Storing solar energy in salt

This article describes the world`s largest power tower incorporating one of the newest commercial solar energy systems and being build in California`s Mojave Desert. The project -- sponsored by the Department of Energy (DOE) and a consortium of western utilities, municipalities, and associations -- is called Solar Two, and it will use molten salt to absorb solar energy and store that energy until it is needed to generate electricity. Construction will be completed on Solar Two in September. Solar thermal systems convert the sun`s rays into electricity by using a thousand or more dual-axis, sun-tracking mirrors, called heliostats, to focus optimum sunlight on the solar receiver of a power tower containing a working fluid. The fluid is heated to a desired temperature and sent to a storage facility. During periods of peak demand, the fluid is circulating through heat exchangers to generate steam used to drive a turbine.