Recent developments in integrated collector storage (ICS) solar water heaters: A review

Abstract

Conversion of solar energy via thermal route is highly efficient, more environmental friendly and economically viable. Integrated Collector Storage Solar Water Heaters (ICSSWHs) convert the solar radiation directly into heat at an appreciable conversion rate and in many cases that happen under concentrated form. These systems are compact, aesthetically attractive and reasonable in construction. They have the potential to reduce environmental impact up to 40% and also have high collection efficiency factor. Despite many advantages, ICS solar water heaters suffer from high thermal losses in the night/overcast sky conditions. Performance of ICSSWH systems is influenced by various parameters such as reflector and absorber types, energy collection and storage arrangements and design parameters of the systems. In this article, various concentrating and non-concentrating ICSSWHs, systems with PCM (Phase Change Material) and heat retention strategies are reviewed. Recent development in the ICSSWHs indicates the potential of reliability of these systems for domestic hot water application at lower cost. The concentrating type ICSSWHs show better collection efficiency at reduced cost, but suffer high night time thermal losses. Further research is needed, especially in CPC-ICSSWHs, for minimizing night time thermal losses.