|
Hydropower
uses the power of water to produce energy. Water sitting in a dam
has potential energy
– the massive volume of water sits behind
a dam until it is allowed to run through turbines. At this point
the water becomes kinetic energy
. It is moving. The running water
spins turbines that run generators, which produce electricity.
 What
comes to mind when you think of water? A long cool drink on a sweltering
hot day? Running through the sprinkler, diving into the deep end?
How about a big burst of electricity? Water’s raw power provides
the energy to produce enough electricity for 28 million Americans
every year. Worldwide, hydropower generates more than 2.3 trillion
kW
hours of electricity, the energy equivalent of 3.6 billion barrels
of oil. Dive in, explore more about the power of water.
 History
For thousands of
years, the pure power of water has been utilized around the world.
Wherever rivers ran, people took advantage of the water’s force
to do the work of grinding grain and operating machinery like mills.
During the 20th century, water’s power was put to
work generating electricity, and continues to be an important fuel
for our huge energy appetite.
How
it Works
 Capturing
water’s energy and transforming it into electricity is a simple
process that often relies on a dam. Hydropower dams are designed
to create a significant drop in the downhill flow of water, which
increases the water’s speed. The falling water is directed
to a turbine through a long tunnel called a penstock. The kinetic
energy of the falling water does the work of turning a turbine.
The turbine is connected to a generator
which spins, producing electricity. The amount of power generated
by this process depends on several variables: the volume of water,
the speed of the water’s flow , and the height of the water’s
fall. As more water is pushed through towards the turbine, the faster
it flows. And the farther it falls, the higher the power output.
A hydropower plant design takes all of these variables into consideration.
Benefits
 Water
is a very clean way to produce power. No emissions, no waste. Hydropower
plants are efficient, reliable and flexible. Their simple design
means maintenance levels are low. The plants don’t have to
ship fuels in, which lowers operating costs. Hydropower plants have
the ability to adapt quickly to satisfy the needs of shifting electrical
demand. Plants contribute to both base
load and peak
load demand for electricity. Day to day, plants produce steady
reliable amounts of electricity. During periods of peak demand,
the plants can bring additional generators online very quickly,
providing more power.
Limitations
 While
hydropower is a clean renewable resource, there are limitations.
Hydropower plants can have dramatic affects on the environment.
- Building
dams can flood land and affect fish and wildlife habitats.
- Dams also
limit the way people can use waterways for transportation.
- Dam construction
can cause significant changes in a river’s flow, affecting
entire ecological systems.
- Dams can
pose a major obstacle to fish, preventing them from moving upstream
to spawn.
Because of
the potential ecological effects, the federal government imposes
strict licensing procedures on hydropower projects, increasing startup
costs. Those startup costs are one of the reasons there hasn’t
been major growth in this energy area. Another reason is the simple
lack of sites. Many of the best sites have already been built on,
limiting growth.
Geographical
Considerations
 The
best sites for dams are mountainous regions with heavy rainfall.
These areas have an abundance of the natural resource needed —
water. They also tend to provide naturally steep drop-offs, one
of the variables important to maximizing water power. Iowa in particular
and the Midwest in general do not provide good opportunities for
hydropower because the region is generally flat. Iowa does have
the Mississippi River as a resource, which provides a large volume
of water, another variable important to producing hydropower.
|
 What
do you think?
As the world’s
appetite for energy grows larger and larger, hydropower will
continue to be an important resource to satisfy our needs.
Should hydropower’s piece of the energy pie be larger?
Is hydropower a practical solution to meet your community’s
energy needs?
|
 Check
it Out!
Explore More
about the inner workings of a hydroelectric
plant. Check out this site from the USGS.
|
Sources
- Brown, Phil.
"Tidal Energy." (Online) http://www.geology.wisc.edu/~pbrown/g410/tidal/tidal.html.
September 2001.
- Grand Coulee
Dam Basin Project. "History of the Columbia Basin Project." (Online)
http://users.owt.com/chubbard/gcdam/html/history.html. September
2001.
- International
Council for Local Environmental Initiatives. "Energy Fact Sheet."
(Online) (Originally published by the Energy Educators of Ontario,
1993.) http://www.iclei.org/efacts/tidal.htm.
September 2001.
- Iowa Department
of Natural Resources. "Hydropower." (Online)
http://www.state.ia.us/dnr/energy/pubs/irerg/hydropower.htm.
June 2001.
- National
Renewable Energy Laboratory. "Hydroelectric Power." (Online) http://www.nrel.gov/lab/pao/hydroelectric.html.
September 2001.
- U.S. Army
Corps of Engineers, Portland District. "The Dalles/John Day/Willow
Creek Project." (Online) http://www.nwp.usace.army.mil/op/D/standard/td/fish/td_fish.htm.
September 2001.
- World Nuclear
Association. "Renewable Energy and Electricity." (Online) http://www.world-nuclear.org/info/inf10.htm.
September 2001.
|
Can
a Fish Climb a Ladder?
 No,
it’s not a bad riddle and the answer is yes – if it’s
a fish ladder. More
Hydro-Powerhouse!
 The
Grand Coulee Dam, located on the Columbia River in Central Washington,
is the largest hydropower producer in the United States and the
third largest in the world. More
|
