Is Hydropower The World’S Largest Source Of Renewable Energy?
Hydropower is electricity generated from the energy of falling or flowing water. It is one of the oldest and most widely-used forms of renewable energy. Hydropower uses the force of water moving from higher to lower elevations through dams, turbines, and generators to produce electricity. Nearly 17% of global electricity production comes from hydropower.
Hydropower has been used for thousands of years, dating back to ancient Greece and China where water wheels were used for mechanical power. In the late 19th century, hydropower played a major role in the electrification of many countries. Today, it remains the largest source of renewable power worldwide.
Global Hydropower Capacity
According to the Low Emissions Scenario report by Statkraft, the total installed global hydropower capacity was 1,308 GW in 2021. This represents a steady increase from 539 GW in 1990. The top five countries for hydropower capacity in 2021 were China (386 GW), Brazil (109 GW), the United States (102 GW), Canada (81 GW) and Russia (48 GW). Hydropower accounts for over 16% of global electricity production and remains the largest source of renewable energy globally.
Statkraft projects that global hydropower capacity could reach 1,649 GW by 2030. Much of the growth is expected to occur in emerging markets, especially China and India. However, mature hydropower markets like Europe and North America are projected to have slower capacity growth. Overall, the share of hydropower in the global energy mix is expected to decrease slightly from 16% currently to 15% by 2030 as other renewables like solar and wind expand more rapidly.
Sources: Low Emissions Scenario report
Hydropower’s Share of Renewable Energy
Among renewable energy sources, hydropower generates the most electricity globally. In 2021, hydropower accounted for around 16% of total global electricity production and over 70% of all renewable electricity production, according to the International Hydropower Association (IHA) [1]. Other major renewable energy sources like wind and solar photovoltaics (PV) generated around 6-7% of global electricity each in 2021.
The generating capacity of hydropower worldwide is about 1,300 gigawatts (GW), compared to around 760 GW for wind power and 700 GW for solar PV, based on IHA data [1]. In terms of electricity generation, hydropower produced around 4,400 terawatt hours (TWh) in 2021, while wind and solar PV generated around 1,800 TWh each.
So in summary, hydropower has nearly twice the installed capacity and generates over twice as much electricity globally compared to the next largest renewable energy sources like wind and solar power. This makes hydropower the predominant and largest source of renewable electricity worldwide.
Hydropower Generation by Country
China is the world’s largest producer of hydropower, generating over 1,270 billion kWh in 2022, according to Statista. China has invested heavily in hydropower dams and stations to meet its large electricity demands. The Three Gorges Dam on the Yangtze River is currently the world’s largest hydropower facility with a capacity of 22,500 MW.
Other top hydropower generating countries include:
– Canada – 377 billion kWh in 2021 (TheGlobalEconomy.com)
– Brazil – 363 billion kWh in 2022 (Statista)
– United States – 260 billion kWh in 2021 (TheGlobalEconomy.com)
These four countries accounted for over 50% of global hydropower generation in recent years. Other major hydropower producers include Russia, India, Norway, Japan and Venezuela.
Hydropower represents about 16% of total electricity production globally. However, the share of hydropower varies significantly by country based on geographical factors like river systems and water resources.
Advantages of Hydropower
Hydropower is considered a renewable energy source because it is produced from flowing water, which is continuously replenished through the water cycle. Unlike fossil fuels, hydropower relies on this endless renewable resource and does not produce greenhouse gas emissions (EnergySage).
Hydropower is also a very reliable energy source when compared to other renewables like wind and solar power. The flow of water in rivers and reservoirs is relatively consistent and predictable, allowing hydropower to provide steady baseload power (Department of Energy). This makes hydropower an excellent complement to intermittent renewable sources.
Lastly, hydropower has relatively low operating and maintenance costs once facilities are constructed. Since it relies on the natural flow of water rather than costly fuel sources, operating costs are minimized (Gracon). This makes the levelized cost of hydroelectricity very affordable in the long run.
Disadvantages of Hydropower
While hydropower offers many benefits, there are some downsides as well. Three major disadvantages of hydropower include:
High Upfront Costs
Constructing a hydropower plant requires substantial upfront capital investment. Building large dams, reservoirs, tunnels, turbines and other infrastructure can cost billions of dollars [1]. The costs need to be weighed against the long-term energy benefits.
Geographical Constraints
Hydropower is limited by suitable geography and water availability. Dams require certain topography and sufficient water flow year-round. Many regions lack hills/mountains and rivers capable of supporting large-scale hydropower. This geographical constraint limits broader use.
Environmental Concerns
Damming rivers can destroy or disrupt local ecosystems and habitats. Slow moving water in reservoirs releases methane and can breed insects. Fish migration routes are blocked by dams. Conservation strategies are required to minimize environmental impacts [2].
Recent Hydropower Projects
In recent years, several major hydropower projects have come online or begun construction around the world. Some examples include:
The Baihetan Dam in China began generating electricity in 2021. With 16GW of installed capacity, it is now the world’s second largest hydropower station behind the Three Gorges Dam (Tractebel).
The Koysha Dam in Ethiopia started operations in 2022. When fully completed in 2024, its 2.2GW capacity will make it Africa’s largest hydroelectric plant (WorldRef).
Nepal has several new major hydropower projects underway, including the 900MW Upper Arun and 679MW Lower Arun projects. These will help the country move closer to its goal of 100% electrification by 2030 (Tractebel).
Brazil’s Belo Monte Dam began operating its last turbine in 2019, making its installed capacity of 11.2GW the fourth largest hydroelectric plant in the world (WorldRef Technologies).
Future Outlook
According to the 2023 World Hydropower Outlook, the future growth and challenges for hydropower are significant. The report projects that global hydropower capacity could double to 2,850 GW by 2050 if the right policies and investments are in place. Much of this growth is expected to come from developing countries in Asia, Africa and Latin America.
However, the outlook highlights several challenges facing the hydropower industry. Climate change and droughts are decreasing water availability in some regions, impacting generation potential. There is also growing competition with other water users in river basins. Additionally, environmental concerns around habitat loss and methane emissions from reservoirs present challenges.
To realize projected growth, the report calls for modernizing existing plants, embracing innovative new technologies like floating solar-hydro hybrids, and gaining social acceptance through benefit sharing and sustainability measures. Overcoming these challenges will require supportive policies, long-term planning and financing access to tap into hydropower’s full potential.
Conclusions
Based on the key facts presented, hydropower is among the world’s largest sources of renewable energy, but it is not the single largest source according to most data.
In 2021, hydropower accounted for around 16% of total global electricity generation and over 70% of renewable electricity generation. This makes it currently the largest single renewable energy source worldwide. However, all non-hydro renewables combined, such as wind, solar, geothermal, and biomass, generated more electricity than hydropower.
The top countries for hydropower generation are China, Brazil, Canada, the United States, and Russia. Together they represent over half of installed hydropower capacity globally. While most growth is occurring in developing countries, especially in Asia, the potential for new major hydropower projects is limited in many regions.
In conclusion, while hydropower is the largest source of renewable electricity globally, it is not the world’s single largest renewable energy source when all other renewables are considered together. Its growth is constrained by geographical limitations and environmental concerns. Therefore, continued expansion of other renewables like wind and solar will be needed to fully transition the world to carbon-free renewable energy.
References
World Hydropower Congress. (2019). 2019 Hydropower Status Report. Retrieved from https://www.hydropower.org/publications/2019-hydropower-status-report
International Energy Agency. (2020). Renewables 2020. Retrieved from https://www.iea.org/reports/renewables-2020
International Hydropower Association. (2020). 2020 Hydropower Status Report. Retrieved from https://www.hydropower.org/publications/2020-hydropower-status-report
International Renewable Energy Agency. (2021). Renewable Capacity Statistics 2021. Retrieved from https://www.irena.org/publications/2021/Mar/Renewable-Capacity-Statistics-2021
Our World in Data. (2020). Renewable Energy. Retrieved from https://ourworldindata.org/renewable-energy
US Energy Information Administration. (2021). Hydropower Explained. Retrieved from https://www.eia.gov/energyexplained/hydropower/
