Energy, exergy, economic and enviro-economic (4E) analysis of gravel coarse aggregate sensible heat storage-assisted single-slope solar still

Abstract

In this work, the energy, exergy, economic and enviro-economic assessments of gravel coarse aggregate sensible heat storage-assisted single-slope solar still are performed. The gravel coarse aggregate sensible heat storage bed preheats the saline water before entering the basin of the solar still and also stores the excess sensible heat. The experimental observations have been made under the climatic conditions of Coimbatore city in India during the year 2018. The experimental results showed that the maximum energy and exergy efficiency of about 32% and 4.7% were observed for 1 cm water depth. The maximum productivity of about 4.21 kg m−2 per day was observed for 1 cm water depth during the period of 12 h of observation. The economic analysis revealed that the cost of distillate per litre was estimated as 0.0618$ with a payback period of 4.3 months. Moreover, it is observed that the proposed solar still configuration has reduced 8.27 tons of CO2 emissions for 1 cm water depth during its life cycle. The parametric analysis results confirmed that the solar irradiation and water depths are the two major parameters influencing the performance of a solar still. Furthermore, the water quality assessment revealed that all the water samples collected from the solar stills are suitable for drinking and also meet the requirements of the Bureau of Indian Standards.