Much has been written about the anticipated large solar array in the Mojave Desert, and the unexpected problems posed by the native population of endangered desert tortoise, the official reptile of the state of California.
While that is still being sorted out, SolarReserve, a Santa Monica-based company, is working on a different type of solar project.
If you’re a fan of this blog site, you may recall I did a story back in 2009 about SolarReserve and its unique application to build a 150-megawatt solar farm in the Sonoran Desert that would store seven hours of the sun’s energy in molten salt. SolarReserve holds the exclusive worldwide license to the molten salt solar power tower technology developed by Pratt & Whitney Rocketdyne, which was successfully demonstrated at the Solar Two power plant in Southern California in the late 1990s.
Now SolarReserve has announced progress on its latest solar – molten salt project – the Crescent Dunes Solar Energy Project, a 110 MW solar thermal power plant located near Tonopah, Nevada.
So far, the company has completed the 540 foot tower for the project. When construction is complete and the plant comes online, this plant is expected to be able to supply Utility NV (Nevada) Energy with solar power between noon and until 10 p.m. or midnight, providing the bulk of that to Las Vegas. Its 10-hour ability to store solar energy through the use of molten salt will make it the longest full-load storage capacity for a solar plant.
The Crescent Dunes project’s general contractor plans to begin installing a field of 10,000 heliostats – billboard-size sun-tracking mirrors – around the tower this summer. Sunlight will be reflected onto a 100-foot receiver which houses a series of tubes of circulating salt. The heliostat field will be about two miles across.
The technology is fascinating.
Salt is stored in a tank at 500 degrees. It’s then pumped up from the base and heated. The salt is then circulated down into another storage tank. When the utility calls for power, the hot salt goes through another heat exchanger on the ground to make steam which drives a traditional electric turbine.
The Crescent Dunes project will produce about 500,000 megawatt-hours per year. A traditional solar photovoltaic project with 110 megawatts capable of peak output would produce less than half that energy on a yearly basis, said Kevin Smith, SolarReserve’s CEO.
There are plenty of pluses to utilizing this technology, not the least of which is that the per kilowatt price of energy it produces is projected to be 13.5 cents per kilowatt-hour. It will go up 1 percent a year during its 25-year power purchase agreement. Still, that’s cheaper than a new nuclear power plant or a coal plant with carbon capture and storage, said Smith, but more expensive than a new natural gas plant.
The technology has already proven itself. But it will be interesting to see if the environmental impact of such a huge operation on potentially vulnerable desert wildlife will be harmful or benign. Like the Mojave Desert project, time will tell.
Filed under: Solar Power Tagged: | carbon capture, coal plant, Crescent Dunes Solar Energy Project, desert tortoise, endangered, environmental, Las Vegas, Mojave Dessert, molten salt, nuclear power, photovoltaic, Pratt & Whitney Rocketdyne, solar, solar thermal, SolarReserve, Sonoran Desert, technology