Performance analysis of a spectrally selective concentrating direct absorption collector

•Collector with spectrally selective liquid filter tested.•Collector design has a Fresnel lens based concentrator and glass receiver.•Collector thermal performance is reported.•Solution flow rate has no impact on collector performance.•Optical concentration (aperture to spot size ratio) has no impact on collector performance. Spectrally selective liquid filters are proposed as a means of efficiently utilizing majority of solar radiation incident on a given area. This paper reports on the outdoor testing done to verify the thermal performance of a spectrally selective liquid under concentrated light. The design consists of a Fresnel lens based concentrator that focuses radiation on to a glass absorber. Collector thermal performance was measured using Copper Sulfate solution as the heat collection fluid. Effect of various parameters on efficiency is also reported. It was found that parameters such as solution flow rate through the absorber and optical concentration as measured by the spot size have an insignificant impact on the thermal performance.