The cable connection for the Krieger's Flak offshore wind farm - being developed in the Baltic Sea by entities from Sweden, Denmark and Germany - is nearing realisation as the first high voltage grid to be built at sea. The transmission grid will transport power from the project, improve grid connection between the three involved countries and function as the blueprint for future offshore high voltage grids in the North Sea and elsewhere.
Krieger's Flak was one of seven potential sites selected for development by an expert offshore wind power panel set up by the Danish government in 2005 to find locations for 4.6 GW of offshore wind capacity. For economic reasons, however, it was one of the lowest ranking in terms of priority. That is now changing, paradoxically also for economic reasons: a subsidy of EUR150 million is now in the offing under the EU's Economic Recovery Plan (Windpower Monthly, June 2009) for the project's cabling. As a result, Krieger's Flak is likely to be among the next wave of Danish offshore wind developments.
All three involved transmission system operators, Denmark's Energinet.dk, Sweden's Svenska Kraftnatt and Germany's Vattenfall Europe Transmission, point out that the Krieger's Flak network can clear some of the bottlenecks that continue to bedevil both the transmission of power and electricity trading in the north European electricity market. The same advantages could also be achieved with a North Sea high voltage grid between Britain and the European mainland, proponents believe.
While the political decisions with regard to Krieger's Flak are being taken by Sweden, which has selected Vattenfall as operator and developer of the part of the project in Swedish waters, and by Germany, where large utility EnBW has the task of installing 80, 3.5-5 MW turbines in German waters, Denmark is in the process of re-evaluating its offshore wind power plan from 2005 to give Krieger's Flak greater priority.
A decision on the EU grant is expected next month and the pressure is now on Denmark to speed up its third of the project process. All EU member states have until July 1, 2010, to present detailed plans for how they intend to meet their renewable energy production commitments under EU law for 20% of energy to come from renewable sources by 2020.
In five years
Vattenfall is intending to install the first 128, 5 MW turbines at Krieger's Flak by 2015. The site has the best offshore winds in Swedish waters, with an average annual wind speed of 9.5 m/s, says Vattenfall's project manager, Goran Loman. Furthermore, it lies outside major shipping routes, is not environmentally sensitive and the geological conditions are good. The added advantage of using the project to improve the high voltage connections between the three countries makes Krieger's Flak a winning location. In Denmark, Krieger's Flak development director Peter Jorgensen says that better interconnection across the Baltic Sea will make the north European electricity market more competitive and increase security of supply, to the benefit of consumers. Jorgensen says the economics of the offshore grid are "really good" since it can be used for power trading at all times the offshore wind farm is not producing at full capacity.
To date, Denmark's plans for Krieger's Flak are two times 200 MW, but Christian Grumstrup Sorensen from national energy company Dong Energy says there is potential for 800 MW in Danish waters. Dong is among the favourites to take on development and construction of the Danish part of Krieger's Flak, along with German utility E.ON and the Swedish division of Vattenfall, which already owns more wind power in Denmark than any other single entity. Once complete, Krieger's Flak could have an installed capacity of 1.8 GW and in ten years could be meeting the electricity requirements of two million households.