Chapter 7 - Benefit-cost analysis and parametric optimization using Taguchi method for a solar water heater

Abstract

Although the hot water obtained from a solar water heater (SWH) is environmentally sustainable, the economic viability is a point of discussion due to high capital cost. Therefore, the aim of this study is to conduct a techno-economic assessment of SWH coupled with Taguchi based optimization. The developed generic economic models have been applied as a case study to three cities located in east-coastal region of India. Two scenarios considered in this study are electricity and LPG based water heating system being replaced by an SWH. Among seven input parameters (capital cost, inlet temperature of water, outlet temperature of water, service life, annual number of days of usage, electricity tariff, LPG tariff) the ‘annual number of days of usage’ is the most sensitive variable. With benefit-cost ratio 1.24 and 1.12 respectively for these two scenarios, the SWH is found to be an economically viable option. The service life should be 7.39 years and annual number of days usage need to be 153 to achieve a break-even (Benefit-cost ratio=1) for this case study. The optimum values of benefit-cost ratio obtained from Taguchi framework are 2.82 and 2.67 respectively for above mentioned two scenarios.