Photovoltaic (PV) power systems convert sunlight directly into electricity. PV system can be contributed to energy generation in the electrical network to provide a sustainable access to electricity and to stimulate development. As result of that, solar system makes power supply more reliable and resilient. Due to weak grid and case of blackouts, PV system can be used as an effective solution to solve problem to provide electrical energy for house load.A residential PV power system enables a homeowner to generate some or all of their daily electrical energy demand on their own roof. In this project, designing PV system to provide all households electrical demand during all day with connection to grid as backup for the system with flexibility to switch the system between off grid and on grid connection.