Sandia starts evaluation of high temperature falling particle receiver at solar tower in US

Researchers at Sandia National Laboratories have commenced two-phase testing of the continuously recirculating falling particle receiver by taking to the top of the tower at National Solar thermal test facility located in the US.

The testing, which will continue throughout this year, is intended to reduce the solar energy systems cost and enhance efficiencies using a system of small particles.

The falling particle receiver is designed by Sandia to drop sand-like ceramic particles through a beam of concentrated sunlight and then store the captured heated particles in an insulated tank.

Unlike conventional molten salt systems, the new technology can capture and store heat at high temperatures that could exceed 1,000°C, without breaking down.

The conventional receiver technologies can operate to maximum temperatures of 600°C.

The testing is aimed at developing a prototype, cost-competitive receiver that will help achieve more than 90% of thermal efficiency at particle temperatures of at least 700°C.

Sandia engineer and project’s principal investigator Cliff Ho said: “This technology will enable higher temperatures and higher efficiency power cycles that will bring down the cost of electricity produced from concentrating solar power.

“In addition, the ability to cheaply and efficiently store thermal energy directly in the heated particles will enable power production at night and on cloudy days.”

During the first phase of testing, researchers will test a Georgia Tech-designed insert, which slows falling particles in order to increase the temperatures as they fall through insider the receiver.

Planned later this year, the second phase will see the removal of insert and the engineers will assess the free-falling curtain configurations.