Climate change and the increased risk of drought are also having an impact on the world's hydropower plants. In the western U. Even the promise of carbon-free electricity from hydropower has been undermined by revelations that decaying organic material in reservoirs releases methane , a potent greenhouse gas that contributes to global warming. However, some argue that the environmental impacts of hydroelectric power can be mitigated and remain low compared with burning fossil fuels.
In some places, small hydro projects can take advantage of existing water flows or infrastructure. Special water intakes and turbines can help make sure water released from a dam is better aerated to address the problem of low dissolved oxygen.
Dams can be planned more strategically to allow fish passages, for example, while water flows at existing dams can be calibrated to give ecosystems more recovery time from flooding cycles. And research continues on ways to make hydropower projects more friendly to the ecosystems around them.
A growing movement is also working to tear down dams that are no longer functioning or needed around the world, with the aim at restoring more natural rivers and the many benefits they provide to wildlife and people, including recreation.
All rights reserved. How hydropower works A typical hydroelectric plant is a system with three parts: a power plant where the electricity is produced, a dam that can be opened or closed to control water flow, and a reservoir where water is stored.
The largest hydropower plants China, Brazil, Canada, the United States, and Russia are the five largest producers of hydropower. Hydropower pros and cons Hydropower has several advantages. Share Tweet Email. Why it's so hard to treat pain in infants. This wild African cat has adapted to life in a big city. Animals Wild Cities This wild African cat has adapted to life in a big city Caracals have learned to hunt around the urban edges of Cape Town, though the predator faces many threats, such as getting hit by cars.
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Animals This frog mysteriously re-evolved a full set of teeth. Multimedia Gallery. Park Passes. Technical Announcements. Employees in the News. Emergency Management. Survey Manual. So just how do we get electricity from water? Actually, hydroelectric and coal-fired power plants produce electricity in a similar way. In both cases a power source is used to turn a propeller-like piece called a turbine. In both cases a power source is used to turn a propeller-like piece called a turbine, which then turns a metal shaft in an electric generator, which is the motor that produces electricity.
A coal-fired power plant uses steam to turn the turbine blades; whereas a hydroelectric plant uses falling water to turn the turbine. The results are the same. Take a look at this diagram courtesy of the Tennessee Valley Authority of a hydroelectric power plant to see the details:. The theory is to build a dam on a large river that has a large drop in elevation there are not many hydroelectric plants in Kansas or Florida. The dam stores lots of water behind it in the reservoir. Near the bottom of the dam wall there is the water intake.
Gravity causes it to fall through the penstock inside the dam. At the end of the penstock there is a turbine propellor, which is turned by the moving water. The shaft from the turbine goes up into the generator, which produces the power. Power lines are connected to the generator that carry electricity to your home and mine.
The water continues past the propellor through the tailrace into the river past the dam. By the way, it is not a good idea to be playing in the water right below a dam when water is released! As to how this generator works, the Corps of Engineers explains it this way: "A hydraulic turbine converts the energy of flowing water into mechanical energy.
A hydroelectric generator converts this mechanical energy into electricity. The operation of a generator is based on the principles discovered by Faraday. He found that when a magnet is moved past a conductor, it causes electricity to flow. In a large generator, electromagnets are made by circulating direct current through loops of wire wound around stacks of magnetic steel laminations.
The capacity to produce this energy is dependent on both the available flow and the height from which it falls. Building up behind a high dam, water accumulates potential energy. This is transformed into mechanical energy when the water rushes down the sluice and strikes the rotary blades of turbine. The turbine's rotation spins electromagnets which generate current in stationary coils of wire.
Finally, the current is put through a transformer where the voltage is increased for long distance transmission over power lines. Falling water produces hydroelectric power. The theory is to build a dam on a large river that has a large drop in elevation there are not many hydroelectric plants in Kansas or Florida.
The dam stores lots of water behind it in the reservoir. Near the bottom of the dam wall there is the water intake. Gravity causes it to fall through the penstock inside the dam. At the end of the penstock there is a turbine propeller , which is turned by the moving water.
The shaft from the turbine goes up into the generator, which produces the power. Power lines are connected to the generator that carry electricity to your home and mine. The water continues past the propeller through the tailrace into the river past the dam.
This chart shows hydroelectric power generation in for the leading hydroelectric-generating countries in the world. China has developed large hydroelectric facilities in the last decade and now lead the world in hydroelectricity usage. But, from north to south and from east to west, countries all over the world make use of hydroelectricity—the main ingredients are a large river and a drop in elevation along with money, of course.
Credit: Energy Information Administration. Water is everywhere, which is fortunate for all of humanity, as water is essential for life. Even though water is not always available in the needed quantity and quality for all people everywhere, people have learned to get and use water for all of their water needs, from drinking, cleaning, irrigating crops, producing electricity, and for just having fun.
So just how do we get electricity from water? Actually, hydroelectric and coal-fired power plants produce electricity in a similar way. In both cases a power source is used to turn a propeller-like piece called a turbine. Nothing is perfect on Earth, and that includes the production of electricity using flowing water.
Hydroelectric-production facilities are indeed not perfect a dam costs a lot to build and also can have negative effects on the environment and local ecology , but there are a number of advantages of hydroelectric-power production as opposed to fossil-fuel power production.
Gravity causes it to fall through the penstock. Demand for electricity is not "flat" and constant. Demand goes up and down during the day, and overnight there is less need for electricity in homes, businesses, and other facilities. For example, here in Atlanta, Georgia at PM on a hot August weekend day, you can bet there is a huge.
Diagram of a hydroelectric generator is courtesy of U. Army Corps of Engineers. As to how this generator works, the Corps of Engineers explains it this way : "A hydraulic turbine converts the energy of flowing water into mechanical energy.
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