BACKGROUND:
Our built environment captures what
nature has given us and tries to use it for the good of the human
society. Students should be aware how human society sometimes affects
other "societies," from ants, elephants, atmosphere and
oceans. Humans are only one of the millions of species on this planet.
The following units in Built Environment focuses on how we use nature's
gifts, whether good or bad. Students as adults, should learn
to research a problem or potential problem and then make decisions based
on solid evidence.
There are many ways to get energy
from nature. Some methods like wind, water, and solar do little to
affect the environment. Other methods like petroleum, gas,
coal, and
nuclear may someday pose a threat to future humans.
Different energy sources can be divided into two
groups -- renewable (an energy source that we can use over and
over again) and nonrenewable (an energy source that we are using
up and cannot be recreated in a short period of time). Water,
wind, and sun provide us with renewable energy source while petroleum,
gas, coal, and the element uranium (used by nuclear power plants) are
nonrenewable.
Water is very powerful. In the past,
falling water turned a flour mill which ground wheat into flour. Today
steam from water or falling water causes a turbine to spin. This
generates electricity. A turbine can do without steam when it is located
at the base of a waterfall or a dam and made to spin by the falling
water alone. This is power produced by hydroelectric energy. It
generates about 16 -20% of all electricity in the United States.
Windmills have been used for
centuries. Holland, a small country in Europe, is noted for their use of
windmills. Many people do not realize that a windmill produces energy.
Wind turns turbines which change the wind power to electrical energy.
Solar power captures energy from the
light rays of the sun. Students may have seen solar powered hot water
tanks. This example is easy for them to understand. However, there are
many solar operated machines such as calculators, that can help make
this understandable for a second grader. Point out that solar energy is
becoming more and more advanced. Coal, gas, petroleum (oil and other
derivatives), and nuclear energy are all used to create electricity by
fueling turbines to create movement, similar to hydroelectric. The
advantage over many of these forms of energy is that the energy can be
created anywhere. Water, wind, and solar all require specialized
conditions to work, and sometimes the conditions prevent energy from
being made. For example, no wind, no energy.
PROCEDURE:
- In this activity, students start
learning the different ways to derive energy. Go over the worksheet to
discuss the different types of energy sources.
- Ask students to decide whether the energy is
renewable (can replace itself) or nonrenewable (cannot replace
itself). Also have them decide if the energy source does not
pollute the atmosphere or pollutes the atmosphere. Then have
them decide if there is problems with the by-products of creating
the energy.
Answers: wind: renewable, clean, no problem ; hydroelectric:
renewable, clean, no problem; solar: renewable, clean, no problem
; coal: non renewable, pollutes, problem with by-products; petroleum:
non renewable, pollutes, problem with by-products;
nuclear: non renewable, pollutes, problem with by-products
- Students can add their own views of benefits
and harm from each energy source to the bottom of the list.
