Summary
Active Time
20-30 minutes
Total Project Time
45 minutes to 1 hour
Key Concepts
energy, solar power, sun, heat, cooking, recycling
Credits
Teisha Rowland, PhD, Science Buddies
Introduction
Have you ever cooked something outside, like for a BBQ or while camping? It can be a lot of fun to be outdoors and enjoy eating the fruits — or burgers — of your cooking labors. Did you know that you can directly use solar power to cook food? This can be done using a solar oven, which is a low-cost, ecologically-friendly technology that seems to have everything going for it. In this science activity, you will build your very own simple solar oven out of a pizza box to gather the sun's rays and cook a tasty treat for you!
This activity is not recommended for use as a science fair project. Good science fair projects have a stronger focus on controlling variables, taking accurate measurements, and analyzing data. To find a science fair project that is just right for you, browse our library of over 1,200 Science Fair Project Ideas or use the Topic Selection Wizard to get a personalized project recommendation.
Materials
- Pizza box. The larger the box, the better the oven should work.
- Pencil or pen
- Ruler
- White school glue
- A sheet of black paper
- Utility knife
- Aluminum foil
- Plastic wrap
- Shipping tape or black electrical tape
- A wooden skewer or pencil
- To do some cooking with your solar oven, you will need sunlight and fairly warm outside temperatures (above 75 degrees Fahrenheit is recommended, and the hotter it is the better). It should also not be windy.
- If you want to cook some s'mores in your solar oven, you will also need graham crackers, marshmallows, and a chocolate bar. You can use an aluminum pie pan or a small piece of aluminum foil as a tray.
Prep Work
- If needed, clean out the pizza box so it is ready to become a solar oven. Remove any cardboard liner that the box came with.
- Adult assistance is recommended for using the utility knife. Use caution when cooking with the solar oven as it can get quite hot!
Instructions
- On the top of the pizza box's lid, draw a square that is about one inch inward from each edge.
- Use a utility knife (and the ruler as a straightedge) to carefully cut along each side of the square you just drew except for the side that runs along the hinge of the box. Cut all the way through the cardboard on those three sides of the square. Then fold the flap back slightly along the attached side.
- Line the inside of the cardboard flap with aluminum foil. Fold the edges of the foil over the flap to help hold the foil in place and glue the foil onto the flap. Keep the foil as smooth as possible.
What do you think the purpose of this foil is?
- Cover the opening made by the flap (in the lid) with a layer of plastic wrap. Attach the plastic wrap to the opening's edges using shipping tape or black electrical tape. Make sure there are no holes in the plastic wrap, and that all of its edges are completely closed onto the lid. Why do you think it is important to make sure the plastic wrap completely seals the lid's opening?
- Line the inside of the box with aluminum foil so that when you shut the box, the entire interior is coated with foil. It is easiest to do this by covering the bottom of the box with foil, and then the covering the inside part of the lid (going around the plastic-covered opening) with foil too. Glue the foil in place. Why do you think you should coat the inside of the box with foil like this?
- Glue or tape a sheet of black paper to the bottom of the box, centered there. This will act as your solar oven's heat sink.
How do you think it will help cook your food?
- Lastly, use a wooden skewer or pencil (and some tape) to prop the solar oven's lid up, at about a 90 degree angle from the rest of the box. Your solar oven is ready to do some cooking!
- If you want to cook a s'more, break a graham cracker in half and place a marshmallow and small piece of chocolate between the cracker halves. Place the prepared s'more on a small square of aluminum foil (slightly larger than the s'more — this will serve as a tray) and put it in your solar oven, on top of the black sheet of paper. Put the solar oven outside where it will get full, direct sunlight for at least 30 minutes, and keep the oven turned so that the flap faces the sun. When the marshmallow is soft, your s'more should be ready to eat and enjoy!
How long does it take to cook the s'more in your solar oven? Does the oven get very warm?
What Happened?
In this activity, you built a simple box-type solar oven that should have been able to cook a s'more in sunny, warm conditions. In some trials using this type of solar oven, at about 85 to 90 degrees Fahrenheit on a sunny afternoon it took about 30 to 35 minutes for the marshmallow to get warm enough to become soft and melt some of the chocolate, and make a tasty, solar-powered treat! In ideal conditions, this solar oven can easily heat up to about 160 to 200 degrees Fahrenheit. Using full, direct sunlight is important for heating this solar oven.Digging Deeper
Solar ovens use solar energy — light and heat emitted from the sun — to cook food, pasteurize water, or even sterilize instruments. How does a solar oven work? The simple answer is that it is designed to absorb more heat than it releases.
The solar oven you build in this activity is a relatively simple one made out of a pizza box, aluminum foil, plastic wrap, and a sheet of black paper. You cut a flap out of the pizza box's lid and line this flap with aluminum foil so that sunlight can be reflected off of the foil and into the box. You also seal the opening with plastic wrap to create a plastic "window" that works like a greenhouse roof, allowing (direct and reflected) sunlight to pass into the box, while also retaining heat. At the bottom of the box, you placed black paper to create a "heat sink." This heat sink works by absorbing direct and reflected sunlight to become warm so that it can then heat up food placed on top of it.
Ask an Expert
Curious about the science? Post your question for our scientists.
For Further Exploration
- There are a lot of variables that you can try to tweak in your solar oven design to make it even better. Can you make your solar oven be more efficient by changing the angle of the reflector flap, using different materials to insulate the oven, or changing the shape or size of your oven?
- One way to quantify how efficient your solar oven is is to use a thermometer to measure the temperature inside of your solar oven over time. How hot can your solar oven get? How does this compare to a real oven?
- The weather outside can significantly affect how well a solar oven performs. How well does your solar oven cook on a warm day versus a very hot day? What about a sunny day versus an overcast day?
- In this activity you made a very simple box-type solar oven, but you could build another solar oven using a more efficient design to make your solar oven get even hotter! Do some research online to find other solar oven designs. How efficient can you make a solar oven be?
Related Resources
Project Ideas
Here is a project that uses direct solar power, gathering the sun's rays for heating/sterilizing water or cooking. It is a low-cost technology that seems to have everything going for it. Does it work? Can you find ways to improve it? Find out with this project.
Read more
Links
- Blog Post: Campground Science
Careers
Career Profile
Does the idea of harvesting the enormous power of the sun interest you? If you find this exciting, then you should think about installing solar photovoltaic panels on your house to collect free electricity from the sun. But how energy efficient is your home already? Can it get better? How many panels would your house need? What would the system look like? You can get the answers to these questions and more from your local solar energy systems engineer. These engineers help their residential and…
Read more
Career Profile
Environmental engineers plan projects around their city or state—like municipal water systems, landfills, recycling centers, or sanitation facilities—that are essential to the health of the people who live there. Environmental engineers also work to minimize the impact of human developments, like new roads or dams, on environments and habitats, and they strive to improve the quality of our air, land, and water.
Read more
Career Profile
Smog, car emissions, industry waste—unfortunately, pollution is a reality that humans have to deal with. However, we can all breathe a little easier with environmental engineering technicians on the job. These people test our water, air, and soil to help us find ways to lessen the impact of pollution.
Read more
Career Profile
Would you like knowing that what you do every day helps the environment and saves money? Well, that is what solar photovoltaic installers do. They outfit buildings and large solar energy farms with photovoltaic systems that convert free sunlight into clean and renewable energy. This is an exciting, emerging field that will enable you to combine a passion for the environment with mechanical and electrical skills.
Read more
Reviews
Explore Our Science Videos
DIY Mini Drone Part 4: Program Drone Steering with Arduino
Flower Dissection – STEM Activity
DIY Hand Sanitizer Spray