Cost-Effective Solar Thermal Energy Storage

University of California Los Angeles (UCLA)
Thermal Energy Storage With Supercritical Fluids
Graphic of UCLA's technology
Program: 
ARPA-E Award: 
$2,420,802
Location: 
Los Angeles, CA
Project Term: 
02/01/2011 to 09/30/2014
Project Status: 
ACTIVE
Technical Categories: 
Critical Need: 
Currently, utility-scale solar thermal plants (>50 MW) run at only about 25% of their actual capacity when not using thermal energy storage because they can't generate power at night without it. Thermal storage makes it possible to increase this capacity to over 60-75%. Therefore, there is a critical need to develop low-cost thermal storage because it would enable deeper penetration of solar thermal power production as a competitive, renewable-based replacement for baseload coal-fired power plants.
Project Innovation + Advantages: 
UCLA and NASA's Jet Propulsion Laboratory (JPL) are creating cost-effective storage systems for solar thermal energy using new materials and designs. A major drawback to the widespread use of solar thermal energy is its inability to cost-effectively supply electric power at night. State-of-the-art energy storage for solar thermal power plants uses molten salt to help store thermal energy. Molten salt systems can be expensive and complex, which is not attractive from a long-term investment standpoint. UCLA and JPL are developing a supercritical fluid-based thermal energy storage system, which would be much less expensive than molten-salt-based systems. The team's design also uses a smaller, modular, single-tank design that is more reliable and scalable for large-scale storage applications.
Impact Summary: 
If successful, the approach taken by UCLA and JPL would reduce the cost of solar thermal energy storage systems by up to 40%, creating a practical and cost-effective energy storage solution for utility-scale thermal and other applications.
Security: 
Increased energy production from solar thermal would lower U.S. reliance on carbon-based fuels.
Environment: 
Renewable energy storage decreases fossil-fuel based electricity use, reducing harmful emissions from the coal-burning power plants that provide 50% of the electricity to American homes and businesses.
Economy: 
Solar thermal energy storage could help make power from renewable energy sources less expensive.
Contacts
ARPA-E Program Director: 
Dr. James Klausner
Project Contact: 
Prof. Richard Wirz
Partners
Jet Propulsion Laboratory