01/17/2013

Solar cooker is a device that uses heat and sun light to cook food. Usually, solar cooker is cheap since it doesn’t use fuel and needs a little maintenance, so you can actually build your own solar cooker instead of buying a cooker. Also, solar cooker is known to reduce the pollution and to save of the forests. “http://greenliving.nationalgeographic.com/three-main-types-solar-ovens-2877.html“. Nevertheless, the popularity of solar oven is not that much because it has some significant disadvantages; since it requires sunlight, it is hard to cook with solar oven in cloudy and winter days. Also, it takes longer time to cook food than fuel cooker and you can’t use it neither inside the house nor in gathering meetings. http://www.doityourself.com/stry/advantages-and-disadvantages-of-using-a-solar-cooker#.UPh34a6nhKk.

However, the challenge for inventing a better oven is accepted. H. S. Udaykumar, a mechanical engineering professor in university of Iowa explains the challenge by saying “First, the cooker should operate in the early morning and late evening when the sun is not at peak. They should be able to cook indoors, sitting down. They cook for two hours each time. The stove top temperature should be about 200C, with heat delivered at approximately 1 KW to the cook surface.”  The challenge was to design a low cost oven that can keep energy to cook for up to 18 hours. Three universities in addition to some Indian teams worked to make almost 10 different ovens designs that can works at night and indoor. https://www.engineeringforchange.org/news/2012/02/04/ten_solar_cookers_that_work_at_night.html

For example, the Scheffler cooker is one of the best designs  for solar ovens that work at night.  It is based on a large parabolic reflector which is easily positioned to focus the sunlight onto water container and well concentrated sand, salt or ceramics in the cooker. The steam of the heated water will cook the food. And the materials in the cooker such as sand will save the heat and energy that they gain from the sunlight all the day so that it will be able to use it at night. This stove can reach temperature that could even burn wood. “http://www.solarcooking.mobi/solar-cooking/types-of-solar-cookers/scheffler-parabolic-cooker.html “and ” https://www.engineeringforchange.org/news/2012/02/04/ten_solar_cookers_that_work_at_night.html “

Another design is the iHawk cooker. A cooker with two storages containers, one for the morning and the other for the night. Basically it uses parabolic reflector pipe to concentrate the light into v-Shaped mirror which reflects the sunlight to an absorber plate. A poylwood box filled with sand and aluminum cans insulated by rice husks contains the absorber plate which lead to the thermal conduction https://www.engineeringforchange.org/news/2012/02/04/ten_solar_cookers_that_work_at_night.html

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