Experimental Analysis of Portable Optical Solar Water Heater

The unchecked consumption of natural resources, to meet our daily requirements, has led to a crisis situation. Natural resources are depleting at alarming levels. At the other extreme, even when the total solar energy absorbed by Earth’s atmosphere, oceans and land masses is approximately 3,850,000 exajoules (EJ) per year, barely a fraction has been exploited to our benefit. To a generation seeking solutions to its energy needs, solar energy offers tremendous potential. Solar hot water heater can save billion thermos of natural gas a year. Solar hot water systems capture energy from the sun to heat water for homes and businesses, thereby displacing the use of natural gas, or in some cases electricity, with free and limitless solar energy. In this study, we have designed and fabricated a solar collector employing plano-convex lens to extract maximum solar energy in limited space. We have also benchmarked the performance of the fabricated solar collector with the existing conventional collectors. Since in the current setup, the average temperature rise of 14 °C is observed for a concentrator surface area of 0.031 m² (446 °C/m²) against the temperature rise of 20.5 °C for a given concentrator area of 0.216 m² (95 °C/m²) in case of a flat plate collector type heater, the present system is found to be more efficient when less concentrator surface area is available for water heating applications. The present system offers the desired prospects of lesser space acquisition and portability benefits at lesser material and labor cost (about INR 2000) which renders the system effective for basic household usage. However, the present system has its own inherent shortcomings of higher convective heat losses due to which lesser temperature rise is achieved when compared to existing conventional collectors.