Optimizing solar energy utilization and energy efficiency through thermal energy storage with phase change materials in a solar water heating system

Abstract

Solar energy (SE) is non-polluting and sustainable. However, the strength of the sun’s rays shifts as the seasons change, the weather shifts, and the day and night cycles. It is possible to store energy as heat, which can then be used for a variety of applications in the future. The primary objective of this research was to extend the time that high water temperature (HWT) was maintained by using phase change materials (PCM) to reduce energy consumption. To test the efficacy of an FPSWHS using 18 % (63 kg) of PCM condensed paraffin wax of type RT42, an experimental rig was constructed. To further expand PCM surface area and speed up charging and discharging, 18 aluminium cylinders were employed. Given the varying weather patterns in the India, this research was also useful in settling on a suitable PCM for SWHS. At 60°C input temperature of water (Tin) and 0.11 kg.s-1 flow rate of mass in water (mw), including RT42 into a water-PCM storage tank reduced power consumption by as much as 5.75 kWh, for a total system energy consumption of 31.4 kWh. The results showed a 27 % drop in daily average carbon footprint and a 27 % increase in overall system efficiency.