Future African hydropower plants not worth the investment, say scientists
Cheaper solar panels and the increasing impact of climate change on Africa's water resources mean that hydropower may no longer be the continent's primary energy source. As a result, most of Africa's planned hydropower plants do not appear to be worth building, according to research by scientists in Brussels.
These are the findings of a study published in Science, in which VUB professors Sebastian Sterl and Wim Thiery participated. With a team of Italian, Austrian and Ethiopian scientists, they concluded that it is no longer cost-effective for Africa to meet its growing energy needs by building new hydropower plants.
Hydropower has traditionally been one of the continent's primary sources of electricity generation. Abundant rainfall, deep gorges, huge rivers and waterfalls mean the continent has all the ingredients to generate vast amounts of electricity from its watercourses. However, it is estimated that only 10 per cent of Africa's hydropower potential is being exploited.
"Our model can determine which plants could be a wise investment and which should not be built"
The international study examined which combination of energy sources would be most cost-effective for African countries. It looked in detail and separately at the impact of all possible or planned future African hydropower plants. "We model each hydropower plant separately," says Angelo Carlino, lead author of the study. "Our model can determine which plants could be a wise investment and which should not be built."
Up to 67 per cent of planned hydropower plants in Africa are not worth the investment, they concluded. This is due to the unprecedented fall in the cost of solar power. Solar and, to a lesser extent, wind power are increasingly able to compete with hydropower. At the same time, climate change is causing more extended periods of drought, significantly impacting Africa's waterways.
"The study's main conclusion is that if the production price of wind and solar power falls, these energy sources will push hydropower out of the market"
"The study's main conclusion is that if the production price of wind and solar power falls, these energy sources will push hydropower out of the market. This is also the case for fossil fuels such as coal and oil," says Thiery, study co-author and VUB climate scientist. "This is happening at a time when climate change is making the African continent warmer, which is also leading to more prolonged droughts."
'Not bad news for the continent'
These droughts affect African watercourses, although some dams use reservoirs to cope with the drought. "For example, the Great Ethiopian Renaissance Dam has a reservoir that can store the entire flow of the Blue Nile," Thiery explains. "But if the drought continues for a long time, even these dams will have problems." In the short term, however, dams may still be cost-effective.
The study says there are still opportunities to build new hydropower plants, particularly in the Congo, Niger and Nile basins. "This depends mainly on the construction period and the development of the construction project," says Thiery. "But it also depends on the region and how climate change manifests locally. In the north and south of Africa, some areas are becoming drier, and in the east of Africa, some areas are becoming wetter."
Thiery says this conclusion "is not bad news for the continent". In light of the findings, the authors call on every country in Africa to engage in strategic energy planning, taking into account the increasing production capacity of wind and solar energy.
A general view of the Blue Nile river as it passes through the Grand Ethiopian Renaissance Dam in Ethiopia © EDUARDO SOTERAS / AFP