What Is Hydroelectricity For Kids Facts?

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What is hydroelectricity?

Hydroelectricity is a form of power or energy that is generated from flowing water. It uses the natural flow of water, through dams and turbines, to create electricity. The force of the moving water turns turbines which are connected to generators. As the turbines spin, they cause the generators to rotate and produce electricity.

Hydroelectric power plants are usually built on or near rivers. Dams are constructed to store water in reservoirs and control the water flow. The water in the reservoir has potential energy because of its height above the turbines. When the water is released from the reservoir, through tunnels and down pipes called penstocks, it flows rapidly towards the turbines. This kinetic energy causes the turbine blades to spin and activate the generators. The generators then convert the mechanical energy from the spinning turbine into electrical energy.

The electricity produced at hydroelectric plants is then fed into power lines and distributed through electrical grids to homes, businesses, schools and other facilities that need power. In summary, hydroelectricity harness the natural power of flowing or falling water to produce clean, renewable electricity.

Source: https://kids.kiddle.co/Hydroelectricity

How does hydroelectricity work?

Hydroelectricity utilizes the natural energy of falling or flowing water to generate electricity. It all starts with the water cycle. As part of this cycle, water from rain and snow flows down from higher elevations eventually making its way into rivers or streams. The flow of the water in rivers and streams contains kinetic energy that can be harnessed and converted into electricity.

To capture this energy, dams are constructed to control the flow of water and direct it through large pipes called penstocks. At the end of the penstock is a turbine, which is similar to a large fan. As the water flows through the penstock and hits the turbine, it causes the turbine blades to spin rapidly like a fan. This turbine is connected to a generator, and the motion of the spinning turbine gets converted by the generator into electrical energy. The electricity is then fed into transmission lines and sent to homes, business, and other consumers.

In summary, falling or flowing water is a source of kinetic energy that can be harnessed to spin turbines and produce electricity through generators, providing hydroelectric power through a renewable process.

Where does hydroelectricity come from?

Hydroelectricity comes from the energy of flowing water. It is usually generated at dams on rivers, where a difference in water height on either side of the dam forms what is called hydraulic head. Water is stored at a higher elevation behind the dam, then travels through devices called turbines as it falls to the lower elevation on the other side. The flowing water causes the turbines to spin, which then spins magnets within an electric generator to produce electricity.

Dams are built to raise the water level and create an artificial waterfall. The height of the water behind the dam compared to in front creates the hydraulic head that drives the power-generating turbines. The greater the hydraulic head, the more potential energy can be captured from the moving water. Rivers with high natural elevations like waterfalls also provide excellent sources for hydroelectricity.

Dams and reservoirs provide a consistent water source to generate electricity, even when seasonal river flows fluctuate. Storing water behind dams also helps prevent flooding downstream. Many dams are multipurpose, providing flood control, irrigation, navigation, and recreation benefits in addition to hydroelectric power generation.

Advantages of Hydroelectricity

One of the main advantages of hydroelectricity is that it is a renewable source of energy. Unlike fossil fuels such as coal, oil and natural gas, we won’t run out of water. As long as there is precipitation and flowing water, hydroelectric power plants can continue generating electricity indefinitely.

Hydroelectricity also does not produce air pollution or greenhouse gases. Fossil fuel power plants emit harmful pollutants like sulfur dioxide, nitrogen oxides and particulate matter. Burning fossil fuels also releases carbon dioxide, a major greenhouse gas contributing to climate change. Since no fuels are combusted to generate electricity at hydroelectric dams, this form of energy is clean and does not contribute to smog or global warming.

Overall, hydroelectricity is considered an environmentally friendly source of renewable power that does not create air pollution or emissions. This makes it preferable over fossil fuels for generating electricity.

Disadvantages of hydroelectricity

While hydroelectric power provides clean, renewable energy, it also has some downsides. Two major disadvantages of hydroelectric dams are:

Disrupts fish migration and ecosystems – Damming rivers to create reservoirs blocks fish migration routes and disrupts ecosystems. Fish like salmon can no longer swim upstream to spawn. Dams also change water levels, temperatures, oxygen levels and flow which impacts native plants and animals. https://kidsdiscover.com/teacherresources/whats-good-and-whats-bad-about-hydropower/

Reservoirs flood areas and force people to relocate – Building hydroelectric dams and their reservoirs leads to flooding upstream areas which can submerge towns, farms and forests. This forces people living in those areas to relocate losing their homes and livelihoods. Large areas can be flooded displacing entire communities.

Interesting facts about hydroelectricity

Hydroelectric dams are some of the largest structures ever built. For example, the Three Gorges Dam in China is over 600 feet tall and stretches for over a mile and a half. It’s the largest hydroelectric dam in the world. The Itaipu Dam on the border of Brazil and Paraguay generates over 12,000 MW of power, making it the second largest hydroelectric dam.

Many countries generate a significant amount of their electricity from hydro power. For example, Norway generates over 95% of its domestic electricity from hydroelectric sources. Canada also relies heavily on hydro power, generating around 60% of its electricity from hydroelectric dams.

Globally, hydroelectricity makes up around 16% of total electricity generation. China leads the world in hydroelectric generation, producing over twice as much hydroelectricity as any other country.

Some of the tallest dams in the United States include the Oroville Dam in California at 770 feet, the Hoover Dam at 726 feet, and the Grand Coulee Dam in Washington at 550 feet.

Hydroelectric dams also serve other important purposes like flood control, irrigation, and recreation. For example, the reservoirs created by dams are often used for boating, swimming, and fishing.

How hydroelectricity impacts the environment

Hydroelectric dams and reservoirs can have significant impacts on the surrounding environment. Here are some of the main effects:

Effects on land, ecosystems and wildlife: Flooding land for a reservoir destroys existing ecosystems and habitats. Plants and animals that lived in the area before the dam have their homes destroyed. Fish migration routes can be blocked, keeping fish from reaching spawning grounds. Sediment that would naturally flow down rivers gets trapped behind dams, eroding downstream areas. Dams also fragment rivers, separating connected habitats.

Preventing erosion and managing water flow: Dams provide some benefits too. They can help prevent erosion by controlling water flow. Reservoirs store water for use in drier times. Dams also allow control over downstream water levels, guarding against floods. However, critics argue river ecosystems benefit from natural high and low water flows. Managing water too precisely disrupts wildlife that depends on seasonal changes.

Major hydroelectric projects

Some of the largest and most notable hydroelectric projects in the world include:

The Three Gorges Dam in China is the world’s largest hydroelectric dam. Completed in 2012, it has a generating capacity of 22,500 megawatts (MW).
The Itaipu Dam on the border between Brazil and Paraguay is the second largest hydroelectric power station, with a generating capacity of 14,000 MW.

The Hoover Dam in the United States, completed in 1936, was the world’s largest hydroelectric power station for many years. It has a capacity of 2,080 MW.

Some other major hydroelectric dams and projects around the world are the Grand Coulee Dam in the U.S., the Sayano-Shushenskaya Dam in Russia, and the Robert-Bourassa generating station in Canada.

History of hydroelectricity for kids timeline

People have utilized the power from flowing water for over 2,000 years, but modern hydroelectric plants first appeared in the late 1800s. According to the EIA, some of the earliest hydroelectric systems were built in the U.S. and parts of Europe in the late 19th century.

One of the first operational hydroelectric power plants was built on the Fox River in Appleton, Wisconsin in 1882. This plant used a 12.5 kilowatt generator to provide electricity to light two paper mills and a home. Over the next few decades, hundreds more small hydropower plants were constructed around mills and manufacturing plants.

In the early 20th century, larger hydroelectric projects began to be constructed to generate electricity for cities and expand electrification. Major dams like the Hoover Dam, Grand Coulee Dam and Niagara Falls were built during this time. According to Ducksters, hydropower grew significantly from the early 1900s onward, accounting for over 40% of the electricity generated in the U.S. by 1940.

Today, hydropower continues to be an important renewable energy source across the world. Large dams and pumped storage facilities provide baseline power generation and grid stability in many countries.

Future of hydroelectricity

Hydroelectric power will continue to play an important role in renewable energy production in the future. With growing concerns about climate change, countries are looking to increase the share of renewables in their energy mix. Hydropower is expected to account for over 16% of renewable electricity generation globally by 2040.

Some of the key trends shaping the future of hydroelectricity include:

Modernization and upgrades of existing facilities to improve efficiency and capacity
New large-scale hydro projects in developing countries, especially in Asia and South America
New technologies like variable speed turbines and pumped storage to balance intermittent renewables like wind and solar

Small scale and micro hydropower development to provide electricity access in remote areas
Developments like hydrokinetic power and low-head hydropower that have lower environmental impacts

However, building new large dams also faces challenges like geological constraints, environmental concerns, and high costs. The focus is shifting towards optimizing existing dams, adding hydro capabilities to non-powered dams, and developing new technologies with lower impacts. With the right policies and technological innovations, hydropower can continue serving as a major pillar of renewable energy production globally.