BrightSource Energy is planning to complete construction of one of world’s largest solar thermal power plants this year, and is now betting on an even more massive project that it hopes will come online by 2016. The Oakland, California, company’s first utility-scale plant, its 370-megawatt Ivanpah facility in the Mojave Desert, uses thousands of software-controlled mirrors to direct sunlight at three central towers that produce steam and power a turbine (see “In Pictures: The World’s Largest Solar Thermal Power Plant”). PG&E and Southern California Edison have entered long-term contracts to buy power from the three units of the project, a sprawling 3,500-acre installation that cost $2.2 billion and is slated to start firing up this summer.