Plans to create the world's biggest alternative energy source in the North Sea have been put on hold.

Six vast wind turbines were supposed to have been producing electricity since last October. Some of the parts for the project, backed by German energy firms E.ON and EWE and Swedish power company Vattenfall, have been delivered but there are no immediate plans to put them together.

“We are sliding towards a dangerous crisis in offshore wind power,” says Fritz Vahrenholt, director of RWE subsidiary Innogy, which operates wind farms along the British coast.

Innogy wants its new Offshore Park Innogy Nordsee 1 to generate 960 megawatts of energy, the equivalent of a nuclear power station. Total investment is expected to be €2.8 billion (£2.5 billion), and the wind farm is to be completed by 2015.

However, the financial crisis is putting the plans in jeopardy, while smaller wind farm investors have overextended themselves in their rush to sink money into pioneering technology.