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The advantages of the hydroelectricity
Hydroelectricity is the term referring to electricity
generated by hydropower; the production of electrical power through the use of
the gravitational force of falling or flowing water. Hydropower has been used
since ancient times to grind flour and perform other tasks. In the mid-1770s,
French engineer Bernard Forest de Bélidor published Architecture Hydraulique
which described vertical- and horizontal-axis hydraulic machines. By the late
19th century, the electrical generator was developed and could now be coupled
with hydraulics.
China is the largest hydroelectricity producer, with
721 terawatt-hours of production in 2010, representing around 17 percent of
domestic electricity use. There are now three hydroelectricity plants larger
than 10 GW: the Three Gorges Dam in China, Itaipu Dam in Brazil, and Guri Dam
in Venezuela.
The cost of hydroelectricity is relatively low, making
it a competitive source of renewable electricity. The average cost of
electricity from a hydro plant larger than 10 megawatts is 3 to 5 U.S. cents
per kilowatt-hour. Hydro is also a flexible source of electricity since plants
can be ramped up and down very quickly to adapt to changing energy demands.
However, damming interrupts the flow of rivers and can harm local ecosystems,
and building large dams and reservoirs often involves displacing people and
wildlife. Once a hydroelectric complex is constructed, the project produces no
direct waste, and has a considerably lower output level of the greenhouse gas
carbon dioxide (CO2) than fossil fuel powered energy plants.
1.
What
does the term “hydroelectricity” mean?