Alstom, the turbine manufacturer, and American Electric Power, the US energy supplier, are to build one of the world's largest trials of "carbon-capture" technology that they hope will cut carbon emissions from coal- and gas-fired power stations.

The two companies said yesterday that they would start with a pilot project to capture emissions of carbon dioxide from AEP's 1,300MW coal-fired Mountaineer plant in West Virginia. Alstom said the project would be ready at the end of 2008 and run for 12-18 months.