Facility that can power 180,000 homes already scheduled for further expansion

The final section of Europe's biggest on-shore wind farm is coming on stream in Scotland, but plans are already under way for expansion.

The £300m Whitelee development in East Renfrewshire already contains 140 huge turbines, each around 110m high, across an area about the size of Glasgow city centre.

Developer ScottishPower Renewables estimates that the farm will generate enough energy to power 180,000 homes.

The group plans to add 81 extra turbines to the site. An application for the first 36 of these is being considered by the Scottish government.

The wind farm contains 140 huge turbines, each 110m high, with plans for 81 more

The farm started producing electricity in January 2008, and as the site nears completion the final stream of turbines is being switched on.

Scotland's first minister, Alex Salmond, is scheduled to perform the official switch-on.

Keith Anderson, director of ScottishPower Renewables, told the BBC the farm was a landmark for the UK given its size and scale, as the first 300MW wind farm in the country.

But he warned more work was required on infrastructure to develop the industry, with particular focus needed on improving power grid connections and capacity to handle larger offshore wind farms and wave and tidal projects.