How to Make a Solar Oven

Last Updated: 5 March, 2019 by Alexander Thomas

How to Make a Solar Oven

Learning how to make a solar oven can be a fun and rewarding experience. Even if you already have a conventional oven, you can do it with your children as part of a solar oven project for a science fair, you can try it with your friends for entertainment on a boring day while camping, or you can make a heavy-duty solar cooker to add to your existing appliances.

At any rate, the process is not a difficult one. Solar oven materials are easy to come by and building the cooker itself takes minimal effort and time. To get the best results with your project, read on.

How to Make a Solar Oven: Supplies and Instructions

Solar ovens might not be as reliable as their conventional counterparts since you can’t set them to a certain temperature and they require sunlight to work, but they can nevertheless come in handy both at home and while camping. They also make impressive solar oven science fair projects and can help you teach your children more about solar energy and sustainability.

Learning how to make a solar oven is quite simple. Below, you’ll find everything you need to know on how to build a solar oven and how to use it once it’s done.

Solar oven materials

Making a solar oven is so facile partly because the project does not require any special materials. Everything you need for a lightweight solar cooker is affordable and easily accessible.

Materials include:

  • Two carton boxes, one of which can be placed inside the other with a margin of at least one inch on all sides. These will serve as the oven proper, where you will place food items for cooking.
  • Shredded paper or newspaper, whichever is available, for insulation
  • Four additional pieces of cardboard that you will use to create reflectors
  • Black construction paper for heat absorbtion
  • Aluminum foil to reflect the sun or, for a more long-term appliance, metallic auto sunshade, aluminum coated bubble wrap, or Mylar food packaging.

How to build a solar oven: Instructions

Fit the smaller box inside the bigger one and fill the space between them with shredded paper or any other insulator (such as newspaper or torn cloth). Next, use black construction paper to cover the entire inside surface of the smaller box in order to ensure maximum absorption of heat.

Cut the four additional cardboard pieces into slightly flared squares with the smaller ends equal to the sides of your large box. Then, cover these shapes with reflective material (aluminum foil, Mylar bubble wrap, or other handy solar oven materials), making sure to smooth out the surfaces.

Finally, attach the four shapes to the top four sides of your large box using glue, staples, or thread. For the solar cooker to work, the reflective surfaces must be above the box, directing sunlight inwards. To achieve this positioning, you can use thread or rope to tie together each two consecutive shapes at the flared ends, thus ensuring that they will prop each other up. Otherwise, you can stake support rods underneath each reflector and glue them together for additional stability.

You’ve now learned how to make a solar oven. Once the reflectors are in position, all you have to do is place the food inside the small box and expose the solar cooker to sunlight.

How to build a solar oven for higher cooking temperatures

If you want to add a heavy-duty solar oven to your kitchen appliances for long-term use, then you’ll need a few additional solar oven materials. Start by acquiring a large metal drum (an oil drum, for instance) and cutting it in half vertically. To make the cooker, you’ll use only one of the two cradle-looking halves.

Clean the drum and measure it carefully. Cut matching surfaces of sheet metal in order to fit all the insides of the drum and secure them by drilling holes and using pop rivets. Once the sheet metal is in position, coat the inside of the oven with “barbecue” rated reflective pain and create a metal lip (or margin) for three of the four sides of the drum.

On this margin, you’ll place a sheet of tempered glass customized to the size of the drum. To finish the job, you’ll need to use spray insulation on the backside of the cooker, drill holes on the bottom for drainage, and create a stable (rectangular) base out of wood, aluminum, or other convenient materials. For additional functionality, you can place an aluminum grill on the bottom of the solar oven and add a magnetic thermometer (heat-resistant) next to it. A job well done!

How to use your DIY solar oven

Time and place are essential aspects of cooking with a solar oven. Ideally, you’ll want to position the cooker in full sunlight, away from any potential shadows, to ensure continuous heat throughout the cooking process. For best results, use jars or dark colored baking pans to contain the food.

To orient the oven correctly, consider that it cooks best when the shadows of reflectors are directly behind the latter. To cook something by noon, you’ll likely want to start the process no later than 10 a.m., whereas a meal to be served in the evening should be in the cooker by 1 or 2 p.m. If you’re about to leave the food inside the oven for the entire day, then simply orient the oven to match the position of the sun at noon.

How Does a Solar Oven Work?

A solar oven or solar cooker is a device that basically uses the energy of the sun, instead of gas or electricity, to heat and cook food outdoors. There are numerous reasons why you might want to learn how to make a solar oven, but before anything, let’s look at the basic principles of this fun appliance. The fundamental principle of a solar oven project is its ability to concentrate sunlight. You basically need a surface (or series of surfaces) that are capable of directing the sun’s rays onto a small cooking area, the smaller the better.

You might think that high enough temperatures to bake or cook are not possible, but people have used this method to melt salt and metal. This is possible because of the second principle of a solar cooker, which is its ability to convert light into energy. You can facilitate this by making sure that your pot is as conductive to heat as possible – matte black maximizes light and heat absorption. Lastly, an efficient solar oven prevents this heat from escaping. A glass lid will often do the trick and even ad a greenhouse effect to the system.

What Can You Cook in a DIY Solar Oven?

You can cook almost anything you’d otherwise be able to prepare in the average kitchen, with the difference that the solar oven materials you used and the design of the project itself will decide the rig’s maximum temperature. In turn, this will also affect cooking time. Without much preparation, you can easily whip up a delicious chili, corn-on-the-cobb, rice, fish, and chicken with veggies on your DIY solar oven. Who would have thought that the sun can sound so delicious? You can start with recipes such as solar oven whole wheat bread and work your way up to a lasagna, and even a beautiful peach cobbler.

For the bread, all you need is roughly 9 cups of whole wheat flower (but you can use rye, or regular flour just as well), 2 tablespoons yeast, half a cup of potato flakes, 2 cups buttermilk (advised but not mandatory, can be replaced with a smaller amount of olive oil), and 4 cups warm water and roughly 1 tablespoon of salt. You can split the mixture in 5 separate loaves, which you should let rise for at least 30 minutes. The bread will need anywhere from 20 to 40 minutes in the oven at around 370 F to be thoroughly done.

Are Solar Oven Science Fair Projects Appropriate?

If you want to learn how to make a solar oven for a science project, this is a great educational opportunity. School science fairs are all about integrating practical skills and theoretical knowledge, so with a bit of handy work and theory, you can easily be a top contender for that best in show ribbon. There are countless benefits that will definitely help you get those extra points from the jury, while also offering a healthy and sustainable alternative to cooking with oil. To begin with, this is a completely safe project as there is no need for dangerous fuels.

As you design your solar oven project, consider that people can save money and resources when using such an appliance. Solar oven materials are safe to use and handle, which makes the whole thing a child-friendly assignment. Other benefits that you might mention in your presentation include the ability to boil water, thereby rendering it potable when there’s no reliable source of clean water, the lack of smoke as a by-product, and a minimal risk to burn food. Finally, another important reason why solar oven science fair projects will be successful is the cooker’s ability to pasteurize food, thereby preserving it for later use.

What Can a Kid Cook in a DIY Solar Oven?

The possibilities are pretty much endless. Aside from enjoying the ingenuity of a solar oven project, you’ll also be able to offer delicious treats to visitors or other participants, if you’re learning how to build a solar oven for a science fair project. From solar cooked chocolate-chip s’mores to solar nachos, quick pizza crackers, and English muffin pizza, you can use your creativity to prep an entire meal from starter to main dish and even dessert in one go. Doing so will greatly improve your project’s score, as it will show it is a feasible and reliable alternative to a stove top.

For instance, for the English muffin pizza, all you need is a muffin (or as many as you want) split in half, roughly 2 tablespoons pizza sauce for every half you plan on making, half a cup of your favorite cheese, grated, and two or three pepperoni slices per half. After you’ve halved your muffin, you spread the sauce on it, follow-up with the cheese, and the pepperoni last. You place your final muffin pizza in a cooking bag, seal it with a tie, place it in the solar cooker and wait until the cheese is melted. It’s as simple as that.

Should You Learn How to Make a Solar Oven when Camping?

Learning how to make a solar oven can be really useful, especially because you can’t take an oven with you while camping. You may be able to take a small electric or gas-powered stovetop, but then you’re just moving your home appliances outdoors instead of enjoying the wilderness, not to mention that systems which rely on gas are also known sources of pollution. Using a solar oven project to make food when camping will be a lesson in self-reliance, as well as survival skills, both for you and your family.

The fact that you don’t need a fire is a great opportunity, since there’s no need for fire making materials, such as fuel or wood. There won’t be any smoke by-product, and you don’t need to be in a specially designated place in order to cook your food outdoors. Anywhere will do as long as there’s sun. If your solar oven materials also come from a sustainable source (which is quite likely and possible), then the project can serve as an example in sustainable building and design. You won’t scare off any wildlife with it, which means you can, for instance, peacefully cook your first caught fish while you’re angling for dinner.