In a recent study, Patrick Lehmann-Grube, an independent researcher, and I reviewed 56 papers that focused on how access to off-grid solar energy impacts household income in Africa. Initially, the available evidence appears to provide strong support, with almost all the papers finding a positive effect.
This was largely based on the finding that SHSs enabled local stalls and kiosks to stay open longer by operating beyond nightfall. The testimony of a Kenyan fruit and vegetable seller is typical. After the addition of a SHS, she reported being able to add “two more hours of trading each day”. Across the studies, additional work hours allowed household income to increase by around US$20–£40 (£17-£33) per month.