Hydropower is the most important and widely-used renewable source of energy. Hydropower represents about 17% (International Energy Agency) of total electricity production. China is the largest producer of hydroelectricity, followed by Canada, Brazil, and the United States (Source: Energy Information Administration).
Hydropower is using water to power machinery or make electricity. Because the water cycle is an endless, constantly recharging system, hydropower is considered a renewable energy. When flowing water is captured and turned into electricity, it is called hydroelectric power or hydropower.
Flowing water creates energy that can be captured and turned into electricity. The most common type of hydroelectric power plant uses a dam on a river to store water in a reservoir. Water released from the reservoir flows through a turbine, spinning it, which in turn activates a generator to produce electricity.
Hydropower became an electricity source in the late 19th century, a few decades after British-American engineer James Francis developed the first modern water turbine. In 1882, the world's first hydroelectric power plant began operating in the United States along the Fox River in Appleton, Wisconsin.
When water flows or falls, energy can be generated. The generation of energy through water is usually carried out in large water power plants, with a number of process steps and the use of several devices, such as turbines and generators. The energy in water can be used to produce electricity.
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 rotor is attached to the turbine shaft, and rotates at a fixed speed.
Hydropower does not pollute the water or the air. However, hydropower facilities can have large environmental impacts by changing the environment and affecting land use, homes, and natural habitats in the dam area. Methane, a strong greenhouse gas, may also form in some reservoirs and be emitted to the atmosphere.
Three Gorges, China – 22.5GW
The 22.5GW Three Gorges hydroelectric power plant in Yichang, Hubei province, China, is the world's biggest hydropower station. It is a conventional impoundment hydropower facility exploiting the water resource of the Yangtze River.There are three main types of conventional hydropower technologies: impoundment (dam), diversion, and pumped storage. Impoundment is the most common type of hydroelectric power plant. An impoundment facility, typically a large hydro-power system, uses a dam to store river water in a reservoir.
Advantages of Hydroelectric Energy
- 1 Renewable. Hydroelectric energy is renewable.
- 2 Green. Generating electricity with hydro energy is not polluting itself.
- 3 Reliable. Hydroelectricity is very reliable energy.
- 4 Flexible. As previously mentioned, adjusting water flow and output of electricity is easy.
- 5 Safe.
Hydropower does not pollute the water or the air. However, hydropower facilities can have large environmental impacts by changing the environment and affecting land use, homes, and natural habitats in the dam area.
A primary use of hydropower energy is to produce electricity. The main ingredients of hydroelectric power plants are dams, rivers and turbines. Plants use dams to create reservoirs where the water is stored. This water is then released through turbines and spun to activate generators and create electricity.
Hydropower is fueled by water, so it's a clean fuel source, meaning it won't pollute the air like power plants that burn fossil fuels, such as coal or natural gas. Hydroelectric power is a domestic source of energy, allowing each state to produce their own energy without being reliant on international fuel sources.
Small-scale hydroelectricity, or hydropower, can be used on a domestic scale to heat your home or run your appliances.
A conventional dam holds water in a man-made lake, or reservoir, behind it. When water is released through the dam, it spins a turbine connected to a generator that produces electricity. The water returns to the river on the downstream side of the dam.
Hydropower. Hydropower is the most widely-used renewable power source, with the global hydroelectric installed capacity exceeding 1,295GW, accounting for more than 18% of the world's total installed power generation capacity and more than 54% of the global renewable power generation capacity.
Hydropower is the most efficient way to generate electricity. Modern hydro turbines can convert as much as 90% of the available energy into electricity. The best fossil fuel plants are only about 50% efficient. In the U.S., hydropower is produced for an average of 0.85 cents per kilowatt-hour (kwh).
Because hydropower plants can generate power to the grid immediately, they provide essential back-up power during major electricity outages or disruptions. In addition to a sustainable fuel source, hydropower efforts produce a number of benefits, such as flood control, irrigation, and water supply.
Hydroelectric power is produced with moving water
At hydropower plants water flows through a pipe, or penstock, then pushes against and turns blades in a turbine to spin a generator to produce electricity. Run-of-the-river systems, where the force of the river's current applies pressure on a turbine.A reservoir is an artificial lake where water is stored. Most reservoirs are formed by constructing dams across rivers. A reservoir can also be formed from a natural lake whose outlet has been dammed to control the water level. It was built in about 3000 BCE to store water to use for irrigation, or watering crops.
Pros and cons of hydropower
| Pros of hydropower | Cons of hydropower |
|---|
| Renewable energy source | Some adverse environmental impact |
| Pairs well with other renewables | Expensive up-front |
| Can meet peak electricity demand | Lack of available reservoirs |
Nuclear power is a clean and efficient way of boiling water to make steam, which turns turbines to produce electricity. Nuclear power plants use low-enriched uranium fuel to produce electricity through a process called fission—the splitting of uranium atoms in a nuclear reactor.
Wind turbines work on a simple principle: instead of using electricity to make wind—like a fan—wind turbines use wind to make electricity. Wind turns the propeller-like blades of a turbine around a rotor, which spins a generator, which creates electricity.
Electricity is most often generated at a power plant by electromechanical generators, primarily driven by heat engines fueled by combustion or nuclear fission but also by other means such as the kinetic energy of flowing water and wind. Other energy sources include solar photovoltaics and geothermal power.
The advantages of wind energy
One wind turbine can be sufficient to generate energy for a household. Because wind is a source of energy which is non-polluting and renewable, the turbines create power without using fossil fuels. That is, without producing greenhouse gases or radioactive or toxic waste.
