The 130 turbine project is expected to provide clean electricity to approximately 75% of households in Cape Cod and the surrounding islands. The decision is likely to trigger the approval of at least half a dozen more projects along the east coast of the US and in the Great Lakes region.

According to Christian Kjaer, chief executive of European Wind Energy Association (EWEA), the approval of the US offshore wind farm marks the birth of a new phase in offshore wind power. The decision is the first step in the transformation from a European market into a new global market led by European companies.

Currently, almost 100% of global offshore turbines are installed in European waters by European developers using European turbines: 830 turbines in nine countries, totalling over 2,000MW of installed offshore capacity at the end of 2009. The UK has reached a record 1,000MW in offshore wind installations, EWEA said.

Mr Kjaer added: “Europe pioneered the onshore wind industry and possesses a clear first-mover advantage in offshore wind energy, which must be retained. We are seeing strong signals from governments all over the world wanting to harness the enormous potential of offshore wind energy to produce carbon-free electricity while powering millions of households.”

In Europe, EWEA estimates that offshore wind projects in the pipeline – more than 100,000MW – will provide 10% of total EU electricity demand.