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Each card jumps to that country's flagship installation and — where a full country profile exists — its dedicated page. Prefer to read start to finish? Scroll on.
🇮🇳
India
Full section on this page
Tehri Dam — India's tallest dam (260.5m), on the Bhagirathi River.
🇨🇳
China
Dedicated project page →
Three Gorges Dam — 22,500 MW, the world's largest power station of any kind.
🇧🇷
Brazil
Dedicated project page →
Itaipu — 14,000 MW, jointly owned with Paraguay, supplies 90% of Paraguay's electricity.
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United States
Full country profile →
Grand Coulee (operating since 1942) and Bath County, the world's largest pumped-storage facility.
🇷🇺
Russia
Full country profile →
Krasnoyarsk — 6,000 MW on the Yenisei River, operating since 1972.
🇻🇪
Venezuela
Jump to Guri Dam
Guri (Simón Bolívar) — supplies approximately 73% of Venezuela's electricity.
🇨🇦
Canada
Jump to Robert-Bourassa
Robert-Bourassa — part of Hydro-Québec's 16,000 MW James Bay Project.
🇫🇷
France
Jump to La Rance
La Rance — the world's largest operational tidal barrage, running since 1966.
🇬🇧
United Kingdom
Jump to MeyGen
MeyGen — the world's largest tidal stream array, Pentland Firth, Scotland.
Prefer installations over countries? Jump straight to the world's 15 largest hydropower facilities, GPS-located ↓
"Water falling is gravity completing a solar cycle. The sun evaporates ocean water, lifts it to mountain heights as rain and snow, and gravity pulls it back to the sea. A hydroelectric dam is simply a way of collecting that gravitational energy on its journey home. The water has no destination — it is always in the process of returning."
— The Energy Codex · observation without separation · thecodex.expert
Cluster 1 · What is it?
What water energy is — precisely
Water energy is the conversion of energy stored in or carried by water into electricity or mechanical power. It is the world's oldest source of mechanical energy and its largest renewable electricity source today. All water energy ultimately derives from the sun — which drives the water cycle by evaporating ocean water and depositing it at elevation as rain and snow.
In plain English: When water sits at a height — in a mountain lake, behind a dam, or in a rain cloud — it has stored energy, the same way a ball held at shoulder height has more energy than one on the ground. When you let it fall, that stored energy converts to motion. A hydroelectric dam captures this: water from a high reservoir falls through a pipe to turbines below. The falling water spins the turbines, which spin a generator, which produces electricity. The water continues on its way downstream, unchanged except that it is now lower. No fuel burned. No emissions from the water itself. The sun will evaporate it again.
The physics of hydropower: Power = ρ × g × Q × H × η, where ρ is water density (1,000 kg/m³), g is gravitational acceleration (9.81 m/s²), Q is flow rate (m³/s), H is the hydraulic head (height difference in metres), and η is overall efficiency (typically 85–90% for large turbines).
A dam with 100 metres of head and 100 m³/s flow generates: 1,000 × 9.81 × 100 × 100 × 0.9 = ~88 MW. This simple formula explains why the world's biggest hydro plants are in locations with large rivers and significant elevation changes — the Yangtze at Three Gorges, the Paraná at Itaipu, the Zambezi at Kariba.
A dam with 100 metres of head and 100 m³/s flow generates: 1,000 × 9.81 × 100 × 100 × 0.9 = ~88 MW. This simple formula explains why the world's biggest hydro plants are in locations with large rivers and significant elevation changes — the Yangtze at Three Gorges, the Paraná at Itaipu, the Zambezi at Kariba.
Source: IRENA — Hydropower Costs · IHA (International Hydropower Association)
Hydroelectric turbine types are selected based on head and flow: Pelton turbines (impulse type, high head >300m, low flow — e.g. Swiss Alps), Francis turbines (reaction type, medium head 40–600m, medium flow — most common globally, used at Three Gorges and Itaipu), Kaplan turbines (reaction axial-flow, low head <40m, high flow — run-of-river plants, tidal barrages). Reversible pump-turbines are used in pumped storage: can operate as either turbine (generating) or pump (storing). Efficiency peaks of 93–95% are achievable in large Francis turbines with optimised runner geometry. Cavitation (formation of vapour bubbles from rapid pressure change) is the primary limiting factor in turbine design at high flow velocities.
Source: IHA — International Hydropower Association · Gordon, J.L. (2001). "Hydraulic turbine efficiency", Canadian Journal of Civil Engineering
1,392 GWGlobal hydro capacity (IRENA 2024)
16%Share of global electricity (IEA)
85–93%Large turbine efficiency
24 g CO₂/kWhLifecycle emissions (IPCC AR6)
50–100 yrsTypical dam operational lifespan
Cluster 3 · Types of water energy
Four types — reservoir, run-of-river, tidal, wave
Reservoir hydropower Most common
A dam creates a reservoir, storing water and creating a head (height difference). Water is released through penstocks (pipes) to turbines as needed — making it dispatchable (controllable). The dominant form of large-scale hydro. Examples: Three Gorges (China), Itaipu (Brazil/Paraguay), Grand Coulee (USA).
Run-of-river hydropower Low impact
Uses natural river flow without large reservoirs. Lower environmental impact and minimal displacement of communities, but output varies with river flow season. Examples: Run-of-river plants on Alpine rivers in Switzerland and Austria; multiple run-of-river projects on the Ganges tributaries in India.
Pumped-storage hydropower Grid battery
Two reservoirs at different elevations. When electricity is cheap (solar peak, low demand), pumps push water uphill. When electricity is expensive (evening peak), water flows downhill generating electricity. The world's largest form of grid-scale energy storage — approximately 170 GW globally. Largest: Bath County, Virginia, USA (3,003 MW). Round-trip efficiency: approximately 70–85%. Source: IEA Hydropower Special Market Report
Tidal energy Ocean tides
Captures energy from the rise and fall of ocean tides, driven by the gravitational pull of the moon and sun. Two approaches:
Tidal stream: Underwater turbines in tidal channels — like wind turbines in water. MeyGen, Scotland (6 MW, 58.58°N 3.22°W) is the world's largest tidal stream array. Predictable output (tides are precisely forecastable). EMEC (European Marine Energy Centre) at Orkney, Scotland is the world's leading tidal test facility.
Tidal barrage: A dam across a tidal estuary. La Rance, France (240 MW, 48.62°N 2.02°W, 1966) remains the world's largest operational tidal barrage. Source: EMEC
Tidal stream: Underwater turbines in tidal channels — like wind turbines in water. MeyGen, Scotland (6 MW, 58.58°N 3.22°W) is the world's largest tidal stream array. Predictable output (tides are precisely forecastable). EMEC (European Marine Energy Centre) at Orkney, Scotland is the world's leading tidal test facility.
Tidal barrage: A dam across a tidal estuary. La Rance, France (240 MW, 48.62°N 2.02°W, 1966) remains the world's largest operational tidal barrage. Source: EMEC
Wave energy Emerging
Captures energy from the up-and-down or back-and-forth motion of ocean waves. Multiple device concepts under development: oscillating water column (OWC), attenuator (Pelamis-type), point absorber, overtopping. Currently at small-scale demonstration phase — no utility-scale commercial wave energy exists. The global wave energy resource is estimated at approximately 29,500 TWh/year (IRENA). Portugal, UK, and Australia lead in wave energy research. Source: IRENA Wave Energy Brief
Cluster 13 · Named instances — major hydropower facilities
The world's 15 largest hydropower installations
GPS coordinates from Global Energy Monitor's Global Hydropower Tracker (CC BY 4.0) and WRI Global Power Plant Database. Capacity figures from operator disclosures and IRENA.
| # | Installation | Country | GPS | Capacity | Type | Operator / notes |
|---|---|---|---|---|---|---|
| 1 | Three Gorges Dam Built ✓ | China | 30.82°N 111.00°E | 22,500 MW | Reservoir | China Three Gorges Corporation · Yangtze River · 34 units · World's largest power station of any kind |
| 2 | Itaipu Dam Built ✓ | Brazil / Paraguay | 25.41°S 54.59°W | 14,000 MW | Reservoir | Itaipu Binacional (joint Brazil-Paraguay) · Paraná River · Supplies 15% of Brazil's electricity, 90% of Paraguay's |
| 3 | Xiluodu | China | 28.25°N 103.64°E | 13,860 MW | Reservoir | China Yangtze Power Co. · Jinsha River · Sichuan/Yunnan |
| 4 | Belo Monte | Brazil | 3.11°S 51.78°W | 11,233 MW | Run-of-river | Norte Energia · Xingu River · Pará state · Largest in Brazil after Itaipu |
| 5 | Guri (Simón Bolívar) | Venezuela | 7.76°N 62.99°W | 10,235 MW | Reservoir | EDELCA / Corpoelec · Caroní River · Supplies ~73% of Venezuela's electricity |
| 6 | Tucuruí | Brazil | 3.83°S 49.62°W | 8,370 MW | Reservoir | Eletronorte · Tocantins River · First large hydro in Amazon basin (1984) |
| 7 | Grand Coulee | USA | 47.96°N 118.98°W | 6,809 MW | Reservoir | US Bureau of Reclamation · Columbia River, Washington · Operating since 1942 |
| 8 | Xiangjiaba | China | 28.64°N 104.37°E | 6,448 MW | Reservoir | China Yangtze Power · Jinsha River · Connected to Three Gorges UHV transmission |
| 9 | Longtan | China | 25.02°N 107.05°E | 6,426 MW | Reservoir | Guizhou Guiyang Hydropower · Hongshui River · Guangxi |
| 10 | Krasnoyarsk | Russia | 55.99°N 92.26°E | 6,000 MW | Reservoir | EN+ Group / RusHydro · Yenisei River · Siberia · Operating since 1972 |
| 11 | Robert-Bourassa | Canada | 53.78°N 77.13°W | 5,616 MW | Reservoir | Hydro-Québec · La Grande River · James Bay · Part of James Bay Project (16,000 MW complex) |
| 12 | Tehri Dam | India | 30.38°N 78.48°E | 1,000 MW + 1,000 MW PSP | Pumped + Reservoir | THDC India Ltd · Bhagirathi River · Uttarakhand · India's tallest dam (260.5m) |
| 13 | Bath County | USA | 38.18°N 79.80°W | 3,003 MW | Pumped storage | Dominion Energy / FirstEnergy · Virginia · World's largest pumped-storage facility |
| 14 | La Rance Tidal Barrage | France | 48.62°N 2.02°W | 240 MW | Tidal barrage | EDF · Rance River estuary · Brittany · World's largest operational tidal barrage · Operating since 1966 |
| 15 | MeyGen Tidal Array | UK | 58.58°N 3.22°W | 6 MW (phase 1) | Tidal stream | Simec Atlantis Energy · Pentland Firth, Scotland · World's largest tidal stream array · Phase 1 operational 2017 |
GPS: GEM Global Hydropower Tracker (CC BY 4.0) · WRI GPPD (CC BY 4.0)
Cluster 2 · Q9 · India and water energy
India and hydropower — 100 years of rivers powering a nation
India's hydropower capacity
India's installed hydropower capacity reached approximately 47 GW by , making it the fifth-largest hydropower market globally. Hydro generates approximately 10–12% of India's electricity.
India's hydropower geography:
The Himalayan river systems — Ganga, Yamuna, Brahmaputra, Indus, and their tributaries — carry enormous hydroelectric potential. The North-Eastern states (Arunachal Pradesh, Sikkim) and Himachal Pradesh have the highest concentration of projects.
India's total hydro potential: Approximately 145 GW of economically exploitable hydropower potential identified (Central Electricity Authority). India has utilised approximately 32% of this potential as of 2024.
Source: Central Electricity Authority (CEA) India
India's hydropower geography:
The Himalayan river systems — Ganga, Yamuna, Brahmaputra, Indus, and their tributaries — carry enormous hydroelectric potential. The North-Eastern states (Arunachal Pradesh, Sikkim) and Himachal Pradesh have the highest concentration of projects.
India's total hydro potential: Approximately 145 GW of economically exploitable hydropower potential identified (Central Electricity Authority). India has utilised approximately 32% of this potential as of 2024.
Source: Central Electricity Authority (CEA) India
India's major hydro projects
Tehri Dam, Uttarakhand · 30.38°N 78.48°E · 1,000 MW + 1,000 MW pumped storage · THDC India Ltd · India's tallest dam at 260.5 metres · Bhagirathi River
Bhakra Nangal, Himachal Pradesh · 31.42°N 76.43°E · 1,325 MW · BBMB · Sutlej River · Operated since 1963 · Nehru called it "the new temple of resurgent India"
Sardar Sarovar, Gujarat · 21.83°N 73.75°E · 1,450 MW · SSNNL · Narmada River · One of the largest dams in Asia
Koyna, Maharashtra · 17.39°N 73.76°E · 1,960 MW · MKVDC · India's largest operational hydropower station
Subansiri Lower, Assam/Arunachal · 27.41°N 94.43°E · 2,000 MW · NHPC · Under development · India's largest hydropower project under construction
Source: NHPC India · CEA India
Bhakra Nangal, Himachal Pradesh · 31.42°N 76.43°E · 1,325 MW · BBMB · Sutlej River · Operated since 1963 · Nehru called it "the new temple of resurgent India"
Sardar Sarovar, Gujarat · 21.83°N 73.75°E · 1,450 MW · SSNNL · Narmada River · One of the largest dams in Asia
Koyna, Maharashtra · 17.39°N 73.76°E · 1,960 MW · MKVDC · India's largest operational hydropower station
Subansiri Lower, Assam/Arunachal · 27.41°N 94.43°E · 2,000 MW · NHPC · Under development · India's largest hydropower project under construction
Source: NHPC India · CEA India
Data note: India's hydro capacity changes as new projects are commissioned. Verify current figures at cea.nic.in.
Cluster 7 · The companies
Who operates the world's water energy — their stories
CT
China Three Gorges Corporation
China · State-owned enterprise · Founded 1993
Founded 1993 specifically to build and operate the Three Gorges Dam project. Now China's largest clean energy enterprise and the world's largest hydropower company. Operates Three Gorges (22,500 MW), Xiluodu (13,860 MW), Xiangjiaba (6,448 MW), and dozens of others. Total installed capacity: approximately 120 GW including wind and solar. Has expanded internationally — owns hydropower assets in Sudan, Pakistan, Brazil, Peru, and Portugal. CEO: Lei Mingshan.
Source: CTGC Annual Report 2023
Source: CTGC Annual Report 2023
HQ
Hydro-Québec
Canada · Crown corporation · Founded 1944
Quebec's provincial electricity utility, established 1944 by nationalisation. Operates the James Bay hydroelectric complex — the largest system of hydroelectric generating stations in the world, with approximately 16,000 MW on the La Grande River alone. Total capacity: approximately 37 GW. Supplies nearly 100% of Quebec's electricity from hydropower. CEO: Michael Sabia. Exports surplus power to New York, Vermont, and New England.
Source: Hydro-Québec Annual Report 2023
Source: Hydro-Québec Annual Report 2023
IB
Itaipu Binacional
Brazil / Paraguay · Binational entity · Founded 1973
A joint Brazil-Paraguay entity created by treaty in 1973 to build and operate the Itaipu Dam. The dam — 14,000 MW — was the world's largest power station from 1984 to 2012. Supplies approximately 15% of Brazil's electricity and approximately 90% of Paraguay's entire electricity needs. Has generated over 3 trillion kWh since commissioning — more than any other plant in history. Equally owned and managed by Brazil's Eletrobras and Paraguay's ANDE.
Source: Itaipu Binacional Annual Report 2023
Source: Itaipu Binacional Annual Report 2023
NH
NHPC India
India · Government of India enterprise · Founded 1975
National Hydroelectric Power Corporation — India's premier hydropower company. Founded 1975. Operates 25 power stations with ~7,100 MW installed capacity across Himachal Pradesh, Uttarakhand, Jammu & Kashmir, Assam, Manipur, and other states. CMD: Rajendra Prasad Goyal. Developing Subansiri Lower (2,000 MW) — India's largest hydropower project under construction. Also expanding into solar and wind energy.
Source: NHPC Annual Report 2023
Source: NHPC Annual Report 2023
EF
EDF (Électricité de France)
France · State-owned · Founded 1946
France's state electricity utility — one of the world's largest energy companies. Operates approximately 400 hydroelectric plants in France totalling ~25 GW, including La Rance tidal barrage (240 MW, the world's largest operational tidal barrage). EDF built France's entire nuclear fleet (56 reactors) and its hydropower network simultaneously. CEO: Luc Rémont. Also operates hydropower in Africa, Latin America, and Asia.
Source: EDF Annual Report 2023
Source: EDF Annual Report 2023
RH
RusHydro
Russia · State majority · Moscow Exchange
Russia's largest hydropower company and the second-largest hydropower generator in the world by capacity. Operates the Sayano-Shushenskaya (6,400 MW), Krasnoyarsk (6,000 MW), and Bratsk (4,515 MW) plants among others. Total installed capacity approximately 38 GW. CEO: Viktor Khmarin. Also operates district heating systems and electricity distribution in the Russian Far East. Source: RusHydro Annual Report 2023
Cluster 4 · Q15 · The pioneers
The people who created hydroelectric power
William Armstrong · 1810–1900 · First hydroelectric power
Lord Armstrong built the world's first hydroelectric power station at Cragside, Northumberland, England in 1878 — GPS approximately 55.33°N 1.85°W. He used a small lake on his estate and a Siemens arc lamp to light his house — making Cragside the first house in the world lit by hydroelectricity. Armstrong was already Britain's foremost hydraulic engineer and arms manufacturer. His demonstration at Cragside proved that falling water could generate electricity reliably, opening the path to commercial hydropower. Source: National Trust — Cragside
Nikola Tesla · 1856–1943 · AC power from Niagara Falls
Tesla's alternating current (AC) system — backed by George Westinghouse and in competition with Edison's DC — was selected for the world's first major AC hydroelectric plant at Niagara Falls in 1895. Tesla's polyphase AC system solved the fundamental problem of transmitting electricity over long distances (DC could only travel a few kilometres). The Niagara Falls plant transmitted AC electricity to Buffalo, New York — 35 km away — proving that hydroelectricity could power entire cities. This was the decisive moment for AC's dominance of the global electrical grid. Source: Library of Congress
Jawaharlal Nehru · 1889–1964 · Dams as temples of modern India
Prime Minister Nehru oversaw the construction of independent India's first major hydroelectric dams — Bhakra Nangal (1963), Hirakud (1957), Nagarjuna Sagar (1967) — calling them "the temples of modern India." These dams simultaneously irrigated millions of acres of farmland, generated electricity for nascent industries, and provided flood control. They were the physical expression of Nehru's vision of a self-sufficient, industrialised India. Bhakra Nangal alone irrigates approximately 10 million acres. Source: CEA India · Historical records
Itaipu engineers · 1974–1984 · Largest dam ever built
The Itaipu Dam, built between 1974 and 1984, required 40,000 workers, moved 50 million tonnes of earth, and used enough iron and steel to build 380 Eiffel Towers. The engineering was led by Brazilian and Paraguayan teams in collaboration with Italian and American consultants. The dam required diverting the Paraná River — the seventh-largest river by flow in the world — through a 2-km bypass channel while the dam was constructed. Chief engineer Dr. Ney Braga and the Brazilian and Paraguayan engineering teams built what was, for 28 years, the world's largest power station. Source: Itaipu Binacional Historical Records
Cluster 5 · What water energy has given the world
What this energy built
Brazil — rivers powering a continent
Brazil generates approximately 60–65% of its electricity from hydropower — among the highest shares for any major economy. The Amazon basin's rivers power South America's largest industrial economy. Itaipu alone produces enough electricity for approximately 40 million Brazilian homes. Hydropower enabled Brazil to industrialise rapidly while maintaining lower per-capita carbon emissions than comparable industrial nations. Source: ANEEL — Brazil National Electric Energy Agency
Paraguay — 100% renewable by rivers
Paraguay generates approximately 100% of its electricity from hydropower — primarily from Itaipu and Yacyretá dams. The country exports its surplus hydroelectricity to Brazil and Argentina, making hydropower its largest export earner. Paraguay's per-capita carbon emissions from electricity are effectively zero. This tiny landlocked country, largely overlooked in energy discussions, is arguably the world's most hydropower-dependent major economy. Source: ANDE — Administración Nacional de Electricidad, Paraguay
India — the Green Revolution and industrial power
The Bhakra Nangal dam system — commissioned 1963 — transformed Punjab and Haryana by providing both irrigation water and electricity for tube-well pumps. This enabled the Green Revolution that fed India through the 1960s–1980s. India's Himalayan hydro projects power the north Indian grid, supply drinking water to millions, and provide the flexibility the grid needs to balance solar and wind intermittency. Source: BBMB — Bhakra Beas Management Board
Cluster 5 · Economics
The cost of water energy
Large hydropower — high upfront, very cheap to run
LCOE (Lazard 2024): $25–90/MWh for large hydro
IRENA global average 2023: $0.026/kWh ($26/MWh) — among cheapest of all technologies
Capacity factor: 30–60% (reservoir), up to 95% (run-of-river on consistent rivers)
CapEx: $1,000–5,000/kW (highly site-specific)
Operating life: 50–100 years (civil structures much longer)
Existing hydro plants generate electricity at extremely low operating cost — often under $10/MWh — because the capital cost was paid long ago. New large hydro is capital-intensive and takes 10–20 years to build.
IRENA global average 2023: $0.026/kWh ($26/MWh) — among cheapest of all technologies
Capacity factor: 30–60% (reservoir), up to 95% (run-of-river on consistent rivers)
CapEx: $1,000–5,000/kW (highly site-specific)
Operating life: 50–100 years (civil structures much longer)
Existing hydro plants generate electricity at extremely low operating cost — often under $10/MWh — because the capital cost was paid long ago. New large hydro is capital-intensive and takes 10–20 years to build.
Source: Lazard LCOE 2024 · IRENA 2023
Pumped storage — the value is in flexibility
Pumped storage LCOE is not the right metric — its value is in flexibility, not cheapness of generation. A pumped storage plant buys cheap electricity (from solar at midday), stores it as water at height, and sells expensive electricity (at evening peak). The arbitrage value depends on the price spread between cheap and peak electricity.
As solar penetration increases, midday prices collapse and evening prices spike — increasing the value of pumped storage. India's target: 18.8 GW of pumped storage capacity by 2031–32 (National Electricity Plan 2023). Source: CEA National Electricity Plan 2023
As solar penetration increases, midday prices collapse and evening prices spike — increasing the value of pumped storage. India's target: 18.8 GW of pumped storage capacity by 2031–32 (National Electricity Plan 2023). Source: CEA National Electricity Plan 2023
Cluster 11 · The future of water energy
What institutional sources project
Tidal energy — predictable and abundant
Tidal energy has one decisive advantage over solar and wind: it is completely predictable — tides can be calculated centuries in advance. The UK, France, Canada, South Korea, and Australia have identified major tidal energy sites. The Pentland Firth (Scotland) alone has a tidal resource estimated at 1.9 GW. South Korea's Incheon Bay has potential for a 1,320 MW tidal barrage. Global tidal energy resource is estimated at approximately 800 GW accessible with current technology. The challenge is cost — tidal turbines operate in a harsh, corrosive environment and maintenance is expensive. Source: EMEC · IEA Ocean Energy Report
Climate change and hydropower risk
Climate change is both an opportunity and a risk for hydropower. Melting glaciers initially increase river flows — temporarily boosting hydro generation — before long-term declines as glaciers retreat. Changing rainfall patterns are already affecting hydro output in Brazil (2021 drought reduced output by 25%) and Europe. The IPCC AR6 projects that globally, hydropower resource potential will change by -10% to +5% by 2100 under 2°C warming scenarios, with large regional variation. Hydropower planning now incorporates climate scenarios in reservoir design. Source: IPCC AR6 Working Group II
Cluster 12 · Reader questions
Six questions people ask — answered
How does a hydroelectric dam generate electricity?
Water stored at height behind a dam has potential energy — like a ball held at shoulder height. When the dam's gates open, water flows down through large pipes called penstocks to turbines at the base. The falling water's kinetic energy spins the turbine blades, which turn a shaft connected to a generator. The generator converts rotational energy into electricity. The electricity travels through transformers and transmission lines to homes and factories. The water continues downstream, unchanged except it is now lower — the sun will evaporate it again and the cycle continues. Power generated depends on how much water flows (flow rate) and how far it falls (head — the height difference).
Source: IHA International Hydropower Association · IRENA Hydropower Brief
What is the world's largest dam?
This depends on what "largest" means. By installed electricity capacity, the Three Gorges Dam in China is the world's largest power station of any kind at 22,500 MW (GPS: 30.82°N 111.00°E), operated by China Three Gorges Corporation on the Yangtze River. By reservoir volume, the Kariba Dam (Zambia/Zimbabwe) holds the world's largest man-made reservoir. By structural volume of the dam itself, the Tarbela Dam in Pakistan holds that record. The Hoover Dam (USA) was the world's largest when completed in 1936. Source: ICOLD (International Commission on Large Dams) · China Three Gorges Corporation.
Source: ICOLD · China Three Gorges Corporation Annual Report 2023
How much of the world's electricity comes from water?
Hydropower generates approximately 4,300 TWh of electricity per year — approximately 15–16% of global electricity production (IEA Renewables 2024). This makes hydropower the world's largest renewable electricity source, and it has held this position for over a century. Countries that generate most of their electricity from hydro include Paraguay (~100%), Norway (~90%), Brazil (~60–65%), Canada (~60%), and New Zealand (~55%). Global hydropower capacity is approximately 1,392 GW (IRENA 2024). Source: IEA Renewables 2024 · IRENA Renewable Capacity Statistics 2024.
Source: IEA Renewables 2024 · IRENA Renewable Capacity Statistics 2024
How much hydropower does India have?
India's installed hydropower capacity is approximately 47 GW as of , generating approximately 10–12% of India's electricity. India is the fifth-largest hydropower market globally. India's identified economically exploitable hydro potential is approximately 145 GW — it has utilised only about 32% of this. The largest operational station is Koyna (1,960 MW, Maharashtra). India's tallest dam is Tehri (260.5 metres, Uttarakhand, 1,000 MW). The largest project under construction is Subansiri Lower (2,000 MW, Assam/Arunachal Pradesh, operated by NHPC). Source: Central Electricity Authority India (CEA) 2024.
Source: Central Electricity Authority (CEA), Government of India, 2024
Is hydropower renewable?
Yes, hydropower is classified as renewable by the IEA, IRENA, and all major international energy bodies. The water cycle — driven by the sun — replenishes river flows continuously. However, hydropower has environmental impacts that other renewables do not: dams flood valleys (displacing communities and habitats), alter river ecosystems downstream, and affect fish migration. The lifecycle carbon footprint of large hydro is approximately 24 g CO2/kWh (IPCC AR6) — very low but not zero, partly because submerged organic matter in reservoirs produces methane in some tropical locations. Run-of-river hydro has a much lower footprint. Source: IPCC AR6 · IEA · IRENA.
Source: IPCC AR6 · IEA · IRENA Renewable Energy Definitions
What is pumped storage and why does it matter?
Pumped storage is a way of storing electricity by using it to pump water uphill. When solar panels or wind turbines produce more electricity than the grid needs (typically midday on a sunny day), the surplus electricity runs pumps that push water from a lower reservoir to an upper reservoir. Later, when electricity demand is high and supply is low (evening peak), the water flows back downhill through turbines to generate electricity. Pumped storage is the world's largest form of grid-scale energy storage — approximately 170 GW globally. As solar and wind grow, their midday surpluses need somewhere to go. Pumped storage is the most proven and cost-effective solution at large scale. India targets 18.8 GW of pumped storage by 2031–32. Source: IEA Hydropower Special Market Report · CEA National Electricity Plan 2023.
Source: IEA Hydropower Special Market Report 2021 · CEA National Electricity Plan 2023
Cluster 10 · Connected pages
Explore further
Complete source register
Every source used on this page
Primary sources — all public, all free to verify
IRENARenewable Capacity Statistics 2024 · Hydropower Costs · Wave Energy Briefirena.org/publications
IEARenewables 2024 · Hydropower Special Market Report 2021 · WEO 2024iea.org/hydropower-special-market-report
Global Energy MonitorGlobal Hydropower Tracker · GPS, capacity, status · CC BY 4.0globalenergymonitor.org/hydropower-tracker
WRI GPPDGlobal Power Plant Database v1.3.0 · CC BY 4.0datasets.wri.org/globalpowerplantdatabase
LazardLevelised Cost of Energy Analysis 2024lazard.com/levelized-cost-of-energy
IPCC AR6Sixth Assessment Report · Lifecycle emissions · Climate change hydropower impactsipcc.ch/report/ar6
IHAInternational Hydropower Association · Hydropower Status Report 2024hydropower.org/status-report-2024
CEA IndiaCentral Electricity Authority · India hydro capacity · National Electricity Plan 2023cea.nic.in
NHPC IndiaAnnual Report 2023 · India hydro projectsnhpcindia.com/annual-report
China Three GorgesAnnual Report 2023 · Three Gorges capacity and operationsctgpc.com.cn/en
Itaipu BinacionalAnnual Report 2023 · Generation history and capacityitaipu.gov.br
EMECEuropean Marine Energy Centre · Tidal and wave energy testing dataemec.org.uk
ANEEL BrazilNational Electric Energy Agency · Brazil hydro statisticsaneel.gov.br
Provenance
Attribution, confidence level, and citation
- Author
- The Codex (Let Us Do It For U), Mumbai, India · hello@thecodex.expert
- Entry type · Confidence
- concept · High — Tier-1 sources (IEA, IRENA, IPCC AR6), verified
- Cite as
- "The Energy Codex", https://thecodex.expert/energy/water/, last updated .