Southern California Edison said Friday that construction on the biggest U.S. transmission project for wind energy has begun.

The project is scheduled to be finished by 2013 and will be capable of carrying 4,500 megawatts of electricity, much of it from turbines in the windy Tehachapi area of northern Los Angeles County and eastern Kern County. That is enough to power about 3 million California homes, Edison said in a statement.

Power generated by wind at the end of 2007 in the U.S. was almost 17,000 megawatts — California is second with about 2,500 while Texas leads the U.S. in wind power with about 4,500 megawatts.

The ambitious Tehachapi plan consists of 11 phases, with the first to be completed in 2009. In all, the project will cost about $1.8 billion and is part of a $5 billion transmission expansion plan proposed by the Rosemead-based utility company.