The amount of electricity per person in sub-Saharan Africa, when you factor out South Africa, is lower today than it was 30 years ago, according to Bill Gates. “That’s kind of a stunning thing,” says Gates in an interview with Quartz. Even the “best-case analysis right now is fairly bleak in terms of how much electrification is likely to come to Africa,” says Gates, citing forecasts from the International Energy Agency. Only 290 million out of 915 million people in sub-Saharan Africa have access to electricity, according to IEA analysis published in 2014—and the number without access was increasing. As you can see in the video above, Gates says that a breakthrough in battery technology could be especially valuable in Africa, making it possible to spread the usage of energy generated from cheap, clean sources out over time. “If you want to tell people to come and build factories and have jobs, it’s not going to come where you say ‘Oh yeah, this factory works when the wind is blowing and otherwise it shuts down.’”