Types of Solar and Low-Fuel Ovens
Solar ovens are primarily constructed from three different designs. Each of the designs has unique advantages, and the choice of design is based largely on the type of food to be cooked, the location in which the oven will be used, and the availability of resources and materials. The following information provides an overview of the various types of solar and low-fuel cookers.
A very common solar oven design, box ovens are essentially boxes with reflectors. The reflector directs the solar energy onto one or more thin black pots absorb the heat to cook the food, while the box insulates to retain the generated heat. Additionally, a transparent cover over the top of the box oven can be added to help trap the heat.
Box ovens are very safe and need little supervision or education in their use; it is difficult to burn food left in a solar oven, and the oven can be left unattended for longer periods of time.
Box ovens can reach internal temperatures of about 300° F (149° C).
A parabolic cooker uses a large, curved reflector to direct energy at a pot. Parabolic cookers reach high temperatures quickly, which reduces cooking time. However, the angle of the reflector requires regular monitoring and adjustment, and generally parabolic cookers can only heat one pot of food at a time.
Although more difficult to construct due to their more complex design, parabolic cookers are capable of reaching temperatures necessary for grilling or frying.
Panel cookers are a hybrid design that incorporates elements of both box ovens and parabolic cookers. They use a paneled reflector that focuses the solar rays on a pot encased in an insulating transparent bag. Panel cookers are simple to construct and require relatively few materials and tools. Also, these ovens do not require as much adjustment and supervision as parabolic cookers.
Panel cookers allow food to reach internal temperatures similar to that of slow cookers and work well with foods that have a high moisture content.
While they are not solar ovens, rocket stoves are important cooking options that assist in the reduction of fuel usage. As many countries have rainy or cold seasons that make it difficult to use consistent solar cooking during, a backup form of cooking is generally needed. Traditional open fires waste wood or other fuel, while chimney shaped clay or sheet metal rocket stoves are able to concentrate heat and use less fuel. Rocket stoves, like solar ovens, are economical and simple to construct and can be considered as a backup to solar cooking methods.