Analysis of energy savings for residential electrical and solar water heating systems

A solar water heating system is a device that takes energy from the sun radiation to raise the water temperature for use of water supply in the home. Water heating is the second-largest household electricity user. Replacing EWHs with a SWHs with an electrical backup can reduce electricity usage. An experimental setup and POLYSUN program were used for a simulation-based approach for evaluating the comparison between (SWHs) and (EWHs) for three different cities in the Kurdistan region of Iraq. The investigated setup consists of a flat plate solar water heating system with a total area of 2.01 m2 and a 200 L storage tank, and it suits a single-family house composed of four people. The numerical simulation results reveal that the use of SWHs decreases substantial energy consumption. For Duhok, Erbil, and Sulaymaniyah cities, the annual saved energy is 1365 kWh, 1383 kWh, and 1459 kWh, constituting a solar fraction of 39.4%, 40.4%, and 34.2% with an annual CO2 reduction of 771 kg, 781 kg, and 824 kg, respectively. The experimental work was also conducted in January 2021 in Erbil City, in the Kurdistan Region. A comparison of electricity consumption between SWHs and EWHs was demonstrated