Solar cookers provide an easy, portable and clean method of cooking food and sterilizing water for people around the world. Aid organizations encourage the use of solar cookers made from simple materials in Third World countries and areas where disaster has cut off access to electricity and cooking fuels. People in more advantaged countries use solar cookers to save money and resources.

Parabolic collectors resemble satellite dishes made of shiny metal. Sun shining on the metal heats it to very high temperatures. The sides of the cooker reflect the heat to the middle of the cooker, where food cooks in a pot or even directly on the metal of the cooker.

Solar box cookers, whether metal, cardboard or Styrofoam, feature an insulated box with a dark base, reflective lid and clear glass or plastic cover. The reflector directs the sun's rays into the box, where heat is absorbed by the dark bottom and trapped by the cover. Heat builds up to temperatures high enough to cook food.

Solar cookers work by collecting heat from the sun and concentrating it to heat a pot or other container for cooking. Cookers feature some kind of reflector to gather and concentrate the sun's rays. Either the cooker itself or the cooking pot stores the heat. Parabolic cookers, because of their large, highly reflective surface, can reach high temperatures very quickly. Solar box cookers take longer to heat up, but retain heat for long periods of time. Cooking food in a box cooker is similar to cooking in an electric slow cooker or crock pot. The food cooks at lower temperatures over a long period. Larger cookers can reach higher temperatures, but take longer to heat up. Solar cookers can be used even in winter in the snow.

Once the cooker is in place, the energy to make it work is free. Solar cookers produce no greenhouse gases and use no oil, gas, wood, coal or other polluting fuel. Families don't have to spend money for fuel. Solar cookers also produce no smoke or cooking fumes. Box cookers are easy to use and don't need tending. Box cookers are also simple to construct and can be made cheaply with only cardboard boxes, aluminum foil and plastic or glass. Parabolic cookers can purify large amounts of water in areas where contaminated water is a problem.

Solar cookers don't work at night or on cloudy days. Parabolic cookers can get dangerously hot. You need to wear sunglasses when looking into a solar cooker, since the sun's reflected rays can hurt your eyes. Food takes a long time to cook in solar box cookers, so you have to plan meals early in the day.

Moist foods such as soups and stews cook best in solar box cookers. You can bake quick breads, brownies and cookies in a solar cooker, but cakes and yeast breads don't turn out as well, because of the variable temperatures inside the cooker. Cooking times for foods in solar cookers varies, so experiment with recipes. Use dark metal cooking pots and pans for the best results. Cast iron and granite-ware pots work well, or paint cookware with black barbecue paint. The paint must state that the paint is food safe when dry.