Considered one of the most efficient renewable sources of energy, hydropower is derived by capturing flowing water and converting it into electrical energy. Just like coal-fired power plants, hydroelectric power plants also make use of a power source (water) to turn a propeller-like machine called turbine. The turbine turns and the electric generator produces electricity.
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How It Works
Large dams are erected on rivers for the purpose of generating hydroelectricity. These dams have the capacity to store millions of gallons of water which flows swiftly through steel or alloy pipes and falls at a great speed from the dam on the hydraulic turbine. This impact turns the turbine and the process converts the energy of the flowing water into mechanical energy. A hydroelectric generator further converts this mechanical energy into electricity, which is then supplied to the surrounding areas to power homes and businesses.
Why Is Hydroelectricity So Much In Demand?
- Building dams and hydroelectric power plants is expensive but the cost of producing electricity thereafter is extremely low. So you can expect minimal electricity bills. This is one of the main reasons behind the high demand for this source of energy.
Since it is a natural and renewable source of energy, it does not emit any harmful pollutants. It is therefore eco-friendly.
Although installing a hydropower system can be expensive, it is cheaper than connecting to the National Grid (if you aren’t already connected). Hence, it makes perfect sense for off-grid homes and offices to invest in small hydro schemes as these are among the most reliable alternatives to mains supply for isolated properties.
Hydropower is believed to have excellent potential for meeting future energy needs. The U.S. Department of Energy (DOE) has already announced that the currently available water resources can satisfy 15% of U.S. energy demand by 2030. There are approximately 54,000 non-powered dams in the U.S. that can be used to generate electricity.
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- Expensive to Install and Maintain
One cannot overlook the fact that the cost of construction and maintenance of dams, power plants, and support infrastructure to produce the power required for everyday use can run into billions of dollars. This directly implies that the high costs of building and maintenance can undermine the overall production cost of electricity.
Building dams on rivers and other water bodies will limit the accessibility of water to people who make their livelihood through agriculture and fishing, thus adversely affecting their income. Most of the time, people caught in such situations are left with no choice but to relocate to other places to make ends meet. This relocation may bring about social unrest among them due to the lost agricultural land.
Impact on the Environment
Land Use: The size of the reservoir created for hydroelectric projects depends on the size of the hydroelectric generators and the topography of the land. However, flooding land to create a hydroelectric reservoir has adverse environmental impacts as it destroys forests, wildlife habitats, and agricultural and scenic lands. In many instances, such as the Three Gorges Dam in China, entire communities have had to be relocated to build reservoirs.
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- Effect on Aquatic Life: Hydroelectric power plants can have many negative effects on aquatic biodiversity. For example, several species of fish and other organisms can be injured and/or killed by turbine blades.
Quality of Water: Water in reservoirs is stagnant as opposed to that in rivers. Due to this, reservoirs tend to have higher levels of sediments and nutrients than normal, which can give rise to the problem of excessive growth of algae and weeds to the extent that the weeds can crowd the river and leave little or no room for other aquatic flora and fauna.
Another challenge here is that water evaporates at a much faster rate in reservoirs than it does in rivers.
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Greenhouse Gas Emissions: Greenhouse gases are emitted at the time of building and disassembling hydroelectric facilities depending upon the size of the reservoir. However, according to recent findings, these emissions do not stop there. Significant amounts of emissions that contribute to global warming are produced during the plant’s operational cycle as well (although these levels are much lower compared to those produced by coal-fired plants).
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It is not possible to build a hydroelectric power plant at a random location as the plant will require specific conditions to be functional. A dam needs to be constructed over a water body which should have enough water to be able to successfully produce electricity. Hence, the construction of such facilities is primarily dependent on areas with ample supply of water.
Hydroelectricity does come with its set of challenges but most of these can be overcome with a little thoughtful planning. As mentioned above, hydroelectricity has far less adverse effects on our ecosystem as compared to other, mainly non-renewable, sources of energy. Therefore, it needs to be systematically tapped into to enable better and more sustainable development of societies worldwide to create a better future for all of us.