Activity Overview: There are many different types of energy, including light energy and heat energy. Solar energy, meaning from the sun, creates both heat energy and light energy. To demonstrate the types of energy that the sun creates, we are going to make a solar oven.

Time: 20-25 minutes for the solar oven build. 5-10 minutes for ingredients preparation and cooking.

Materials: Marshmallows, Graham Crackers, Chocolate Pieces, Aluminum Foil, Cardboard Box, Piece of Cardboard Larger Than the Box

Preparation: Make sure your cardboard piece can be leaned against the box where a large portion of the top covers the top of the box. Alternatively, you can use a pizza box and cut out a small part of the top of the box to lean open in place of the cardboard piece.

CAUTION: S’mores and ingredients may be hot. Be careful when touching and eating the cooked s’mores.

Directions:

1. Make a Solar Oven:
   1. Wrap the inside of the box, including the sides, in aluminum foil.
   2. Wrap the larger cardboard piece in aluminum foil.
2. Place the ingredients for the s’mores in the box:
   1. Break a graham cracker in half, placing one half of the cracker on the bottom of the box.
   2. Place a marshmallow on top of the graham cracker, placing a square of chocolate on top of the marshmallow.
   3. Repeat until you have made as many smores as will fit on the surface of the box.
3. Place the box of s’mores outside in the sun. Prop the larger cardboard piece against the box, where the top of it leans out over the top of the box, so the sun will reflect into the box.
4. Once the s’mores have melted, place the second half of the graham cracker on top of the marshmallow and enjoy!

Discussion:

1. What is happening when you place the uncooked smores in the solar oven?
2. What kind of energy is being used?
3. Why place the chocolate on top of the marshmallow?
4. How does the aluminum foil help?

Discussion Answers:

1. They are being cooked by the sun.
2. Solar energy is a type of heat energy, created by the sun.
3. When the chocolate melts from the light of and heat of the sun, it heats the marshmallow causing it to cook.
4. Aluminum foil reflects the sunlight, helping the oven to heat quicker. It amplifies the sun’s heat and concentrates it into the oven.

Extension: Compare and Contrast

After you have filled and set the solar oven, place another set of ingredients outside the box. Ask students to monitor the "cooking" of the s'mores inside and outside the solar oven. What do they observe? Those inside the oven will melt faster than those outside due to the reflection and intensification of the sun's heat.

If you have access to an oven thermometer or a wired thermometer probe, such as the ones used with grilling or barbecuing meat, take a measurement of the temperature inside the box. Compare this with the temperature reading outside the box. Show students how the reflection of the sun's rays has increased the temperature. Exercise caution around all heat sources, even those powered by the sun.

Resources:

WPSU Penn State PBS has produced a robust set of instructions to create your solar oven using a pizza box, aluminum foil, and black construction paper. You can find their instructions and video on PBS LearningMedia.

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