BT is to go green by using wind farms to generate up to 25 percent of its existing UK electricity requirements by 2016.
The wind farm scheme represents the UK's biggest corporate wind power project outside of the energy sector.
The project, costing up to £250m, will bring together third party funding and renewable energy partners to safeguard future supplies of green energy for BT as part of the company's strategy to reduce carbon emissions.
BT is one of Britain's biggest consumers of electricity, with an annual requirement of around 0.7 percent of the UK's entire consumption.
BT's wind farms could generate a total of 250 megawatts of electricity - enough to meet the power needs of 122,000 homes or a city the size of Coventry.
The telecom giant is currently identifying high wind-yield sites on or adjacent to BT-owned land for development with the aim of generating power from 2012 onwards.
BT's group finance director Hanif Lalani said: "There is a pressing need for industry to cut carbon in ways that make business sense. BT has already achieved a 60 percent reduction in its carbon emissions, and is committed to reducing them further to 80 percent by 2016. Our wind energy plans play an important part in reaching that target."
Secretary of state John Hutton said BT's initiative was "a great example of how businesses can contribute and help us meet our ambitious target to dramatically increase the amount of energy we get from renewable sources. I hope that other organisations and individuals will be inspired to match their commitment."
BT already benefits from the UK's biggest green electricity contract, and in January extended its deal with nPower and British Gas Business.