Energy and exergy investigation of industrial coal debris effect on solar still

Abstract

Renewable energy‐based desalination systems are one of the main sources of human sustenance to address the climate damage of their fossil fuel‐based counterparts. Drinking water is not available in some remote areas and this causes a problem so there is a real need to develop simple and handy methods to solve this problem. Solar distillation is a simple, cost‐effective, and environmentally friendly process. It entails evaporating dirty water with free solar energy to obtain pure water. This study aims to achieve the highest performance of solar stills by using industrial coal debris as low‐cost and locally available energy storage materials. These coals help to increase the rates of absorption of solar radiation and improve the rates of heat transfer to the basin water. In addition, aluminum waste represents thermal storage materials. Two identical solar stills were exposed to the sun for 10 h, resulting in identical meteorological conditions. The first solar still was taken as the reference (RSS), and the second solar still which contains the carbon debris as low‐cost and locally available energy storage materials, it is the modified solar still (MSS). The results showed that carbon debris improved the accumulative productivity from 3.233 to 4.066 kg/m2, with an improvement rate of 25.76%. Also, the average thermal efficiency of RSS and MSS reached 27.98% and 34.79%, respectively. According to the economic analysis, the sum invested in the building of the two solar stills is recovered in 45 days for RSS and 35 days for MSS.