Solar hot water and stand-alone PV systems for a mosque in Riyadh

Special designs for Solar Water Heating System (SWHS) and Photovoltaic Systems (PVS) for mosques situated in Riyadh, are presented in this paper. The emphasis is toward the technical as well as the economic aspects of both systems. The factors that effect the design, such as location and size of the SWHS and PVS in the mosque, orientation of the mosque, the effect of the minaret shade, the duration of the daily five praying times, and the holy Islamic month of Ramadan (fasting month) have been studied. Also, the electric load of the mosque has been modified by proposing energy efficient equipment for the sake of energy conservation. A comparison of both solar systems (SWHS & PVS) with and without electric grid have been analyzed. A comparison between the solar water heating system and a conventional electric water heater shows that the utilization of solar water heating systems in mosques situated either in urban or rural areas is feasible. The payback period for SWHS is found to be 3.7 years and less than 1 year for 1500 liter and 3000 liter capacity respectively. This payback period is based on the highly subsidized electricity tariff (0.10 SR/kWh). Whereas, on the other hand, a stand-alone PV system is still expensive as compared with energy from the electrical grid, being in the range from 7 to 16 times higher. However, the PV systems add considerable value to the social (community) services of the mosque.