German engineering firm REpower has sealed what is believed to be the largest ever contract in the offshore wind business, after signing a framework agreement with RWE for the delivery of up to 250 turbines.

The deal is worth a potential EUR2 billion for REpower, which is owned by India’s Suzlon, and will see the installation of the company’s 5M and 6M offshore wind turbines around the coasts of the Netherlands, the UK and Germany.

The framework agreement – between REpower Systems and RWE’s renewable energy arm RWE Innogy – schedules the first 30 units for delivery in 2011. These will be installed in the planned Innogy Nordsee 1 wind farm, a 960 MW installation off the coast of the East Frisian Island of Juist.

Delivery volumes will rise in subsequent years, says RWE. “The agreement allows for significant flexibility across the full range of our offshore projects under development, including important markets like the Netherlands and the UK,” said Kevin McCullough, COO of RWE Innogy.

The deal is also one of the largest contracts ever to be signed in the history of the wind industry, and indicates RWE’s commitment to continued investment in the offshore wind sector.

“This agreement underlines once again quite clearly that RWE Innogy is maintaining a high investment tempo even in times of financial crisis,” said Prof. Fritz Vahrenholt, Chairman of the Board of RWE Innogy.

Per Hornung Pedersen, CEO of REpower Systems AG, said: “This represents a positive signal for the entire wind industry particularly against the background of the current economic situation. When completed, Innogy Nordsee 1 will be able to make a significant contribution to the climate goals of the German government and the European Union.”

The Innogy Nordsee 1 wind farm will be located 40 km to the north of Juist and will involve the installation of 180 wind turbines of the 5 and 6 MW class in water depths of 26-34 m. It is due to be operational by 2015, according to data from the European Wind Energy Association (EWEA).

REpower’s 5M and 6M turbines are among the largest and most powerful wind energy systems in the world. The 5M and 6M turbines, with an output of 5 MW and 6 MW respectively, have a rotor diameter of 126 m and a turbine house the size of a semi-detached house.

REpower is currently installing the first three machines of the 6M series in an onshore project in Germany near the border with Denmark. There are currently 17 of its 5M units operational.