My great-grandfather had a microgrid. He had installed electricity for his ranching station near Wagga Wagga, Australia, and cables ran to the surrounding houses. When he left the office in the evening, he would flick the power off and then back on again. To the neighbours this was no doubt a quirk of the new electricity supply, but to my great-grandma it was a signal that he was on his way home.
Microgrids were common in the early days of electrification. Factories or wealthy households invested in an electricity supply, and it would be regulated and distributed within a small local area. As power reached more and more people and councils and utility companies invested in larger scale plants, those smaller grids were gradually standardised and incorporated into regional and eventually national grids.
Britain only has a handful of microgrids, such as the one at the Centre for Alternative Technology. The connectivity of a large grid is too useful to bother with localised systems any more. But they are being rediscovered in developing countries where many people don’t yet have electricity.
Over 600 million people in Africa and 300 million in India lack access to electricity. That means expensive and dangerous kerosene lamps, and nothing more than battery operated devices – no fridges, computers, no power tools. Providing power would make an enormous contribution to improving lives in developing countries, but it’s not easy. Unlike Britain, many African countries are vast in size, making a national grid a distant prospect. Many villages are just too far to run power out to, and too small to make the investment worthwhile.
That’s where microgrids come in, paired with cheaper renewable energy. A wind or solar installation can be run into a power management system that either distributes the power or stores it in batteries, depending on demand, and from there run out into the village. Solar is the most obvious source of power, but in some places micro-hydro is possible. An Indian company called Husk runs a couple of dozen microgrids powered by biomass, using post-harvest waste from rice farming. These grids often offer fairly low levels of power at first, enough for lighting and recharging phones, but this makes a major difference in itself. As companies get established and build a customer base – and it is mostly private companies setting up such services – then grids can be scaled up in due course.
As well as remote villages, micro-grids can also play a role in cities where the existing grid is straining under demand. Interconnecting clusters of smaller grids, preferably with a variety of power sources, can make a city power supply more resilient. Hospitals, universities or other facilities that want uninterrupted power could also benefit from a micro-grid.
Until recently, these sorts of smaller grids weren’t economical. The only power source that could work at that scale was diesel generators, and that was too expensive to be practical. As the price of renewable energy falls, all sorts of new opportunities are opening up for those without power. And just as we’ve seen with mobile phones and landlines, many communities in the developing world will leapfrog a generation of technology and get clean, renewable energy first time around.