BrightSource Energy Inc. has won a $1.4 billion loan guarantee from the U.S. Department of Energy to build three concentrated solar power plants in the Mojave Desert, just weeks after the company scaled back plans to address concerns over the desert tortoise.  The complex will generate 392 megawatts of electricity using thousands of mirrors to focus the power of the sun to create steam that drives electrical turbines. It'll produce enough power for about 140,000 homes. Pacific Gas & Electric and Southern California Edison Co. signed up to buy power from the plants, which will be built by Bechtel and create about 1,000 construction jobs and 86 permanent jobs. Construction on the first plant is expected to begin in the second half of 2010.