Abstract
Energy consumption is one of the most important variables that have an impact on the environment. One of the nations in the world with the highest per capita electrical energy usage is the Kingdom of Saudi Arabia. Many attempts are being made in Kingdom of Saudi Arabia to lower energy consumption and electricity consumption to achieve sustainability. In this work, the data on the energy consumption of two mosques in Hail City were analyzed, and the opportunities for energy conservation and the use of solar energy were studied to make mosques sustainable. Annual energy use intensity was determined to be 100 and 121 kWh/m 2 for the Al-Khashil and Al-Jamil mosques, respectively. While Al-Khashil's mosque envelope is insulated, energy efficiency measures implemented to the walls, roof, and windows of Al-Jamil's mosque resulted in reductions in energy consumption of 27%, 13%, and 6%, respectively. The most effective energy efficiency option is a heating, ventilation, and air conditioning system with a high energy efficiency ratio, which can reduce cooling demand by more than 30%. If the condition of Saudi Building Code 601 is met, then it has the potential to cut energy usage by 35.4% and 63.3% for Al-Khashil and Al-Jamil, respectively. Due to coronavirus disease 2019, Al-Khashil's electricity usage was reduced by 58,737 kWh, or 39.9%, in 2020 compared to 2019. When using data from RETScreen and ATLAS, there were inconsistencies of up to 28%, but for DesignBuilder, the findings were the closest to the billing data. The mosques Al-Khashil and Al-Jamil have a combined yearly photovoltaic energy output from the suggested systems of around 135.93 MWh and 33.98 MWh, respectively. For the mosques, Al-Khashil and Al-Jamil, the yearly yield factor and capacity factor were both 1887.9 kWh/kWp/year and 21.9%, respectively. The annual greenhouse gas emission reductions from photovoltaic systems for Al-Khashil and Al-Jamil were 102.9 tCO 2 and 25.72 tCO 2 , respectively. Concerning economics, the following results were obtained: The levelized cost of energy of photovoltaic systems is 0.0901 SR/kWh (0.024 $/kWh); the net present value and internal rate of return for photovoltaic systems are not suitable as a result of the current prices and the system applied in the Kingdom of Saudi Arabia. If the electricity produced from photovoltaic systems is injected into the grid at a rate of 0.32 SR/kWh, which is comparable to the SEC tariff for the mosque or government sector, then the simple payback time is 5.14 years.