Building a solar cooker is easy and inexpensive. There are a variety of designs and materials a solar oven can use but they all rely on the following concepts:
- Concentration of sunlight; Reflective material is used to concentrate the light.
- Conversion of light to heat; Black cookware will absorb more light resulting in more heat generated.
- Greenhouse effect; Using a transparent material will allow light in which converts to heat gradually raising the temperature.
Using all three of these concepts together will produce the best results in a solar oven. Any reflective material can be used to create a solar oven. One of the easier to obtain is aluminum foil. On the right you can see one made from a car windshield reflector. Most store bought solar ovens use mylar due to its even light distribution and high reflectivity. Once you’ve chosen a reflective material you need to build a support structure that will focus the light over a large area onto the cooking container. This can be made from cardboard, wood, sheet metal, or whatever you feel confident with or have available.
It’s a good idea to construct this reflector outside in the sunlight so you can be sure the light is being reflected into the proper place. Once you have your reflector created you’ll need something to cook in. As mentioned above black cookware will work the best. It’s easiest to just buy a pot or other black cookware but efficiency may be improved by custom building a cooking box. As seen in the picture above you should lift your cookware off the reflector to allow light to strike it from below. Any kind of stand that allows light through will work for this. Your solar oven can be used to cook anything that a normal oven can. You’ll just have to leave it cooking longer.
Finally you’ll also need to enclose your cooking area so that heat can’t escape. One of the most simple methods of accomplishing this is to just use cookware that has a lid with a good seal. Of course, as with all the components of a solar oven the more “leak proof” this container is the better performance you’ll get out of your cooker. Another easy and inexpensive way to accomplish this is to use an oven bag that is tied closed and simply place the cooking container inside it.
Cooking time varies greatly depending on how much sunlight you’re receiving, what you’re cooking, how well designed the oven is. Be aware that opening the cooker to check on your food will release the heat resulting in longer cooking times. This can be easily avoided by placing a thermometer in the cooker so you know how long and what temperature your food has been cooking which can be used to roughly estimate when it will be finished without opening the cooker.
Just remember the three basic components of any solar oven, reflector, cooking container, and heat container. You can find many designs and material ideas online. However, being creative and using what you have available is the best bet. Despite what you might think a solar oven can cook anything just as well as a conventional oven. All you need is patience and you can enjoy renewable, free energy for cooking almost anything.Sponsors: