How did a bunch of cardboard boxes become a solar oven and win the Green Contest?
When Jon Bohmer sat down with his two little girls for a simple project they could work on together, he didn’t realize they’d hit upon a solution to one of the world’s biggest problems for just $5: A solar-powered oven. Inventor Jon Bohmer with the oven he has made out of a cardboard box. The ingeniously simple design uses two cardboard boxes, one inside the other, and 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 concentrate the heat. The trapped rays make the inside hot enough to cook casseroles, bake bread and boil water. What the box also does is eliminate the need in developing countries for rural residents to cut down trees for firewood. About 3 billion people around the world do so, adding to deforestation and, in turn, global warming. By allowing users to boil water, the simple device could also potentially save the millions of children who die from drinking unclean water. Bohmer’s invention on
This is the £50,000 winner of a contest to find the world’s greenest invention – a solar-powered oven made from cardboard. The cooker took the FT Climate Change Challenge crown after beating 300 other creations, including a food additive which stops cows passing wind. The Kyoto Box oven – which costs just £3.50 to make – can cook casseroles, boil water and bake bread. It is made from two boxes, one inside the other with an acrylic cover, which lets the sun’s power in and traps it. Black paint on the inner box and silver foil on the outer help concentrate the heat while a layer of straw or newspaper between the two provides insulation. Sources: http://blog.makezine.com/archive/2009/04/cardboard_box_wins_uk_green_contest.
