Introduction: How to Make a Simple Cardboard Solar Oven

The sun is arguably one of the humanity's most important tool for survival. It gives off practically unlimited amounts of light that is used by plants to generate energy and animals for heat. It can be used to generate electricity with solar panels, hot water with solar hot water heaters, and many other uses. Even though technology can be very useful, for example gas ovens, natural and simple technologies like solar ovens can reduce fossil fuel use or even replace fossil fuels in places that don't have abundant resources, and it's an enjoyable project. The materials used can mostly be found locally from recycled sources which makes it even more sustainable.


Thank you all for your insights on a better, more healthy oven.

First: use black cardboard paper or High Temp Black Grill paint for less chemicals in food

Second: Use Pizza Box for less volume to heat up for Pizza, Eggs, Hardboiled eggs, and put a thermometer in there to test that it is up to sufficient temperatures before eating

Third: For increased efficiency, heating use 4 foot aluminum foil reflector next to your oven facing SOUTH. For slow thermal cooking use a 1 - 1.5 cubic foot box with soda cans filled with water in to preserve THERMAL MASS.

Fourth: The larger alumnum foil will STRONGLY INCREASE HEAT in a fast way, with potential temperatures up to 300 degrees. Results will vary with climate and strength of sun.

Cheers and happy Friday,

Step 1: Finding Tools and Materials

I recommend taking one trip to locate/buy tools and materials for this job. The following materials are necessary:

-2 medium to large cardboard boxes that fit inside each other with 3-4 inches or so of space around the sides of the box. Also you can use a LARGE and Medium pizza box and similarly create insulation and a smaller space to heat up. Also necessary is a large piece of cardboard for the reflector that is as wide as the widest part of the large box and about 2-3 feet long. These can be found at most stores, just ask an employee for boxes they don't need anymore.

-1 roll of aluminum foil (75 feet is enough)
-a piece of glass or plastic fits over top of the larger box. This can be found at window stores; they often have extra glass laying around for free.
-tape measurer
-razor knife
-school glue
-black spray paint or black construction paper
-enough newspaper that will, crumpled, fill a bottom row and the sides in between the two boxes. This can be found at recycling centers.
-duct or foil tape
-two small pieces of wood (optional)

Step 2: Cutting Off Flaps of Smaller Box

Cut off the four flaps of the smaller box so they don't get in the way.

Step 3: Crumpled Paper on the Bottom

Crumple up pieces of newspaper one at a time until the bottom of the large box is lined. This will be an insulation that keeps retains heat in the box.

Step 4: Spraypaint the Small Box Black

Either spraypaint with Char-Broil High Temperature Grill Paint on the inside bottom of the small box black or glue a sheet of black construction paper. fitted to the size of the box, to the inside bottom of the small box. I recommend doing this outside and try to not inhale the fumes.

Step 5: Glue Aluminum Foil on Insides of Small Box

Squeeze a generous amount of glue on one side of the inside of the small box and then cover it with aluminum foil with a little bit extra over the top of the box so it the foil stays in place. Then do the same for the remaining three sides.

Step 6: Insulating the Sides

Crumple up one piece of newspaper at a time and fit it around the sides up to the top.

Step 7: Cut the Flap for the Reflector

Cut a piece of cardboard that is as wide as the widest part of the large box and about 2-3 feet long.

Step 8: Installing the Reflector Flap

Put the cut piece of cardboard a few inches down on one side of the box and then tape it to a flap of the large box. (Optional: you can cut two small holes in the piece of cardboard and flap of large box once they are together and put two small pieces of wood in place two help hold the cardboard pieces together.)

Step 9: Putting Aluminum Foil on Reflector Flap

Apply a generous amount of school glue on one side of the reflector flap and cut aluminum foil to cover the entire side of the flap.

Step 10: Place Glass or Plastic on Top of Large Box

Lastly, place the piece of glass or plastic on top of the large box and tilt the reflector in towards the center of the boxes. To cook something, find out how hot your new solar oven gets by putting solar oven in an open place with as few obstacles around to reduce shadows, and then face the reflector towards the sun. Then, place a thermometer inside and check it occasionally to determine how hot your solar oven gets. Feel free to experiment with different methods of cooking things, or look online for guides on how to cook using your solar oven. Thanks for reducing your fossil fuel use, cooking a more natural way, and I hope you make some scrumptious meals!