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The Kerr hydroelectric dam in Montana, USA.

Hydroelectricity Facts

This article looks at some interesting hydroelectricity facts. Hydroelectricity is a clean, renewable and highly efficient source of power. Countries all over the world generate electricity at hydroelectric dams.


First, let’s take a look at some historical facts.

  • Lester Allan Pelton is considered to be the founding father of hydroelectricity. Pelton was born in Ohio, USA in 1829 and first patented his ‘Pelton Wheel’ in 1880.
  • The design of modern hydroelectric turbines has been inspired by the Pelton Wheel. Examples of modern turbines are the Turgo and Banki designs.

General Facts

Below you’ll find some general facts about hydroelectricity.

  • Hydropower is the world’s leading renewable energy source by far. As a result, hydropower produces more electricity than solar, wind and geothermal energy sources.
  • Most hydroelectric facilities make use of a dam to store a water supply. Such dams can then be called upon as and when needed. Other facilities can be located next to fast-flowing streams or rivers.
  • The largest hydroelectric facility in the world is the Three Gorges Dam in China. In 2012, the Three Gorges project had an installed capacity of 22,500 MW (22.5 GW.)
  • Hydropower is free after any construction and operating costs. Because of this, it can help to boost a country’s economy. It can also help make a country less vulnerable to fluctuations in the price of coal, oil, and gas.

Production & Consumption

These facts relate to the production and consumption of hydroelectricity. Some of the facts are based on figures obtained from BP’s Statistical Review of World Energy 2014. This review provides figures for world energy consumption in 2013.

  • We can generate hydroelectricity by harnessing the kinetic energy in flowing water. The water source can be a fast-flowing stream or a static body of water (such as a reservoir.)
  • We produce more electricity from hydropower than all other renewable energy technologies put together.
  • In 2013, hydroelectricity consumption was 3782 TWh.
  • Globally, in 2013, the world generated more electricity from hydropower than nuclear power. The consumption of nuclear power was just 2489 TWh.
  • China produces the most hydroelectricity. In 2013, the country generated 911.6 TWh. As a result, China shadowed second-place Brazil who generated just 385.4 TWh.
  • The Asia-Pacific region generated the most hydroelectricity in 2013. The quantity generated was 1364.3 TWh. China was a key producer of the vast majority of this.
  • Some countries produce the majority of their electricity supply from hydroelectricity. These countries are; Brazil, Norway, and Paraguay.


Interested in how efficient hydropower is? If so, the following facts might be of interest to you.

  • Modern hydroelectric turbines have a very high-efficiency rate – somewhere around 90%. As a result, they can convert 90% of the kinetic energy of flowing water into electricity.
  • Hydroelectricity has a quick reaction time. Therefore, it is suited to meeting spikes in electricity demand. It is common for power companies to release water into hydroelectric dams at specific times. This helps to meet any predicted spike in electricity demand. Such spikes are common during the commercial breaks of prime-time TV shows.

Environmental Facts

Hydroelectric facilities have various impacts on the environment. Some of these are good whilst others are bad. The facts below help to explain the environmental impacts of hydroelectricity.

  • Hydroelectricity has no direct carbon dioxide emissions. However, there is some concern over the release of methane from the water of man-made hydroelectric dams. Rotting vegetation formed by the flooding of land to create a dam can be a cause of this.
  • Globally, the use of hydroelectricity prevented the equivalent of 855.8 million tonnes of oil from being consumed in 2013. This figure is according to BP’s statistical review of world energy in 2014.
  • Hydroelectric dams have various impacts on the ecosystem of a river. As a result of this, issues can be found locally, upstream or downstream.