A variety of fluids have been tested to transport the sun’s heat, including water, air, oil, and sodium, but molten salt was selected as best. Molten salt is used in solar power tower systems because it is liquid at atmosphere pressure, it provides an efficient, low-cost medium in which to store thermal energy, its operating temperatures are compatible with today’s high-pressure and high-temperature steam turbines, and it is non-flammable and nontoxic. In addition, molten salt is used in the chemical and metals industries as a heat-transport fluid, so experience with molten-salt systems exists in non-solar settings. [Source Wikipedia]
California has approved a new solar project that could revolutionize how we use energy from the sun – namely because it will be able to keep producing electricity even after night falls. SolarReserve‘s Rice Solar Energy Project uses molten salt to store solar thermal energy. Since the salt will be able to reach temperatures over 1000 degrees Fahrenheit and retain most of the heat it collects during the day, the plant will have the ability to keep churning out heat long after the sun goes down.
Read More at Inhabitat.