(Review fossil fuels. Have bulletin board with alternative energy sources displayed.) Our demand for energy increases every year. We use oil and gas to run our homes, schools, factories and cars. But as we use these fossil fuels, they will eventually decrease. Conserving energy will make our supply of fossil fuels last longer. Conservation will not make our supplies last forever, for they are nonrenewable. When they are used up, they cannot be replaced. (Discuss non-renewable.)
We can increase our supply of energy resources to meet our increasing demand for energy by using ENERGY ALTERNATIVES. An energy alternative is an energy resource that is not a fossil fuel. Some alternative energy sources are new ideas. Others have been used in the past. Each one has advantages and disadvantages. Through the years studies have proven that some of these alternatives may cause a greater threat to us by using them than by not using them. On the bulletin board you see pictures of these alternative energy sources. WIND energy has been used to pump water from wells. Windmills can supply electricity for our homes.
WATER energy can be used to produce electricity. Hydroelectric power is electricity produced from water turning turbines.
TIDAL energy is present in the regular rise and fall of ocean water along a coast. There are only about 25 good locations for tidal power plants in the world.
GEOTHERMAL energy is from the heat of rocks and water in the earth. Old Faithful Geyser is a perfect example of this. Water and steam sprays from a hole in the ground where water is heated to such a point that it boils and turns to steam. Holes can be drilled in rocks to release this energy.
NUCLEAR energy is the energy stored in the nucleus of every atom. This is released by splitting atoms by a process called fission which produces heat energy and electricity. Nuclear energy has a very high cost and can be very economical to look for other alternatives.
SOLAR energy is energy from the sun produced by nuclear fusion in the sun.
This week we will be working in groups to research these different kinds of alternative energy sources. You will be responsible for making a poster to explain a particular alternative and write a report to give information on that source. Each group will also demonstrate that source with a model and/or experiment to show how it works. Library books, pictures, diagrams, encyclopedias are available for you to use. We will report back as a group in three days to share with the others. I will help you with your reports and experiments.
You may work in groups and select one of the following activities to do and report on to the class.
1. Waterwheel
Materials: Compass, cm ruler, cardboard, scissors, 15 cm long wire, tape, string, water, small paper box or lightweight container, two paper cups, two small heavy objects that will fit into cups, large pan, container with spout
a. Use compass - draw 4 cm radius on stiff cardboard. Cut out circle.
b. Draw five lines, 3 cm long, from edge to center of circle. Cut lines to for five blades.
c. Bend inward one side of each blade to make a wheel.
d. Insert wire into center of wheel. Tape both sides of wheel to wire that will form the shaft of wheel (where it is folded down.)
e. Tie one end of 15 cm long string to shaft. Tie other end to box or container.
f. Cut small rectangle from tops of two cups.
g. Place both cups in pan - one at each end. Place heavy object in each cup to hold it down. Rest shaft of wheel across both cups.
h. Use container with spout to slowly pour water over wheel from a height of about 10 cm. Does it move?
i. Hold wheel so part of it is under water. Does it turn?
j. Hold wheel over empty jar. Pour water on one edge. Does water turn the wheel?
2. Windmill
Materials: Cardboard wheel cut from milk carton, knitting needle or long nail, empty jar, pitcher of water
a. Cut round piece of cardboard from milk carton; make cuts to divide circle into fourths up to center point.
b. Fold edges up and down so that each section has part folded up and part folded down.
c. Push needle or nail through the middle. You now have a wheel that can turn. Push it with finger or blow on it. Does it turn?
3. Chain Reaction
Materials: One box dominoes
a. Set up box of dominoes so that each domino is on end facing next domino. They should be about 3 or 4 cm apart.
b. Push first domino toward others to demonstrate chain reaction.
4. Fission
Materials: Plastic balls, balloon, pin
a. Place balls inside balloon.
b. Blow up balloon. This represents an atom that will undergo fission.
c. Pop balloon. The pop is like energy released. The balls are the neutrons that are released.
5. Solar Cooker
Materials: cardboard box, aluminum foil, coat hanger, poster board, two nuts/bolts, hot dog
a. Cut out one whole side of box and cut adjoining side so the sides are slanted at about a 30 or 40 degree angle. Punch a hole on each side of box to put hanger through.
b. Bend hanger to look like crank.
c. Line inside of box with aluminum foil.
d. Slide hot dog onto hanger.
e. Put hanger into holes in box.
f. Put in front of window.
g. Record how long it takes to heat.
6. Solar Energy
Materials: Large spoon, salt, water, two cups, large bowl (deeper than cups), clear plastic food wrap, tape or large rubber bands, marble
a. Add one spoonful of salt to cup of water. Mix well.
b. Pour into bowl.
c. Place clean cup right side up in middle of bowl.
d. Cover bowl with clear plastic wrap and tape to the sides (or use rubber bands).
e. Place marble in center (above cup). Do not let plastic touch cup.
f. Leave bowl in sunlight until water collects in cup. Lightly tap marble (on the wrap) to collect more water.
g. Remove wrap and let water in cup evaporate completely.
h. Rub bottom of bowl and cup with finger what did you feel?
How did solar energy help make fresh water?
