Don’t Waste the Energy!
Goal: To help students understand that recycling helps save energy as well as space in
the landfill.
Subjects: Visual Arts, Social Studies, Language Arts, Information Skills
Vocabulary: energy- conserve- renewable resource- nonrenewable resource- aluminum
HDPE plastic- PET plastic- cullet- bauxite ore- petroleum- uranium- coal
Background:
What is energy? It’s that stuff you just can’t find when your mom tells you to
clean your room or rake the yard or do your homework. What your mom doesn’t seem to
understand is that you have to conserve your energy incase your friends come by and
want you to go with them to shoot a few hoops at the park. If you’ve used all your energy
doing your math, there’s none left for basketball.
You and I both know that’s not true. Your energy is a renewable resource If you
eat a good supper and get a good night’s sleep, chances are you’ll have plenty of energy
the next day to do your chores and play basketball.
The same is true for some of the resources used to make what ends up in our
landfills. Most of our trash is paper, which comes from trees, which is a renewable
resource. But what about the energy used to turn those trees into paper airplanes? That
takes lots of electricity. It’s possible to sue water or wind or the sun to generate
electricity, but most power companies use coal or uranium or petroleum. Those are
resources we have to dig out of the ground, and once they’re used up, there will be no
more. That makes them nonrenewable resources.
We can cut down on the amount of energy we used to make things like paper by
recycling it instead of throwing it in the trash. Manufacturers who use recycled paper
save 40 percent of the energy they would need if they made paper from trees. One ton of
recycled newspaper saves 17 trees and 7000 gallons of water.
Recycling plastics helps save trees, too. Many of the products that in the past have
been made from wood are now being made from recycled plastics. That includes things
like insulation for houses, park benches and even plastic “lumber”. Pop and milk bottles
are easiest to recycle. Pop bottles are made from polyethylene terephthalate (PET
plastic. Recycled PET plastic can be used to make fiber, building materials and more
containers. Milk bottles are made of high density polyethylene (HDPE) plastic, which
can be recycled into bottles, toys, pipes, crates, and many other things. These are two
kinds of recycled plastic can also be mixed to make garbage pails, manhole covers, park
benches, plastic lumber, and railroad ties.
Bottle glass is made from another non-renewable resource, sand. Sand is
plentiful, but changing it into glass takes a lot of energy. The sand is melted with burnt
lime or limestone and soda ash in a 2700-degree furnace. Most manufacturers now mix
cullet (recycled glass that has been crushed) with the other ingredients. This cuts down
on the amount of energy needed. The amount of energy saved recycling one glass bottle is
enough to light a 100 watt bulb for four hours.
Aluminum is made from bauxite ore, a non-renewable resource mined overseas.
The bauxite is shipped to a refining plant after it is taken from the ground. Machines
crush the ore into a white powder into a molten mass. This is poured into a form and
cooled, then rolled into sheets which are made into cans. From one ton of bauxite ore,
the manufacturers can only get 500 pounds of pure aluminum.
Recycled aluminum is simply melted and recast and uses only 5 percent of the
energy needed to make aluminum from bauxite. It takes as little as 90 days for a recycled
can to show up as a new can in your mother’s grocery cart.
Recycling one aluminum can saves enough electricity to light a 100- watt light
bulb for 3 ½ hours. The electrical energy saved through aluminum can recycling in 1989
was enough to power over 6.8 million homes for an entire year. Since recycled aluminum
doesn’t have to be taken from the ground and shipped from overseas, it saves gasoline
too. Each ton of aluminum recycled saves nearly 2000 gallons of gasoline. Recycling one
12-ounce aluminum can saves the equivalent of six ounces of gasoline. Throwing the can
into the trash is like pouring six ounces of gasoline on the ground.
Activity: Make your own paper (see attached activity sheet)
Related Activities:
1. Have students bring their journals from “Bouncing Balls in Bubble Packs” to
class and share what kinds of packaging they have used. Discuss what kinds of
plastic are most household plastics made from? Are they generally recyclable are
recycling centers?
2. Have students use their journals to calculate the number of aluminum cans each
has thrown away. Then have them calculate the equivalent gasoline they would
save (one can = 6 oz) if they recycled all their cans for a month, then a year. How
much gasoline would the entire class save?
3. Have students list the raw materials used to make paper, plastic, metal cans,
aluminum, rubber, etc. Make sure you include oil as the source of energy for
making these products. Provide students with encyclopedias or other reference
books and have them find out where the raw materials are found. The have them
pinpoint the locations on a world map.