US investor-owned utility Southern California Edison (SCE) has signed power purchase agreements with Solar Millennium, LLC.

The agreements, which are subject to approval of the California Public Utilities Commission, call for the development of two, 242 MW power plants, with the option to expand to include a third 242 MW plant, for a total of 726 MW of solar thermal power, and provide for the purchase of the output by SCE over 20 years.

All three parabolic trough solar power projects are expected to begin operation between 2013 and 2014. Investment for these utility-scale plants is estimated to be over $1 billion each.

The projects will interconnect to transmission lines close to the site locations near Ridgecrest, Desert Center, and Blythe, California.

The joint venture of Solar Millennium AG and MAN Ferrostaal Inc. will be involved in the construction of the plants.

In February this year, SCE had signed a series of contracts with BrightSource Energy for 1300 MW of solar thermal power.

Read more: SCE, Solar Millennium