Among all the types of renewable energy, hydro energy is one of the most prominent ones. Governments all across the world have set up mechanisms to harness hydro energy. India also has a huge number of dams, nearly 2000 dams across the country. Like all other forms of energy, there are various advantages and disadvantages of hydro energy.
WHAT IS HYDRO ENERGY?
Hydropower is the energy obtained from water. Running water through turbines convert the kinetic energy of water into mechanical energy. This is done by constructing dams on already existing water bodies. These dams create a reservoir of the water present in the water body. Water falls from a height which creates force to turn the turbines.
Furthermore, tidal energy is another form of hydropower. Tidal power is the result of the moon and the sun’s gravitational influence on the ocean. Height differences between high and low tides create tidal currents in coastal areas, and these currents can be strong enough to drive turbines.
WHEN DID HUMANS START USING HYDRO ENERGY?
The history of hydropower started over 2000 years ago, when water wheels were being used by the ancient Greeks to grind grain. However, some of the first innovations in using water for power were conceived in China during the Han Dynasty between 202 BC and 9 AD. The world’s first hydroelectric project was used to power a single lamp in the Cragside country house in Northumberland, England, in 1878. In North America, hydropower plants were installed at Grand Rapids, Michigan (1880), Ottawa, Ontario (1881), Dolgeville, New York (1881), and Niagara Falls, New York (1881). They were used to supply mills and light some local buildings.
WHAT ARE THE TYPES OF HYDROPOWER PLANTS?
There are three types of hydropower facilities: impoundment, diversion, and pumped storage.
An impoundment facility uses a dam to store river water in a reservoir. Water released from the reservoir flows through a turbine, spinning it, which in turn activates a generator to produce electricity. It is typically a large hydropower system. Moreover, it is the most common form of hydroelectric system.
A diversion hydropower plant is an example of hydroelectric power plants that do not require a dam. Sometimes called run-of-river, this facility channels a portion of a river through a canal or penstock. It may not require the use of a dam.
A pumped storage hydropower facility works like a battery. It stores the electricity generated by other power sources like solar, wind, and nuclear for later use. It does so by pumping water uphill to a reservoir at higher elevation from a second reservoir at a lower elevation. During periods of low demand, it stores energy by pumping water to the upper reservoir. However, when demand is high, it releases the water back to the lower reservoir. This turns a turbine, generating electricity.
In India, dams have been a topic of immense debate and discussion. There have been protests and movements across the country to oppose the construction of dams.
So, do these have legitimate reasons for their protests or is it just party politics?
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Let’s find out.
Advantages of Hydro Energy
Because of the original resource in its case, hydro energy will always be a viable energy source. The Earth is covered with 71% water, so no matter what apocalypse the planet might face, it’ll always have water, and it’ll always be a source for energy. Hydro energy also does not consume any water. So, it does not reduce the amount of water that is available for future use.
As previously mentioned, this form of energy does not affect the amount of water that is available for future use. Hence, it is just as much a viable source of energy for the current generation as it is for the future ones.
Dams constructed for generation of hydro energy create a body of stagnant water. This allows for the water to be used for fishing, boating, et cetera. This allows the government to generate additional revenue.
Generation of hydro energy creates employment opportunities in two phases: construction and operation. The construction of dams is a lengthy process. It takes years, and is done on a huge scale. Thus, it allows hundreds of workers to be employed for the construction of the dam, for the transportation of construction material. Secondly, while the dam is operational, there is staff required to operate the machines, for their maintenance, for cleaning the premises, et cetera. This also provides job opportunities for many people.
A major advantage of hydropower is that its generation is a completely controlled process. This allows the operators of dams to control the flow of the water as needed, If low energy output is needed, the flow of water can be slowed. Additionally, it also makes repairs easy. If one of the turbines needs to be repaired, water flow can be stopped until it is fixed, which also ensures that the turbine is not damaged further.
Apart from using a resource that is abundantly available and not reducing it, this energy source also does not pollute that resource. It does not add harmful chemicals to the water, thus making it still usable for other purposes. It does not release harmful toxins into the air either.
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Disadvantages of Hydro Energy
Dams requires the entire volume of a water body to be stored in a relatively smaller area. This leads to flooding in nearby areas. Hence, communities leaving in or around areas where dams are constructed need to leave their homes and relocate to far off places. Given that these dams are usually constructed in or near forests, the communities displaced are often tribal communities. Tribal communities have cultural attachment with the places that they live in, and do not have the resources to properly relocate, thus making it more difficult.
Destruction of Wildlife
Reservoirs of hydro energy plants flood nearby areas. This doesn’t just affect human life. It also has a disastrous impact on wildlife around the plant. Many animals drown, and the others are forced to flee their natural habitats, thus endangering their species. Unlike human inhabitants, they are not given (or promised, rather) help by the government.
Impact on Marine Life
The way that hydropower is generated, it changes the flow of the water. Hence, this changes the quality of the water. In addition to that, it also impacts the marine life in that particular water body. There are various factors that affect marine habitats, such as water level, water velocity and shelter opportunities and access to food. Hydropower plants change all of these.
Hydro energy is one of the most expensive forms of renewable energy. It involves the construction of large scale plants. Moreover, given the huge cost involved and the environmental impacts of the construction of these plants, stopping the usage of this energy at a particular plant is also not an option.
Pros and Cons of Hydro Energy
|Sustainable||Destruction of Wildlife|
|Additional Revenue||Impact on Marine Life|