Rooftop solar is a set of solar panels on a home's roof that makes some of the home's own electricity. Add a battery and an electric car, and the house becomes a small power station. It makes power, stores it, uses it and sometimes sells it. Like any power station, it needs to be controlled, and software does that.
A home like this faces the same questions every hour. Should the solar power run the house, charge the battery or charge the car? Should the home buy power from the grid now, or wait until it is cheaper? Should it send its spare power to the grid? These questions matter because of how homes are billed. In India, the state electricity company, called the discom, gives a home with rooftop solar credit on its bill for the units the home sends to the grid. This arrangement is called net metering. The central government's rules also require discoms to charge different rates at different hours of the day, called time-of-day rates. For homes, these rates start once a smart meter is fitted. They make the timing of the home's use matter more. The home is one part of the grid edge.
India is putting panels on many roofs. The central government's PM Surya Ghar: Muft Bijli Yojana scheme gives homes a subsidy for rooftop systems. Most Indian homes already know the idea of a battery for power cuts, so a solar-plus-battery system is easy to picture. Two products on this page, the smart electrical panel and the utility data API, are sold mainly in the United States so far, and their pages say so. Much of the engineering for them is done in Chennai and Bengaluru.
Take, for example, a home owner in Indore who wants rooftop panels. An installer first designs the system in solar design software and quotes a price. After the panels are fitted, a smart electrical panel decides where each unit of power goes. The electricity company's bill and meter data can be read by other apps through a utility data API. A neighbour who lives in a flat without a roof can buy a share of a solar plant elsewhere through community solar.