This demonstration helps to explain the difference between the use of fossil fuels compared to renewable energy sources. It also includes a demonstration of solar absorption and reflection. The demonstration includes the direct use of solar energy which of course requires a sunny day.

Age Group: All ages although the questions you ask them will vary depending on average age.

Materials required

Background

Electricity
You should first learn from what sources your electricity is supplied. Your utility company refers to this as their fuel mix because few electric utilities produce their power from a single energy source. The fossil fuels most commonly used are coal and natural gas although some may include oil.

For most utilities, solar energy is not included in their fuel mix.

The most common renewable fuel source used is hydro-power.

Heating
The most common heating systems are fueled by natural gas, oil and electricity.

Transportation
Petroleum (oil, gasoline) is the fossil fuel that we use the most in the United States and its primary use is gasoline for our cars.

Set Up
As you ask your audience the following questions, the level of their knowledge about energy will soon become apparent. Help them find the answers and fill in when needed.

Where does the electricity in your school come from?

How is it made?

What are fossil fuels?
If no response, ask "what are fossils?"
(even the youngest of audiences will usually refer to dinosaurs which you can relate directly to fossil fuels)

When coal, oil or natural gas is burned what else do we get besides heat? (discuss pollution and its effect on air, land and water)

What is a renewable energy?
(younger audiences will often refer to recycling)
(renewable energy sources can be used again and again)

Can anyone name a renewable energy?
(solar - includes wind, hydro-power, and trees/biomass)

The Demonstration
Ask for two volunteers but pick a boy and a girl. Give the girl the magnifying glass and give the black paper to the boy. (boys tend to try to burn everything in sight - including the demonstrator) Ask for another volunteer and give him/her the match and striker.

Tell the audience that the match represents fossil fuels; gas, coal, or oil.
Tell the volunteer to light the match.
(be sure he/she is holding the bottom of the match and any wind will blow the flame away from fingers.)(As the match burns) Just like fossil fuels we get heat (the match goes out and smokes) and some pollution.

Ask him/her to light the match again.
(they will probably hesitate but ask them to try anyway - often they will quickly state that it can't light again)

Why not?
(the usual response is "because it's gone" or something to that effect)

That's right, you can use fossil fuels once and they're gone forever.

Now let's look at renewable energy
(the magnifying glass should be held perpendicular to the sun - your volunteer may need your help. The black paper is moved slowly toward the magnifying glass until the magnified sunlight is a small dot. The black paper will begin to smoke almost immediately - CAUTION - help move the paper away quickly before it begins to burn.Will it do it again? (repeat the above - and allow paper to smoke)

Can we do it again? Can we do it tomorrow? Next week? Next month? (the response will be yes to each of these questions so ask the next question quickly after their response and then ask:

Can we do it tomorrow night? (no)

(the lesson of course is that renewable energy can be used over and over again and the sun is expected to last at least 5 billion more years.)

(you may allow the volunteer who burnt the match to participate now with the renewable experiment to demonstrate that anyone can use renewable energy)

(Next, let them try again using the white piece of paper. The paper will eventually burn but it takes much more time because the white paper reflects the energy away. Allow them a short time to burn the white paper and then have them try the black paper again which smokes almost immediately.)

Why does the black paper burn so easily compared to the white paper?
(reflection vs. absorption - you might question the audience about clothing colors for different seasons or even the color choice for a roof)