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#10443. What does the term in Geography Anticline mean?

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#6177.

2331) Hydroelectricity

Gist

Hydroelectricity is the electricity generated by hydropower, which uses the power of moving water to produce energy. This is typically achieved by harnessing the force of falling water, often through dams that create reservoirs and control water flow. The water then passes through turbines, which are connected to generators that produce electricity.

Summary

Hydroelectricity is electricity made by generators that are turned by the movement of water. It is usually made with dams that partly block a river to make a reservoir of water. Water is released, and the pressure of the dam (potential energy stored in the dam) forces the water down pipes that lead to a turbine. This causes the turbine to turn, to turn a generator which makes electricity.

This renewable energy method makes about one sixth of the world's electricity. It produces less pollution than the fires of steam engines do. Some places such as Norway and Quebec get most of their electricity this way.

Because all methods have advantages and disadvantages, most countries have several ways to generate electricity. For example, hydroelectric methods have certain advantages, and atomic energy has quite different advantage.For most countries today, hydroelectric energy is the preferred, or one of the preferred methods. Mainly because it is a renewable energy which means that you can reuse it and it will never run out.

Advantages

The way the electricity is produced does not harm the environment as much as fossil fuels like oil or coal do. Hydroelectricity is very powerful and safe, and produces no waste.

An important advantage of hydroelectric dams is their ability to be used as a peaking power plant. When the electricity demand declines, the dam simply stores more water. Water that has been stored in a reservoir can be released (let go) when needed, so the energy can be made quickly. Some hydroelectricity generators use pumped storage to store excess energy (often during the night), by using the electricity to pump water up into a basin. Electricity can be generated when demand increases. This flexibility also makes hydroelectricity a good match for less controllable intermittent energy sources. When the wind is not blowing or the sun is not shining, hydroelectricity can be created.

Using stored water in river dams is sometimes complicated by irrigation needs which may happen out of phase with peak electrical demands.

Another advantage is that hydroelectricity cannot run out as long as there is a good water supply. Once the dam is built, the electricity costs very little, no waste or pollution is produced, and electricity can be generated whenever it is needed.

A few hydro turbines do not have a dam but instead use the current of the "run of the river". They produce less electricity and cannot store energy for later use.

Disadvantages

The building of large dams to hold water can damage the environment. In 1983, the Australian government stopped the Tasmanian state government from building a dam on the Gordon River in Tasmania after a huge public protest. The dam would have flooded the Franklin River. The Three Gorges Dam in China is the world's largest hydroelectricity project, and the world's largest power plant of any kind. The dam has flooded a huge area, meaning that 1.2 million people had to be moved. Scientists are concerned about many problems with the dam, such as pollution, silt, and the danger of the dam wall breaking. Also it doesn’t provide many jobs for people, is expensive to run and set up and is a real danger to marine life.

Details

Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other renewable sources combined and also more than nuclear power. Hydropower can provide large amounts of low-carbon electricity on demand, making it a key element for creating secure and clean electricity supply systems. A hydroelectric power station that has a dam and reservoir is a flexible source, since the amount of electricity produced can be increased or decreased in seconds or minutes in response to varying electricity demand. Once a hydroelectric complex is constructed, it produces no direct waste, and almost always emits considerably less greenhouse gas than fossil fuel-powered energy plants. However, when constructed in lowland rainforest areas, where part of the forest is inundated, substantial amounts of greenhouse gases may be emitted.

Construction of a hydroelectric complex can have significant environmental impact, principally in loss of arable land and population displacement. They also disrupt the natural ecology of the river involved, affecting habitats and ecosystems, and siltation and erosion patterns. While dams can ameliorate the risks of flooding, dam failure can be catastrophic.

In 2021, global installed hydropower electrical capacity reached almost 1,400 GW, the highest among all renewable energy technologies. Hydroelectricity plays a leading role in countries like Brazil, Norway and China. but there are geographical limits and environmental issues. Tidal power can be used in coastal regions.

China added 24 GW in 2022, accounting for nearly three-quarters of global hydropower capacity additions. Europe added 2 GW, the largest amount for the region since 1990. Meanwhile, globally, hydropower generation increased by 70 TWh (up 2%) in 2022 and remains the largest renewable energy source, surpassing all other technologies combined.

History

Hydropower has been used since ancient times to grind flour and perform other tasks. In the late 18th century hydraulic power provided the energy source needed for the start of the Industrial Revolution. In the mid-1700s, French engineer Bernard Forest de Bélidor published Architecture Hydraulique, which described vertical- and horizontal-axis hydraulic machines, and in 1771 Richard Arkwright's combination of water power, the water frame, and continuous production played a significant part in the development of the factory system, with modern employment practices. In the 1840s, hydraulic power networks were developed to generate and transmit hydro power to end users.

By the late 19th century, the electrical generator was developed and could now be coupled with hydraulics. The growing demand arising from the Industrial Revolution would drive development as well. In 1878, the world's first hydroelectric power scheme was developed at Cragside in Northumberland, England, by William Armstrong. It was used to power a single arc lamp in his art gallery. The old Schoelkopf Power Station No. 1, US, near Niagara Falls, began to produce electricity in 1881. The first Edison hydroelectric power station, the Vulcan Street Plant, began operating September 30, 1882, in Appleton, Wisconsin, with an output of about 12.5 kilowatts. By 1886 there were 45 hydroelectric power stations in the United States and Canada; and by 1889 there were 200 in the United States alone.

At the beginning of the 20th century, many small hydroelectric power stations were being constructed by commercial companies in mountains near metropolitan areas. Grenoble, France held the International Exhibition of Hydropower and Tourism, with over one million visitors 1925. By 1920, when 40% of the power produced in the United States was hydroelectric, the Federal Power Act was enacted into law. The Act created the Federal Power Commission to regulate hydroelectric power stations on federal land and water. As the power stations became larger, their associated dams developed additional purposes, including flood control, irrigation and navigation. Federal funding became necessary for large-scale development, and federally owned corporations, such as the Tennessee Valley Authority (1933) and the Bonneville Power Administration (1937) were created. Additionally, the Bureau of Reclamation which had begun a series of western US irrigation projects in the early 20th century, was now constructing large hydroelectric projects such as the 1928 Hoover Dam. The United States Army Corps of Engineers was also involved in hydroelectric development, completing the Bonneville Dam in 1937 and being recognized by the Flood Control Act of 1936 as the premier federal flood control agency.

Hydroelectric power stations continued to become larger throughout the 20th century. Hydropower was referred to as "white coal". Hoover Dam's initial 1,345 MW power station was the world's largest hydroelectric power station in 1936; it was eclipsed by the 6,809 MW Grand Coulee Dam in 1942. The Itaipu Dam opened in 1984 in South America as the largest, producing 14 GW, but was surpassed in 2008 by the Three Gorges Dam in China at 22.5 GW. Hydroelectricity would eventually supply some countries, including Norway, Democratic Republic of the Congo, Paraguay and Brazil, with over 85% of their electricity.

Future potential

In 2021 the International Energy Agency (IEA) said that more efforts are needed to help limit climate change. Some countries have highly developed their hydropower potential and have very little room for growth: Switzerland produces 88% of its potential and Mexico 80%. In 2022, the IEA released a main-case forecast of 141 GW generated by hydropower over 2022–2027, which is slightly lower than deployment achieved from 2017–2022. Because environmental permitting and construction times are long, they estimate hydropower potential will remain limited, with only an additional 40 GW deemed possible in the accelerated case.

Modernization of existing infrastructure

In 2021 the IEA said that major modernisation refurbishments are required.

Additional Information

Hydroelectric energy, also called hydroelectric power or hydroelectricity, is a form of energy that harnesses the power of water in motion—such as water flowing over a waterfall—to generate electricity. People have used this force for millennia. Over 2,000 years ago, people in Greece used flowing water to turn the wheel of their mill to ground wheat into flour.

How Does Hydroelectric Energy Work?

Most hydroelectric power plants have a reservoir of water, a gate or valve to control how much water flows out of the reservoir, and an outlet or place where the water ends up after flowing downward. Water gains potential energy just before it spills over the top of a dam or flows down a hill. The potential energy is converted into kinetic energy as water flows downhill. The water can be used to turn the blades of a turbine to generate electricity, which is distributed to the power plant’s customers.

Types of Hydroelectric Energy Plants

There are three different types of hydroelectric energy plants, the most common being an impoundment facility. In an impoundment facility, a dam is used to control the flow of water stored in a pool or reservoir. When more energy is needed, water is released from the dam. Once water is released, gravity takes over and the water flows downward through a turbine. As the blades of the turbine spin, they power a generator.

Another type of hydroelectric energy plant is a diversion facility. This type of plant is unique because it does not use a dam. Instead, it uses a series of canals to channel flowing river water toward the generator-powering turbines.

The third type of plant is called a pumped-storage facility. This plant collects the energy produced from solar, wind, and nuclear power and stores it for future use. The plant stores energy by pumping water uphill from a pool at a lower elevation to a reservoir located at a higher elevation. When there is high demand for electricity, water located in the higher pool is released. As this water flows back down to the lower reservoir, it turns a turbine to generate more electricity.

How Widely Is Hydroelectric Energy Used Around the World?

Hydroelectric energy is the most commonly-used renewable source of electricity. China is the largest producer of hydroelectricity. Other top producers of hydropower around the world include the United States, Brazil, Canada, India, and Russia. Approximately 71 percent of all of the renewable electricity generated on Earth is from hydropower.

What Is the Largest Hydroelectric Power Plant in the World?

The Three Gorges Dam in China, which holds back the Yangtze River, is the largest hydroelectric dam in the world, in terms of electricity production. The dam is 2,335 meters (7,660 feet) long and 185 meters (607 feet) tall, and has enough generators to produce 22,500 megawatts of power.

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