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Hydroelectric
Power
 Hydroelectric power, or hydroelectricity,
is generated
by the force of falling water. (Hydro comes from the Greek word for water.) It’s one of the cleanest sources
of energy, and it’s also the most reliable and costs the least.
That means that TVA’s hydroelectric
power plants are able provide electricity at a reasonable cost
to families, schools, farms, factories, and businesses.
How does
hydroelectric power work?
Water is needed to run a hydroelectric
power-generating unit. The water is held behind a dam, forming
an artificial lake, or reservoir. The force of the water being released
from the reservoir through the dam spins the blades of a giant turbine. The turbine
is connected to the generator that makes electricity as it spins.
After passing through the turbine, the water flows back into the
river on the other side of the dam.
TVA uses water to make electricity
at 29 hydroelectric dams
and one pumped-storage power plant (at Raccoon
Mountain near Chattanooga, Tennessee). Together these plants
produced about 13.9 million megawatt hours of electricity in
2004, enough electricity to power nearly one million homes for a year. |
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How
does a pumped-storage plant work?
A pumped-storage
plant uses two reservoirs, one located at a much higher elevation
than the other. During times when people are not using a lot of electricity,
such as nights and weekends, water is pumped from the lower to the upper
reservoir.
Thus,
the water is stored for
use during weekdays when people need more electricity. The stored
water can be released to turn the turbines and generate electricity
as it flows back down to the lower reservoir. Read more about TVA’s Raccoon
Mountain Pumped Storage Plant.
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