Hydropower also known as water power or water energy, is the use of falling or fast-running water to produce electricity or power machines. This is achieved by converting a water source's gravitational potential or kinetic energy to produce power. Hydropower is a method of sustainable energy production. Hydropower is now used principally for hydroelectric power generation and is also applied as one-half of an energy storage system known as pumped-storage hydroelectricity.
Hydropower is an attractive alternative to fossil fuels as it does not directly produce carbon dioxide or other atmospheric pollutants and it provides a relatively consistent source of power. Nonetheless, it has economic, sociological, and environmental downsides and requires a sufficiently energetic water source, such as a river or elevated lake. International institutions such as the World Bank view hydropower as a low-carbon means of economic development.
Hydropower has a long history
Hydropower is one of the oldest sources of energy for producing mechanical and electrical energy, and up until 2019, it was the largest source of total annual U.S. renewable electricity generation. Thousands of years ago, people used hydropower to turn paddle wheels on rivers to grind grain. Before steam power and electricity were available, grain and lumber mills were powered directly with hydropower. The first industrial use of hydropower to generate electricity in the United States was in 1880 to power 16 brush-arc lamps at the Wolverine Chair Factory in Grand Rapids, Michigan. The first U.S. hydroelectric power plant to sell electricity opened on the Fox River near Appleton, Wisconsin, on September 30, 1882.
About 1,450 conventional and 40 pumped-storage hydropower plants are operating in the United States. The oldest operating U.S. hydropower facility is the Whiting plant in Whiting, Wisconsin, which started operating in 1891 and has a total generation capacity of about 4 megawatts (MW). Most U.S. hydroelectricity is produced at large dams on major rivers, and most of these hydroelectric dams were built before the mid-1970s by federal government agencies. The largest U.S. hydropower facility, and the largest U.S. electric power plant in electric generation capacity, is the Grand Coulee hydro dam on the Columbia River in Washington State, with 6,765 MW total generation capacity.
Types of Hydropower Plants
Hydropower plants are categorized based on their design and scale:
- Run-of-the-River Plants: These facilities use the natural flow of a river without significant storage. They are ideal for regions with consistent water flow.
- Storage (Reservoir) Plants: These plants involve damming a river to create a reservoir, which stores water for controlled release, ensuring a steady power supply.
- Pumped Storage Plants: These act as energy storage systems, pumping water to an upper reservoir during low demand periods and releasing it during peak demand to generate electricity.
- Micro-Hydropower Systems: Small-scale systems designed for localized electricity generation, often used in remote areas.
The Global Impact of Hydropower
Hydropower accounts for approximately 16% of the world’s electricity generation, making it the largest source of renewable energy. Countries like China, Brazil, Canada, and the United States lead in hydropower capacity, leveraging their vast river systems and water resources.
Source: Introspective Market Research
Hydropower is currently the largest renewable source of electricity globally – though that is expected to change by the end of this decade. Growth in capacity is forecast to remain stable through 2030, driven by additions in China, India, Africa and Southeast Asia.
The overarching headline this year is the growth in the global hydropower fleet to 1,416GW in 2023. Conventional hydropower capacity grew by 7.2GW to 1,237GW, while pumped storage hydropower (PSH) grew by 6.5GW to 179GW. The conventional hydropower capacity addition was the lowest single-year delivery this century, though the longer-term average is relatively stable at about 20GW per year. PSH delivery has been trending upwards, though from a lower base.
The Advantages of Hydropower
- Renewable and Sustainable: Hydropower harnesses water, a naturally replenishing resource. Unlike fossil fuels, it doesn’t deplete finite resources or release harmful greenhouse gases.
- Reliable Energy Source: Hydropower plants provide a consistent and stable energy supply. Reservoir-based systems can store water to ensure electricity generation even during dry periods.
- Low Operating Costs: Once a hydropower plant is constructed, operational and maintenance costs are relatively low compared to other energy sources.
- Environmental Benefits: Hydropower emits significantly fewer greenhouse gases compared to fossil fuels. It also supports flood control, irrigation, and water supply in many regions.
- Energy Storage Capability: Pumped storage plants play a vital role in balancing energy grids, storing excess electricity and releasing it during high demand periods.
Regional overview and outlook
Source: Introspective Market Research
North and Central America
Hydropower development in North and Central America has been relatively stagnant regarding new greenfield projects. In the U.S., nearly half of the non-federal hydropower fleet requires relicensing by 2035, highlighting an opportunity for modernisation. Canada’s Site C project in British Columbia, a 1,100 MW facility, remains the region's only major new construction. Regulatory updates are expected to spur development and revitalise existing assets.
Hydropower currently accounts for nearly 27% of total U.S. utility-scale renewable electricity generation and 5.7% of total U.S. utility-scale electricity generation.
South America
Hydropower remains pivotal in South America, contributing 45% of the region’s electricity supply. Despite a temporary decline due to droughts in early 2023, generation increased by 16 TWh from 2022, reaching 728 TWh. Hydropower continues to provide robust energy support, with infrastructure upgrades and new project commitments reinforcing its role as an energy cornerstone.
Europe
Greenfield hydropower projects saw limited commissioning in Europe during 2023, but the modernisation of existing plants gained momentum. Hydropower generation reached 637.23 TWh, recovering from drought-related declines in 2022. Pumped Storage Hydropower (PSH) projects gained traction to meet growing system flexibility needs. The EU Renewable Energy Directive revision, setting a 42.5% renewable energy target by 2030, underscores Europe’s decarbonisation focus.
As the second largest renewable electricity source, hydropower continues to be an important energy source. According to Eurostat, it accounted in 2022 for 29.9% of the EU’s renewable electricity production and provided 12.3% of the EU’s electricity.
Africa
Sub-Saharan Africa relies on hydropower for 40% of its electricity, with nearly 90% of potential untapped. In 2023, 2 GW of new capacity brought the total to 42 GW, but regulatory and market challenges hindered further progress. Private investment and public-private partnerships, such as Nigeria’s Zungeru project and Burundi’s Mpanda project, are critical to unlocking hydropower’s potential.
South and Central Asia
Significant progress was made in South and Central Asia, with modernisation efforts and new PSH initiatives in India. Projects like Bhutan’s and Pakistan’s nearing completion will bolster regional capacity. Interconnectivity projects like CASA-1000 are fostering cooperation, while agreements in Central Asia, such as the Kambarata 1 initiative, demonstrate the region’s commitment to shared hydropower development.
Opportunities for Hydropower Development
- Untapped Potential in Emerging Markets: Many developing countries, particularly in Africa, South Asia, and Latin America, possess vast untapped hydropower resources. Strategic investments in these regions can support rural electrification, improve energy security, and boost economic development.
- Modernization of Existing Infrastructure: Aging hydropower plants in developed nations offer opportunities for modernization. Upgrading turbines, generators, and control systems can enhance efficiency, extend operational life, and increase output without new construction.
- Small and Micro Hydropower: Small-scale and micro-hydropower systems provide viable options for remote and off-grid communities. These systems are particularly suited for decentralized energy production, reducing reliance on fossil fuels.
- Pumped Storage Systems: With the rise of intermittent renewable energy sources like solar and wind, pumped storage hydropower offers a critical solution for energy storage and grid stability. Expanding pumped storage capacity can enable the integration of more renewables into energy grids.
- Climate Change Adaptation: Hydropower reservoirs can play a dual role in energy generation and water resource management. By regulating water flow, hydropower systems can mitigate the impacts of droughts and floods, supporting climate resilience.
- Hybrid Energy Systems: Integration of hydropower with other renewable energy sources, such as floating solar panels on reservoirs, enhances resource utilization and provides consistent energy supply.
- Green Financing and Policy Support: Growing global emphasis on clean energy and net-zero goals has increased access to green financing, government incentives, and international collaborations for hydropower projects.
Conclusion:
Hydropower is a cornerstone of global renewable energy, offering a sustainable, low-emission, and reliable energy source. Its versatility spans run-of-the-river systems, storage plants, and pumped storage solutions, supporting energy grids and climate resilience. While challenges such as environmental concerns, aging infrastructure, and regional disparities exist, modernization efforts and investments in untapped potential, especially in emerging markets, offer significant opportunities.
The integration of hydropower with other renewables and the growing support for green financing further bolster its role in achieving global decarbonization goals. As a proven and adaptable energy source, hydropower remains essential for a sustainable energy future.
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