Have you ever gone sun-bathing and ended up way too hot? The sun’s rays produce intense heat.
Those rays can be focused in order to produce the heat needed to cook food. Some people in poor rural countries like India and Sudan use solar cooking as their main way to cook foods.
Solar is a renewable energy which means we can use it again and again without causing pollution.
The solar oven focuses sunlight into a small space causing it to heat up quickly. A well-designed solar oven can reach 285° F or 140.556°C. That’s hot enough to roast meats or bake bread.
You can purchase a solar oven but it’s so much cheaper to make one out of common household materials.
The materials all have a specific purpose.
We will be using aluminum foil to reflect the light and direct more of the sun’s warm rays into the box. This helps the oven heat up faster.
Just like a blacktop road gets hot. Dark colors absorb light which converts to heat. That’s why we paint the cardboard box black.
We also want the box to be insulated so the heat stays inside. So, like in your home, we will put some insulation between the “walls”.
You can build this solar oven with easy to find materials. You may need to purchase a few inexpensive things.
Paint the inside bottom of the smaller box black with your spray paint. Wear a painter’s mask or bandana over your mouth and nose when spray painting. That way you don’t breathe in the fumes.
Let the paint dry. This only takes about twenty minutes.
While the smaller box dries, use the markers to decorate the outside of your box if desired. If you don’t want to decorate just move on to step two.
While the small box is drying you can work on placing insulation inside your big box. The insulation will help keep the heat inside the oven so that the food can cook consistently.
I like to use the ½ inch pieces of Styrofoam that are often used in packaging. This is also a good way to recycle them and reduce waste!
Cut the Styrofoam into pieces and glue them to the sides of the larger box.
You can also use newspaper if that is more convenient for you. After the smaller box dries, you will crumple the newspaper into balls and stuff it between the two boxes. It's ok if there are spaces between the newspaper. Those air pockets will hold the heat in.
When you put the two boxes together the tops should be level. If need be, put a magazine or two under the smaller box to raise it up.
Cover the four inside sides of the smaller box with aluminum foil. Use the scotch tape to adhere it to the sides of the box.
You will also cover the top tabs of the big box with aluminum foil. These will act as a reflector.
You will want to have the shiny sides of the foil facing outward.
Place the smaller box inside the bigger box. Adjust the boxes so the sides are even. To do this add newspaper or magazines to raise up the smaller box.
Place duct tape around the side of your piece of picture tape. Wear gloves because glass can be sharp.
Place the glass over the smaller box. Attach the glass to smaller box with some duct tape. You will only duct tape one side of the glass. You want to be able to open it like a lid.
Place the thermometer inside your oven.
You can place your solar oven on a patio where the rocks or concrete help it to warm up.
You can also place it on a picnic table, so it won’t get stepped on.
Position the solar oven so that it is in full sun. Use the flaps on the box to angle them towards the sun. Think about the sun’s rays bouncing back into the box.
A 45-degree angle works best. You can use sticks to prop the box sides in the position you want.
You can tilt your solar oven slightly to help it align with the sun. However, remember if you have food in the oven, it will tilt too.
You will need to do some experimenting to learn how to cook in the solar oven.
Typically, it takes two to three times as long to cook in the solar oven as in a conventional oven. This is because the heat is not forced.
The good news is that it’s a lot harder to burn your food in a solar oven.
Keep an eye on your oven and the position of the sun in the sky. You may need to adjust your box to make sure you are catching the best rays.
Smores are the perfect outside fun food. They are simple to make with just three ingredients – graham crackers, mini marshmallows, and chocolate. You can use either chocolate baking chips (the sweet ones) or chunks from a Hershey bar.
Just assemble them by layering chocolate and marshmallows on the graham crackers. Place them in a pie pan or small baking sheet that fits in your oven.
Allow them to heat until melted.
Slice open the English muffins and spread tomato sauce on both sides. Add your favorite toppings and cover with some shredded mozzarella cheese. Bake in your solar oven until the cheese is well melted.
Other things that work in the solar oven are soups and baked beans. I like to use a solar oven to set my dough in when I'm making bread. It gives it a nice airy rise.
This is a great project, and you can cook simple dishes well. However, don’t try to cook meat in a box solar oven because it does not get hot enough.
For a great oven to take camping I recommend the SunFlair Solar Oven. The temperature reaches a high of 285° F so still lighter cooking. They are also handy in the summer around the house when you don’t want the stove heating up the kitchen.
I have a SunFlair and use it to dehydrate vegetables, heat soups, make burritos, and prime the bread dough. They also work well for sun tea.
If you are looking to do some serious cooking with a solar oven you will need a Sun Oven. Their basic model can reach a temperature of 360° F. They will even boil water.