Bright sunlight and broiling temperatures may make it hard to save money on electric bills, but they also happen to be ideal conditions for conducting a fun, affordable and tasty summertime science experiment with your kids.
With a little work, you and your little ones can make a solar oven out of a simple pizza box that will get hot enough to warm up family-favorite treats like cookies and s’mores while teaching your children about solar power. The solar oven won’t get hot enough to cook raw ingredients or bake treats from scratch, so make sure those cookies are already baked before you warm them up.
Before You Start Building: Things You’ll Need
Before you get started, you’ll need to collect a few things to build and use your pizza box solar oven:
- 1 pizza box — use one that’s in pretty good shape or stop by your local pizza place and ask for a box
- 1 pencil or pen
- 1 sheet of notebook paper
- 1 ruler, wooden dowel or stick
- Aluminum foil
- Black construction paper
- Clear plastic wrap
Building Your Pizza Box Solar Oven
You and your kids can build a pizza box solar oven in eight easy steps:
- Start by making sure that the pizza box is folded neatly into its normal, sturdy box shape and that the lid is closed.
- Place the sheet of notebook paper on top of the pizza box lid. Place it in the center and use the pencil or pen to trace its outline onto the pizza box lid.
- Use the scissors to carefully cut a flap into the pizza box lid. Follow the outline of the notebook paper as a guide and cut along the two long edges and one of the short edges. Be careful not to cut the bottom of the box.
- To complete the flap, gently fold it back along the uncut edge until it forms a crease.
- With the flap folded back, wrap the underside (inside) face of the flap with aluminum foil. To secure the foil, tape it firmly on the other (outside) side of the flap. Since the foil will be used to reflect the sun’s light to warm your treats, make sure the tape doesn’t wrap around to the foil-covered part of the flap where it can block the sunlight reflecting off the foil.
- Open the pizza box and place the sheet of black construction paper on the bottom of the box. If necessary, use the scissors to cut the sheet to fit. The construction paper will help to absorb the sun’s heat.
- Close the pizza box and open the flap. Roll up some sheets of newspaper about 1 to 1 1/2 inches thick and feed them through the open flap and around the inside edges of the box. The rolled up newspapers will provide insulation that helps contain the sun’s heat. Use tape on the bottom of the rolls of newspapers to hold them in place.
- Finally, create a “window” over the flap opening on the pizza box lid with plastic wrap. To do this, cut two pieces of plastic wrap that are each 1 inch larger than the flap opening. First, open the pizza box lid and tightly cover the inside opening with one piece of plastic wrap. Tape it down firmly to secure it, but keep the tape from covering any part of the window. Then, close the pizza box lid and do the same on the outside of the flap. The result is like a double-paned window that creates a layer of insulated hot air inside the box.
Using Your Pizza Box Solar Oven
Using your pizza box solar oven is as simple as 1–2–3:
- Place your solar oven outside on a sunny day, warm or cold. The solar oven will still work on cold days, just place a towel underneath it for insulation.
- Open the box, put your treat inside and close the box.
- Open the flap and turn the box so the foil faces the sun and the back of the flap casts a shadow straight back from the flap. Move the flap up and down until you see sunlight reflected on your treat and the secure the flap open the ruler, dowel or stick.
That’s it. Just wait about 30 minutes for the box to heat up and then enjoy your warmed treat!
U.S. Department of Energy: Roofus’ Solar & Efficient Home website, “Build a Pizza Box Solar Oven.”