Experimental investigation of a passive type solar still with double wedge shape glass cover

Abstract

Solar thermal energy-based desalination systems such as solar stills deliver fresh distilled water at zero carbon emission levels. In this paper, passive type solar still with double wedge shape glass cover is experimentally investigated for its performance, and economics factor is analyzed. This new design solar still model is Twin Wedge Solar Still (TWSS). The economics of the system concerning cost per litre is also presented. The performance of TWSS is weighed against that of a Conventional Solar Still (CSS) in this study. The novel glass cover shape design of the TWSS increases the condensation surface area, increasing the condensation rate, thus enabling the TWSS to deliver 2.68 L of fresh distilled water per m2 area of the solar still. The CSS yielded only two-third of TWSS for the same constraints, thus making TWSS 51.5% more efficient than CSS. The economic analysis shows that TWSS possess a lesser cost per litre rate (0.028 $/l) than CSS, which aids it to achieve a shorter payback period (one year for TWSS). The simple and symmetrical design of the TWSS makes it more advantageous than other unique and new design solar stills. As a future study, the integration of thermal energy storage components in the basin structure is proposed to increase the vaporation rate of the TWSS.