A solar oven or solar furnace is a way of harnessing the sun's power to cook food. A metal box forms the simplest solar oven. A set of large mirors or a large Fresnel lens to focus sunlight to a single point may also be added. On a sunny day a black baking tray or cooking pot can convert thousands of watts of light directly into heat. Temperatures in the oven can reach 400 degrees F (200°C).
Apart from the obvious need for sunlight and the need to aim the solar oven before use, using a solar oven is not substantially different from a regular oven. However since they use no fuel they are free to run. Humanitarian organizations are promoting their use worldwide to help slow deforestation and desertification caused by the need for firewood with which to cook.
The first known western solar oven was built by Horace de Saussure in 1767.
Diffusion of innovations theory, discussed in the book of the same name by Everett Rogers, discusses adoption of solar ovens in Lesotho. Although solar ovens were safer and cheaper to use than oil burning ovens, Lesotho women resisted using them. Agencies such as the Peace Corps have tried to use "change agents" to influence the women. But these change agents have differed from the women in class and norms and were not effective in spurring change. Researchers have found that the diffusion process works better if the change agent trains a local aide who belongs to local social networks and can better influence locals.
See also: solar box cooker
