Pattern Energy Group LP, a closely held energy developer, said its Ocotillo wind farm in southern California has begun providing power for Sempra Energy’s San Diego Gas & Electric utility.

The 265-megawatt project in Imperial Valley entered operation last month, San Francisco-based Pattern said today in a statement. Ocotillo consists of 94 Siemens AG (SIE) turbines, and an additional 18 will be installed in the spring to provide enough energy for about 125,000 homes a year once fully operational, according to the statement.

SDG&E has a 20-year contract to purchase all of Ocotillo’s power. The wind farm is the first clean-energy project to transmit power across the utility’s 117-mile (188-kilometer) SunRise Powerlink transmission line, which was completed in June and will eventually deliver 1,000 megawatts of electricity into San Diego, Pattern said.

To contact the reporter on this story: Andrew Herndon in San Francisco at aherndon2@bloomberg.net

To contact the editor responsible for this story: Jasmina Kelemen at jkelemen2@bloomberg.net