Sacramento's Solar Cookers International, will take the global stage Friday in Florence, Italy. The nongovernmental organization, which is dedicated to saving the world with solar power, will receive an award from the World Renewable Energy Congress. The secret of the group's success is the CooKit," a 3-by-4-foot piece of cardboard lined with aluminum foil that harnesses the sun's rays to cook food and pasteurize water. About 90,000 "CooKits" are heating up in Africa, where they are being manufactured and sold for $8 or $9. The group has helped introduce 500,000 solar cookers to 25 nations where people spend half their $1-a-day wages to buy firewood to cook their meals, said Bob Metcalf, a microbiologist who co-founded the group in 1987. Solar cookers allow them to spend that money on food instead of firewood, said Metcalf, who teaches at California State University, Sacramento. Metcalf says he hopes the award will get him 30 minutes with Bill Gates or some other investor to spread the gospel of the CooKit, which could be used by "2.5 billion people today" who rely on wood, charcoal or animal dung to cook meals. Metcalf also invented the Water Pasteurization Indicator -- a reusable sealed test tube with wax that melts when food or water has been pasteurized at 149 degrees Fahrenheit. "It takes about 90 minutes in the sun," he said. For more information, go to www.solarcookers.org.