A solar cooker is a device which uses the energy of direct sunlight to heat, cook or pasteurise drink and other food materials. Many solar cookers currently in use are relatively inexpensive, low-tech devices, although some are as powerful or as expensive as traditional stoves and advanced, large-scale solar cookers can cook for hundreds of people.
Because they use no fuel and cost nothing to operate, many nonprofit organizations are promoting their use worldwide in order to help reduce fuel costs (especially where monetary reciprocity is low) and air pollution, and to slow down the deforestation and desertification caused by gathering firewood for cooking.
Solar Cooker Comparisons: Solar Cookers, Solar Ovens, Solar Grills, and More
When someone mentions solar cooking and solar cookers, the image that often comes to mind is a box with a glass top and reflectors standing up around the lid. You might have baked chocolate chip cookies in one like that during summer camp. Maybe you even helped construct it using cardboard and aluminum foil. But this is just one kind of solar cooking technology. There are different solar cookers: each with its strengths, each with its uses.
It turns out that human ingenuity has devised a myriad of designs for cooking with the sun, but most fall into one of three main categories: solar panel cookers, solar ovens and parabolic solar stoves. All three concepts are based on the same cool idea: to concentrate sunlight onto cookware, produce heat, and prepare food. The big difference is how they concentrate light.
Solar Cooker: Solar Panel Cooker
Solar panel cookers are the simplest and most affordable type of solar cooker. They typically generate the lowest temperatures. They use flat or slightly curved reflective surfaces to concentrate light onto cookware. You unfold the panels, align them to the sun, enclose the pot in a heat-resistant plastic bag, glass bowl, or polypropylene greenhouse, place the pot inside the cooker, and that’s it! The beauty of this design is its simplicity and affordability.
Panel cookers are most effective when sheltered from the wind. Because they are not insulated, they are not recommended for use below 18 C or 65 F. Panel cookers are best for slow, one-pot dishes like beans, stews, and soups. On a temperate day under a cloudless sky, beans, rice, veggies, and stews can be cooked in a panel cooker in 2-4 hours.
For the most efficient cooking, a panel cooker should be re-positioned once every hour to track the sun. You can also put a panel cooker outside in the morning, point it at solar noon before leaving for work, and have a cooked entree ready when you get home.
Let the sun do the job when you are away. Slow cooking gives delicious flavors and is safe to leave untended. (Do not use the all-day method with meats because a panel cooker will not sustain a safe temperature into the late afternoon. The food will be cooked but it may cool before you eat it.)
Solar Cookers: Solar Oven (also called box cookers)
Solar ovens are similar to panel cookers, but they use an insulated box to retain heat, along with a set of reflective panels to concentrate solar energy. These insulated boxes are well suited for baking. The sunlight hits the panels and bounces into the box, where the heat gets trapped.
Solar ovens can reach temperatures comparable to those of traditional gas and electric ovens (in the region of 400°F). A solar oven is just as easy as your oven in your indoor kitchen. Consider using dark-colored bakeware, which absorbs and retains heat better than light-colored pans and casseroles.
Although they retain more heat than panel cookers, solar ovens are also slow-cookers. They heat up gradually to baking and roasting temperatures. They are perfect for setting up your meal, forgetting about it for several hours, and coming back to a sumptuous repast.
Solar Cookers: Parabolic Solar Stove (solar cooker)
Parabolic solar stoves concentrate sunlight to the cookware, and the most efficient ones generates temperatures over 450°F. They are analogous to traditional stove-top burners and grills, but some solar stoves can heat up faster than traditional stoves.
Parabolic solar stoves can cook from just after sunrise until just before sunset even in sub-zero temperatures, as long as they have direct access to the sun. They generate heat by using a curved reflector to concentrate light on the bottom of the cookware, much like a traditional gas or electric burner.
The power of a solar stove’s output is determined by the quality, size, and curvature of the reflector. As an example, the reflective material of SolSource Classic is a polymer (plastic) doped in aluminum. This makes it shiny, durable and lightweight, and formable in a perfect 3D parabola.
Because solar stoves heat up so fast and get so hot, they are ideally suited for grilling, boiling, steaming, frying, and sautéing. With a little ingenuity, you can bake and roast as well.
Because of the high heat, the rapid cooking, and the movement of the sun across the sky, we recommend you stay near your solar stove while cooking, just as you would keep a close eye on any high-temperature stovetop cookery.
Parabolic Solar Stoves:
Putting It All Together
While some types of solar cookers are better for baking and others for stove-top cooking, you don’t have to choose between them. Just like in your indoor kitchen, you have both an oven and a stove–and maybe a toaster oven and a microwave besides.
Try designing your own solar kitchen, powered 100% by the sun! Most of our favorite solar chefs combine solar cookers to make a meal, playing on the strengths of each – solar stoves for fast, powerful cooking and solar ovens or panel cookers for slow, gradual cooking.
With just a little imagination you can assemble a gourmet multi-course feast without striking a match, burning an ounce of fossil fuel, or emitting any more carbon dioxide than comes out with a laugh!