Maximizing solar energy utilization and controlling electrical consumption in domestic water heaters by integrating with aluminum reflector

Abstract

Environmental concerns and rising energy costs require innovative solutions for household water heating. This work presents an innovative strategy for an evacuated tube-based electric/solar water heater (ESWH) incorporated with an aluminum reflector, which significantly reduces dependence on grid electricity. The whole area of the solar collector is about 2 m2, 100 L of storage each, and the rated power of the electric heater is 3 kW. Compared to existing ESWHs, the developed system achieves a significant 15.4% enhancement in annual energy consumption over hybrid models and a staggering 46.2% reduction compared to conventional electric heaters. The key improvement lies in the integration of an aluminum reflector beneath the evacuated tubes. This simple yet effective modification demonstrably enhances solar energy capture, leading to substantial grid energy savings. Our research thoroughly evaluated the system in Iraq-Baghdad's climatic conditions. Three identical water heating systems operated simultaneously under varying configurations: solar-only, electric-only, ESWH without reflector, and ESWH with reflector. A full test process relating four operation scenarios across a full day provided thorough insights into the energy consumption profile and the system's performance. The findings show the significant potential of the proposed water heater design to contribute to environmental sustainability, energy security, and reduced house energy bills. This study covers the way for wider adoption of eco-friendly and cost-effective solar water heating solutions.