Declining cost of renewables and climate change curb the need for African hydropower expansion

Abstract

Across continental Africa, more than 300 new hydropower projects are under consideration to meet the future energy demand that is expected based on the growing population and increasing energy access. Yet large uncertainties associated with hydroclimatic and socioeconomic changes challenge hydropower planning. In this work, we show that only 40 to 68% of the candidate hydropower capacity in Africa is economically attractive. By analyzing the African energy systems’ development from 2020 to 2050 for different scenarios of energy demand, land-use change, and climate impacts on water availability, we find that wind and solar outcompete hydropower by 2030. An additional 1.8 to 4% increase in annual continental investment ensures reliability against future hydroclimatic variability. However, cooperation between countries is needed to overcome the divergent spatial distribution of investment costs and potential energy deficits.

Avoiding ecosystem and social impacts of hydropower, wind, and solar in Southern Africa’s low-carbon electricity system

“…Imposing a carbon cap increases the cost-competitiveness of hydropower as a source of low-carbon electricity in higher impact scenarios, but when social and environmental exclusions are applied, the reliance on hydropower is very similar to unconstrained emissions scenarios—only 25% of planned or proposed hydropower capacity or 10 GW is necessary and cost-competitive by 2040. This is generally consistent with other studies that explore power system portfolios with varying shares of hydropower capacity and found that solar PV and wind capacity coupled with flexible gas generation are the primary substitutes for hydropower 9 , 11 , 12 , 27 . Studies that have examined optimal technology investments in response to restricting wind and solar PV development due to environmental protections found an overall shift from wind to solar PV 16 , 47 , which we observe for some, but not all, scenarios in Southern Africa.…”

“…Studies that have examined optimal technology investments in response to restricting wind and solar PV development due to environmental protections found an overall shift from wind to solar PV 16 , 47 , which we observe for some, but not all, scenarios in Southern Africa. A comparison with basin-level hydropower results from Carlino et al (2023) reveals some notable differences in how much hydropower is deemed cost competitive in Southern Africa 27 . Carlino et al (2023) found that 12–13 GW of hydropower capacity was selected in the Congo basin across all scenarios, whereas our results found only 2–4.8 GW of Congo basin projects to be cost-competitive.…”

“…Yet, this is the type of analysis needed to identify which hydropower projects can be cost-effectively substituted 4 , 25 . While Chowhury et al 26 and Carlino et al 27 both examine cost-competitiveness of specific hydropower plants in the African region or subregion in a capacity-expansion framework, finding that about half of proposed hydropower projects are economic, neither attempt to screen projects based on socio-environmental criteria and thus, remaining plants may still impose high environmental or social costs.…”

Leapfrogging the darkness: contextualising the meaning of energy transitions for African countries

“…Solar irradiance levels in Africa generally exceed those of other continents, and various regions within SSA offer substantial wind energy potential, with ample land suitable for solar and wind power plants without conflicting with other land uses (Sterl et al 2022). Several countries also boast important hydroelectric power potential, which can play important near-term roles to mitigate solar and wind intermittency (Sterl 2021a(Sterl , 2021b, although recent research suggests hydropower will rapidly cede in importance towards mid-century (Carlino et al 2023).…”