🍳 Make your own Solar Cooker

Earlier in the lesson, we had learned about the difference between passive and active solar technologies. Passive solar designs convert sunlight into usable heat and cause air movement to heat and cool living spaces, without relying on mechanical or electrical devices.

Famous examples of passive solar designs include greenhouses, Trombe walls, and of course, solar cookers.

This is a quick tutorial on making your own simple solar oven/cooker to cook a marshmallow and learn about the sun energy’s ability to absorb and retain heat.

Supplies Needed 

• Pringles can or other cylindrical container (regular or half-sized)
• exacto knife
• a small piece of plastic wrap
• skewer
• tape
• marshmallow
• thermometer (optional)

Instructions 

1. Empty the can.
2. Use an exacto knife to cut a rectangle on the side of the can. It may help to draw the rectangle with a sharpie first. Save the leftover piece for later.
3. Using your skewer, cut a hole through the plastic lid to rest inside the can.
4. Take your marshmallow and set it inside the can and through the skewer like a kabob. If you can, you can use the exacto knife to poke the skewer through the aluminum on the other side of the can, so the skewer and marshmallow can rest straight.
5. Cut a rectangular piece of plastic wrap slightly bigger than the hole you cut.
6. Use tape to stick the plastic wrap over the rectangular hole. Make sure it is air tight! This is used to retain heat better.
7. Set your solar oven facing the sun and see how your marshmallow cooks! You can use the leftover piece of aluminum can and bend it to position the can to face the sun better.

You can also try this experiment with a hot dog, but make sure you check the temperature of the hot dog to make sure it is properly cooked! You can even try the same thing with a pizza box and cook all sorts of different things.

Try experimenting with more methods to make your solar oven work even better, like adding tin foil, black paper, or newspaper for insulation.

Once light enters the foil-lined can, the light energy from the sun is converted to heat energy and melts the food. The foil helps reflect light so more light energy is transferred to the marshmallow, while the plastic wrap helps trap the heat inside.

Adding black paper absorbs more of the heat since dark colors absorb light better. Adding newspaper makes sure that the heat stays where it is instead of escaping out the sides of the oven.

Your solar oven can reach about 200° F on a sunny day but will take longer to heat things than a normal oven. It is easy to use and safe to leave alone while the energy from the sun cooks your food!

Want to learn more about how passive solar designs are being used for making sustainable buildings and living spaces? Check out this page on the Williams College website.