REVIEW OF SOLAR COOKER DESIGNS
MGM College, Udupi – 576 102, INDIA
This is a HTML version of the article which appeared in TIDE, Vol 8, No. 1, March 1998 Page 1-37. This paper is now presented here in 16 parts.
This review presents about 56 major designs , 59 variations and 66 drawings of solar cookers. Test data published by other researcher is compiled and a new set of parameters is suggested for testing solar cookers, reflectors, and insulating material. This compilation recommends do – it-yourself box-type solar cookers incorporated in the house for the rural areas (type BDM 2, concept IX). For urban areas, the best suited design would be Prof. Bowman’s design with slight modifications (Type MP 3a, Concept IV). Another design for small towns, where smaller houses are more in number, is the roof-top water lens whose focus is suitably deflected to the bottom of the cooking vessel (Type LCA 3a, Concept VI).Of other viable designs Bernards 'COOKIT' appears to be the best suited, other designs are also discussed. ( Update 6 more new designs have been added since this site was launched in June 1999, for details see at the end of this part and also in the respective sections )
PLEASE NOTE:
CONTRIBUTORS TO THIS SITE
Acknowledgements
The author acknowledges the help and encouragement extended by the late Prof. P.S. Shivram, Head, Department of Printing Technology and Energy Centre, MIT, Manipal , who was solely responsible for the publication of the earlier review in 1995. In fact the work on Solar Cookers was launched here at Udupi way back in 1975 and it was Ms Janet Alarcon of VITA and Sri. G K Gopalakrishnan, Chief Documentation officer, TERI , ( then located at Mumbai ) who not only enthused me forther but helped me by sending tons of information. And now, especially to Dr. M C Shukla of TERI, New Delhi, for having recognized this work and encourage compilation of this abridged and updated version, and getting it published in TIDE. I am also grateful to Ms. Bev Blum, Vice President, Solar Cooker International, USA. for encouraging me to put this paper on WEB. I am also grateful to Prof. Sureshramana Mayya, Department of Commerce, at our College for taking special interest in converting this paper into HTML format. ( for other links see at the end of References )
PROLOGUE
( Read this before you go further )
This site was launched in June 1999, since then over 1000 interested persons have visited the site, and many of them have spoken very high of it and some have also suggested changes which have been incorporated. New designs and works too have been added. But before one continues further I request them to read this prologue.
Many of the Solar Cooker Enthusiasts are still keen on fabricating perfect Parabolic reflectors! But this aspect has been dealt in detail under the section and many of the Stalwarts like Prof. T. E. Bowman of Florida Institute of Technology, and also Prof. Roger Bernard of France have suggested using Plane mirrors. I guess it would be much easier to do so.
Remember the insulated Box of Box type Gosh Solar Cooker. Prof. Barbera Kerr and several others had suggested using paper balls, straw and a wide variety of materials for making the box and the insulation to go in-between. Inventors like Patel ( 1981, Ref. 74, ) had in fact suggested inverted Glass Jar in sted of a very heavy and combersome insulated Box. Later Prof. Bernard had suggested the use of such a Jar for his 'COOKIT' design. Glass Jars are costly and are prone for breakage so Prof. Barbera Kerr used clear plastic bags to cover the cooking pots very successfully. Prof. Bowman too had realised the importance of the insulation of Cooking vessel and he had suggested FOAM GLASS boxes around cooking pots for the FIT designs. Recently Deris uses two such clear jars ( Glass or heat resistant Polycarbonate jars ), inverted over the cooking pots where the light is concentrated by a circle of ordinary mirrors! I guess the solar Cooking can not be made simpler than this.
At this juncture I wish to introduce the work being pursued by Prof. David Delaney of Canada. Taking the cue from Prof. Bernard, and Barbera Kerr he is attempting to improve this Glass Jar concept. Covering the Cooking pot with a Glass jar has two problems, handling the cooking pot and its contents become difficult, and condensation of moisture inside the glass container affects the transmission of solar light to the pot. So he suggests use of a upright jar of not more than 2 inches in diameter of the cooking pot. Use of a suitable collar of card board or more stable material for placing the pot into the jar, and also a cooking pot with a clear glass 'insulated' lid. I feel that these suggestions are very apt, but at the sametime find that the Glass jars of that type are rather costly upto Rs. 400 ( $ 10 ) especially because Gosh type Solar Cookers of 2' x 2' were being sold in our country at Rs. 450 to 650! ( $ 12 to 16 only ). I do not suggest that the Box type of Cookers are better, but an attempt is needed to find a suitable material to cover the cooking pot.
Table of Contents
History
Spherical reflector
Fresnel reflectors
Cylindro-parabolic
Plane mirrors
Parabolic mirrors
Rigid parabolas
Shallow parabolic cookers
Deep parabolas
Asymmetrical parabolas
Collapsible parabolas
Box without reflectors
Box with reflectors
Box with single reflector
Box with three reflectors
Box with four reflectors
Box with four plus four reflectors
Chemical cookers
Evaluation of cookers
Some recommendations
Conclusions
Refrences S to W-- & OTHER LINKS
Solar energy is the primary source of energy for our planet. Increased utilization of the same would result in an all-round benefit, both in terms of cleaner environment and monetary gain, for the individual users as well as the nation. Use of solar energy would save a lot of time and money for the user and this could be effectively diverted for increased productive activities and monetary gains which means better living standards and overall prosperity. The Gujarat Energy Development Agency (GEDA 1979) calculates that the use of solar cookers by about 2000 families for 10 years would mean a saving of Rs 3.6 million in terms of reduced firewood consumption, or Rs. 100 million worth coal or Rs. 8.55 million worth kerosene (as per 1979 prices).
History
The history of solar cooking goes back to dim recess of antiquity. The use of solar power to ignite altar fires has been mentioned (Meinel, Meinel 1997). References indicate the use of sun rays to melt chemicals and metals. The very first solar furnace was fabricated in France by the famed naturalist George Louis Leclere Buffon (1707 – 1788). However, the first reference relating to solar cooking was that of Nicholas-de-Saussure (1740 – 1799). There are over 50 major designs of solar cookers, some of which are patented, and more than 100 variations. Of these, this review covers about 59 of the most important variations. The main purpose of this compilation is to present all possible major designs and their variations so as to prevent the solar cooker designer from wasting time on a design which has already been under the Sun. An attempt is made to cover most of the designs, but if there are any omissions then the designers may please send the details (Kundapur 1995). Though the description of the cooker is brief, accompanying diagrams would fill the void. As regards dimensions, adequate guidelines are given in the respective sections, but for concentrating type the area should preferably be more than 1.5 sq. m, and in the case of box type, it should be around 0.6 sq. m.
The solar cookers presented in the review are classified under THREE categories:
The Concentrator type, concentrate the sun’s rays either on to the top or at the bottom of the cooking pot, was the pioneering design. Naturally maximum variations are found under this category and 28 designs are discussed here. The Box type design was one of the first solar cookers to appear under the sun, and is one of the popular designs now. Eleven major designs of this type are described here. The Indirect type solar cookers are those that have collectors outside and the cooking area or plate is inside the house. Some exotic designs are covered here and 11 major designs find place in this review (Chart I).
| Concentrator Type LIGHT FROM ABOVE LIGHT FROM BELOW
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Box-type designs
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Indirect Types
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( for details See Chart Ia ) |
( for details See Chart Ib ) |
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(