Although proven technologically a half century ago, the use of molten salt to generate electricity has never before been commercialized. That may be changed soon as the dormant facility just off I-15 near Barstow, CA is reactivated and expanded to provide energy for 100,000 homes, the Los Angeles Times reports.
The article quotes Solar Reserve president Terry Murphy, owner of the plant.
The plant could begin operating by early 2013. It would use an array of 15,000 heliostats, or large tilting mirrors about 25 feet wide, to direct sunlight to a solar collector atop a 600-foot-tall tower -- somewhat like a lighthouse in reverse.
The mirrors would heat up molten salt flowing through the receiver to more than 1,000 degrees, hot enough to turn water into powerful steam in a device called a heat exchanger. The steam, like that coming out of a nozzle of a boiling tea kettle, would drive a turbine to create electricity.
The molten salt, once cooled, would then be pumped back through the solar collector to start the process all over again. "The plant has no emissions, and if you have a leak or something, you can just shovel it up and take it home with you to use for your barbecue," Murphy said.
The molten salt can be stored for days if not weeks and then used to generate electricity at any time. Many other solar technologies work only when the sun is shining. Storing electricity in a battery works for cars and homes but not on a massive scale that would be needed to power thousands of homes.
"You can put that into a storage tank that would look much like a tank at an oil refinery," Murphy said. "We can store that energy almost indefinitely."
While there are high hopes for the technology, some environmentalists have criticized solar-thermal plants for requiring vast tracts of land as well as precious water for generating steam and for cooling the turbines.
The array of the mirrored heliostats for the SolarReserve plant would take up about two square miles. Transmission lines would also be needed to transport the power where it's needed. With dozens of solar, wind and geothermal projects planned for California's deserts, some fear that this unique habitat will be destroyed.
But SolarReserve officials said that the plant would use one-tenth the amount of water required by a conventional plant and that mirrors will be "benign" to the environment.
The technology, with the exception of using salt, is similar to those that Rocketdyne engineers developed for the nation's more notable space programs.
Log in or create a user account to comment.