Harness the power of the sun for learning and snacking! In this fun STEM activity, you and your child will build a solar oven—a simple device that uses sunlight to heat food. It’s an amazing hands-on way to learn about energy, heat transfer, and the greenhouse effect… with gooey S’mores as a reward!
🔧 What You’ll Need:
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A cardboard box with a lid (at least 3" deep, big enough for a pie tin)
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Aluminum foil
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Clear plastic wrap
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Glue stick
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Tape (any kind)
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A stick to prop the flap open (skewer, ruler, etc.)
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Ruler or straight edge
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Box cutter or X-Acto knife (ADULT SUPERVISION REQUIRED!)
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Aluminum pie pan
🔨 How to Make Your Solar Oven
⚠️ Safety First: Ask an adult to help with cutting.
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Cut the Flap:
Use a ruler and box cutter to cut a three-sided flap on the top of the box lid, leaving a 1-inch border on three sides. Leave one side attached to create a flap that lifts open. -
Add Reflector Foil:
Cover the underside of the flap with aluminum foil. Use the glue stick to attach it smoothly. -
Line the Box:
Line the inside of the box with foil as well, pressing it down flat and gluing in place. -
Create the Window:
Tape two layers of clear plastic wrap over the hole you cut—one on the inside of the lid, one on the outside. This traps heat while letting sunlight in. -
Add a Prop:
Use a stick, ruler, or skewer to hold the flap open at an angle to reflect sunlight into the oven. Tape it in place if needed.
🔥 Time to Bake S'mores!
Wait for a sunny day with temperatures at or above 85°F. Preheat your oven by setting it in full sunlight with the flap propped open for 30 minutes.
To make solar S’mores, you’ll need:
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Graham crackers
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Large marshmallows
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Thin chocolate bars
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Aluminum pie pan
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Napkins (trust us!)
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Break graham crackers into squares and place four in the pie pan.
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Place one marshmallow on each square.
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Top with chocolate pieces after the marshmallows warm up (marshmallows take longer to melt than chocolate).
Place the pie pan in your preheated solar oven, close the lid tightly, and prop up the foil flap to reflect more sunlight into the box. Wait and watch as the marshmallows soften and the chocolate gets melty!
Why It Works:
Your solar oven traps the sun’s energy, creating a mini greenhouse effect. The foil reflects light into the box, and the plastic wrap keeps the warm air inside, heating your snacks slowly but surely.
"Once your solar oven is working, it’s a great way to enjoy a sweet treat while learning about solar energy and how the Sun can power fun activities."
Credit: Nasa: Climate Kids - https://climatekids.nasa.gov/smores/
Looking for more fun hands-on projects that mix science and fun? Stay tuned to our blog for more awesome activities the whole family can enjoy!