EERE's New Projects

A Small-Particle Receiver for Brayton Cycles

Awardee Details

San Diego State University


DOE Amount 

San Diego State University (SDSU) is demonstrating a new receiver design that uses air as the heat-transfer fluid. The University's innovative small-particle heat-exchange receiver (SPHER) uses carbon particles to enhance performance and achieve higher thermal efficiency.

The SDSU research team is working to design, construct, and test a revolutionary, high-temperature solar receiver in the multi-megawatt range that can drive a gas turbine to generate low-cost electricity. 

The concept of a volumetric, selective, and continually replenishable absorber is entirely unique. SPHER uses a dilute suspension of carbon nanoparticles dispersed in air to absorb highly-concentrated solar flux volumetrically inside a windowed pressure vessel, rather than on a solid surface as in most other receivers. The small-sized particles rapidly transfer heat to the surrounding air and then oxidize as temperatures increase. A hot, pressurized, clear gas stream consisting almost entirely of air with a small amount of carbon dioxide is then available to drive a gas turbine or be used for a process. This system can readily be hybridized with natural gas plants.


  • Validate the SPHER concept by demonstrating for the first time a pressurized solar receiver with a window greater than 1 meter in diameter
  • Produce a reliable, low-cost, high-efficiency, high-temperature receiver approaching the 5-megawatt scale capable of powering a gas turbine for electricity production
  • Prove the capability of the receiver to generate pressurized, high-temperature air at high efficiencies via prototype testing at the National Solar Thermal Test Facility at Sandia National Laboratories