Experimental investigation of the thermoelectric and double-glazed glass effects on the performance of a solar still

Abstract

Due to water scarcity, the use of solar stills and their improvements have been widely taken into account. In this regard, researchers are always looking for solutions to improve the performance of solar stills because of their low efficiency. Hence, this study experimentally investigated the effect of adding thermoelectric coolers, a cold air channel, and double-glazed glass on increasing the performance of a conventional solar still. The modified solar still was equipped with six thermoelectric cooler modules under the solar still. The hot sides of the modules were connected to the solar still plate to increase the temperature of the inside water, while the cold parts were used to cool the air blown from a channel toward the double-glazed glass on the solar still. The performance of two solar stills (solar still and the modified solar still) was compared for 2 days in Sabzevar city, in the northeast of Iran. The important analyses, including freshwater production, energy and exergy performances, and economic view are compared. Based on the results, the daily freshwater production, energy efficiency, and exergy efficiency of the modified solar still were improved by 570 %, 137 %, and 215 %, respectively, compared to those in the conventional solar still. The economic analysis results indicated that under optimal conditions (i = 5 %), the cost of distilled water was 0.0326 $/L and 0.0739 $/L for the modified solar still and conventional solar still, respectively. Also, using the modified solar still, the payback period reduced by about 1.74 years (payback period for the modified solar still and conventional solar still was obtained at 1.30 and 3.04 years, respectively).