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close this book Boiling Point No. 36 - November 1995
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View the document New Prospects in Solar Cooking-The GTZ Solar Cooker manual
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Solar Energy in the Home

Solar cooking was the main theme of our April 1991 issue (Boiling Point 24) and has been reported in many other issues. Included in this issue are descriptions of different types of solar cookers, and articles which both support and question their use. This theme has been chosen again in the hope that we shall learn of some new developments and stimulate more realistic research based on user needs rather than inventors' imaginations.

IT and GIZ are frequently asked for their assessment of the suitability of solar cookers for use in developing countries. Regrettably, they are not convinced of the general appropriateness of solar cookers in their present stage of development, and so are not directly involved in their promotion.

The idea of harnessing a free source of energy is very attractive but the simple fact (usually ignored) is that the capital and maintenance costs of solar cookers which are effective, durable and easy to use and make, are far beyond the means of the poor. At present, solar cookers are a luxury in the Third World for those who are already relatively well off.

Other reasons why solar cookers have been found inappropriate and unacceptable to the needs of poor people in developing countries are their high cost, and the fact that they do not operate in bad weather or at times convenient for women to do their family cooking. They may also require the cook to be standing in the hot sun when cooking. Some basic foods such as potatoes, cassava, yarns and beans need to be well boiled before they can be safely put into a solar cooker. This means that two stoves are needed, and the cooking process takes several times longer than with the traditional three-stone fire or a simple mud or clay stove. It's Stove and Household Energy (SHE) prograrnme has concentrated on researching, developing and promoting improved biomass stoves to suit the local customs and conditions, which can save a quarter to a third of the fuel normally used.

There are some circumstances in which solar cookers have performed satisfactorily and appear to be acceptable to the users, such as refugee camps. We will continue to monitor solar developments and hope to receive a reliable report of a programme disseminating more than about 1000 solar cookers, without large subsidies, and which are still in use. Until then, we regret we are not able to recommend any of the many ingenious designs we have received.

There is an enormous amount of written material on solar cooking, with hundreds of papers and books produced over the last 20 years or more, mostly promoting new designs. The most comprehensive of these is probably the GTZ/GATE solar manual discussed below.