On-Grid Flat Plate Solar Water Heater Collector Application for Electrical Energy Saving Contribution

This study introduces a novel approach in Baghdad, Iraq, where flat plate solar heaters are directly connected to the electric heater without the use of storage tanks. This setup operates in a manner similar to solar cells connected to the electric grid, without the need for electrical energy storage during daylight hours (on-grid). A series of solar heaters, covering a total area of 3 m2, have been linked to the electric water heater. This arrangement allows the water supplied to the electric heater to either be pre-heated by the solar heaters or delivered directly. The percentage of electrical energy saved to obtain 100 liters of hot water at 40 °C using a water mixer was 53% and 57% when adjusting the electrical heater thermostat to 60 °C and 80 °C, respectively. This was found by comparing the electrical energy usage of the electric heater in both cases (preheating and direct supply).