Hydroelectric energies Rivers energy Sea energy Hydropower plants

Hydroelectric energies Rivers energy Sea energy

Hydropower plants p p p Worldwide, hydropower plants produce about 24 percent of the world's electricity and supply more than 1 billion people with power. Hydropower is the second source of electricity in France. In France it is 12% of the total electricity production, with an average production capacity of 70 TWh per year

How does it work ? Hydropower plants are based on a rather simple concept p Hydropower plants harness water's energy and use simple mechanics to convert that energy into electricity. p Water flowing through a dam turns a turbine which turns a generator. p

Here are the basic components of a conventional hydropower plant p p p p Dam - Most hydropower plants rely on a dam that holds back water, creating a large reservoir. Often, this reservoir is used as a recreational lake Intake - Gates on the dam open and gravity pulls the water through the penstock, a pipeline that leads to the turbine. Water builds up pressure as it flows through this pipe Turbine - The water strikes and turns the large blades of a turbine, which is attached to a generator above it by way of a shaft. The most common type of turbine for hydropower plants is the Francis Turbine, which looks like a big disc with curved blades. A turbine can weigh as much as 172 tons and turn at a rate of 90 revolutions per minute (rpm) Generators - As the turbine blades turn, so do a series of magnets inside the generator. Giant magnets rotate past copper coils, producing alternating current (AC) by moving electrons. Transformer - The transformer inside the powerhouse takes the AC and converts it to higher-voltage current Power lines - Out of every power plant come four wires: the three phases of power being produced simultaneously plus a neutral or ground common to all three Outflow - Used water is carried through pipelines, called tailraces, and re -enters the river downstream

Here are the basic components of a conventional hydropower plant

Pumped-storage hydroelectric plant

Pumped-storage hydroelectric plant: p A plant that usually generates electric energy during peak load periods by using water previously pumped into an elevated storage reservoir during off-peak periods when excess generating capacity is available to do so. When additional generating capacity is needed, the water can be released from the reservoir through a conduit to turbine generators located in a power plant at a lower level.

Hydroelectric production

The Rance tidal power plant The dam of the plant measures 332. 5 meters

The Rance tidal power plant, power from the ocean p p p The Rance site lent itself well to such a project. First, because the amplitude between low and high tides is one of the highest in the world (it reaches up to 13. 5 metres during equinoctial tides) Second, because the estuary offers a reservoir of 22 km 2 capable of impounding 180 million m 3. At peak periods, 18, 000 m 3 of water per second go through the estuary, or a flow that is ten times greater than that of the Rhone River. To harness such power, the estuary had to be blocked by a 750 metres long and 13 metres high structure. Twenty-five years of studies and six years of construction works were needed to erect the Rance tidal power plant. Since 1967, this facility, the only full-scale power station of this type in the world, generates 600 million k. Wh every year, enough to provide energy to 250 000 households.