A utility data API is a service that connects to customers' accounts at their electricity companies, reads their bills and meter data, and supplies them to other companies' apps. An API is a way for one piece of software to ask another for data in a fixed format. Here, the apps of solar companies, energy-saving tools and car chargers ask the service for a home's electricity data. This product is sold mainly in the United States, where an electricity company is called a utility, and so it is named that way.
The problem it solves is that every electricity company keeps its data in its own format, behind its own website. A solar company that wants to quote a home owner needs the past year of bills. Without this service, the home owner must find the bills and type the numbers in. With it, the home owner gives permission once. Usually the home owner types the username and password for the electricity company's website into the service's form, and the service logs in with them. Some electricity companies instead let the home owner approve the sharing on their own website. The service then reads the bills and the meter readings, converts them to one standard format and sends them to the app. The apps that use the data pay the service, because the data saves them from asking every customer for papers.
Say a solar installer's app in Colorado asks a home owner for permission to see the last 12 months of electricity data. The home owner agrees. The service reads the 12 bills and the hourly meter data from the electricity company. The installer's app then sees that the home uses most power in the evening, and it sizes a battery for it.
The data comes from the smart meter, which measures how much power the home uses and sends it to the electricity company. Software can then work out which appliance used the power, using energy disaggregation. The same data lets a subscriber's share of a plant be credited on the bill in community solar.
In India, each state discom keeps its own bills and its own website, and there is no single service of this kind yet. The Ministry of Power has tested the India Energy Stack, a common set of digital standards for exchanging power-sector data, with six discoms in five states. Smart meters are now being installed in Indian homes, and they will produce the same kind of hourly data. Engineering for such products is done in Chennai.
The service is part of rooftop solar.