Solar plant with molten-salt storage gets green light

Solar Reserve said today it has the federal permitting approvals it needs to begin construction of a concentrated solar power plant with enough storage to operate after the sun goes down.

The Santa Monica, Calif.-based company said the U.S. Department of the Interior approved the "record of decision" for a 110-megawatt solar thermal power plant in Nye County, near Tonopah, Nev. With the authorization, Solar Reserve expects it can start construction by mid-2011.

This Crescent Dunes project will use a field of sun-tracking mirrors, called heliostats, to reflect light onto a tower that holds molten salt. The heated molten salt flows to a storage tank and then is pumped into a steam generator, which uses a process called a Rankine cycle to generate electricity from the heat.

The storage will allow the plant to pump power into the grid all afternoon and up to eight hours after sunset. Storage is valuable to renewable-energy plant operators because supplying electricity at all times of the day allows them to charge more for their power.

Solar Reserve signed a power purchase agreement with NV Energy for the electricity produced at the plant, which should be enough to supply 75,000 Nevada homes.

The technology from Solar Reserve was licensed from United Technologies subsidiary Rocketdyne and is already used at another plant in the U.S. Solar Reserve is also developing projects in California and Arizona.