Pizza box (The larger the box, the better the oven should work.)
Pencil or pen
Ruler
Utility knife
Aluminum foil
White school glue
Plastic wrap
Shipping tape or black electrical tape
A sheet of black paper
A wooden skewer or pencil
Instructions
If needed, clean out the pizza box so it is ready to become a solar oven. Remove any liners that the box came with.
On the top of the pizza box's lid, draw a square that is about one inch inward from each edge.
Carefully cut along each side of the square you just drew except for the side that runs along the hinge of the box. Cut all the way through the cardboard on those three sides of the square. Then fold the flap back slightly along the attached side.
Line the inside of the cardboard flap with aluminum foil. Fold the edges of the foil over the flap to help hold the foil in place and glue the foil onto the flap. Keep the foil as smooth as possible.
Cover the opening made by the flap (in the lid) with a layer of plastic wrap. Attach the plastic wrap to the opening's edges using shipping tape or black electrical tape. Make sure there are no holes in the plastic wrap and that all of its edges are completely attached to the lid.
Line the inside of the box with aluminum foil so that when you shut the box the entire interior is coated with foil. It is easiest to do this by covering the bottom of the box with foil and then covering the inside part of the lid (going around the plastic-covered opening) with foil, too. Glue the foil in place.
Glue or tape a sheet of black paper to the bottom of the box, centered there. This will act as your solar oven's heat sink.
Lastly, use a wooden skewer or pencil (and some tape) to prop the solar oven's lid up, at about a 90-degree angle from the rest of the box.
Leave the solar oven outside on a hot day (non-windy days of at least 85 degrees Fahrenheit work best).
Science Behind It
The light is drawn to the black sheet of paper. The tin foil reflects light into the pizza box. The plastic wrap keeps more heat in the box than what it releases, causing the inside of the box to become warmer than the outside to cook the food inside the box. The cardboard acts as insulation to retain the heat in the box for a while.
Tips
It is suggested that you do this project in a cooking project and do it on a sunny warm day so your food can cook. Also be prepared with another project as this will take a while to have cooked food even if it is hot outside. The oven can get between 160 and 200 degrees Fahrenheit. Ideas for things to cook: