We asked leading expert on Solar Cookers, Dr. Ashok Kundapur, for his opinion on which is the best, and which is the cheapest acceptable Solar Cooker. Dr Kandapur has listed over 60 main types of solar cookers and more than 100 variations of them in his site http://solcooker.tripod.com. He believes the best solar cooker is yet to come, and when it comes, it will allow cooking inside the kitchen instead of directly under the sun’s rays, and also allow cooking at night.
As of today, says Dr Kundapar, “a Cooker which comes close to the ambitious model described above is the one designed by Scheffler of Germany. The Scheffler Cooker, it is a shallow parabolic reflector with a long focus.
” Thus the sun rays could be directed into the kitchen where the cooking can be done. When the cooking is completed, the focused sun rays could be used to store the heat into a metal block. The Cooker is available in large size too and world over several Hostels and big establishments are using such Scheffler cooker. A domestic model with 2 m dia costs about Rs. 8,500 in India, a price at which it is considered to be a bit costly. Cooking With the Sun: How to Build and Use Solar Cookers – Buy it from Amazon
Solar Box Cookers are very popular in India, they are also known as Gosh Type Cookers. These cookers can be
made from cardboard and other such materials. The Cooker can be of any size and thus lot of food can be cooked. The cooker has double glazed Insulated Box in which the cooking pots/boxes are kept. There could be one to 4 mirrors to reflect more sunlight into the box. Cooking time varies from one-and-a-half hour to two hours. Manufacturer in India is http://www.rohitassolarcooker.com/.
Regular Solar Parabolic Cookers, popularly known as SK 10 0r SK 14 are available in the market. Most types of cooking, such a frying, roasting and boiling can be done in this type of cooker. The focused rays can generate the temperature up to 3000 C . It costs about Rs. 7,500 in India. A slight variation of the same concept, but where it is easy to approach the cooking vessel, has been designed by a German company and it is called a Papillon. The design is being marketed in Africa. SK 14 type is to be preferred over other models with smaller diameter.
supplies SK 14 as well as other interesting but effective cooker designed by Prof. Roger Bernhard, called as Nelpa Cooker By far the best low cost cooker is COOKIT designed by a French Designer Prof. Roger Bernard. This cooker also called as Panel Cooker is the number one on the popularity list. It can be constructed with just about US $ 3-4 . It can be used to baking as well as cooking. Is known to generate heat upto 1200C. Used with a low cost heat saving device called as Greenhouse guard, the cooker performs very well.
Mr. G Diasanna of Africa designed a low cost heat guard and it has been slightly improved by me. The diagrams mentioned here gives details of construction of Cookit as well as the Guard.
To make your own Cookit take a cardboard, preferably 3 mm thick, or such other flat sheet of about 124 x 100 cm. Stick a bright Aluminized Polyester sheet on one side to the entire surface. Such Aluminised sheets are available is Stationary stores as gift wrapper material. Mark the lines and cut the sheet as directed in the drawing and fold it accordingly.
Cookit is ready. This Cooker can cook up to half a kg of rice or other material.
Solar Guard or the Greenhouse guard is a transparent cover which fits around the cooking vessel. Mrs.
Barbara Kerr, Solar cooker pioneer of USA, suggest a transparent plastic cover around the vessel. Mr G.
Diasanna of Africa made a wire frame which is bigger than the cooking vessel and wrapped a transparent plastic sheet around it, this enclosure is open at the bottom. I have tried to modify this type of guard, by making a cylindrical cover made of transparent plastic like Poly Propylene ( PP) , this is open on top as well as bottom, and is supported by wire frame.
Top of this cylinder is covered by a transparent hat like cover made of PP sheet. With this arrangement it would be easy to watch the material being cooked and perform such tasks like stirring without loss of much heat. The diagram enclosed gives a clear idea as make a solar guard. Thus the Cookit and the solar guard will cost just about $ 3- 4.
When the COOKIT’s assembled it would look like this. The part of reflector facing you reflects the rays on to the cooking vessel. This part would also act like a wind guard. The Three fold main reflector at the back of the cooking vessel will have only three folds and not 5 as in the photo. This 5 fold was due to folding of the Cookitfor easy packing.
Solar Houshold Energy (SHE) (http://www.she-inc.org) of USA has evolved an all Glass Heat Guard and a cooking vessel. Together with the Cookit it costs about US $ 30. Mr Derris of USA supplies several types of cookers and materials to make cookers. (http://www.cleardomesolar.com )