Vattenfall has been given the go-ahead by the UK Government for a 76-turbine wind farm between Neath and Aberdare in South Wales.
Pen y Cymoedd wind farm is estimated to generate enough electricity to power the equivalent of 206,000 homes a year. The turbines, each up to 145 metres high, will have a total capacity of 299 megawatts (MW), giving the wind farm the highest generating capacity of any onshore wind farm in England and Wales.
Vattenfall said it would cost around £300 million to build the wind farm, creating or supporting around 300 jobs in Wales, and once a final investment decision has been taken construction could start next year with the first electricity generated in 2016.
Charles Hendry, the UK’s Energy Minister, said: "Onshore wind plays an important role in enhancing our energy security. It is the cheapest form of renewable electricity and reduces our reliance on foreign fuel.
"This project in South Wales will generate vast amounts of home-grown renewable electricity and provide a significant benefits package for the local community."
The green light for the project comes after the Government released a joint report with industry body RenewableUK highlighting the benefits to the economy of onshore wind, including for local communities.
Vattenfall has pledged a benefits package to the community potentially worth £55 million, including £3 million for habitat management and £6,000 a year for each megawatt of electricity paid into a community fund.
Piers Guy, Vattenfall's head of onshore wind development in the UK, said: "Pen y Cymoedd is a major project that could be worth more than £1 billion to the UK economy.
"We have consistently stated our commitment to making sure that we maximise the value of Pen y Cymoedd to the region and to Wales. This is now our priority."
He added: "This project shows what onshore wind energy investments can offer Wales over the short and long term.
"Through this project we will be supporting the delivery of national and local priorities: from creating local jobs, supply chain opportunities and apprenticeship schemes to supporting tourism initiatives, community services and facilities."