How To: Build a Solar Oven

In this activity, students will use various materials to focus the sun's rays and make solar s'mores, while learning about the effect of sunlight through a glass (also known as the greenhouse effect).

Where does solar energy come from?

The sun is a powerful source of energy. In fact, the sunlight that shines on the Earth in one hour could meet the world's energy demands for an entire year! We can use this solar power in two different ways: as a heat source, and as an energy source. People have been using the sun as a heat source for thousands of years, but only recently have we become effective at using it as an energy source.

The sun has produced energy for billions of years. Solar energy is the solar radiation that reaches the earth. Solar energy can be converted directly or indirectly into other forms of energy, such as heat and electricity. Solar energy is used for heating water, space heating of buildings, agriculture, and generating electrical energy. The major drawbacks of solar energy are the intermittent and variable manner in which it arrives at the earths surface, and the large area required to collect it at a useful rate.

Building the Solar Oven


  • Cardboard Box
  • Aluminum foil
  • Plastic wrap
  • Mirrors
  • Tape
  • Scissors
  • A stick or straw
  • Chocolate, marshmallows, and graham crackers
  • Small plates

What To Do:

  1. Cut the top off a cardboard box
  2. Line the inside of the box with aluminum foil
  3. Prepare s'mores - marshmallows and chocolate sandwiched between graham crackers. Put a s'more on a plate inside the box.
  4. Place mirrors in various places around the inside of the box to direct and reflect the sun's rays to the s'more (use the stick or straw to prop it up).
  5. Cover the top of the box in four layers of plastic wrap (to let the light rays in and to keep the heat from escaping).


  • Put a thermometer inside the solar oven and measure the temperature.
  • Discuss how the sunlight going through the plastic is affecting the s'more vs how the greenhouse effect impacts the planet.

Check out this handy video to get a step by step tutorial on how to turn a box into a solar oven.


Once you've build your solar oven, share your project with BC Green Games and receive a free field trip to Science World!