"It's so hot out, you can fry an egg on the sidewalk!" - says everyone in the summer. That's not entirely false. You may (or may not, I haven't tried) to fry an egg on the sidewalk, but you can definitely harness the powerful energy of the Sun to cook food.
The average intensity of solar energy reaching the top of Earth’s atmosphere directly facing the Sun is about 1,360 watts per square meter—about as wide as your out-stretched arms. As a comparison, most microwaves use about 1,000 watts. That means that if you could capture and reuse all the solar energy arriving in a single square meter at the top of the atmosphere, you’d have enough power to run a refrigerator all day. Talk about solar power.
The Sun is the source of all light and most heat energy in our Solar System. In a sense, it is the Solar System since it comprises 99.8% of the Solar System’s mass. This roiling nuclear furnace, held together by gravity and intense magnetic fields, makes life on Earth possible and its potential to provide a renewable source of energy is limitless. So it shouldn’t come as surprise that sunlight can also be used to cook your food!
For those chefs out there, nothing beats good old-fashioned convection oven for roasting a turkey or baking a cake. But you’re still using energy to run that oven. Solar ovens are a cheaper alternative for cooking food, and can be constructed using some basic household materials like a pizza box, construction paper, aluminum foil, and plastic. From my own experience, they are pretty good at cooking a pizza or making s’mores when placed in direct sunlight! Learn how to make your own here.
More sophisticated kits are available online if you want to scale up your operation, and range in price from $50 to over $2,000. Check out a mid-range model at www.solarhome.org. Solar ovens are also helping people in developing countries in places like Africa where families are using the Sun’s energy to pasteurize water and cook food, providing economic benefits and helping the environment.
This is a great project for kids, as well! As the weather warms up and the days become longer, try making your own solar oven and share your results with us. What sort of food did you cook? Did you alter or change your design so that your oven cooked your food more efficiently?
The Adler is celebrating the return of warmer weather with special Sun-themed programming for Spring Break: Here Comes the Sun! So come down and build your own solar oven at our “Homegrown Solar Science” workshops on Fridays from March 22 – April 27.
Written by Kyle Sater, senior educator for public programs at the Adler Planetarium.