Productivity correlation and economic analysis of floating wick basin type vertical multiple effect diffusion solar still with waste heat recovery

In this study, experiments were performed with floating wick basin type vertical multiple effect diffusion solar still with waste heat recovery (FW-BVMED-HR) by varying several design and operational parameters. The FW-BVMED-HR still had floating wicks in the basin and a heat exchanger for waste heat recovery. The experimental database of present study was used to develop productivity correlation to predict the productivity of FW-BVMED-HR still. The productivity correlation has been further used for economic analysis of FW-BVMED-HR still, based on life cycle costing of the system. The capital cost of this still with increasing number of effects, from 2 to 7, is computed. The annual cost of operating this still based on a life cycle of 10 and 25 years is estimated. The average annual distillate and minimum unit cost of distillate, for increasing number of effects is determined. The minimum cost of distillate obtained for the 7 effect FW-BVMED-HR solar still is estimated to be Rs. 5.45/kg, for a life cycle of 25 years and for interest rate 0.16. With lower interest rate of 0.12, the cost of distillate reduces significantly to Rs. 4.52/kg. The still is found to be economically viable with low payback period.