Hydropower
Hydropower is one of the oldest sources of
energy. Thousands of years ago in ancient Egypt,
it was used to turn paddle wheels to grind grain.
In the United States, hydropower has been in use
since the late 1800s. The first U.S. hydroelectric
power plant opened in 1882 on the Fox River in
Wisconsin.Today more than half of the renewable
energy we use in America comes from hydopower.
TRY IT!
On a warm day, try making your own water turbine
with help from an adult:
Materials: String, tape, plastic one-liter empty
soda bottle, hammer/nail, water
Carefully punch four holes into the empty soda bot-
tle using scissors or a nail and hammer. The holes
should be on the bottom corners equal distance apart.
Tape the holes so they are plugged. Cut enough string
to wrap around the neck of the bottle. Choose to hold
Moving water carries mechanical energy, which the bottle off the ground or find an object that will hold
is the sum of potential energy (stored energy) it off the ground, like a tree branch, and tie it to that
and kinetic energy (energy in motion). Using
object. Pour water into the bottle, filling it at least half
the mechanical energy found in a large flowing
full of water. Unplug the tape from the holes and the
river or waterfall created by a dam allows
water will come out of the bottle. The bottle will spin
electricity to be produced. Power is created when faster and faster as the water is pushed out of the
holes. The water pushes against the bottle with equal
the water flows through a pipe, or penstock, then
pushes against blades that turn in a turbine to spin and opposite force, demonstrating Newton’s third law
of motion. This law says that for every action (force)
a generator to produce electricity.
there is an equal and opposite reaction (force).
Hydropower plant at
Boulder, Colorado
www.growingyourfuture.com
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