Investigating energy efficiency and solar energy in Saudi mosques to achieve zero energy or zero bill

Energy is essential to achieve thermal comfort; however, energy consumption leads to environmental degradation. This study analyzed the energy consumption of two masjids in the Kingdom of Saudi Arabia (KSA) and identified opportunities for rationalizing energy consumption. A photovoltaic (PV) system was used to ensure that the conditions of nearly zero bill building (nZBB) or nearly zero energy building (nZEB) were fulfilled. The energy use intensities of the AlJamil and Al-Omar masjids were 111 kWh/m2 and 121 kWh/m2, respectively. The average electricity consumption per worshiper for the Al-Omar masjid was 1.35 kWh/prayer and that for the AlJamil masjid was 1.03 kWh/prayer. The end-use energy was the highest for cooling, accounting for 72-74 % of the total consumption; lighting accounted for 11-12 % of the total consumption at the two masjids. Approximately 60 % of the air-conditioning (AC) energy load was saved by improving the envelope; the electricity requirement for ACs increased by up to 30 % as the ambient temperature increased from 32 degrees C to 46 degrees C. Changing the set-point temperature from 20 degrees C to 27 degrees C afforded electrical energy savings of approximately 27 % for a summer day. The environmental benefits of using solar energy were also identified. (c) 2023 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).