Solar cooking

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Default.png    See also the Solar cooking category.
for subtopics, how-tos, project pages, designs, organization pages and more.


Contents

[edit] Introduction

Most solar cookers work on basic principles: sunlight is converted to heat energy that is retained for cooking. Sunlight is the "fuel." The requirements for solar cooking are very simple. You must be able to place the solar cooker in a location that gets sun for several hours and be protected from strong wind. Solar cookers, obviously do not work at night or on very cloudy days. The sunlight is absorbed on dark surfaces that heat up. Food cooks best in dark, shallow, thin metal pots with dark, tight-fitting lids to hold in heat and moisture. To retain the heat created when the black pot absorbs the suns rays some form of transparent cover is needed. This can be as simple as a clear plastic bag or as complicated as evacuated multiple layers of glass. One method to speed the cooking process is to use reflectors to increase the concentration of sunlight on your collector.

The unquestioned authority on solar cooking is Solar Cookers International (SCI). They spread solar cooking awareness and skills worldwide, particularly in areas with plentiful sunshine and diminishing sources of cooking fuel. SCI has enabled 30,000 families in Africa to cook with the sun's energy, freeing women and children from the burdens of gathering wood and carrying it for miles.

SCI also maintains an excellent wiki of solar cooker designs.

[edit] Designs

Solar cookers are solar concentrators where precision and efficiency has been sacrificed for ease of construction and use of readily available materials. Inexact geometries that still allow for water boiling or bread baking temperatures are used.

Solar cookers are usually of the solar funnel, Parabolic (e.g. Focus-balanced paraboloid) or compound parabolic type. See also Using Two Parabolic Troughs to Simulate a Paraboloid.

Some calculations relevant to the design of solar cookers with paraboloidal reflectors can be found on the Sun related calculations page.

[edit] Solar Cookers World Network

The Solar Cookers World Network is an alliance of more than 500 non-governmental organizations (NGOs), manufacturers, and individuals actively promoting solar cooking in more than 100 countries. This wiki-based site allows Network participants to share information and collaborate on projects and research. Solar cooking is an important part of Integrated Cooking, which also includes the use of fuel-efficient woodstoves and heat-retention cookers.

[edit] Solar cooking and violence

Solar cooking has an unexpected relationship - good and bad - with violence.

  • Anecdotes exist that solar cookers are not promoted by some NGOs in Africa due to domestic violence. When the weather has not been suitable for cooking, and the husband returns home to find no meal ready, he may become violent towards his wife. (This raises other issues, but one immediate issue is not to aggravate the victim's situation by having an unreliable cooker.)[verification needed]
  • In Darfur, solar cooking has meant women have not had to leave safe areas searching for firewood - thus these cookers are keeping them out of harms way.

Note that in the case of domestic violence and the failure of the meal to cook, there is a technological solution: integrated cooking (see Wikia:Solarcooking:Integrated cooking method).

The points above come from email conversations. I hope to find get people with experience in these things to contribute to Appropedia. --Chriswaterguy · talk 00:20, 31 October 2007 (PDT)

[edit] Sierra Nevada College Solar Oven Project

For their ENVS 353 Alternative Energy Systems' course, Sierra Nevada College students Tiago Galletti, Andrew Jordan, Parker Martin, and Zach Schomp made available to students two solar cookers. One involved improvements to a prototype designed by former Sierra Nevada College President and inventor Ben Solomon. This cooker was improved mainly by sealing the gaps which were releasing heat and by adding insulation around the outside. The other solar cooker was simply made from cardboard, aluminum foil, and glue. The students used the pdf template from the CooKit website which provided a proven design (link provided under "External Links").

Solar cookers can also be used to pasteurize water. Millions of people become sick each year from drinking contaminated water and about 1.3 billion people do not have access to safe drinking water, including nearly half the population of sub-Saharan Africa. In many of the most severely affected regions, sunshine is an abundant source of energy. Pasteurizing water makes it safe to drink and can be done at temperatures well below boiling. (71°C or 160°F)

These solar cookers will provide students with an alternative option to microwaving their food or eating the food provided by the cafeteria which is not always the best nor healthiest. We have provided them with recipes (also in "External Links") and we hope to get momentum going with these ovens in hopes that the school will serve healthier foods.

Fig 1: Cookit template solar cooker  
Fig 2: Improved solar cooker  

[edit] Interwiki links

[edit] External links


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