Some 600 million people in India have been left without power after parts of the country's massive electricity grid collapsed Tuesday. While the cause isn't yet clear, the outage isn't surprising. India's grid has long been strained, with demand often exceeding supply by hundreds of megawatts, forcing regular rolling blackouts in some areas.
A big part of the solution is obvious: more power plants, more power lines, and an increased supply of coal and other fossil fuels—in India, many power plants don't operate at full capacity because they can't get enough fuel. But another part could be technology that's already starting to catch on in many parts of the developing world: microgrids.
Instead of relying only on large, centralized power plants, microgrids supply a small area with electricity from distributed sources—such as diesel generators combined with solar panels with battery storage. These localized grids can operate either attached to the national grid or apart from it, in many cases allowing businesses and hospitals and other organizations to keep going without a hiccup when the larger grid goes down.
The technology is already becoming popular in India because businesses can't simply count on the grid. "There is a tremendous amount of investment that Indian companies have to make in captive generation as a backup strategy," says Rohan Parikh, head of green initiatives at Infosys, a software company with 10 campuses across India, each with its own backup power supply. Infosys is also working on the software that helps control microgrids.
Microgrids are an extension of on-site generators, or dedicated power supplies, sometimes called captive generation. But they have several advantages over the simple backup diesel generators that are keeping many essential services in India going right now. They use a variety of resources for power, not just diesel generators, which makes them more reliable. So they can keep running, at least in a limited way, even if supplies of diesel fuel get cut off.
They can also be cleaner—if solar is used as part of the energy mix. And now that solar panel prices have fallen, distributed solar can be cheaper than running diesel generators alone for backup power. "Solar power is very attractive when compared to diesel generators in the daytime," Parikh says.
Microgrids also offer benefits for the larger grid. Utilities can call on businesses running microgrids to disconnect to ease strain during times of peak demand. That could reduce the number of power outages in a country like India.
Microgrids are no panacea. There's a limit to the amount of solar power that can be installed on a given site, for example. Parikh estimates that on-site solar will only ever account for 10 to 15 percent of the power demands of a given campus—there's just not enough roof space and open land to do much more than that. Batteries are also too expensive to store much solar power for use when the sun isn't shining. Therefore, to some extent, microgrids will need to rely on conventional fossil fuels to keep running.
Microgrids may also be important as countries such as India continue to develop, bringing power to more people even as power demand increases. One vision is that, as India develops, it could become a network of many microgrids, each connected but able to survive independently. Outages that affect entire states could become a thing of the past.
While news reports suggested that there are 600 million people who lost power with this week's outages, that's almost certainly an overestimate—if only because hundreds of millions of people in India didn't have grid power to start with. Some of these people are starting to get power for the first time, via microgrids.