Abstract
The aim of this research is to improve the amount of freshwater yield of a square base pyramidal solar still (SBPSS) using porous material with and without black coating for sustainable water harvesting. Seven separate cases, i.e., smooth basin (C-A1), an absorber plate with clay pots facing upward (C-A2), upward-downward (C-A3), downward (C-A4) and clay pots with black coating facing upward (C-A5), upward-downward (C-A6), downward (C-A7), were tested under the meteorological conditions of Andhra Pradesh (16.6834°N, 80.3904°E), India. To mitigate the impact of fluctuations in solar radiation, the tests were carried out specifically from 7:00 AM to 7:00 PM, focusing on days, especially, with clear sky. The influence of porous material and black coating on the performance of SBPSS is investigated from the viewpoints of thermo-exergo-economic parameters. By putting clay pots inside the basin, the freshwater yield increases up to 2.04 L/m(2) for C-A4, while the yield enhances further by black coating (C-A7) to 2.38 L/m(2). Findings revealed the overall daily thermal efficiencies for C-A7, C-A6, C-A4, C-A5, C-A3, C-A2, and C-A1 as 32.17%, 30.26%, 28.10%, 27.74%, 26.49%, 25.41%, and 17.00%, respectively. Additionally, the daily exergy values are 1.25%, 1.38%, 1.52%, 1.70%, 1.86%, 2.23%, and 2.78% for C-A1, C-A2, C-A3, C-A4, C-A5, C-A6, and C-A7. The optimal configuration was C-A7, exhibiting thermal and exergy efficiencies that surpassed C-A1 by 89.24% and 122.58%, respectively. Moreover, the daily productivity improved by 90.76%, accompanied by a cost reduction of 44.51%, and a reduction in payback period by 159 days. Among all, C-A5 achieves the highest CO(2) mitigation at 7.06 tons/year, followed by C-A7 at 6.63 tons/year.