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Teach...build...learn...renewable energy!
Hydroelectric Generator
A Renewable Energy Project Kit
The Pembina Institute
Most machines that make electricity need
some form of mechanical energy to get
things started. Mechanical energy spins the
generator to make the electricity. In the case of
hydroelectricity, the mechanical energy comes from
large volumes of falling water. For more than 100
years, the simplest way to produce the volumes of
falling water needed to make electricity has been to
build a dam. A dam stops the natural fl ow of a river,
building up a deep reservoir behind it. However,
large dams and reservoirs are not always appropriate,
especially in the more ecologically sensitive areas of
the planet.
For making small
amounts of
electricity without
building a dam, the
small-scale
hydroelectric
generator is often
the best solution,
especially where
fast-fl owing
streams on steep
slopes are close
by. A small-scale
hydro system
usually consists of an enclosed water wheel or
turbine, which is made to spin by jets of high-
velocity water. The water is taken from the stream
and moved down slope to the turbine through a
long pipe called a penstock. Water fl owing through
the penstock picks up speed, and is directed at the
blades of the turbine by nozzles. The turbine spins
continuously, as long as there is water to drive it.
The turbine is connected to an electrical generator,
and the electricity is then available for running
appliances or charging batteries. The spent water is
returned to the stream. This kind of system is called
a “micro-hydro” system, “run-of-stream hydro” or
“low-impact hydro.”
In this activity, you will use plastic spoons to build a
model of a simple micro-hydro system. It generates
surprising amounts of electricity, provided you have
a supply of pressurized water, such as from a lab
sink. This model closely resembles real micro-hydro
designs, and can produce enough electricity to light
a sm