Climate change, hydrological variability, and declining cost of renewables reduce economic viability of African hydropower potential
Abstract
African population growth and expected increase in energy access require large infrastructural investments in new power capacity to meet future power demand. As emission reductions are discussed at the global level, capacity expansion plans at the local level try to leverage low-carbon electricity sources and exploit the untapped hydropower potential with 300 new hydropower projects for a total of around 100 GW. Yet, climate and socio-economic changes will impact the hydrological regime and the water demand. These factors make future hydropower generation uncertain and motivate an integrated approach for energy system planning.
Here, we analyze future African energy system development from 2020 to 2050 based on the OSeMOSYS-TEMBA energy system model. We rely on the ISIMIP2b scenarios to integrate coherently final energy demands, land-use change, and climate impacts on water availability. We consider individual candidate hydropower projects information and design capacity expansion plans under median and very dry hydrology. Our results show that between 34% to 65% of the candidate projects are cost-optimal and that the relevance of hydropower rapidly declines over time as other renewables become cheaper. The economically viable hydropower potential is moslty in the Nile, Congo and Niger river basins. In addition to high capacity factor and nominal capacity, the presence of transmission lines and the proximity to other large hydropower plants are factors driving the prioritization of each project. Finally, while the cost of capacity expansion under median and very dry hydrology are similar at the continental scale, local investments vary substantially. This finding points towards the need for incentives and cooperation to hedge against dry hydrological conditions. Our results show that integrating the whole energy system in hydropower planning can produce useful insights for selecting which projects and river basin should be prioritized. At the same time, we show that the proposed alternatives should be evaluated at different spatial scales (continental, basin-level and national) to monitor the implications that remain implicit behind large-scale power capacity expansion planning.- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFMGC12B..06C