Hydroelectric power

Hydroelectricity, or hydroelectric power, is electricity obtained from hydropower. It comes from the potential energy of dammed water, waterfalls, tides, etc. The mechanical energy of the moving water is converted to electrical energy by a water turbine driving a generator. Most hydroelectric power is generated at dams or other places where water descends from a height, however, power is drawn on coasts with strong tides as well (such as the Bay of Fundy near the coast of North America). Hydroelectricity is a renewable energy source, since the water that flows in rivers has come from rain or snow, and tides are driven by the rotation of the earth.

The energy that may be extracted from water depends not only on the volume but on the difference in height between the water crest (or source) and the water outflow. This height difference is called the head. The amount of the potential energy in water is directly proportional to the head. For this reason, to build dams as high as possible is rather advantageous in order to produce the maximum electrical energy.

Hydroelectric power, using the potential energy of rivers, now supplies 20% of world electricity. The largest hydroelectric plants in Russia are located on the Volga, Kama, Ob', Yenisey, and Angara rivers, where large reservoirs were built in massive Soviet energy projects. Thermoelectric and hydroelectric plants - located in Siberia because of available fuels and water power - send power to the European part of Russia through a system of high-voltage transmission lines.

While many hydroelectric schemes supply public electricity networks, some projects to be used for private commercial purposes have been created. For example, aluminium processing requires substantial amounts of electricity, and there are hydropower stations in Britain’s Scottish Highlands, designed and constructed during the early years of the 20th century. In many parts of Canada hydroelectricity is used so extensively that the word "hydro" is used to refer to any electricity delivered by a power utility. The government-run power utilities in some provinces are called "BC Hydro," "Hydro Quebec" and "Hydro One".

· Transcribe the following words, practice reading them, give Russian equivalents:

Hydropower, specifically, currently, descend, height, renewable, volume, amount, advantageous, scheme, process, require, substantial, extensively, deliver, utility

· Are the following sentences true or false? Correct the false sentences

1. Water turbine converts electrical energy into mechanical energy.

2. Most of hydroelectric power is drawn from the tides.

3. Hydroelectricity is a renewable energy source.

4. The energy extracted from water does not depend on the water head.

5. The higher the dam is, the greater amount of electrical energy is produced.

6. Hydroelectricity is extensively used in aluminium industry.

· Answer the questions.

1. What is the source of hydroelectricity or hydroelectric power?

2. What device converts the mechanical energy of moving water to electrical energy?

3. What places are most suitable for generating hydroelectric power?

4. What is the main advantage of hydroelectricity as an energy source?

5. What causes tides?

6. Why is it necessary to build dams as high as possible in order to produce the maximum

electrical energy?

7. In what parts of the globe is hydroelectricity used very extensively?

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