A soaring structure on the south side of the Department of Energy’s National Solar Thermal Test Facility combines two cutting-edge technologies in concentrating solar energy (CSP).
A soaring structure on the south side of the Department of Energy’s National Solar Thermal Test Facility combines two cutting-edge technologies in concentrating solar energy: Compact Linear Fresnel Reflectors and molten salt thermal storage. Using them together is a pioneering concept.
A team of Sandia National Laboratories and AREVA Solar engineers examines the focal point of the sunlight reflected from the rows of mirrors on the ground. (Randy Montoya/Sandia National Labs)
Today’s Compact Linear Fresnel systems use water or oil as the thermal fluid to capture heat from solar collectors. The hot fluid heats water and converts it into superheated steam to drive a turbine connected to a generator that produces electricity.
With significant input from Sandia researchers, AREVA Solar designed the 100-foot-tall A-frame structure and Compact Linear Fresnel Reflectors, which are mirrors arranged in rows at ground level. The goal is to explore a different technology to collect and store heat generated by the reflectors in molten salt. If the system proves to be efficient and effective, AREVA will consider the technology for its solar plants around the world.
“Our goal is to demonstrate the viability and performance of a Linear Fresnel system that uses molten salt as a working fluid, thus allowing us to offer steam at higher temperatures (up to 585 degrees Celsius, or 1,085 degrees Fahrenheit) and also deliver a cost-competitive storage solution for concentrating solar power projects,” said Robert Gamble, general manager, North America at AREVA Solar.
AREVA Solar approached Sandia because of its unique Molten Salt Test Loop and Sandia researchers’ accompanying expertise. The $10 million Molten Salt Test Loop, known as MSTL, was completed in late 2012 and is the only test facility in the nation that can provide real concentrating solar power-plant conditions and collect data to help companies make commercial decisions. Sandia researchers have been testing components for external customers and have developed the expertise to help design and conduct experiments.
“A customer can come to us with an idea, and we have the knowledge to help them shape that idea into a working test,” said Sandia engineer Bill Kolb. “In the world of molten salt, this is where you come for expertise.”
“This really is based on an industry need for thermal storage, so what we have here is a proof-of-concept demonstration project, aimed at an industry need. The idea is all the feedback and lessons we learn will be fed into our optimized design for the power industry,” said AREVA’s lead project engineer Antoine Bera.