Viability assessment of solar distillation for desalination in coastal locations of Indian sub-continent – Thermodynamic, condensate quality and enviro-economic aspects

Abstract

In the current investigation, viable solar desalting sites in coastal India are identified by detailed thermodynamic and enviro-economic analyses. Mathematical model developed for thermodynamic performance assessment is validated using experiments conducted in inclined solar distillation unit under the climatic condition of Chennai (13.08°N, 80.27°E). Distillation unit produced high quality condensate even from highly saline (40,600 to 60,656 mg/L salinity) feed water. Availability analysis indicated the magnitude of improvement potential, availability destruction, losses and ways for further improvement. Maximum condensate yield, energy and availability efficiency of distillation unit is around 7.09 L/d, 53.45% and 5.39%, respectively for Nellore (one of the east coast locations). Condensate production cost of 18.16 to 32.78 USD/kL and desired availability output of 1.80 to 3.38 kWh/USD invested are observed for the distillation unit at 5.0% interest rate. Maximum yearly average life cycle conversion efficiency, net carbon-dioxide, sulphur-dioxide and nitrous oxide emission alleviated by the unit is around 39.19%, 25.83 tons, 185.73 kg and 75.86 kg, respectively. Viability assessment indicated positive signs for deployment of solar distillation units in 14 locations of coastal India. The proposed solar distillation unit requires lower evaporation area compared to other passive solar distillation units installed in India for the same production capacity.