Chapter 5
106
Figure 5-11.
Hydroelectric
power can be even
generated by small
rivers and low
dams. This plant,
operated by a
small midwestern
city, generates
enough electricity
to operate a
sewage treatment
facility serving
several adjoining
communities.
Undershot waterwheel
Overshot waterwheel
A
B
Figure 5-10. The two types of
waterwheels. A—Overshot
waterwheels are driven by water
falling from above.
B—Undershot wheels are
driven from below.
Overshot
waterwheel: A
waterwheel that
relies on an eleva-
tion change and
makes use of the
weight of the
water, in addition
to the water’s
force.
The overshot waterwheel relies on an elevation change and makes use
of the weight of the water, in addition to the water ’s force. The undershot
waterwheel does not require a significant elevation change and primarily
makes use of the force of the flowing water. Although flowing waters do
not power manufacturing plants anymore, flowing water is still a valuable
source of energy. Hydroelectric energy is the use of flowing waters from
waterfalls and dams to produce electricity. See Figure 5-11.