They generate power during the day time which is utilized fully by powering captive loads and feed excess power to the grid as long as grid is available. In case, where solar power is not sufficient due to cloud cover etc., the captive loads are served by drawing power from the grid. The grid-interactive rooftop system can work on net metering basis wherein the beneficiary pays to the utility on net meter reading basis only. Alternatively, two meters can also be installed to major the export and import of power separately. Many such power plants can be installed at the roofs of residential, commercial complex, housing societies, community centers, government organizations, private institutions etc. Ideally, grid interactive systems do not require battery back-up as grid acts as the back-up for feeding excess solar power and vice-versa. However, to enhance the performance reliability of the overall systems, a minimum battery backup of one hour of load capacity is recommended.

You are mitigating the dependence on fossil fuel based electricity generation and encourage environment friendly Solar electricity generation. In addition to your saving on electricity bills, you can also earn on your investment on Grid connected Rooftop Solar Power Plant with net metering /feed-in-tariff facilities. The excess power generated by Solar Power Plant will be feed to the grid and DISCOMS will pay for excess power feeded to grid. You are lowering carbon dioxide emission and helping combat global climate change.