The sunstove is a solar box cooker developed over the years by Margaret Bennett and Dick Wareham. Margaret"s story, as she articulates in Science in Africa, started during 1989 at a World Conference of the World Association of Girl Guides and Girl Scouts, a delegation from Solar Cookers International presented their cardboard solar cooker. It was suggested that sunny countries such as South Africa should take up this idea and, through their members the Girl Guides, should attempt to spread the solar cooker concept.
As an Adult Trainer within the Girl Guide Association, Margaret Bennett was tasked with taking the solar cooking concept out to South Africa, a country renowned for its abundance of sunlight hours. The initial plan to spread the word was to assist rural woman with the making of their own solar cooker and then to have this knowledge passed on to neighbours, and so on and so forth. Initially the idea did not take off as expected, mostly due to a lack of easily available materials and expertise.
This approach was abandoned and Margaret Bennett looked into designing and manufacturing the solar cookers herself. She approached the largest corrugate manufacturer in South Africa, Nampak, for assistance. She asked them to manufacture a kit solar box that could be sent out and assembled on site. They put in a huge amount of time and effort in perfecting the bonding of aluminum foil to heavy-duty cardboard and produced a great solar cooker, at least in theory.
Unfortunately the material input costs of this initial model were prohibitive and Margaret Bennett experienced a lot of cost-resistance. In addition, the design itself proved to be problematic. The large reflector held up by a prop stick was a huge nuisance. It either fell flat or acted as a sail and carried the solar cooker away in the wind. It was difficult to train inexperienced users to align it properly around 2 axes, and if it wasn't focused, it didn't cook.
At that juncture, serendipity came into force and through a series of events Margaret Bennett teamed up with Dick Wareham who had designed a solar cooker model without a reflector but with sloped sides and tilted window to compensate. Their biggest challenge proved to be the logistics of distributing their Sunstove solar cooker around South Africa as they discovered that the round Sunstove solar cooker did not travel very well. The Sunstove tended to distort in transit, which became problematic.
This problem was overcome by designing and manufacturing a mould using a blow moulding process, and ultimately a robust Sunstove solar cooker emerged that would withstand rough handling during transport and actually stack together to cut costs. The current Sunstove model performs even better than the original design, it is less complicated to manufacture, it travels well and only weights 11lbs (5kg) and costs less than $50.
To read more about the Sunstove and other similar solar cookers click on this link to get instant access to my ebook Sun Solar Cooking.
In addition you can get immediate access to my free mini course on solar cooking by clicking here.
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