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The following article details the four main types of solar cookers.
Please write point-form notes along with a sketch on each type in preparation for tomorrow.
Four Basic Types of Solar Cookers
There are four basic types of solar cookers – panel cookers, box cookers (sometimes called box ovens), parabolic cookers, and tube cookers. Each of these basic types of solar cookers meet a specific need and specific type of cooking.
Panel Cookers
Panel cookers resemble an open, three sided box. The bottom and side panels of the box are covered with shiny material creating reflectors. The sun rays hit the shiny panels and are redirected into the center of the box.
A “heat trap” is used in the center of the box to capture the sun rays. Heat traps can be made from anything that is clear and allows the UV rays to pass through. Common heat traps are clear cooking bags used to cook turkeys; large glass bowls with one turned upside down on top of the other; and a small, clear jar placed inside of a larger clear jar.
The dark cooking container is placed inside of the heat trap. When the redirected UV rays hit the pot, the molecules begin vibrating which creates heat. The heat trap prevents the heated molecules from dissipating, creating a super heated vessel. Temperatures reach 250° F (121° C) – 300°F (149°C). This type of cooker is good for general cooking of soups, meats, vegetables, casseroles, and desserts.
Box Oven Solar Cookers
The box oven is the most well known type of solar cooker. It is very much like the panel cooker above, except that the open side is covered by clear glass or plexiglass, creating an air tight heat trap or oven in the center of the box. Commercial brands, as well as homemade models, have a layer of insulation between two walls that holds in the heat. In addition, the inside of the box is usually painted black to create a heat sink as well. Finally, most box oven cookers also have large shiny panels to redirect the UV rays down into the heat trap.
Because the center cavity of the oven is usually larger than the heat trap found in the panel cooker, the box oven can hold a larger cooking pot. Because the center cavity of the oven is well insulated, it can reach higher temperatures than a panel cooker. Temperatures reach between 250° F (121°C) – 400°F(204°C).
By and large, even with all of the differences, panel cookers and box ovens are very much the same. Because the solar oven gets hotter, it will of course cook faster. However, given a little bit of extra time, the panel cooker will produce the same amazing results.
What Can Box Ovens and Panel Cookers Cook?
Both types of cookers cook slowly, much like an electric slow cooker. In general, they can cook anything that can be simmered in a slow cooker; roasted in the oven; cooked in the microwave; or cooked on the stove top (except for frying.)
Parabolic Solar Cookers
Parabolic solar cookers are shaped like parabolic satellite dishes. The dish is covered with a shiny material that makes the entire surface reflective. In short, sunlight comes into the dish and is reflected back up to a center focal point. A cooking vessel is placed above the reflective surface at the focal point. The concentrated UV rays reach extremely high temperatures of 500°F ( 260°C) – 700°F (371°C) that are capable of frying, and grilling.
What Can Parabolic Solar Cooker Cook?
Because of the high temperatures, parabolic cookers can fry, grill, and even pop popcorn.
Evacuated Tube Cookers
Evacuated tube cookers are fairly new on the market, but are quickly becoming everyone’s favorite. Made from a large evacuated glass tube, surrounded by shiny reflector panels, the glass tube can reach temperatures of 550°F (290°C) or greater. The cooker gets hot enough to cook meat, bread, vegetables, and dessert.
Evacuated tube cookers are still solar cookers and need the sunlight to cook, however, the tube cookers does well even under cloudy skies.
A note of caution: Glass is glass and all normal precautions regarding heated glass must be observed. DO NOT pre-heat the glass tube prior to cooking. DO NOT put cold food into a hot glass cooker. DO NOT leave an empty tube cooker focused to the sun.
