Rooftop solar power plants has its PV panels mounted on the rooftop of a residential or commercial or industrial roof of an existing building. In urban buildings, rooftop installations are more feasible because it utilizes unused building roofs. Rooftop solar power plants are small installations in kW scale and can go up to 2 MW for large roof space. It can be installed on the building with pitched roof, flat roof, shed roof, and curved roof. Grid connected rooftop solar power plants are the most simplest and cost effective installation. It is not competent to back up power during outages. DC power generated by PV modules or array or string mounted on roof is converted to AC power by inverter, which feeds the existing load. During power generation through PV solar, power drawn from grid gets reduced. In the case of excessive power generation, energy fed backs to grid. Depending on policy, power that is pushed back into the grid is purchased by utility or adjusted in billing cycle.