Tap to Read ➤

Hydroelectric Energy Pros and Cons

Suketu Mehta Mar 10, 2020
Hydroelectric energy is the 'cleanest' major power source in the modern world. Read on to find out more about its various pros and cons.
Hydroelectric energy is one of the oldest sources of power known by man.
However, over the years, the methods used for the process have evolved thanks to technological advancements. Mills powered by waterwheels placed in rivers have been replaced by dams and turbines these days. Hydroelectric power is used to produce almost a quarter of the global electricity needs.
Electricity produced in this manner is much-desired, since a hydroelectric power plant does not cause pollution, is environmental friendly, and is very much renewable, as opposed to fossil fuels. However, hydroelectricity has its inevitable share of drawbacks. Let's find out more about this crucial source of energy.

Your browser doesn't support HTML5 video.

Hydroelectricity Generation

Technically, only running water and a turbine are required to generate electricity. 
Modern hydroelectric projects, however, store the river's water in reservoirs instead of directly letting it onto the turbines. This technique facilitates production of much more electricity than just placing a turbine in running water.

Your browser doesn't support HTML5 video.

The kinetic energy of water falling onto the turbines is used to move turbines, which are connected to a generator, which produces electricity from the movement of the turbine.
The amount of electricity generated from a power plant depends on two factors: the height from which the water falls upon the turbines, and the volume of the water. Although the height is much more important in producing more energy, extraordinary height can often not be achieved in dams, which thus have to rely primarily on the volume of the water.

Cheers and Jeers for Hydroelectric Energy


  • Electricity produced through the hydroelectric energy generation method is produced without any pollution or harmful environmental effects. Neither are any dangerous greenhouse gases emitted, nor is burning of fossil fuels necessary to generate electricity this way.
  • Hydroelectric power plants generate renewable energy. This means that the source of the energy won't run out anytime soon. Since running water, unlike fossil fuels, will always remain a constant, hydroelectric energy has no expiry date.
  • The dams are useful for storing water, which can then be used for providing nearby areas with water in case of a drought or a famine. If the water does not need to be provided as drinking water, boating, swimming, surfing, and other water sports can generate a financial surplus with minimal investment.
  • It is simpler and cheaper to maintain a hydroelectric power plant than a nuclear power plant and breakdowns are also fewer.
  • Since the process to generate electricity is quite simple and doesn't involve heavy machinery, combustion, or risky nuclear reactions, hydroelectric plants last long and since the power generation process is mostly automated, less labor is needed to operate and supervise the power station.
  • Among renewable sources of energy, such as solar power or wind power, hydroelectricity is without doubt the most consistent and reliable source of energy. Outputs from solar or wind-powered generators can change according to the respective natural conditions.
While hydroelectric power stations can also be caught short by severe droughts, large reservoirs enable them to continue operation even when little input is being provided by the river itself.


  • Hydroelectric energy plants alter the environment in their surroundings to a great extent. River ecosystems are based on the continual flow of water. The backwaters from reservoirs severely change the conditions, turning it into a swampy, lake biome.
  • The flooding also forces countless terrestrial animals to relocate.
  • The flood from the backwater also forces human settlements, sometimes several villages, to relocate.
  • Terrestrial plants submerged in the backwaters produce a greenhouse gas named methane. Methane is capable of trapping much more heat than carbon dioxide (pound for pound, more than 20 times that of CO2) and thus contributes much more to global warming.
Although it is a rare occurrence, a dam can break. This can cause terrible damage to human lives and property, as well as nature.
Going through the pros and cons makes us understand that although there are no major disadvantages in producing energy this way, there are a few minor drawbacks, when it comes to the construction and location of the power plant. However, hydroelectric energy still remains an excellent and inexpensive source of producing electricity.