How to Make a Pizza Box Solar Oven

Need a sunny-day science experiment? Making a solar oven from a delivery pizza box is a fun way to spend an afternoon. This solar oven can reach temperatures of about 250 degrees Fahrenheit and can be used for a variety of food-related projects. Cooking items in this oven will probably take at least twice as long as cooking items in a conventional oven, but this solar oven gives children the opportunity to learn firsthand about harnessing the sun's energy.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Pizza box
• Tape measure
• Pencil
• X-acto knife
• Foil
• Packing tape
• Black paper
• Scissors
• Clear plastic sheeting
• Wooden dowel
• Aluminum pan

1. Open up a cardboard delivery pizza box. Brush out all crumbs and make sure the box is free of cheese and grease. Remove the square cardboard liner from the bottom of the box, if it's still in place.

2. Close the pizza box. Measure and mark a 1-inch border around the top of the box, creating an inset square. Cut out three sides of the square with an X-acto knife, leaving the side parallel to the hinge attached to the box. Fold up the flap and line the bottom of it with a square of aluminum foil. When taping the foil in place, be sure it's smooth.

3. Open up the pizza box and line the bottom with foil. Tape black paper over the foil. The foil keeps the box warm, but the black paper absorbs the heat to create a cooking surface.

4. Close the pizza box and the flap on top. Roll out the clear plastic sheeting and cut out a plastic square that is the same size as the pizza box. Open up the box and tape the plastic square to the underside of the lid, pulling it as tight as possible. The tight plastic will create a window that is revealed when the inset, foil-lined flap is folded up. Make sure that the edges of the plastic are tightly sealed by the tape all the way around so that no air can get into the box.

5. Close the box and pull up the foil-lined flap. Use a wooden dowel to prop open the flap; a dowel is required because it is stiff enough to support the flap for long periods of time, but lightweight enough not to damage the cardboard. When the foil-lined flap is propped open with the dowel, it will direct the sunlight through the window and into the oven. To use, allow the oven to preheat outside for about 45 minutes. Put food in an aluminum pan, then open the box and situate the pan underneath the window. Allow food to cook for about twice the recommended time. (For diagrams of the entire process, see Resources below.)

Tips & Warnings

• Non-raw foods that visibly show when they are ready are best for this project. Examples include marshmallows, bread topped with processed cheese or hot dogs. Ask local pizza delivery restaurants if they will donate or sell unused boxes for this project. Used boxes are fine, but clean ones won't give food a greasy flavor.
• Always check the internal temperature of perishable foods before consuming them if they're cooked in this oven. The temperature that the food needs to reach to safely eat depends on the ingredients; check the packaging. If the food fails to reach a safe temperature, pop it in the microwave for 10 to 30 seconds, or until it's heated through.

Resources

• Diagrams of making a pizza box solar oven