Solar Thermal Primer

Depending on where you are, Planet Earth's surface generally receives from 1 to 4.5kWh per m2 of Solar energy per day.

This amount of energy is sufficient to give you sunburn with sufficient exposure time, but not enough to cook.

Since critical temperature is required for cooking, if we can concentrate the amount of solar energy to a small point, the concentrated solar thermal energy could be raised to a temperature that is sufficient to do meaningful cooking. Imagine using a magnifying glass to concentrate sunlight to a point strong enough to burn a hole on a sheet of paper.

Another way of converting sunlight into cooking fuel is through trapping and accumulation like that of a glass house. Trapped solar thermal heat if accumulated and prevent from being lost to the ambient can raise to a critical temperature that is sufficient for cooking.

The key to mining free energy from the Sun as fuel is therefore in concentrating sunlight to reach a critical cooking temperature point of at least 65degrees Celsius through the process of concentration and/or accumulation.

Parabolic and Fresnel type cookers concentrate sunlight to a smaller point to reach temperatures that cook and Box Cookers and Solar Kettles using solar vacuum tubes technology accumulate trapped solar heat and prevent its lost to the ambient by insulation. Panel Cookers are hybrid Solar Cookers employing a combination of concentration and accumulation.