Design, fabrication and performance evaluation of a hybrid photovoltaic thermal (PVT) double slope active solar still Original Research Article

A modified photovoltaic thermal (PVT) double slope active solar still was designed and fabricated for remote locations. The system has been installed at the campus of KIET, Ghaziabad (India) and its performance has been experimentally evaluated under field conditions in natural and forced circulation mode (series and parallel). Photovoltaic operated DC water pump has been used between solar still and photovoltaic (PV) integrated flat plate collector to re-circulate the water through the collectors and transfer it to the solar still. The production rate has been accelerated to 1.4 times than the single slope hybrid (PVT) active solar still and obtained highest (7.54 kg/day) for the parallel configuration in forced mode in the month of October, 2010. The daily average energy efficiency of the solar still is obtained as 17.4%. Comparative results have been predicted on annual basis with the single slope hybrid (PVT) active solar still accounting 250, 275 and 300 clear days in a year. We have found that energy payback time is significantly reduced by almost 30% in present design with less capital investment.