Solar Cookie Oven
Scientific principle: Solar energy Time required: 1 hour
Usually, ovens are powered using electricity or gas. This experiment uses the sun’s own natural energy – or solar power – to heat an oven that bakes cookies.
• Pizza box (or cereal box)
• Utility knife
• Aluminium foil
• Plastic wrap
• Sticky tape (or glue)
• Black paper
• Warm, sunny day!
• Cookie dough: 15g (1 Tbsp) butter, 30g (2 Tbsp) sugar, 25g (4 Tbsp) plain flour, 5ml (1 tsp) milk
1. Use a pencil and ruler to mark 2.5cm (1 inch) in from each side on the pizza box lid and draw a square to connect the marks. 2. Cut along the front and side lines of the square with the utility knife. Fold along the back line so it acts as a hinge. 3. Line the inside of the flap and the inside walls of the box with foil, and tape or glue in place. 4. Seal the cut- out window shape by taping a sheet of plastic wrap over the hole. 5. Glue or tape a sheet of black paper to the bottom of the inside of the box. 6. Mix the cookie dough ingredients and roll into small balls. 7. Arrange the balls of dough on a sheet of foil and place on top of the black paper inside the box. 8. Prop the cut- out lid at a 90° angle using a pencil and some tape. Leave outside facing the sun until the cookie balls flatten out (anything from 15 to 60 minutes). 9. Carefully remove cookies from the box and allow to cool – then eat!