Performance improvement of the conical solar still using hollow copper tubes in the basin with CO2 mitigation and economic analysis

•The performance of a conical solar still with hollow copper tubes is investigated.•An experimental analysis is carried out.•Economic, CO2 mitigation, and carbon credit analysis are studied.•Modified solar stills that use hollow copper tubes are highly beneficial. This study investigates the performance of the two configurations of the conical solar still; the first is a conventional conical solar still (CCSS), while the second uses hollow copper tubes (CSS-HCT) in the water basin. The present work novelty is investigating the enhancement effect of hollow copper tubes on the operation of conical SS, which has not been studied to date. The experimental work was performed at the El-Oued University, Algeria, in April 2024. The results indicated that the soft water produced by the conical solar distiller with hollow copper tubes increased considerably compared to the conventional one. The cumulative production of the improved solar still is 6.05 l/m2/day, while that of the traditional system is 3.82 l/m2/day, which means that the water yield was improved by 58.33 % when using hollow copper tubes. At the same time, the daily overall efficiency of the CSS-HCT was 69.51 %, while that of the conventional system was 50.06 %. These results reflect that CSS-HCT represents better performance options than conventional conical distillers. Additionally, the enviro-economic analysis for the two configurations indicated that the carbon credit produced by the CSS-HCT is 2.5 times that of the CCSS. From economic and carbon mitigation points of view, both the exergy-economic and exergy-environment analyses indicated that solar stills that use hollow copper tubes are highly beneficial.