Hydropower is one of the most popular technologies used to generate electrical energy. Almost 17% of the world’s total energy is contributed by hydropower plants. Hydropower is a low-carbon technology as hydropower reservoirs emit about 35-70 times less greenhouse gas (GHG) compared to thermal power plants. However, there exist some environmental threats such as flood risk, loss of habitat for fishes and other water animals, etc. The main component of generating energy using a hydropower plant is a dam. The water stored in a dam is rich in potential energy. When the gates of the dam are opened, the water flows out, and the potential energy is converted to kinetic energy. This kinetic energy is further employed to rotate the turbine blades, causing conversion of kinetic energy into mechanical energy. Finally, this mechanical energy is coupled to the generator that converts it into electrical energy through a process called electromagnetic induction. The world’s largest hydropower plant, Three Gorges Dam, is located in China.
Hydropower plants, as the name suggests, make use of water as a raw material to generate electricity; morever, water is not consumed during the process of energy production. So, there is no reduction in the quantity of water. The same water is utilized again and again in order to generate electricity. This enables the raw material to be available for an infinitely long duration of time. Hence, hydropower can be listed under the category of renewable energy.
The process of power generation using hydroelectric plants is a clean method of energy generation. They do not release any waste products into the environment. Unlike other modes of energy generation such as coal, petroleum, etc., hydropower does not leave any residue behind. No pollutants are excreted into the air or in the water. Hence, no toxic ejection at all makes this technology even more popular and preferable than the others.
The reliability of hydroelectricity is quite high because the raw material is present and will be available till the water runs out from the earth. Other sources of energy generation are unreliable as the sun may go down, wind velocity might not be sufficient, etc.
The energy generated by hydropower plant makes use of water stored in huge dams. This water when kept at a particular height possesses high potential energy. When the gates of the dam are opened, the water gushes out, and the potential energy is converted into kinetic energy. This energy is then fed to a setup, where kinetic energy is converted into mechanical energy, which is further used to generate electricity. This flow of water through the gates of the dam is adjustable. Therefore, more energy can be generated on the days of greater consumption. This adjustable generation is one of the greatest merits of using hydroelectricity.
5. Create Lakes
The process of power generation using water requires the building of dams. During the construction, artificial lakes get created that serve to be one of the prime places of tourist attraction. It helps to generate economic profit and increases the revenue of the government. Hence, building hydropower plants improves the appearance of the city where they are located by adding a sightseeing point for tourists.
To pace up the development of a region, dams or industries are often built nearby. The reason is that for building a dam, a huge stock of material is required. A safe passage is required that enables this construction material to reach the site securely. Therefore, the area nearby requires proper maintenance of roads and buildings. Hence, the area surrounding the dam is more rapidly and efficiently built and maintained. The hydropower plants do not only develop and produce electricity, but they are also responsible for the progress of nearby cities and towns.
7. Price Stability
Since the raw material for energy generation using hydropower is infinitely available, the energy produced by it is continuous and uninterrupted. A hydropower plant guarantees energy production even during the most extreme conditions. Unlike other conventional sources of energy such as coal, natural gas, etc. the price of the power generated using water is comparatively stable. There are very rare chances of price hikes when the energy is supplied from hydropower.
Hydropower plants do not release any toxic gases in the air during or after the process of energy production. Hence, the air quality is not demolished and the clean level of air is maintained. This helps in saving the environment from the adverse effects of climate change. Also, hydropower plants do not have any direct contribution to global warming, air quality index destruction, and other related phenomena that might disrupt the earth’s health.
1. Impact on Wildlife
Due to the construction of dams, the natural flow of water is disrupted. It has an adverse impact on wildlife habitat as the animals living nearby might not be able to access the water. Apart from this, it also hampers the survival of some species of fish for a long time, and hence, the animals that rely on fishes for their regular food requirements suffer major losses. This is one of the major disadvantages of using hydro-electricity.
2. Limited Plant Locations
Before setting up the base for the construction of a hydropower plant, a strict requirement list has to be followed. It includes soil type identification, precipitation level measurement, proper height calculation, etc. There are only a few sites that properly meet all these requirements. Hence, a limited number of power plants can be constructed. Therefore, the energy generated is restricted to some extent.
3. Set-up Cost
Dam building requires a great amount of material, money, and manpower. The construction process is often time-consuming and requires highly skilled and experienced people. The highest-paying engineers are hired to take proper follow-up and analyze the structure on a regular basis. The builder is required to acquire the best building material in order to increase the power plant’s life. Keeping all these factors in mind the expenses increase. Therefore, the installation cost is quite high.
4. Carbon and Methane Emissions
Despite being a cleaner alternative to produce power, a significant amount of carbon and methane are released. These toxic emissions make the scientists and researchers to carry on the search for a better alternative that can generate power with extreme efficiency i.e., with minimum or zero production of carbon content. This makes it a toxic method to produce power. However, this disadvantage is suppressed by various other advantages such as renewability, reliability, etc.
The performance of hydroelectricity is highly affected by droughts. In the absence of water, there is no possible way to produce energy using hydropower plants. This long term loss of precipitation is totally unpredictable. Therefore, droughts cause an irretrievable scarcity of energy. To overcome this undersupply of energy, one can do nothing but wait for nature to repair and overcome the situation of drought.
6. Flood Risk
In case the dam is not built with perfection, it is susceptible to break down and cause an uncontrollable flow of water. The nearby cities, towns, and villages are quite vulnerable to floods. This causes an economical crisis and life losses. During an earthquake, the areas located near a dam are most sensitive and likely to suffer huge damage. Often, such areas are marked as red alert areas, and people are evacuated in advance to avoid any sort of mishap, which causes a major inconvenience to the people.
7. Environmental Effects
Poor water quality, damaged wildlife habitat, deviated flow of rivers, etc. are some of the adverse environmental effects that the earth is most likely to suffer due to the application of hydropower technology. Hence, a hydropower plant is not as eco friendly as it seems.
8. Hydrology Dependence
The generation of electricity in hydropower plants strongly depends on the water cycle. The heat from the sun causes the water present on the earth’s surface to evaporate and form clouds. These clouds further result in precipitation i.e., rain or snowfall. The water from precipitation gets collected in rivers, oceans, and seas. The water cycle is then repeated again and again. The precipitation levels may vary from time to time, and therefore, the water required for the hydropower plants vary accordingly. Hence, the energy generated differs according to the rainfall levels. This hydrology dependence is one major disadvantage of hydropower plants.