An interconnected grid of North Sea wind farms with an output of 68,400 megawatts could serve up to 70 million households by 2030, Jan Vande Putte of Greenpeace Belgium told journalists at a briefing in Brussels on 3 September.
Constructing such a grid, as outlined in a new report commissioned by Greenpeace, would cost around €15-20 billion. Lucrative cross border electricity trading would allow investors to quickly recuperate the construction costs, according to the NGO.
"Building a North Sea grid is not just a pipe dream; it's common sense both environmentally and financially. Greenpeace calls on the Commission to deliver a strong EU Action Plan for offshore wind and to push for a coordinated approach to make this scenario a reality," said Greenpeace campaigner Frauke Thies in a statement.
The Commission is due to present an action plan on offshore wind this autumn, as part of a wider EU Strategic Energy Review. The plan will include recommendations on how to coordinate member states' efforts to realise such large-scale offshore wind projects, according to Commission official Hans van Steen, who attended the briefing.
Van Steen, who is head of unit for renewables regulatory policy in the Commission's energy directorate (DG TREN), welcomed the report, describing it as "very good" and "convincing".
"We do need a relatively large contribution" from offshore wind to realise the EU's 20% target for renewable energy use by 2020, he said. And although the target of nearly 70,000 MW is "ambitious", it is nonetheless "realistic", he added.
The right mix
Despite this endorsement, the Commission is at odds with Greenpeace over how to back up such a grid.
Wind turbines cannot guarantee a constant level of electricity production at all times and must be integrated with other electricity sources, including power storage facilities, that can be called upon when the wind is not blowing.
"Due to their must-run status, nuclear power plants cannot complement deviations between supply and demand" caused by fluctuations in wind power generation, according to the report. Other measures are preferred, including stored electricity in the form of reservoir hydro power, home or district-based power generation and gas-fired power stations that can respond quickly to increases in electricity demand, it says.
But the Commission "is not entirely sure" whether such a grid could be complemented by nuclear or even coal-fired power stations, Van Steen said. Brussels has come out firmly in support of nuclear as a key part of the EU's future energy mix, and the EU is pushing for the continued use of coal under the condition that coal-fired power plants can be made 'clean' through carbon capture and other technologies.
Taming the consumer?
Among the mechanisms proposed in the report to ensure that a massive wind power grid can be relied upon to provide a reliable power supply is 'controllable demand'.
"The concept is based on reducing demand during periods of scarcity [...] and shifting it to periods of abundance," explains the report.
Price mechanisms, whereby electricity is cheaper in times of higher output and more expensive at lower production times, could be used in such a scenario, explained Achim Woyte of the consultancy 3E, which prepared the report. And power storage facilities could be loaded at times of high (and cheap) output to be called upon later.
But while certain large industrial installations already make use of such mechanisms, implementing demand control at household level would be much more difficult, Woyte added.