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Thermal Energy Storage R&D

Featured Resource

Learn more about NREL's capabilities in thermal storage and advanced heat transfer fluids.

Thermal energy storage (TES) research at NREL focuses on reducing the costs of thermal storage and electricity from concentrating solar power (CSP) plants. NREL's TES effort contributes to these goals through materials and systems development, analysis, and modeling.

CSP systems may include TES—a means of storing thermal energy for later use—to generate electricity any time when it is most needed and valuable, whether during the day, night, or cloudy intervals.

Opportunities and Potential Impact

TES usually reduces the levelized cost of electricity (LCOE) compared to a system without storage because of better utilization of the power block. However, adding TES does increase the capital cost of a CSP plant. Advanced heat-transfer fluids (HTFs) and storage materials with improved thermophysical properties represent a clear opportunity to significantly improve power plant performance and lower LCOE.

Current Research Projects and Our Innovation

NREL's research on TES focuses on several key areas:

  • HTFs and thermal storage systems—Developing and deploying novel, high-temperature HTFs through both modeling and experiment.
  • Containment materials—Understanding the degradation mechanisms for TES and HTF containment materials and developing protective coatings to mitigate the degradation.

Competitively Funded Projects

NREL has won competitive DOE awards to fund the following projects:

Facilities and Capabilities

  • Storage Materials Laboratory—A new facility at NREL's Energy Systems Integration Facility (ESIF) used to perform comprehensive measurement and characterization for HTFs and storage materials.
  • Storage Process and Components Laboratory—A facility in which NREL characterizes and determines performance of storage fluids and systems in a process environment at temperatures up to 800°C (1470°F).
  • Solar Technology Acceleration Center (SolarTAC)—A facility used to demonstrate thermal energy storage systems at a 1-megawatt scale integrated with a solar collector field.
  • Molecular dynamics modeling—A technique to predict and improve compatibilities and thermophysical properties of HTFs and thermal storage materials.

Through innovative research and unique experience, facilities, and capabilities, NREL is working to accomplish the goal of the U.S. Department of Energy's SunShot Initiative to make installed large-scale solar energy systems cost-competitive with other energy sources by 2020.