Sandia began first-of-its-kind testing using its continuously recirculating falling-particle receiver atop the National Solar Thermal Test Facility (NSTTF). The falling-particle receiver drops sand-like ceramic particles through NSTTF’s concentrated sunlight beam, capturing and storing the heated particles in an insulated tank. Compared to conventional molten-salt systems, the falling particle receiver creates more available energy and cheaper storage costs with less material needed for heat transfer.  Sandia’s goal is to develop a prototype, cost-competitive falling-particle receiver with the potential for thermal efficiency greater than 90% and particle temperatures of at least 700°C.