In this research, our team wants to research power usage in a mosque. In this case we will do our research in Darul Ma'arif Mosque, which is located in Pondok Kelapa, at the border of Jakarta and Bekasi. This research is focused on analyzing the power usage in Darul Ma’arif mosque, and will try to calculate the cost of operation in Darul Ma’arif mosque. After we successfully calculate the cost of the mosque operation, we will try to evaluate the current mosque energy strategy, and will try to do efficiency in power usage of the mosque energy usage. After that we can determine that how much cost we save using new energy strategy, and applied on the mosque itself