In resonance with the renewed vitality in our efforts to "go green," not just at school, but across the country and the world, three sections of Dave Heidel's
chemistry students have been building and testing solar-powered cookers. And, forget the stainless steel décor — these $5 units are made out of cardboard boxes.
"Think of how much CO2 could be eliminated if we could cut the amount generated by wood-fire cooking by half," says Mr. Heidel.
The idea of solar cookers is not new, but inventor Jon Bohmer recently refined the design first conceived of in the 70s with his Kyoto Box
. The ingeniously simple device uses two cardboard boxes, one inside the other, with an acrylic cover that lets in the sun's rays and traps them. Black paint on the inner box and silver foil on the outer one help to concentrate the heat. The trapped rays make the inside hot enough to cook casseroles, bake bread and boil water.
The day for testing the HIES Kyoto cookers found the chemistry students under a warm spring sun, but battling an unanticipated factor — a stiff breeze. The foil-lined cardboard deflectors fluttered frustratingly. "We hadn't counted on this," exclaimed Peyton Warley
, as he struggled to contain the reflector wings of his oven. Nevertheless, there was great excitement as the students watched the temperature readings climb. Probes inserted into the canisters of water inside the ovens recorded and graphed data on their laptops. One group's cooker showed a respectable temperature rise of 14° C over a 40-minute period.
The goals are these, Mr. Heidel told his students: "First you have to get to at least 82°C so you can cook food and sterilize water. Second, you want it to be cheap; otherwise, the poor people in third world nations couldn’t afford to get it. Third, it has to be easy to assemble. And fourth, you would like it to be durable."
For more information on solar-powered cooking, visit these sites: