Experimental investigations of a novel solar still with heat storage materials - energy, exergy, economic and environmental analyses

Current study aims in finding the combined effect of using rectangular fins, gravels (G) and phase change material (PCM) on the performance of pyramid solar still. Two solar stills, one of conventional type (CSS) and other of modified solar still (MSS) which uses fins and PCM inside the basin, are fabricated. Experiments are conducted at Greater Noida (28 degrees 28 ' N, 77 degrees 30 ' E) of Uttar Pradesh, India, during May 2023. The influence of solar still design modifications (CSS and MSS) and adding gravels (CSS + G and MSS + G) on the performance of solar stills is investigated in terms of productivity, energy, exergy, economic, and environmental parameters. Experimental results show an enhancement of about 84 %, 38 % and 32 % in daily productivity for MSS + G, CSS + G and MSS, respectively, than CSS. The MSS + G shows the highest improvement in energy (81.1 %) and exergy efficiency (273 %) with significant reduction in costs per liter of yield produced (29.2 %) and payback period (29 %) when compared with CSS. About 76 % rise in carbon credits earned is observed for MSS + G than CSS while mitigating the CO2 emission of 19.14 tons. Conclusively, the innovative design (MSS + G) not only offers cost-effective yield production but also plays a crucial role in promoting environmental sustainability by reducing CO2 emissions.