Reconsidering hydropower in the African energy transition

African nations are striving to meet increasing energy demands driven by population growth and improving living standards. To reduce emissions, many national capacity expansion plans are attempting to use low-carbon electricity sources and exploit the untapped continental hydropower potential with 300 new hydropower projects planned for a total of around 100 GW of new installed capacity. However, climate, socio-economic, and technological changes are making these investments in new dams more risky and less economically efficient.

In this talk, we discuss the role of hydropower projects across different power capacity expansion pathways in Africa. Our multi-scale analysis is built on an integrated modeling framework that combines an Integrated Assessment Model (GCAM), an energy system planning model (OSeMOSYS-TEMBA), a power system model (PowNet), and a strategic river basin-scale reservoir system model. This framework allows the simulation of different future scenarios that harmonize global climate policies, land-use change, climate impacts on water availability, final energy demands, and multipurpose reservoir operations.

Our results show that, depending on the scenario considered, between 32 and 60% of the proposed hydropower capacity is not cost-optimal. Moreover, our analysis suggests that hardly any new hydropower will be built after 2030, meaning that its role in terms of installed capacity and generation will gradually decrease in favor of solar and wind power. Besides, floating photovoltaics might also represent a low-impact alternative to hydroelectric dams, producing 20-100% of the electricity from planned hydroelectric dams depending on the scale of deployment of this new technology on existing hydroelectric infrastructure at the African power pool scale. Lastly, we show how policy fragmentation between developed and developing countries in their approach to land use change emissions can have negative side effects on local water demands, producing favorable conditions for the realization of extensive agricultural projects in Africa that increase local irrigation demands and constrain the availability of water resources for hydropower production.

These findings show that strategic planning of water-energy systems is essential to navigate the complex landscape of hydropower development in Africa. By adopting a systemic approach, African nations can identify cost-efficient climate-resilient hydropower projects that will contribute in securing a sustainable and resilient energy future.