A solar cooker is a device which uses the energy of direct sunlight to heat, cook or pasteurize drink and other food materials. Many solar cookers currently in use are relatively inexpensive, low-tech devices, although some are as powerful or as expensive as traditional stoves, and advanced, large-scale solar cookers can cook for hundreds of people. Because they use no fuel and cost nothing to operate, many nonprofit organizations are promoting their use worldwide in order to help reduce fuel costs and air pollution, and to help slow down deforestation and desertification.
The first academic description of the principles of a solar cooker is by the Swiss geologist, meteorologist, physicist, mountaineer and Alpine explorer Horace-Bénédict de Saussure, in 1767. The principle of cooking meals from the sun was largely developed in the French Foreign Legion, in the 1870s. Different kinds of solar cookers (more than 300 models of solar cooker had been made so far) use somewhat different methods of cooking, but most follow the same basic principles.