Performance testing of a spectral beam splitting hybrid PVT solar receiver for linear concentrators

A novel spectral beam splitting photovoltaic/thermal (PVT) solar receiver for linear concentrators has been developed capable of generating high-grade thermal energy concurrently with electricity. This paper evaluates the initial field testing of this receiver which combines a selective absorption heat transfer fluid (Propylene Glycol) with a band pass optical filter to achieve efficient spectral splitting. Wavelengths of light between 700 nm and 1100 nm are directed to the silicon PV cells, with the remaining wavelengths absorbed directly as heat. A prototype has been constructed and mounted to a parabolic trough concentrator with 42x geometrical concentration ratio. Results demonstrated considerable promise for this technique. High grade heat thermal efficiencies of 31% relative to the thermal beam splitting fraction were achieved at a receiver temperature of 120 degrees C, with a total system efficiency of 50%. Electrical yields of approximately 3.8% relative to the total incident power were measured. While lower than expected we expect with minor modifications system efficiencies beyond 75% will be achievable.