The windfarm will power 320,000 homes and create 200 jobs.
Plans to build Europe's largest onshore wind farm in South Lanarkshire have been approved by Scottish ministers.
The 152-turbine Clyde wind farm near Abington, will be capable of powering up to 320,000 homes.
The £600m scheme from Scottish and Southern Energy (SSE) is expected to create 200 jobs during construction, with 30 staff employed on completion.
At present, the largest wind farm in Scotland is currently being built on Eaglesham Moor to the south of Glasgow.
Details of the Clyde wind farm were announced by First Minister Alex Salmond at the World Renewable Energy Congress in Glasgow.
"The Scottish Government has an ambitious target to generate 31% of Scotland's electricity demand from renewable sources by 2011 and 50% by 2020," he said.
"Today's announcement makes it virtually certain that the 2011 target will be met early and represents a significant milestone on the way to achieving the 2020 target.
"Scotland has a clear, competitive advantage in developing clean, green energy sources such as wind, wave and tidal power.
"We have put renewable energy at the heart of our vision of increasing sustainable, economic growth."
The approval for the development between Biggar and Moffat follows a public inquiry which was concluded in 2006.
Construction is due to begin within the next year, with final completion in 2011.
The phased build will see turbines erected in clusters on either side of the M74 motorway.
Ian Marchant, chief executive of SSE, said: "Projects like Clyde are essential if Scotland and the UK are to have any hope of meeting legally-binding EU targets for renewable energy.
"Giving the Clyde wind farm consent is evidence of a willingness to take decisions which are consistent with that ambition."
Approval for the project was welcomed by WWF Scotland director, Dr Richard Dixon.
"The Clyde wind farm is a good proposal because it is close to major centres of population, who will use the power it generates, and away from Scotland's most valuable landscapes," he said.
"Scotland needs more of this sort of large, central belt wind farm to help us move quickly to clean, green energy."
Once operational, Clyde wind farm will will have a total capacity of 548 megawatts (MW).
The under-construction wind farm on Eaglesham Moor will have a total capacity of 322MW.
Currently the biggest operational wind farm in Europe is the Maranchon wind farm in Guadalajara, Spain, which has a generating capacity of 208MW.