Solar technology could lead to bigger power plants

A technology that has been under development in the US has been declared successful by the US Department of Energy and a private consortium led by Southern California Edison. Ultimately, the technology could lead to bigger solar power plants.

Solar Two, a 10 MW “power tower” project located in Bartsow, California has demonstrated a unique storage system, which can deliver power to the grid for 153 hours. It can also deliver electricity on demand on a 24-hour basis.

The $55m design uses 2000 sun tracking mirrors that reflect sunlight on to a receiver at the top of a 91 m (300 ft) tower. The receiver is made up of hundreds of vertical tubes that have molten salt flowing through them.

The concentration of sunlight on the tubes heats the salt to as high as 565 degreesC (1050 degrees F). It then flows to a tank at the bottom of the tower where it is either stored or sent to heat water to produce steam for a nearby steam turbine-generator.