Huge gallons of water falling from a high altitude hit the blades of a hydroelectric turbine and voila! You have the bulb glowing at your house! Though, the working of a hydroelectric energy is not so simple, it is an explanation in a nut shell. The term, ‘Hydroelectric energy’ refers to the power which is obtained by harnessing the potential energy or the gravitational force of flowing water. The water is stored in a reservoir and is released downstream through a pipe. The water then hits the blades of the turbine, which in turn drives a generator to produce electricity. One of the most widely used and necessary form of renewable sources of energy, hydroelectric power has several benefits in store for mankind. However, nothing is perfect or perfectly efficient! The production of this energy is also associated with some major drawbacks.
In the following, we will first have an overview on the benefits which the hydroelectric energy offers. This will be followed by the drawbacks.
As I mentioned, hydroelectric energy works without the use of fuel like oil, uranium, etc., and this fact makes this energy an inexhaustible fuel source. As there is no intervention of any fuel, the electricity produced is very cost-effective, eco-friendly and most importantly, inflation-resistant.
Unlike other alternative renewable sources of electricity such as wind or sun, the hydroelectric energy can be used for generating a continuous supply of electricity. Thus, the amount of electricity produced by hydroelectric power is stable and can be controlled; as in the power can be initiated and put on halt within a matter of moments. This turns out to be advantageous during times when any compensation for variability in demand from the grid is required. For example, during peak times of electricity requirement, water can be released to generate extra power. On the other hand, when there is a surplus of energy and it is not needed, it can be added to the grid for further use.
If we only keep our consideration till the hydroelectric energy and not the power plants, then it can be said that it is pollution less. There is also, no production of any radioactive waste in the generation of this energy. Also, minimal man power is required to run a hydroelectric station, as most of them run on automated machines. This further makes electricity cost-effective. The power stations can lilt in any size, depending on the source of water to operate them. The power stations, once built can last for more than a hundred years. Once the construction costs are recovered, the energy can be attributed to be almost free.
Environmental turmoil is one of the major disadvantage of generating hydroelectric energy. Aquatic eco-system is one of the major realms which get immensely affected. The river environment is affected as the dam changes the upstream and downstream of the river. Several species of fish have to swim against the water stream during their breeding season, but they are not able to as the dam creates hindrances in their path.
The plants which get destroyed due to floods caused by the dams, decay in an anaerobic environment. This in turn, results in the production of methane, a potent greenhouse gas. The damage caused by this process is considered to more harmful than the forest which would have decayed naturally.
The construction of hydroelectric dams is set up at the cost of relocating the population of the site of the reservoirs. Large-scale human displacement occurs when the dams are set and in the absence of inappropriate compensation, oppositions and major disagreements become obvious results.
Places which entirely depend on hydroelectric energy may have to face major issues if there is any shortage of water. As global warming is on the rise, climatic changes are obvious and so are undesired patterns in rainfall; some areas may receive lesser than others.
A slight error in the construction of the dams, leaves a lurking risk behind; a risk of the dam getting collapsed and affecting the lives of humans, plants and animals. Banqiao Dam in China, is an apt example of this fact. The failure of this dam cost the lives of more than 100 thousand people and homes of about a million.
To conclude, I would like to cite that hydroelectric energy in itself presents no disadvantages for the environment. Whatever goes behind the production of this useful energy, be it the construction, dams, projects, etc., are the ones which have some severe drawbacks, as mentioned above. However, as I mentioned, nothing is perfect and there is a price to be paid for everything which is used or created to be used.