“It’s not us trying to profit out of poverty, which is the way it gets painted by some quarters,” says Woods. Instead, he stresses that sustainability must also be considered from a financial perspective. That means that while non-profit organizations make valuable contributions, large-scale electrification efforts meant to spur economic activity may have to rely in the long run on the fruits of that economic activity. The IEA estimates that universal access to modern energy will cost $756 billion in investments all told. It will be challenging enough to come up with that kind of money, so a model where running costs are paid for by customers might make sense once communities receive the initial kick-start.

The extent to which renewables could support developed urban areas in more advanced countries is less clear. Woods is doubtful that a country like India, which experienced a blackout affecting 620 million people this summer, could successfully reinforce its energy supply on a mass scale using solar technology alone. That isn’t to say there’s not a vital role for renewable energy in developing Asia. The degree of change needed to make an impact in neighboring Bangladesh, for example, is significant, with 96 million people lacking electricity. Yet with a largely rural population and the world’s highest population density, there appear to be ample opportunities for small-scale renewable energy to make a big difference.