Floating photovoltaics may reduce the risk of hydro-dominated energy development in Africa

Floating photovoltaics (FPV) is fast becoming cost-competitive, but its social and environmental impacts are under debate. Meanwhile, developing economies anticipate hundreds of new dams over the next decade, with social and environmental implications for the next century. In this context, we estimate that FPV could produce 20–100% of the electricity expected from Africa’s planned hydropower depending on the scale of FPV deployment and its cost and efficiency relative to land-based photovoltaics. Here, at the system scale, we show that the same capital investment earmarked for planned dams in the Zambezi watercourse could be used more efficiently by building fewer reservoirs and substituting the energy supply with FPV. This approach yields an energy output 12% less variable and more robust to long-term hydrological changes. Our findings suggest that FPV’s potential to avoid the environmental, social and financial risks of hydro-dominated energy development may outweigh its potential impacts on existing reservoir uses.