Cheap illumination’s benefits in remote areas may be limited

FOR sunny places not connected to the electricity grid, the falling price of solar panels and LED lighting promises a bright future. No more smoky, lung-damaging kerosene lamps. Greater security and safety. More ways to connect with the world—even if that involves only something as simple as being able to charge a mobile phone. And, above all, the chance to work or study into the evening and thus improve both a family’s immediate economic circumstances and its children’s future prospects. It is a tale of hope. But as a study just published in Science Advances, by Michaël Aklin of the University of Pittsburgh and his colleagues, shows, these potentially glowing benefits can in some cases amount to not very much at all.

More than 1bn people around the world have no access to electricity. Providing them with off-grid solar power is something almost all development experts agree is A Good Thing. Yet the evidence for how beneficial it really is was largely observational. Off-grid solar has not been put through the rigours of a large, randomised, controlled trial, of the sort that scientific researchers like to use to test relationships between cause and effect. To fix this oversight, Dr Aklin set about organising just such an experiment.

He and his colleagues teamed up with Mera Gao Power (MGP), one of India’s providers of solar-power systems. Their volunteers lived in small villages, all of which lacked electricity, in the Barabanki district of Uttar Pradesh, a state in northern India. Of the 81 villages in the study, 41 were left alone, to act as controls. In the other 40, MGP offered to install a basic, solar-powered minigrid service provided that at least ten households per village subscribed 100 rupees (about $1.70) each a month to be connected to it. That sum represents about 2% of a typical household’s expenditure. Those that signed up then had their homes fitted with two bright LED lights and a mobile-phone charging-point.

Connection to a minigrid brought some advantages. Households using solar power in this way cut their consumption of unsubsidised kerosene by a fifth—though, because a limited supply of kerosene is subsidised by the government in this part of Uttar Pradesh, the actual sum saved amounted to about 48 rupees per month, only half of the cost of the (unsubsidised) grid connection. When it came to social benefits from the use of solar power, though, Dr Aklin and his colleagues found little or no evidence of their existence. People did not work longer hours, did not start new businesses and did not study more. Overall, in this case at least, the researchers concluded that solar power had few measurable effects.

This certainly was not what had been hoped for. Dr Aklin conjectures that the explanation may lie with the relatively paltry nature of what was offered, which amounted to an hour or two’s extra lighting per day. That is a fair observation, but bigger, more complex systems that would make substantially larger amounts of solar power available would probably be too expensive for villagers in this area.

What would make a big difference, says Dr Aklin, are better batteries that can garner more of the sun’s bounty in the first place. “If batteries were cheaper and could store more power,” he observes, “off-grid companies could offer larger systems that enable rural households to run appliances and machinery.” That, rather than a bit of light in the evening, might really promote economic activity.

As it happens, the cost and performance of batteries is steadily improving, not least because of the development of electric cars. And even if new batteries remain too expensive for use in village solar systems, perhaps second-hand ones that are no longer up to the job of providing the oomph for vehicles will be able to help power villages instead.