The Thanet Offshore Wind Farm – the world’s largest – is to receive £150 million in backing from the European Investment Bank (EIB).
The funding goes to Swedish energy company Vattenfall, which built the £780 million 100-turbine wind farm off the Kent Coast.
The EIB, which offers long-term loans to projects meeting EU policy aims, described the farm, which is seven miles off Foreness Point in Thanet, as "an important step in enabling the UK to achieve renewable energy targets and generating 15 per cent of energy needs from renewable sources by 2020".
EIB vice-president for the UK Simon Brooks said: "The Thanet Offshore wind farm demonstrates how offshore wind can achieve economies of scale and make a significant contribution to renewable energy supply. The EIB is committed to supporting expansion of the offshore sector to increase experience and drive commercialisation of cutting edge technology."
EIB support was conditional on the farm meeting a series of environmental assessments, including an evaluation of the project's potential impact on marine and birds.
Johan Gyllenhoff, Vattenfall's group treasurer, said: "We are proud to have built the world's largest offshore wind farm, and we are very pleased with EIB long-term funding support at attractive terms and conditions, providing an alternative to bond markets."
Work began on the Thanet Offshore Wind Farm Work in 2008 and it was completed in June last year. The farm was inaugurated in a ceremony three months later. The 380ft-high turbines are spread over an area of nearly 14 square miles and can generate enough electricity to power 200,000 homes.
Vattenfall also owns the 30-turbine Kentish Flats wind farm, off Herne Bay, which was one of the UK's first such projects when it opened five years ago.
The EIB, which is expected to fund a transmission link connecting the Thanet wind farm to the national grid, is also supporting the London Array Offshore Wind Farm, work on which began in March this year. When completed it is expected to take over the title of the world's largest offshore wind farm, supplying energy to 750,000 homes - about a quarter of Greater London.
The EIB, owned by the EU member states, uses funds to back EU-related projects from motorways and rail links to hospitals, universities, high-tech industries and energy schemes. Between 2006 and 2010, it has given long-term low-interest finance totalling more than £17 billion to UK developments.