Since man discovered that power can be derived from the energy of falling or fast-running water, the race to harness it has been growing. Countries all over the world have invested heavily in constructing hydroelectric power stations to cater for the ever-rising demand for electricity. The cost of hydroelectricity is relatively low, making it a competitive source of renewable electricity. The hydro station consumes no water, unlike coal or gas plants.
Here are the top 20 largest hydroelectric power stations in the world.
| Rank | Name | Country | Installed capacity |
| 1. | Three Gorges Dam | China | 22,500 MW |
| 2. | Itaipu Dam | Brazil, Paraguay | 14,000 MW |
| 3. | Xiluodu | China | 13,860 MW |
| 4. | Belo Monte | Brazil | 11,233 MW |
| 5. | Guri | Venezuela | 10,235 MW |
| 6. | Tucuruí | Brazil | 8,370 MW |
| 7. | Grand Coulee | United States | 6,809 MW |
| 8. | Xiangjiaba | China | 6,448 MW |
| 9. | Longtan Dam | China | 6,426 MW |
| 10. | Sayano-Shushenskaya | Russia | 6,400 MW |
| 11. | Krasnoyarsk | Russia | 6,000 MW |
| 12. | Nuozhadu | China | 5,850 MW |
| 13. | Robert-Bourassa | Canada | 5,616 MW |
| 14. | Churchill Falls | Canada | 5,428 MW |
| 15. | Tarbela Dam | Pakistan | 4,888 MW |
| 16. | Jinping-II | China | 4,800 MW |
| 17. | Bratsk | Russia | 4,515 MW |
| 18. | Laxiwa Dam | China | 4,200 MW |
| 19. | Xiaowan Dam | China | 4,200 MW |
| 20. | Ust Ilimskaya | Russia | 3,840 MW |
