Back to Project Listings

Make A Pizza Box Solar Oven

The pizza box solar oven is a great project for kids because it demonstrates two of the three basic principles of passive solar design working in concert with each other to accomplish a goal the kids can really relate to: making something yummy!

Solar-cooked hot dogs

The principles demonstrated are:

The third principle of passive solar design - thermal mass, can also be experimented with the solar oven. If you are interested in this option, see the project "Build a Passive Solar Design Laboratory" for ideas. Large amounts of food will provide some thermal mass, causing the oven to heat up more slowly.

Besides explaining these principles in the process of building and using the ovens, here are several other points you might want to make:

The simplest pizza box solar oven design, as given below, can get up to two hundred degrees fahrenheit on a warm sunny day, enough, for example, to make "s'mores" (graham cracker sandwiches of chocolate chips and marshmellows). Several optional features will enable the oven to get even hotter, which may be desirable in cooler weather, or for more serious cooking. One should allow ample time for cooking - roughly twice as long as would take in a conventional oven, and for smore's, it works best to leave the sandwiches open while cooking so that direct sunlight falls on the marshmellows and chocolate chips). We do not recommend trying to use the oven outside in temperatures below about 60 degrees Fahrenheit. If its cool outside, try a sunny window sill.

Note: Many pizza shop owners will be more than willing to donate boxes. In return, you may want to ask a local reporter to cover the event, and ask the reporter to specifically mention the pizza shop's donation in any news article that appears.

Materials needed for a single oven (simplest design)

Note: Avoid materials that you think might become toxic when heated

Tools needed

Instructions

  1. Assemble the pizza box, and open it up. 
  2. Glue aluminum foil to all inside surfaces of the sides except the top of the box, with the shiny surface facing in. This will create a "radiation trap" that will trap, by reflection, invisible (low-frequency) radiation that is radiated by the food and air inside the box.
  3. On the top flap of the pizza box draw a square with a marker with edges spaced 1" from the four sides of the box.
  4. Cut along three of the lines, on the sides and on the front edge of the box, leaving the fourth line along the box's hinge uncut. Then fold open the flap, making a crease on the fourth line (see the figure above).  Note: Extra supervision make be needed during this step, because students often cut along the fourth line as well by mistake.
  5. Glue aluminum foil to the inside surface of the top flap, with shiny side visible! This will form reflector, to reflect sunlight into the oven. Be careful to make as few wrinkles as possible, and smooth out whatever wrinkles occur.
  6. Tape the black construction paper to the bottom of the box. This will help to absorb the incoming sunlight.
  7. Carefully stretch the plastic wrap over the opening of the box, sealing the edges with tape to seal the air in. 
  8. Cover any air leaks around the box edges with tape, except while making sure that the box can still be opened, so you can place food inside the box and remove it later.
  9. Go outside in the sunlight and place oven on a flat, level surface.
  10. Place food on some foil (or a paper plate) and place inside the oven. 
  11. Use string and masking tape to tie back and adjust the reflector, so that sunlight is reflected into the oven, and especially onto the pie tin.
  12. Let food cook, and check reflector angle now and then to make sure sunlight is getting inside the oven.
  13. Enjoy your solar treat! 

Optional Features

The earliest pizza box solar oven design we are aware of was created in 1976 by Barbara Kerr.

return to project listing