberalisation of the Dutch energy market and an end to direct subsidies for wind development in 1995. Accepting the report, Wijers says the project qualifies for assistance under the government's CO2 reduction programme and that some NLG 60 million of the programme's multi-million budget will be reserved for an offshore project subsidy. "I hope the first electricity generated at sea will be in use by the beginning of the next century," says Wijers, labelling the experimental project "a challenge to Dutch industry."

Hurdles ahead

The money pledged by government so far may prove insufficient, however. While the Novem study states that at least NLG 40 million must be made available, this could rise to as much as NLG 120 million if the market value of the electricity generated falls to NLG 0.12/kWh from the projected NLG 0.14/kWh.

Another hurdle to be cleared is the lengthy planning procedure. While municipal ordinances and zoning plans stipulate the uses to which sites on land may be put, no such zoning plan exists for the North Sea. The wind farm project may well have to compete with other planned offshore projects such as an extension to Amsterdam's Schiphol Airport.

The report recommends that the government make the final decision on where the wind farm should be located after extensive consultations with potential investors, nature and environmental organisations and other relevant lobby groups. It also recommends that a study be conducted into the wind farm's impact on the environment which, while not required by law, would increase public support for the scheme. All in all, planning permission is expected to take around two years.

Public interest has focused on the wind plant's likely location. The feasibility study identifies two potential sites -- one about eight kilometres off the coast of IJmuiden in the province of North Holland and another in the mouth of the Western Scheldt river in the southern province of Zeeland. Novem favours the IJmuiden site, which would cost some NLG 456 million to develop and generate an estimated 250-300 GWh a year.

Although the Western Scheldt option is cheaper at around NLG 446 million -- and involves working in shallower waters -- its power output would be 15% down on the IJmuiden site. "Based on the spatial and ecological consequences for the two research locations worked out for the project, the IJmuiden 2 (location) transpires to be slightly favoured," Novem states, adding "the technical and economic conditions show a clear preference for IJmuiden 2."

Bridging the gap

The project is intended as a preliminary step to the development of larger wind farms further into the North Sea. This "experimental" dimension is emphasised throughout the study. Earlier studies have shown that construction costs increase the further offshore a wind farm is sited, due to the deeper waters which require heavier supports for the turbines. Consequently only large scale wind farms of several hundred megawatts are likely to be economically viable a long way offshore, but the high initial cost coupled with a lack of experience in this field would make such a project too much of a financial risk.

The near shore project will bridge the technology gap at a fraction of the price, and any potential developer would have to take into account the project's research dimension, the study says. The most important aspect is how the turbines can be adapted to make them more suitable for offshore use, the study concludes.

Based on existing technology, the near shore project must seek ways of scaling up the turbines to increase their capacity while at the same time reducing the need for maintenance. Remote monitoring and control of the turbines is also required and their resistance to the corrosive effects of sea water will also need to be increased. For this to be achieved, contractors must first conduct a land based programme which includes a compulsory test period of at least one year for insurance purposes, the study recommends.

Meanwhile residents near the two sites earmarked for possible development broadly favour more wind power. Of the 1200 people polled, 94% say they think wind energy is a good idea. Over 90% of the poll's respondents in the Western Scheldt area reacted positively to the notion of a wind farm being situated in the river mouth, while 87% of IJmuiden respondents approved the construction of a wind farm eight kilometres out to sea.

Have you registered with us yet?

Register now to enjoy more articles
and free email bulletins.

Sign up now
Already registered?
Sign in