Dear Solar Guy, I have heard that solar cookers can be practical - can cook both vegetables and meat. Could you explain how well they work, how widely they are used and their cost. Carolyn Legume, Turkey, TX. ----------------------------------------- Dear Carolyn, Yes, they certainly are practical, though it takes more time for the cooking and one is somewhat dependent on the weather, though even under somewhat overcast conditions these devices work. There are a wide variety of solar cooker designs. You will note one advertisement in the last issue of the solar reflector for a very high performance solar cooker built in the Austin area. Then there are other designs that are much simpler and less expensive, which require better solar conditions, won't achieve as high a temperature and will require more cooking time. So the answer to your question, "it depends". In any case, most of these devices require that the solar conditions be moderate to good, that the food be prepared well ahead of time so that the cooking can be accomplished during the mid-hours of the day for consumption later. But the temperatures achievable are well above the pasteurization temperature (about 170 F) and at or above the nominal water boiling point. While these temperature are typically below the conventional cooking temperature, cooking is achieved more slowly and over a longer period of time, and the food is claimed to be superior. At the recent Solar 98 ASES meeting in Albuquerque, I was highly impressed by an impromptu presentation by a fellow from Solar Cookers International. They decided a couple of years ago to design a very inexpensive, practical solar cooker for use in underdeveloped countries. About the same time the mass of refugees from Rawanda was becoming a major international concern. In the end they developed an 'erector' type cooker made from a single sheet of corrugated cardboard (about 4 ft x 6 ft) - aluminized on one side and water-proofed on the other. The sheet was 'stamped' so that it could be folded into an interlocking 'box' with back and side reflecting panels. To achieve the desired temperatures the 'crock pot' is placed in a clear plastic bag - i.e. the green-house effect. In this way temperatures in the 'pasteurization to boiling' range can be achieved. The amazing part is that these cookers were manufactured in Kenya at a cost of about $3.50. They were shipped to the refugee areas as pallets of several hundred cardboard sheets and distributed to the refugees. It is estimated that a solar cooker can save about a ton of wood per year and that about 1.5 billion persons are affected by wood fuel shortage. The loss of vegetated areas in some parts of the world has resulted in a serious affect on the environment - loss of this sustainable resource itself, erosion and flooding. It was really impressive to see a need being met in such a cost effective way. For more information on solar cooking you might contact Steve Cook at UTEP (915) 747-6646, or Marge Wood at Abilene Christian Univ. (915) 674-2341. Solar Cookers International (SCI) can be reached at FAX (916) 455-4498 or on the Web at The Solar Guy.