April 2, 2008

The Mojave Desert is mostly known for its relentless heat that pours down from the beaming sun. In a move of turning lemons into lemonade, PG&E has announced the building of three large solar power plants to be built in the barren region, enough to power 375,000 homes. PG&E signed the biggest contract in its history today with BrightSource Energy, which will build the solar thermal plant facilities. They could be up and running as early as 2011.

The announcement comes amid a looming deadline, which states that by 2010, publicly owned California utilities such as PG&E must get 20 percent of their power from renewable sources. However, they can meet the requirement with contracts if the projects are operating by 2013. PG&E has already exceeded that goal through its contracts, according to the San Jose Mercury News.

The power plants will rely on recycled groundwater. Water used to spin turbines will be cooled “through a system much like a car radiator” and fed through the process again. Unlike traditional panels that sit on roofs of buildings, solar thermal plants use curved mirrors to focus sunlight on liquid-filled tubes. The concentrated light heats the liquid, which is used to generate steam and run a turbine.

This ambitious project is consistent with calls to reduce greenhouse gas emissions in California. Supplying power to buildings is one of the major sources of emissions and it is encouraging to see action in mitigating this ongoing issue.