Effect of cooling condensing cover on the performance of N‑identical photovoltaic thermal‑compound parabolic concentrator active solar still: a comparative study

In this work, photovoltaic thermal-compound parabolic concentrators (PVT-CPC) are integrated to a single slope solar still (SS-SS) through a heat exchanger placed in the basin. A continuous water flow is provided over the condensing cover of SS-SS for yield enhancement. An effect of cooling condensing cover on energy and exergy analysis (thermal and electrical) together with the production cost of distilled water (₹/kg) has been studied for the following three cases: (I) the proposed partially covered photovoltaic thermal-compound parabolic concentrator single slope solar still (PVT-CPC-SS-SS), (II) fully covered thermal-compound parabolic concentrator single slope solar still (PVT-CPC-SS-SS), and (III) flat plate thermalcompound parabolic concentrator single slope solar still (FPC-CPC-SS-SS). Design parameters have been optimized for maximum distillate output (energy) and exergy on annual performance basis. Moreover, higher daily yield (37.9 kg) is obtained for case (iii). In addition, higher electrical module efficiency (13%) is obtained for case (ii) for the month of January when the solar cell temperature is 55 °C at the optimized conditions. However, the proposed system gives daily yield (35.78 kg) and generates electricity at module efficiency of 12%. The energy payback time of the proposed system is estimated to be 2 years.