Last week SolarReserve announced that it completed assembling the molten salt receiver panels that top the 540 foot solar power tower at the Crescent Dunes Solar Energy Plant near Tonopah, NV. When it’s completed and commissioned later this year, the 110 megawatt concentrating solar project will be the first commercial-scale CSP project in the U.S. to use thermal energy storage, allowing it to store enough energy to produce electricity for 10 hours without the sun, according to SolarReserve.
The system is one of a handful of giant CSP systems that are nearing completion in the U.S. southwest. Others include BrightSource’s Ivanpah Solar Energy Generating System, a three tower, 377 megawatt CSP system that is also slated for completion this year. However, that system doesn’t feature energy storage and can generate electricity only during the day.
“This technology can generate almost twice as much energy as a comparably sized solar facility, including facilities powered by photovoltaic panels or by a direct steam tower,” said SolarReserve CEO Kevin Smith. The Crescent Dunes system is located on roughly 1,600 acres of Bureau of Land Management-managed land. For comparison BrightSource’s Ivanpah project is located on 3,500 acres of BLM land.
To minimize the need for water cool the system at Crescent Dunes it uses a low-water hybrid cooling system. “A combination of both wet and dry cooling, depending on the ambient temperature of the air,” Mullenix said. “This hybrid system will save up to 600 acre-feet per year of water when compared to a traditionally wet-cooled power plant. We have the option to utilize dry cooling in markets if necessary, but that becomes a market choice as well as an economic and engineering choice.” The dry-cooling systems can be more expensive to implement, however.
SolarReserves CSP systems can be sized as needed, according to SolarReserve Senior Vice President of Operations Stephen Mullennix. “Our CSP technology can be sized to whatever nameplate the utility desires. For example, the almost identical plant in Rice, CA which we plan to finance this year, will have a 150 MW turbine nameplate capacity,” he said. Both systems will generate approximately 500,000 megawatt hours of electricity annually. “Ultimately, the customer’s needs determine if we put a larger turbine or a smaller turbine on the generating side, and thus whether we deliver power over greater or fewer hours per day. In the extreme, if a utility customer would want power delivered 24 hours per day, we would do so with a smaller nameplate capacity.”
The Crescent Dunes project is SolarReserve’s leading project, but it’s also developing other projects, like the Rice project and other projects in South Africa. The Rice Solar Energy Plant, which has a 25-year PPA with PG&E, is scheduled to begin construction activities in early 2014, Mullenix said. The company is also in late stage development at the Crossroads Solar Energy Project and the Quartzsite Solar Energy Project, both in Arizona, and the Saguache Solar Energy Project in Colorado. “All of which are fully permitted and are in the power marketing phase. Internationally, we have a number of CSP projects in development in Spain, South Africa, the Middle East North Africa (MENA) region, Latin America and Australia,” he said. “Our view is that we will continue to be successful in the US, and will also focus keenly on key international markets.”
While Mullenix said the company’s core business is CSP with energy storgage, it’s also developing some photovoltaics. “On the PV side, we have the two 75 megawatt projects in construction in South Africa. We have won the additional 88MW tender in South Africa, and we will bid additional PV projects in subsequent bidding rounds alongside our CSP project bids,” he said.