Hydropower
Hydropower is one of the oldest and most reliable sources of renewable energy. As of 2023, it was the largest source of renewable electricity generation globally, contributing significantly to the energy mix in many countries.
Hydropower harnesses the energy of moving water to generate electricity. Most hydropower plants are typically located near rivers or lakes where there is sufficient water flow. There are three types of hydropower facilities 1.
Run-of-the-river systems: Here, the force of the river’s current applies pressure on turbines. The higher the volume of the water flow, the higher the amount of energy.
Storage systems: Water accumulates in reservoirs created by dams on streams and rivers and is released through hydro turbines to generate electricity.
Pumped-storage hydropower: Water is pumped from a water source up to a storage reservoir that is elevated on a higher ground. The water is released from the upper reservoir to power hydroturbines located at a lower ground. The higher the elavation of the reservoir, the higher the energy obtained.
In 2023, China was the leading country in hydropower generation worldwide, generating a capacity of 1,245.17 TWh. It was followed by Brazil(431.28 TWh), Canada(365.39 TWh), United States(233.96 TWh) and Russia(200.60 TWh).
Investment in hydropower energy in Europe peaked in 2011 and has been declining ever since. The Fukushima catastrophe2 made countries rethink their energy strategy towards renewable sources leading to enhanced investment in hydropower. But due to various factors, among them distortion in market prices due to high subsidies3 in wind and solar power generation, investment in hydropower has been on a downward trend in the last 15 years 4.
Despite Africa having vast water resources, it only has a total installed hydropower capacity of 42GW, which is only 10% of the continent’s hydropower potential. Ethiopia has the highest installed capacity (4,825 MW) followed by Angola (3,836 MW) and South Africa (3,600 MW) 5.
Access to finance and infrastructural inadequacies have been identified as the main factors inhibiting progress in hydropower development in the region. However, public-private partnerships are helping to accelerate hydropower development. With most hydropower plants being over 20 years old, there is a growing need to upgrade them. The African Development Bank (AfDB) is spearheading efforts to upgrade twelve hydropower plants through a US$1 billion investment 6.
Hydropower is not only today’s leading source of low carbon electricity, but it is equipped to offer the greatest grid flexibility in terms of reliability and safety. It is expected to become a predominant source of dispatchable electricity 7, contributing more than 40% of electricity production by 2050. To provide dependable low-carbon electricity and serve as a reliable backup to wind and solar power, hydropower capacity must be increased by an additional 1,300 GW, reaching a total capacity of 2,700 GW by 20508.
Next: Solar energy
Footnotes
A subsidy is a financial assistance or support provided by the government to help lower the cost of a good or service. It can take the form of direct payments, tax breaks, or reduced prices, making it more affordable for consumers or encouraging production. In this case, subsidies make the development of solar and wind power more affordable and attractive to investors, compared to hydropower.↩︎
International Hydropower Association Regional Profiles: Africa↩︎
International Hydropower Associations: Africa adds 2GW hydropower capacity in 2023 but stark gap remains↩︎
A dispatchable source of electricity refers to an electrical power system, such as a power plant, that can be turned on or off; in other words they can adjust their power output supplied to the electrical grid on demand.↩︎