Anacortes Early Learning Partners Blog

Materials
Large pizza box
Pencil and ruler
Craft knife/scissors
Aluminum foil
Scissors
Glue stick
Black construction paper
Clear packing tape
Clear plastic wrap
Stick or dowel
Snack of choice (example: s’mores)

Teach your children the importance of the three R’s: recycle, reduce and reuse with this fun project that turns last night’s pizza box into a super cool solar oven!

Instructions

1. On the top of the pizza box, draw a square that is an inch smaller than the lid all the way around. Use the craft knife (adults only) to cut through the cardboard along three sides and then fold the cardboard up along the uncut line to form a flap.

2. Glue aluminum foil, shiny side out, to the bottom of the flap, keeping it as wrinkle-free as you can.

3. Glue another piece of foil to the inside bottom of the box, then tape black construction paper on top of the foil.

4. Tape clear plastic wrap to the underside of the lid to seal the opening created by the flap. For the best results, the seal should be as airtight as possible.

5. Place your oven outdoors in direct sunlight with the flap opened toward the sun. For each s’more, center two graham crackers on the construction paper. Top one with     chocolate and the other with a marshmallow. Close the box and then use a stick or dowel to prop the flap open at the angle that reflects the most sunlight into the box . Check it   periodically to adjust the angle.

6. Within an hour the chocolate squares and marshmallows should melt enough to      assemble into s’mores. Cooking in a solar oven takes about twice as long as conventional oven cooking times.

Teach What’s Happening:

In the greenhouse effect, atmospheric gases allow sunlight to pass through to the earth’s surface but keep the heat it generates from escaping back into space. The solar oven works on the same principle. The foil flap gathers sunlight and reflects it through the plastic and into the oven, doubling the amount of incoming light. The black paper absorbs the light and converts it to heat, and the clear  plastic allows the sun to shine in while keeping all that heat from escaping. As more light hits the black paper, more heat is created and trapped. After an hour or so on a sunny day, the oven can be as hot as 275 degrees — hot enough to melt chocolate and marshmallows!