In April 2009 a Norwegian with studies in the United States (Berkeley, California) and living in Kenya, Jon Böhmer, took a prize "green" of $ 75,000 (NOK 568,000) for a very cheap solar oven: costs only 6 , $ 6 (5 euros). With the oven can cook food in casseroles, boil water or bake bread. It consists of two boxes, one to another, covered with acrylic to give power to enter and keep Sorel there. Inner box is painted black and silver foil outer heat facilitates concentration, while a layer of straw or newspaper between the two provides insulation. The oven is addressed to the three billion people who use firewood to cook in developing countries. Barbara Kerr and Sherry Cole was the first serious promoters of solar cooking box in the 70s and its plans could be found in a book published by the Peace Corps in the 60s. Solar ovens allow water purification by heating it. A water heated to 65 degrees away diseases common in poor water quality, often present in developing countries and responsible for millions of deaths. On the other hand, cooking with wood smoke gives rise to respiratory diseases responsible the deaths of 1.6 million people / year worldwide. Also, by using solar ovens are avoided deforestation and carbon dioxide emissions into the atmosphere.