Solar water heating based on Bellville weather conditions in winter

Abstract

Hot water supply is a daily necessity for various purposes ranging from industrial to domestic usage. However, the availability of hot water supply is dependent on reliable energy systems to heat the water. The load shedding plan declared the energy crisis in South Africa. Therefore, exploring alternative energy methods for hot water supply is critical, especially renewable energy resources. The use of natural resources such as solar energy to heat water is highly impacted or limited by the resources and environmental conditions existing at the area of interest. The use of the solar water heating system based on Bellville; South Africa was the undertaken study. This study reports on the experimental investigation that was conducted on a 50 L water geyser, which was solar-based. The test rig that was constructed and tested was an active solar water heating system. It was tested over a period of 10 days under the environmental conditions experienced in mid-winter season of South Africa. A 20 tubed evacuated tube collector unit was used, and it was found that in mid-winter of the highest water temperature that the system could reach was above 65 °C and the lowest was 30 °C. Intriguing outputs were found in the study which revealed that, on the days that yield the highest solar irradiation did not necessarily produce the hottest water temperature. Therefore, scrutinizing the impact of other parameters that contributed to the overall water temperature output was necessary. From the tests it was observed that the wind velocity together with other environmental parameters effectively had an impact on the water temperature yield by an evacuated tube system.