Solar cookers are the safest and cleanest mode of cooking food. They utilize solar energy, which is available freely and abundantly, to cook food. Solar cookers are being promoted extensively in countries like India, China and number of African countries which are rich in solar energy. Depending upon the method in which solar energy is utilized in solar cookers, they are divided into various types. Explore some of the most popular types below.
Box Type Solar Cookers
These are most widely used type of solar cookers. They can be rectangular or circular in shape. The box type of solar cooker comprises of the enclosed space where the vessel containing the raw food is kept. At the top of the box there is a glass that allows the sunrays to pass through it and get concentrated inside the box.
There are two methods of cooking the food. In first type the concentrated sunrays directly fall of the cooking vessel and cook the food. In the second method, a black surface is applied in the inner surface of box, which absorbs the sunrays and converts it into heat thus heating the food and creating a mini greenhouse effect. In either case the box is covered with the insulating material to avoid heat leaking out. It could also include a reflective surface at the top of the box instead of glass.
Althou box cookers are slow they provide even heating of the food. Box types of solar cookers are easy to make and use, safe, and cheap.
Panel Type of Solar Cookers
These are very cheap solar cookers, and the easiest to construct. These are also known as CooKit models. Panel solar cookers comprise of four panels, which are covered with a reflective material like aluminum foil. Sunlight falling on the panels is reflected to the middle portion of the box formed by the panels, where the cooking vessel is kept. Due to concentrated sunrays the food gets heated and cooked. The panels are ordinary cardboard on which the aluminum foil, similar to the one found in cigarette packets, is applied.
Though they are easy to make, they are less effective in windy atmospheres as the heat will be blown away. They are also not able to absorb sufficient quantity of heat in cloudy atmosphere.
Parabolic Type of Solar Cookers
The parabolic type of solar cooker comprises of reflective metal sheets joined together to form an umbrella sort of shape. When the sunrays fall on the metal sheets the energy is concentrated into a small area, where the cooking vessel is placed. In the parabolic solar cooker solar energy is highly concentrated; hence they are the fastest type of all the solar cookers.
The parabolic type of solar cookers requires precision design so that the solar energy gets concentrated at the exact right place. If the concentrated energy does not falls on the cooking vessel, the food will not cook efficiently.
Images source: www.solarcookers.org.