What is hydroelectricity for kids

This decreased environmental impact depends strongly on the balance between stream flow and power production. Micro hydro is a term used for hydroelectric power installations that typically produce up to kW of power.

These installations can provide power to an isolated home or small community, or are sometimes connected to electric power networks. There are many of these installations around the world, particularly in developing nations as they can provide an economical source of energy without purchase of fuel. Micro hydro systems complement photovoltaic solar energy systems because in many areas, water flow, and thus available hydro power, is highest in the winter when solar energy is at a minimum.

Pico hydro is a term used for hydroelectric power generation of under 5 kW. It is useful in small, remote communities that require only a small amount of electricity. For example, to power one or two fluorescent light bulbs and a TV or radio for a few homes.

Even smaller turbines of W may power a single home in a developing country with a drop of only 1 m 3 ft. A Pico-hydro setup is typically run-of-the-river , meaning that dams are not used, but rather pipes divert some of the flow, drop this down a gradient, and through the turbine before returning it to the stream.

An underground power station is generally used at large facilities and makes use of a large natural height difference between two waterways, such as a waterfall or mountain lake. An underground tunnel is constructed to take water from the high reservoir to the generating hall built in an underground cavern near the lowest point of the water tunnel and a horizontal tailrace taking water away to the lower outlet waterway.

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. Hydroelectricity can be made very quickly. This makes it useful for times when demand for electricity is high. Today, tidal energy systems generate electricity. Producing tidal energy economically requires a tidal range of at least 10 feet.

One type of tidal energy system uses a structure similar to a dam called a barrage. The barrage is installed across an inlet of an ocean bay or lagoon that forms a tidal basin. Sluice gates on the barrage control water levels and flow rates to allow the tidal basin to fill on the incoming high tides and to empty through an electricity turbine system on the outgoing ebb tide. A two-way tidal power system generates electricity from both the incoming and outgoing tides.

A potential disadvantage of tidal power is the effect a tidal station can have on plants and animals in estuaries of the tidal basin. Tidal barrages can change the tidal level in the basin and increase turbidity the amount of matter in suspension in the water. They can also affect navigation and recreation. Several tidal power barrages operate around the world.

The oldest and second-largest operating tidal power plant is in La Rance, France, with MW of electricity generation capacity.

China, Russia, and South Korea all have smaller tidal power plants. The United States does not have any tidal power plants, and it only has a few sites where tidal energy could be economical to produce.

France, England, Canada, and Russia have much more potential to use tidal power. Tidal turbines look similar to wind turbines. They can be placed on the sea floor where there is strong tidal flow. Because water is about times denser than air, tidal turbines have to be much sturdier and heavier than wind turbines.

Tidal turbines are more expensive to build than wind turbines but capture more energy with the same size blades. A demonstration tidal turbine project is under development in the East River of New York. A tidal fence is a type of tidal power system that has vertical axis turbines mounted in a fence or row placed on the sea bed, similar to tidal turbines.

Water passing through the turbines generates electricity. As of the end of , no tidal fence projects were operating. Waves form as wind blows over the surface of open water in oceans and lakes.

Ocean waves contain tremendous energy. The theoretical annual energy potential of waves off the coasts of the United States is estimated to be as much as 2. The west coasts of the United States and Europe, and the coasts of Japan and New Zealand, have potential sites for harnessing wave energy. Many different methods and technologies for capturing and converting wave energy to electricity are under development.

These methods include placing devices on or just below the surface of the water and anchoring devices to the ocean floor. Let's Explore Coal. Nuclear Energy. Alternative Energy. Play It Safe! Energy Efficiency. Energy Fun Lab. About Hydropower Water is another very important energy resource.

History of Hydropower Since ancient times people have found ways to harness the energy produced by moving water. Just a moment This application uses your local weather and energy rates. The amount of electricity generated from each power plant depends on the quantity of the flowing water and the height from which it falls. The Snowy Mountains Scheme is a famous Australian hydroelectricity project. Operating since , it diverts water from melting snow and rain in the Snowy Mountains to produce hydroelectricity.

Tides are another source of hydro energy. Like waves, it is difficult to harness the power of tides; but scientists are working on it.