Experimental performance evaluation of a hybrid CST receiver for linear concentrators

Abstract

Hybrid concentrating solar thermal (CST) receivers allow for the simultaneous production of thermal and electrical energy. However, the thermal output from these receivers is typically limited by the maximum operating temperature of the solar cells, which are coupled to the thermal fluid. Spectral beam splitting provides a means for removing this direct coupling and allowing for thermal outputs significantly above the operating temperature of the photovoltaic (PV) cells. RMIT University has developed a novel beam splitting hybrid CST receiver which uses a combination of selective liquid absorption and long pass optical filter to spectrally split concentrated solar radiation. Using this approach light between 700 nm-1200 nm was directed to a linear arrangement of silicon PV cells, while the remaining wavelengths of light were directly absorbed as thermal energy. A full-scale prototype receiver was mounted to a commercially available parabolic trough concentrator to measure its performance. Results demonstrated a total thermal efficiency of 46.5% together with an electrical yield of 3.6%. Sources of performance reduction were identified and discussed. Show more