[amor de cosmos]

Sandia Labs harnessing the sun’s energy with tiny particles
September 16, 2013

ALBUQUERQUE, N.M. – Engineers at Sandia National Laboratories, along with partner institutions Georgia Tech, Bucknell University, King Saud University and the German Aerospace Center (DLR), are using a falling particle receiver to more efficiently convert the sun’s energy to electricity in large-scale, concentrating solar power plants.

Falling particle receiver technology is attractive because it can cost-effectively capture and store heat at higher temperatures without breaking down, which is an issue for conventional molten salts. The falling particle receiver developed at Sandia drops sand-like ceramic particles through a beam of concentrated sunlight, and captures and stores the heated particles in an insulated container below. The technique enables operating temperatures of nearly 1,000 degrees Celsius. Such high temperatures translate into greater availability of energy and cheaper storage costs because at higher temperatures, less heat-transfer material is needed.

Central receiver systems use mirrors to concentrate sunlight on a target, typically a fluid, to generate heat, which powers a turbine and generator to produce electricity. Currently, such systems offer about 40 percent thermal-to-electric efficiency. The falling particle receiver enables higher temperatures and can work with higher-temperature power cycles that can achieve efficiencies of 50 percent or more.

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