Water is a gift of nature and is one of the most precious resources that mankind has been bestowed with. However, in recent years, we have exploited it just like other natural resources in order to benefit from its innate abilities. The force generated by water currents are used today to produce electricity that literally runs the entire planet.
The force and speed of running water can be used to turn turbine generators to produce electricity. Hydroelectric power is the world’s second source of electricity. It supplies about 16% of India’s commercial energy and about 28% of its electricity.
About 23000 MW of hydel energy is produced in India alone. But proper water utilizations are done successfully in developed countries like the United States, the United Kingdom, and other European countries. For example, 75% of total electricity generated in South America is hydel power. It is however, heavily dependent on rains.
Water that is needed to run a hydroelectric power generation unit is usually held in a reservoir or lake behind the dam and the force of the water being released from the reservoir through the dams, spins the blades of turbine. The turbine is connected to the generator that produces electricity. After passing through the turbine, the water re-enters the river on the downstream side of the dam.
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Advantages of hydroelectricity
- Hydroelectricity is the power of electricity generated by water currents. Thus no harmful gases are emitted into the atmosphere to cause pollution, thereby making hydropower a clean energy source. Because of this, hydroelectric power plants also can help in the reduction of carbon footprint on our environment.
- Since the water used is not modified in any form in terms of its chemical composition or physical behaviors, this water literally remains unchanged and there is no loss of water. It can be reused again and again.
- Water is a renewable resource, thus this form of energy generation is a sustainable one and improves our ecological balance which as a result increases our chances of survival in a changed environment that is to come in future.
- Many hydroelectric power generation plants can give peak outputs immediately after the plant of turned on. There is no waiting time for the power to rise to a threshold. This function is particularly helpful in situations when there is an emergency need for electricity like power cuts and electricity failures in hospitals, buildings, heavy machinery industries and construction.
- Hydroelectric plants mostly use the water from artificial and perennial lakes which are extremely important for irrigation. In times of draught, water from these reservoirs can easily be released to be used by the farmers.
- Impoundment hydropower facilities have the benefit of providing some side recreational benefits of the water in the reservoirs like swimming, fishing, boating etc. In order to get the permit for the construction of such reservoirs, the constructors have to first lay down before the government the benefits that the plant will give to the local people of the area and then only the decision of allowing the construction is finalized.
Disadvantages of hydropower
- The dams constructed for the hydroelectric power generation facility often becomes the cause of floods when excess water is released in order to generate more electricity.
- The dams can also cause flooding of farmlands thus degenerating and water logging cultivable farmlands converting them into marshes.
- The water released after it turns the turbine is usually at a very high temperature. When cold water enters the turbine, as a result of high kinetic energy, large quantities of heat is generated which when released into the river stream might cause a situation of thermal shock which not only pollutes the water bodies but is also detrimental for the survival of aquatic animals which may die when subjected to heat.
- These reservoirs and dams that need to be constructed for harnessing the hydel power often need huge areas of forest covers to be cleared to make way for smooth and speedy construction. This reduces the forest cover of the area which not only degenerates the ecological balance but also renders the fauna of the area homeless. This is also harmful for the environment as plants help to curb pollution by taking in carbon monoxide and giving out oxygen.
- Not only trees, a large number of people also have to be displaces from particular area to build a dam there. These people lose their land as well as homes and because of government incompetencies, they are not reimbursed properly for their losses. This creates social problems and builds distrust for the government in the minds of the people. Many notable campaigns and activities have been started against the ill-effects of indiscriminate dam construction for energy. The principal and most famous of them all is the Narmada Bachao Andolan (NBA) started by activist Medha Patkar protesting against the dams constructed throughout the Narmada at different places. This movement not only protests against dam construction for hydroelectricity but also for other causes too.
- Most hydroelectricity plants require energy to turn the turbines initially and then it is cut off and the speed of the water alone turns the turbines. This initial amount of electricity is usually provided through thermal electricity which uses fossil fuels like coal to run. This creates pollution and damages the environment and also does not completely exonerate hydropower and purely clean form of energy.
- Construction of hydroelectric power plants require extensive and expensive machinery as well as large amount of skilled labour. This makes the entire project a monetarily intensive one. Thus it takes a long time for the investment to pay off because there are maintenance costs too which are very high.
Just like everything else in the world there are both advantages and disadvantages of hydro energy. But still, with all these problems, too, hydropower remains an extremely sustainable source of resource management and conversation than the conventional thermal power using the burning of fossil fuel.
Sustainability is the need of the hour in this ever growing world of industrialization and subsequent pollution. It’s where we live, so we better take care of it! Would you rather live in a polluted dump? Hydropower is an extremely easy yet effective way of cementing a bright sustainable future for us and our generations to follow thus promoting biodiversity.