Europe's largest onshore wind farm, in East Renfrewshire, is set for a massive expansion.
Operator ScottishPower Renewables will add another 75 turbines to the Whitelee wind farm south of Glasgow by 2012.
This will bring the number of turbines on the site to 215, and raise electricity generating capacity by two thirds.
The 140 turbines currently at the wind farm can produce enough electricity to power 180,000 homes. The expansion will increase its generating capacity increase from 322MW to 539MW, enough to power about 300,000 homes.
Simon Christian, UK director of ScottishPower Renewables, said: "The agreement with Alstom means that work will start shortly on this major extension at Whitelee wind farm, and we expect to be generating electricity by 2012.
"By itself at 217MW, the extension would be one of the largest onshore wind farms in the UK, so we are starting another major construction project in Scotland.”
Christian said the extension project would also provide up to 200 jobs.