To meet the needs of a growing population in a manner that is socially equitable, economically viable, and environmentally sustainable, Africa's electricity sector will require a major transformation. It has already undergone some important changes over the past decade. Efforts to expand access to electricity have proceeded at a slightly faster pace than anticipated 10 years ago. In parallel, the deployment of renewable energy technologies has progressed apace, despite new discoveries of natural gas across the continent and favored by the volatility of oil prices. Nonetheless, the expansion and modernization of Africa's electricity sector need heightened efforts, as evidenced by current electrification rates, generation-capacity levels, and security-of-supply indicators. We identify a suite of actions that, if implemented, would put Africa's electricity sector on track to sharply increase electrification rates across the continent while securing long-term access to affordable cleaner energy, and reducing greenhouse-gas emissions and emissions of local-air pollutants.