Build a solar oven

Build a solar oven

Cook a tasty treat using sunlight!

So far the summer has been pretty warm, so let's find out how you can use the sun to cook some delicious food!

What you need:

  • Cardboard pizza box
  • Scissors
  • Tin foil
  • Sellotape
  • Clingfilm or zip-lock bag
  • Black paper or paint
  • Newspapers or shredded paper
  • Ruler
  • Glass dish or plate
  • Tasty food to cook. Try marshmallows, toast or cheesy nachos.
  • Oven gloves

How to:

Ask an adult for help using scissors and handling hot food.

Use the scissors to cut a flap in the lid of the pizza box. Cut along three sides, leaving around two centimetres between the sides of the flap and the edges of the lid. Fold the flap back so it stands up when the box lid is closed.

Cover the inner side of the flap with tin foil.

Sellotape cling film or a zip-lock bag over the hole in the lid of the pizza box. This will create a clear, airtight seal.

Paint the bottom of the box black, or line it with black paper.

To insulate your oven so it keeps in heat, put shredded paper or rolled up sheets of newspaper around the sides of the pizza box. Make sure you leave enough space for your food! You should still be able to close the box lid.

Build a solar oven

Set up your solar oven outside on a sunny day, between 11am-3pm. Make sure you choose a sunny spot. Adjust the flap so that it reflects the most sunlight possible onto the cling film covered hole in the box lid. Use a ruler to prop open the flap at the right angle. This will pre-heat the solar oven and make sure the inside is hot when you put your food in.

After you have pre-heated the oven, put the food you want to cook on a clear glass dish or plate and put it inside your solar oven. Remember to make sure as much sunlight as possible is reflected onto the cling film covered hole in the box. You can grill cheesy nachos, make hot, buttered toast or melt marshmallows. It will take longer to cook food than in a normal oven, but it will be tasty!

When the food is done, open the lid of your solar oven and use oven gloves to lift the glass plate out of the oven.

Have a look at this picture of a solar oven. Instead of black paper, the inside is covered in tin foil. You could experiment and see which one works best!

Solar oven (c) Abri_Beluga

Bread cooking in a solar oven (c) Abri_Beluga

If it doesn't work, perhaps you need to try again on a sunnier day, or move the solar oven to a sunnier spot. Throughout the cooking you can move the solar oven or readjust the flap to make sure as much sunlight as possible is getting inside the box. Remember that it will take longer to cook food in a solar oven, so be patient!

What's happening?

The tin foil on your solar oven reflects sunlight and the sun's heat into the box. The cling film seal creates a seal so that air can't escape. The sun's energy heats up the air inside the box and cooks the food. The black paper absorbs heat to make sure that as little as possible escapes. Newspaper insulates the box, preventing heat escaping.