Still, the presence of hydroelectric dams can often change migration patterns and hurt fish populations. In the Columbia River Basin in the Pacific Northwest, for example, salmon and steelhead have lost access to about 40 percent of their historic habitat because of dams.
Hydropower plants can also cause low dissolved oxygen levels in the water, which is harmful to river habitats. Other wildlife can be affected as well: In Indonesia, a hydroelectric project threatens rare Tapanuli orangutans because it stands to fragment their habitat. 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. Read This Next Wild parakeets have taken a liking to London. Animals Wild Cities Wild parakeets have taken a liking to London Love them or hate them, there's no denying their growing numbers have added an explosion of color to the city's streets.
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All generating units have four main parts: a turbine, a rotor basically a series of magnets , a shaft connecting the turbine to the rotor, and a stator basically a coil of copper wire. The force of the falling water spins blades in the turbine, which turn the shaft connected to the rotor, making it spin and creating a magnetic field as its magnets sweep past the coils of copper wire in the stator.
But in there was little need for a generator because the commercial technologies that relied on electricity — such as electric lights — had not yet appeared. In time, thanks to electricity, Americans would discard their ice boxes for refrigerators and replace their coal or wood-burning stoves with electric ranges, furnaces, and hot water heaters. Electricity eased the routines of daily life and improved the American standard of living as it brought with it electric irons, washing machines, and toasters.
Electricity also erased time and space when it powered the radio, which brought entertainment and the distant world to the door of ordinary Americans. But unlike Adams, the general public embraced electricity whole-heartedly as the evening suddenly was as bright as the day, a phenomenon showcased at new amusement parks and spectacularly illuminated world fairs. By , 10 percent of American homes had electricity.
Just days after the Pearl Street Station went online, H. Rogers, a businessman in Appleton, Wisconsin, connected an Edison dynamo to a waterwheel on the Fox River. By August , 40 to 50 hydroelectric powerplants were online or under construction in the United States and Canada. Finding a way to send electricity traveling across the miles to outlying areas and places without a ready water source was an obstacle that, once overcome, would lead to great expansion of the electric light and power industry.
DC, on the other hand, could not be so easily converted from one voltage to another, making it more expensive and less efficient to transmit over longer distances. George Westinghouse, using a complete AC system developed by Tesla motors combined with generators and transformers , won the AC-DC battle in when he harnessed the power of Niagara Falls to transmit electric power to Buffalo, New York — 26 miles distant.
By , AC powerplants powered by Niagara Falls were producing one-fifth of all electricity generated in the United States. The Niagara power was transmitted to cities and industries in the East and upper Midwest. The invention of the wheel was soon followed by the invention of the water wheel, a device that uses the downward motion of streams, rivers and other bodies of water to mechanically power another device. The earliest known version of the water wheel comes from mid-4th century BC Mesopotamia, a horizontal, propeller-like contraption that was used to turn millstones for grinding flour.
It proved to be effective and the design was caught on in southern Europe and China. The basic mechanism of the water wheel spread across much of the Old World Eurasia and Africa and took on several different forms, but the core concept remained the same.
As the water mill was refined further, its energy efficiency rose. Understanding hydraulics was essential to the development of modern hydroelectricity because when the electrical generator was developed in the late 19th century, it could be coupled with hydraulics to generate hydroelectricity.
Roughly around the same time, the Hungarian inventor and engineer Johann Segner developed his version of the reactive water turbine, also known as the Segner wheel. The Segner wheel had a vertical axis and makes use of hydrostatic pressure to eject water from a nozzle, creating a rotational force. In many ways it served as a prototype for modern water turbines.
The Industrial Revolution speeded up the evolution towards hydroelectric power as water mills were gradually converted into water turbines. In , James B. His high-efficiency turbines could match the unique flow conditions of individual bodies of water. To this day, it remains to be the most widely utilized turbine in operation.
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