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Hydroelectricity Pros and Cons

Parashar Joshi Feb 20, 2020
Hydroelectricity is increasingly being looked at as a feasible source of renewable energy. In the simplest of terms, it is the electricity that is generated using flowing water, or that water which is stored in a reservoir. Although hydroelectricity is a renewable and highly beneficial energy resource, it is essential to consider its possible negative effects on the environment and take necessary steps to prevent any environmental loss.

Fish and Ladder...

A fish ladder, also known as fishway, is a structure built on or around dams and water locks to help the fish pass the artificial barriers on their way while migrating. The construction of the ladder is such that the fish are able to swim over a few low steps and reach the other side of the river or ocean.
A large volume of water is stored in a reservoir at a high altitude. A power generation plant, consisting of multiple turbines is constructed downstream, at a much lower altitude. The reservoir and the power generation plant are connected by large pipelines known as penstocks.

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When water is released from the reservoir, it flows down the penstock at a high speed towards the turbine.
Naturally, the speed at which the water flows down the penstock will be directly proportional to the difference between the altitudes of the reservoir and the turbine. As the water flows down, its potential energy gets converted into kinetic energy, which therein works the turbine blades and produces electricity. This is how hydroelectric power is generated.
Now that you are aware of how hydroelectricity is generated, let us take a look at the various pros and cons of hydroelectricity. First, the good part, i.e. the pros or advantages of hydroelectricity.


✔ Hydroelectricity is undoubtedly the most widely-used form of renewable energy as compared to other energy forms such as solar energy, tidal energy, wind energy, etc. It is also the most feasible of all renewable energy options and therefore, the most popular.
✔ In terms of reliability and consistency, hydroelectricity is way ahead of its other renewable energy counterparts. No wonder then, that hydroelectric power is a preferred choice, not just for small-scale industries, but also for heavy-duty industries and manufacturing plants.
✔ Hydroelectric power is completely independent of fossil fuels or other perishable resources. It does not involve any combustion or burning of fuel, coal, etc. and therefore, does not release any toxic chemicals in the atmosphere and nor does it create any harmful byproducts.
✔ A hydroelectric power installation can be beneficial for fish breeding.
✔ The operational cost of a hydroelectricity plant is quite low and it is also a clean way of producing energy. Also, the water can be reused for agriculture, irrigation, civic water supply, etc., therefore losses are minimal.
Also, the large volume of water in the reservoir often serves the purpose for recreational activities such as water sports, which makes the location a tourist spot as well.
✔ Hydroelectricity power stations have a really long life and hence, they can generate electricity for many years, rather decades.
✔ The time required for a hydro power station to shut down and restart is way too less than other power stations. Where other power stations, normally take eight hours to restart, a hydro power station can restart in just a few minutes (sometimes even seconds).


✘ One of the major cons of hydroelectricity is the need for a large enough reservoir. Constructing a large reservoir is a major challenge, both in terms of time and money. Also, it often involves relocation of families who happen to be residing in the area that has been approved for the construction of the reservoir.
✘ Regardless of how strong and unbreakable a reservoir but to generate hydroelectricity may seem, there is always the theoretical risk of it giving way in the event of unexpected heavy and prolonged torrential rain. Although such incidents are rare, if they indeed do happen, they can cause mass damage to livelihood.
✘ In some cases, constructing a reservoir or damming a river at a certain location may lead to adverse ecological effects on its immediate surroundings. In other words, it cannot be constructed just anywhere; a proper land examination is a must prior to hydro power station construction.
✘ Silt is a problem that adversely affects quite a few reservoirs, and consequently, the respective hydroelectric power plants as well.
✘ The amount of hydroelectricity generated depends largely on the altitude difference between the reservoir and the turbine, thus, finding a suitable place for both the reservoir and the turbine often becomes a problem.
✘ Droughts can have a severely adverse impact on hydroelectric power generation.
✘ Earthquakes are a major concern when it comes to hydroelectricity generation. It has been observed that in China and Uttarakhand (India) large dam constructions are responsible for the massive earthquakes occurred in these regions.
✘ Land usage is a crucial factor in hydroelectricity generation. If not planned wisely, a dam construction can amount to wastage of land. The driveways constructed to access the dam also leads to more land usage.