The panel style Cookit, which is made of cardboard and aluminum foil is the simplest type of solar cooker. Advantages: It's very cheap, it can be manufactured anywhere by anyone; it works well with the lightweight aluminum pots that most refugees and others in the developing world already have; once the food is in, the cook can go off and do other things. The Cookit only needs to be turned once or twice during the cooking process to keep it facing the sun.