Cost-Effective Solar Thermal Energy Storage

Default ARPA-E Project Image

OPEN 2009
Los Angeles, California
Project Term:
02/01/2011 - 09/30/2016

Technology Description:

The University of California, Los Angeles (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.

Potential Impact:

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.


Increased energy production from solar thermal would lower U.S. reliance on carbon-based fuels.


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.


Solar thermal energy storage could help make power from renewable energy sources less expensive.


ARPA-E Program Director:
Dr. Eric Rohlfing
Project Contact:
Prof. Richard Wirz
Press and General Inquiries Email:
Project Contact Email:


Jet Propulsion Laboratory

Related Projects

Release Date: