U.S. Department of Energy - Energy Efficiency and Renewable Energy

SunShot Initiative

Dish Stirling High-Performance Thermal Storage

Sandia National Laboratories logo Schematic of a circular CSP dish showing arrows modeling the movement of vapor and condensation between the dish and the heat pipe receiver on the front and heat pipe transport to a rear-mounted PCM and engine.

The proposed latent energy storage system for SNL's dish-Stirling power generation provides more optimum balance of the dish system, reduces cantilevered weight, and allows closing of the "pedestal gap." Image from Sandia National Laboratories

Sandia National Laboratories (SNL) is working with the National Renewable Energy Laboratory (NREL) and the University of Connecticut, under the National Laboratory R&D competitive funding opportunity, to demonstrate key thermal energy storage (TES) system components for dish Stirling power generation. Current dish Stirling systems do not feature TES, but have been identified as having a strong potential of meeting the SunShot cost goal of $0.06/kWh.

Approach

The research team is demonstrating a TES system that combines latent heat transport and latent heat storage, providing up to 6 hours of storage on a 25-kWe dish Stirling system. The end product of this project will be a representative subscale test device with a recommended phase change material (PCM), heat pipe input and output specifications, and systems-level design guidance for integration into a high-performance dish Stirling system. The effort focuses on several development areas:

  • Solar heat pipe receiver performance and life design and testing
  • PCM selection, characterization, and basic compatibility
  • PCM compatibility with shell materials
  • PCM freeze-thaw and thermal transport modeling
  • PCM interface design, development, and optimization
  • Systems-level proof-of-concept hardware testing
  • Systems-level modeling and optimization

Innovation

In this dish Stirling design, the storage and the engine are both moved to the rear of the dish. This placement provides more optimum balance of the dish system, reduces cantilevered weight, and allows closing of the "pedestal gap," leading to a more efficient structural design. The size and duration of the proposed TES system will enable utility-scale dish Stirling systems to have the same ability to dispatch power when needed and allow dish Stirling systems to produce power into the evening and nighttime, similar to other forms of concentrating solar power (CSP) technology with storage. Combining TES with dish Stirling systems, which are currently the highest efficiency CSP technology, will enhance this technology's ability to meet the CSP SunShot goals.

Publications, Patents, and Awards

At this time, this project does not have published articles, patents, or awards.

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Learn about other DOE competitive awards for concentrating solar power research that are in progress.