It seems like there are solar solutions for everything: water heaters, televisions, and even ovens. The question is though, how effective are the solar options – like a solar cooker – compared to traditional ovens?
Basically – do solar cookers work?
I’m here to tell you that they do. Properly-made DIY solar cookers can cook food at temps of 200 – 300 F and commercial solar cookers can heat food to temperatures of 400 – 500 F.
They will take longer than a gas or electric oven to fully cook food, but not by much. All they need, though, is solar energy. There’s no need for electricity or gas, which in my opinion is pretty cool, especially with the high prices of utilities these days.
How do Solar Cookers work?
Whether you are making a DIY solar cooker or purchasing a commercial type, the concept for cooking with the sun is the same, using radiation and conduction to cook.
Reflective material (aluminum foil, aluminum panels, or mirrors) redirects the sun’s rays to the cooking area, which usually has a black background and is surrounded by some kind of insulation.
The black will absorb the heat and the insulating material (newspaper, aluminum nitride or a vacuum tube) retains heat, too.
This makes the cooking area heat up (thermal energy) and begin cooking.
The difference between solar cookers is mostly how high the temperature can get.
Of course, there are different sizes and weights, too: ones that can hold 1-2 big pots and others that require you to put all the food and ingredients inside a little tray that sits in the oven (cylinder tube cookers), and ones that can fold down and be easily carried for camping or a day at the beach.
How high the temperature can get in a solar oven depends on:
- How much sunlight is directed to the solar cooker (strong sun, direct sunlight = more heat)
- How well the reflective material redirects the sun’s rays (crappy aluminum foil = poor reflection and less heat)
- How well the insulation traps in heat
- How sunny the day is, if it is partly cloudy, your solar cooker will not get as hot.
Another aspect that can make a huge difference with solar cooking are the color and type of pots or pans you use.
Never use white cooking pots – they will reflect the light back OUT of your solar cooker, which is exactly what you do not want (same with shiny pots and pans).
Go for heavy, black pots that absorb heat and keep it in. Cast iron is great. And put a lid on everything, too.
Solar cookers vary in size, but you’ll find these same aspects in almost all solar cookers: reflective material to direct the sun’s rays to a central cooking area and insulation to hold in the heat.
What the reflective material is made out of, and how effective the insulation is are the main differences that make one solar oven better than another.
Different types of Solar cookers
You can buy a solar cooker, or make your own, but to be honest, I’ve always found the homemade ones to be a little disappointing.
BUT, with the right materials and know-how, solar cookers can be easy to make. In fact, they are a common children’s science experiment to understand solar radiation or thermal energy.
Commercial- manufactured
Tube solar cookers
This is top-of-the-line for convenient solar cooking. These are small enough and light enough to take camping, but sturdy enough to be your regular everyday oven choice, too. And, because they retain heat so well (use a vacuum to insulate) they will continue cooking food for some time, even after sunset.
Max temperature: 550 F
Reflective material: Aluminum
Insulation: Vacuum tube
Drawbacks: the cooking area is small, all items go inside a cooking tray. It cannot hold a full pot. This is ideal for 1 – 4 people.
Other features: The GoSun brand of cylinder solar cookers has an option of a back-up battery, in case the sun disappears halfway through cooking, you can still finish preparing your meal.
Concave reflective mirrors ensure you don’t have to move to follow the sun’s rays for 5-6 hours.
I have a Go Sun Sport and I LOVE it. It is so easy to use and cooks food just as well as my oven without the high energy bill. It was well worth the cost.
If you’re interested in one, check out the GoSun Sport if you have a small family or the GoSun Fusion for those of you with more mouths to feed.
Parabolic Cookers
These come in various sizes, from small (camping-size) to massive ones. However, the design of the reflective panels that channels everything to the center of the parabola makes it one of the most efficient cookers that do not require any additional insulation.
Max temperature: 500 F
Reflective material: Stainless Steel
Insulation: N/A
Drawbacks: Without insulation, no sun means cooking halts. You also need to regularly turn them to maximize the sun’s angle, which is hard because these things can be a little unsteady. These solar cookers heat up in as little as 10 minutes, though, so when the sun is there, these cook food quickly.
Other features: because it is so big (and heats so well, so fast) it’s awesome for big families and can hold a full pot, with no problem.
Solar Bag Cookers
A great beginner option, these little solar bags pack down small but can do a lot. Most of them fit a regular pot and are a cheap option. There is no assembly for most, so it’s a good way to see how you like solar cooking before you decide to build your own or purchase a commercial solar oven.
Max temperature: 280 F (regular temp is 180F)
Reflective material: Foil
Insulation: reinforced EPE foam
Drawbacks: Don’t get to high temps, and take a long time to cook. You should start early if you’re using a solar bag to make dinner, and you may not be able to safely cook meat.
I’d think of these more as solar warmers than solar cookers, but if you want a cost-effective way to keep your food warm, look no further.
DIY
It’s easy to make a basic solar oven with materials you probably already have lying around: a mirror, pane of glass or clear plastic, some wood – or even sturdy cardboard.
Make sure you use insulation (which could be newspaper, packing foam or leftover home insulation – the reflective kind is a win-win for a solar oven) and paint the background of the cooking surface black to absorb the heat to get the maximum thermal energy to power your oven.
A basic cardboard box solar oven can get up to 300 F if the aluminum foil sides are angled properly (45 degrees) and get direct sunlight.
Other homemade box solar cookers can be made of wood and mirrors and filled with quality insulation to conserve even more heat. These can get up to temps of 350 F within 30 minutes, which is on par with commercial solar ovens.
How do Solar Ovens compare to Traditional Ovens?
Solar ovens (or solar cookers) can cook most of the same things that a traditional oven can cook – but it usually takes a little longer, but only by a little bit.
In general, you can cook bread, pizzas, casseroles, eggs, cookies, cakes and more in a solar oven, just like a traditional one.
While a traditional oven takes mere minutes to pre-heat and reach temps of 250F or higher, a solar oven might take 30 minutes to reach that temperature.
Some solar ovens reach temps of over 500F – more than enough to roast meat. But not all designs can reach that temperature or maintain it to safely cook meat. The GoSun Solar ovens can.
In some cases, you should cut the meat up into smaller pieces and remove bones to speed up the cooking process, and consider using a thermometer to measure the oven’s temperature, just to be on the safe side.
What’s the difference between a solar oven and a solar cooker?
Solar ovens and solar cookers are the same thing, it’s just a preference of name.
Since most people think of an oven for baking and roasting, it could limit the perception of what you can do with a solar oven. I like to say ‘solar cooker’ because you can steam, simmer, roast, bake, cook, and heat leftovers in it.
What are some of the benefits of using a solar oven?
Sure, a solar cooker isn’t as fast as a traditional oven – but it’s free! You never have to pay for gas or connect to electricity.
- Off-grid solution that’s also good for the environment
- Requires no fuel source – just the sun’s rays – so you’ll save money long-term
- Acts as a slow cooker
- Can make yourself for cheap
- Works as a food dehydrator, oven and microwave all in one!
A solar cooker is a great off-grid solution, especially for folks who have a homestead in the sunny tropics.
