Getting Started in Solar Cooking

Guest post by Paul T. Martin
Paul writes at The Suburban Dad Survivalist.

Are you looking for an easy and inexpensive way to prepare foods in a grid-down environment? Depending on where you live, solar cooking may provide you with great options beyond meal preparation.

As the name implies, solar cooking utilizes energy from the sun to prepare foods. As with any solar energy application, there are limitations to how well this works. The biggest downside to utilizing solar cooking as part of your preparedness plan is that it requires adequate exposure to the sun. Depending on where you live in the United States, solar energy options can have varying degrees of utility.

That’s not to say that people of the preparedness community should shun solar cooking if they live at high latitudes, where limited wintertime sun exposure and extensive cloud cover make solar energy applications impractical. The upside to living in high latitude areas is that in the summertime, residents have tremendous access to solar energy. For these residents, the tool may be limited to seasonal use, but given the benefits and inexpensive cost, it can broaden the options preppers have for cooking and heating water.


Why solar cooking?

Using the sun’s energy to prepare your meals has a number of advantages. First and foremost, the fuel source is free and renewable. There’s no need to store energy for your solar cooking devices. As long as you have good access to the sun, you will have the ability to prepare a wide variety of meals that you would normally prepare and modern kitchen with full utilities.

Solar cooking comes with another advantage over traditional cooking methods, in that it does not require the chef to be exposed to tremendous amounts of heat. Unlike cooking on an open fire or on a grill, solar cooking generates very little additional heat, limiting the energy transfer just to those cooking utensils being utilized in the preparation of the meal.

Many in the preparedness community are rightfully concerned about operational security and maintaining “smell discipline” during grid down operations. These people worry that the smell of smoke or charcoal may give away their activities or location. With solar cooking, there is no byproduct: no smoke and no charred remains of burnt wood. Depending on the type of solar cooking device are using, it is possible for the smell of cooked food to waft outside of your yard or property; however, that risk can be managed in large part by placing your cooking device in such a place where people are unlikely to be downwind from it.

In addition to preparing food, solar cooking devices have other applications as well. They can be used to pasteurize water (although they cannot remove non-pathogenic materials such as dirt and chemicals). Recent medical research shows that solar ovens can be used to safely sterilize medical instruments, making them ideal for use in third world applications as well as in grid down conditions. In addition, solar cookers can be used to start fires. Often when I am demonstrating my solar cooker at field day events and to neighbors, I will take a 2x4 or log and set it on the spot where you would normally place a pot. Assuming that you have the mirror angle correctly and in full sun conditions, it takes but a matter of seconds before the log or 2x4 will burst into flames.

Some people say that solar cooked foods taste better; many of the same people go on to say that it is impossible to burn food in a solar oven. While I cannot attest to taste differences between foods cooked using solar energy versus conventional means, I can certainly dispel the myth that it is impossible to burn foods using solar cooking techniques: you absolutely can burn food in a solar oven or on a solar cooker.

When many people think of solar cooking, they think of science or scout projects they made using an old box with the interior covered in aluminum foil. While it is certainly possible to make solar cooking devices, the two that I use are commercially made. Unless you are a tinkerer or are very handy at building things, I suspect most people’s success with solar cooking will depend largely upon their decision to purchase commercially made (and thus better engineered) solar cooking devices.


What kind of solar cooking devices are there?

Most solar cooking devices can be placed in one of two categories – solar ovens and solar cookers.

Solar ovens are just like the name implies: these box-like devices replace the conventional ovens you have in your home. Most of these devices consist of a box with a glass door on the front of it. Reflective panels surround the glass door, effectively reflecting the sun’s rays into the box through the glass door. The interior of the box is painted black to help absorb and retain heat. These devices are used just as you would use the oven in your kitchen.

Solar cookers look a bit more exotic. These devices usually consist of a large reflective dish, called a parabola, which aims the sun’s light at an area roughly 40 to 50 square inches. Pots and pans sit on top of this area of intense energy, which is capable of boiling water, frying bacon and even setting logs on fire. The solar cooker replaces the conventional stovetop in your kitchen.

These devices vary in price, depending on manufacturing quality. You will likely pay somewhere in the neighborhood of $200 - $300 for commercially made solar cooking device.


How well do these devices work in cloudy or cold conditions?

Clouds definitely present a problem for solar cooking devices. Overcast skies generally do not bode well for solar cooking, while partly cloudy skies – when the sun is blocked intermittently – can still yield positive conditions for solar cooking. Cold weather, interestingly, has little to no bearing on the effectiveness of solar cooking. In fact, I generally find that temperatures in my solar oven are generally higher in the winter than in the summer, due to the lack of humidity in the wintertime.


What are some tips on getting started and solar cooking?

First and foremost, you’ll have to decide what sort of cooking device to build or purchase. If I were starting out, I would want a solar oven. It has more utility than a solar cooker and is easier to store. Keep in mind that when you have a solar cooker with a five foot parabola, you will need a place to store a five foot parabola. Mine hangs upside down on the ceiling of my tool shed.

Your choice of cooking containers will be as important as your choice of cooking device. For solar ovens, pots and pans that have thin walls and are dark in color work best. The thin walls allow for easier transfer of heat to the food, and the dark color aids in heat retention. You will quickly learn – as I did – that you do not want to use your solar oven pots and pans with your solar cooker. The solar cooker's energy concentration is simply too great for thin-walled cooking utensils.

For my solar cooker, I generally use either a cast-iron skillet or clear Pyrex. When you’re using a solar cooker, find the most indestructible utensils in your kitchen. I damaged a number of my wife’s various conventional oven trays and my solar oven utensils by using them with my solar cooker. Don’t make that mistake!

Solar cooking does require a bit more planning than conventional cooking. Not only must you allow the solar oven time to heat up (which can take longer than conventional ovens), but due to the fact the sun is always moving, you will constantly be making adjustments to both your oven and solar cooker throughout the day. My advice is to budget ample time to get your solar cooking device set up and oriented to the sun. Allow additional time to move the cooking device every so often to track the sun’s movement across the sky.

“Making hay while the sun shines” isn't just a folksy saying for farmers; it’s very applicable to solar chefs as well. If you see that there’s an increased chance of clouds or rain in the forecast, you may want to do as much solar cooking as you can while the sun is expected to be out.

The learning curve for solar cooking is not steep, but it does exist. The best way to learn how to solar cook is to simply practice. Whenever I obtain a new solar cooking device, the first test I always do is to see how long it will take to heat a gallon of water to its maximum temperature. Knowing this piece of data will teach you a lot about how to operate the cooking device as well as its capabilities and limitations.

There is no substitute for actually using your solar cooking devices now, when the stakes are low. Practice heating up your lunch leftovers in the solar oven. Practice brewing tea with your solar cooker. Then you can branch into making soups, baking loaves of bread, cooking a pot roast, and even frying bacon.

Solar cooking will not be the only cooking method you will want to have in your preparedness inventory, but it does provide you with a tremendous amount of flexibility without the need of collecting or storing fuel. Give it a try!