We've been reading up on solar cookers, which use concentrated solar heat to cook food. These usually take the form of an enclosed box oven or a large dish or surface that collects and concentrates heat on the baking dish. You can see video of how these work at this Solar Slow Cooker site, which encourages you to unplug your CrockPot, take it outside, and plunk it in the middle of one of their concentrating solar cookers.
Solar cookers have been used in many countries where fuel resources are low or where war and unrest make cooking by more traditional methods difficult. They have also been used for water pasteurization in remote areas.
We like the idea of using one, especially for camping or an extended cabin stay. Have you ever used a solar cooker?
(Photo credit: Solar Cooking.org)