A solar cooker refers to a device that uses sunlight energy to heat, sterilize or cook food and drinks. They require no fuel to operate (aside from the sunshine) lowering the operation cost. Nowadays most people are opting to use solar oven cookers, as they are both cheap and
environmental friendly. A lot of information has been published on how a person can build his or her own solar cookers.
There are different types of solar cookers and Simple Box Cookers are the most common and easiest to make especially during an emergency. The cookers require low energy to make a meal estimated at 4% average on the normal budget. They are relatively easy to use and they work best during summer time. They also have a medium maintenance level as their durability depends entirely on how a person takes care of them. Its skill level is basic so it can be used by anyone.
How to build a solar cooker
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Here is a list of all things a person needs to make a solar oven:
- aluminum foil
- small and large cardboard boxes
- non-toxic glues, scissors
- Non-toxic Invisible Tape
- plastic wrap
- Black Construction Paper
All these materials can be easily accessed during an emergency.
Instructions on how to construct a solar oven
Get two boxes, which fit, in the other with the smaller one leaving a space of about 2-3inches all round. The space should be filed using newspapers. Crumpled newspaper should be used in lining the bottoms side of outer box. The inner box should be fitted inside the larger box the space between them filled using crumpled newspaper. Using aluminum foil, line the inner sides of the inner box.
Then use the non-toxic tape to fold the foil edges above the outer box in order to keep it intact. The Black Construction Paper is used to line the lower side of the inner box to act as the heat absorber. A piece of cardboard should then be laid above the outer box then trace its shape on the cardboard. From trace line, add about two inches all round then cut it out to come up with a reflector.
The piece of the cardboard should be covered using the aluminum foil and the wrinkles smoothed out. The aluminum foil should be secured on the cardboard using non-toxic tape or non-toxic glue. The reflector is then stapled on the backside of the outer box. The oven should be placed in such a way that the reflector faces the direction of the sun when the box opens up for maximum heat. The pot with the food should be placed inside the inner box. On top of the large box, stretch a wrapper, which is clear, and secure it using a tape all round the whole box.
The solar cooker should be in a position to withstand high temperatures of around 150 Degrees C (300 Degrees F) without out-gassing or melting. This temperature is not hot enough for the standard oven but can cook food only that it takes a longer time since the solar oven is not hot enough. Only food with less moisture can get to a temperature of around 100 Degrees (212 Degrees F), for those with more moisture it will be hard to get to that temperature. Since the food cannot reach high temperatures, it is still safe for a person to leave the food inside the cooker all day long without burning it.
Some solar cookers can get to a temperature of 600 Degrees F but most traditional ones have a range between 250 and 350 Degrees F. The temperature is very sufficient in cooking almost all food.
The temperatures are sufficient for food preparation as well as preservation like pasteurizing and sterilizing. Pasteurizing is normally achieved at 65 Degrees Celsius (150 degrees F) while maintaining the temperature for 20 minutes. It can sterilize water that boils at 100 Degrees Celsius (212 degrees F) and this makes it a good tool during a disaster as people can access clean water and food.
Depending on the weather the person is experiencing the food can take a longer or a shorter time to get ready but generally food takes about twice the duration of time they would take on a conventional cooker. Solar cookers should be cleaned thoroughly to avoid cases of food contamination as well as food poisoning.