A parabolic solar cooker is essentially a solar thermal collector [1] used to cook food or pasteurize water. Parabolic designs have been used for centuries. The idea to concentrate light using curved mirrors was developed by the Greeks, Aztecs, Incas, Romans and Chinese. The Incas used bronze and gold for their mirrors and they built structures that were several stories high. This technology seems to have appeared around the same time for each of the civilizations.
There are many designs and models for parabolic solar cookers. Some are made with locally gathered scrap materials while others are manufactured using highly machined, durable but more expensive materials. Here are links to and photos of a number of parabolic solar cooker designs.
Danger from concentrated sunlight
A parabolic cooker concentrates sunlight. Ordinary sunlight is already dangerous (if the sun is viewed directly without protection) so concentrated sunlight can be much more so. (There is a story that someone in the USA damaged their eyes in this way.[verification needed])
Ways of reducing the danger include:
- Safety rules.[1]
- Design. Note that these mostly reduce the danger rather than eliminate it.
- Putting the focal point inside the parabola, so
- A table to protects the cook from burns and dazzles.[2] (How does this work?) It obviously can't block too much, or it will block the sun from the doing its work.
- Keeping the parabola small.
- designing the parabola to avoid a small sharp focal point. This requires that the cooking vessel have a relatively large
Notes
- ↑ E.g. Safety Rules (from the AMSI Solar Cooker Project)
- ↑ http://solarcooking.org/images/gallery-para.htm Parabolic Cookers] (The Solar Cooking Archive)
See also
External links
- Build a Solar Cooker - plans at The Solar Cooking Archive (solarcooking.org)