Climate Impacts on African Hydropower

Hydropower plant
In this report

Africa is projected to experience increasing climate hazards for the remainder of the 21st century, which are likely to pose a challenge to hydropower generation in Africa. To minimise the adverse effects of climate change, hydropower is needed to enhance Africa’s resilience to climate change. Resilient hydropower can play a key role in allowing Africa to meet the Sustainable Development Goals (SDGs), implement clean energy transitions, and adapt to climate change.

This report aims to enhance the climate resilience of African hydropower through a climate risk and impact assessment, and by introducing potential resilience measures. It qualitatively assesses climate risks to African hydropower and examines potential climate impacts quantitatively, comparing two climate scenarios. Based on the assessment, it identifies measures to enhance climate resilience and provides policy recommendations.

Executive summary

Currently, hydropower accounts for 17% of the electricity generation in Africa on average. In some countries, such as the Democratic Republic of Congo, Ethiopia, Malawi, Mozambique, Uganda, and Zambia, the share of hydropower in electricity generation exceeds 80%. This share may potentially increase to more than 23% by 2040, as part of the ongoing effort towards clean energy transition and universal energy access in Africa.

Expanding the share of hydropower in Africa may increase a country’s exposure to climate hazards and risks to electricity systems if carried out without assessing the potential impacts of climate change. Africa is one of the regions most susceptible to climate change. The continent is already experiencing increased anomalies in climate patterns and is likely to experience greater climate impacts for the remainder of the 21st century. For instance, southern Africa is likely to experience a drier climate with more frequent incidences of low precipitation, while east Africa is predicted to experience a wetter climate with more frequent heavy rainfall. In addition to these future anomalies in climate patterns, the continent’s high sensitivity to water availability and its low adaptive capacity compound African hydropower’s vulnerability to climate change. 

This report assesses climate impacts on African hydropower generation using general circulation models (GCM) and global hydrological models (GHM) comparing two different greenhouse gas (GHG) concentration pathways (which are associated with the level of global warming of below 2°C and around 3°C by 2100, respectively). The assessment considers 80% installed hydropower capacity in 13 African countries between 2020 and 2099, comparing projected results with values from the baseline period from 2010 to 2019.

From now until the end of the century, the mean hydropower capacity factor of selected hydropower plants is projected to decrease due to climate change in both scenarios. The average capacity factor of analysed African hydropower plants is likely to decrease by approximately 3% between 2060‑99 compared to the baseline period 2010‑19. The projected accumulative loss in generation output due to climate change for the remainder of the 21st century is approximately 130 terawatt-hours (TWh); this is equivalent to the current total annual generation output from all African hydropower plants.

Average hydropower capacity factor of selected African hydropower plants, 2020-2099, relative to the baseline level of 2010-2019

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The projected decrease in the regional mean hydropower capacity factor may generate false impressions regarding future climate impacts on African hydropower. This may prompt the conclusion that climate change and different levels of global warming will have insignificant impacts on future hydropower capacity factors.

However, country-specific data show that climate change will have significant impacts on most African countries, although the patterns of change may vary from one country to the other. For example, the hydropower capacity factor in Morocco, Zambia, Zimbabwe, the Democratic Republic of Congo and Mozambique are projected to decline considerably, while the decrease would be offset by an increase in the hydropower capacity of the Nile basin countries, notably Egypt, Sudan and Kenya.

Country-specific data also show that these climate impacts will be largely affected by the level of GHG concentration. Morocco, Zambia and Zimbabwe are likely to experience a larger decrease in hydropower capacity factor with higher GHG concentrations. However, the larger decrease in the hydropower capacity factor in these countries will be offset by a higher increase in the Nile basin countries. This will eventually generate the same level of decline of approximately 3% in the regional mean hydropower capacity factor in both scenarios.

Changes in hydropower capacity factor in the Around 3°C Scenario, 2020-2099, relative to the baseline period

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Changes in hydropower capacity factor in the Below 2°C Scenario, 2020-2099, relative to the baseline period

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The uneven distribution of climate impacts across the continent will require a tailored approach for each country. Countries around the Congo and Zambezi basins will need to cope with a drop in the hydropower capacity factors while the Nile basin countries are projected to see an increase for the remainder of the 21st century.

Changes in hydropower capacity factor in Congo and Zambezi Basins, 2020-2099, relative to the baseline 2010-2019

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Changes in hydropower capacity factor in the Nile Basin, 2020-2099, relative to the baseline 2010-2019

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Changes in hydropower capacity factor in Northern Africa (Morocco), 2020-2099, relative to the baseline 2010-2019

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Changes in hydropower capacity factor in West Africa (Ghana), 2020-2099, relative to the baseline 2010-2019

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This spatial variation in the hydropower capacity factor is likely to be starker with a higher GHG concentration. Under the Below 2°C scenario, countries in the Congo and Zambezi basins are likely to see a decrease of over 6.5%, while the Nile basin countries experience an increase of over 2% between 2060‑99. In the Around 3°C scenario, the Congo and Zambezi basin countries may see a greater drop, over 7% on average, in hydropower capacity. In contrast, the Nile basin countries are likely to see an increase by more than 7%.

Change in hydropower capacity factors in Africa in the Around 3°C Scenario compared to the baseline

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Change in hydropower capacity factors in Africa in the Below 2°C Scenario compared to the baseline

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Another challenge caused by climate change is the increased year-to-year variability in hydropower capacity factors. Most hydropower plants studied in Egypt, Ethiopia, Ghana, Morocco, and Sudan are likely to experience increasing fluctuation in their capacity factors for the remainder of the century.

This variability is projected to be stronger with higher global GHG concentrations, and become an increasingly serious concern for reliable electricity supply. Under the Around 3°C scenario, the variability in hydropower capacity factors is likely to become exacerbated. Of the plants analysed, 85% present stronger fluctuations in hydropower capacity factors under the Around 3°C scenario than the Below 2°C scenario.

Variability of hydropower capacity factors in Africa in the Around 3°C scenario, 2020-2099

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Variability of hydropower capacity factors in Africa in the Below 2°C scenario, 2020-2099

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The enhanced climate resilience of African hydropower can bring multiple benefits. Resilient hydropower systems will help deliver the Sustainable Development Goals (SDGs) and minimise losses incurred by climate impacts. Resilient hydropower can also provide adaptation benefits by limiting climate impacts on water resources.

However, there is no one-size-fits-all solution to enhance the resilience of hydropower plants because of the wide range of patterns and magnitude of climate impacts. A tailored combination of resilience measures based on systematic assessments of climate risks and impacts will assist countries and operators in increasing the resilience of their systems.

Governments are expected to play a central role in identifying and implementing appropriate resilience measures for African hydropower. They can provide technical support for forecasting changes in climate patterns and offer financial support to increase the resilience of hydropower projects. Moreover, governments can introduce policies, regulations and guidelines to integrate climate resilience considerations into the planning, operation and maintenance of hydropower. Governments can also develop, support and implement capacity-building activities for risk and impact assessments, emergency response and recovery in the public and private sectors.