A project team led by GTI to develop a hybrid solar collector that simultaneously generates electricity and high-temperature on-demand heat has met critical Department of Energy Advanced Research Projects Agency-Energy (ARPA-E) project milestones.
The ultra-high-efficiency novel hybrid solar converter has a double-mirror design optimized to capture as much of the energy in sunlight as possible, generating both electricity and storable heat (for later use) within the same system. An innovative collector design transforms commonly used parabolic trough concentrated solar power (CSP) into a higher-efficiency, spectrum-splitting receiver, and integrates high-temperature thermal transfer and storage media to generate variable electric power and high-temperature dispatchable heat.
The team composed of GTI, University of California at Merced (UC Merced), and MicroLink Devices, Inc. recently completed successful testing of the hybrid system. Two nominal 5 kW integrated field prototypes that include storage were demonstrated. The first uses a secondary mirror in the thermal receiver (thermal-only) to deliver 650°C dispatchable heat, and the second uses a secondary photovoltaic (PV) reflector (thermal-PV) to deliver both variable electricity and dispatchable 600°C heat.
The project, funded by ARPA-E under the Full-Spectrum Optimized Conversion and Utilization of Sunlight (FOCUS) program, is aimed at advancing new technologies beyond current PV and CSP technologies. Disruptive new solar conversion and storage technology options can enable a much higher penetration of solar energy generation into the U.S. energy mix, overcoming high cost barriers to market adoption. This hybrid solar energy system has the potential to provide renewable power at grid-competitive prices along with high-quality thermal energy.
The new technology could play a role in opening the microgrid market for dispatchable electricity and solar energy use in industrial process heating. Based on cost-benefit analysis, the research team is proposing to scale up and demonstrate a 60 kW thermal-only collector with particle thermal energy storage for on-demand process heating at an industrial plant in California.