Solar Cookers: What are they and how do they work?
Tags: Cookers, Eco Build, Handmade, Kettles, light, Plastic Bags, Rainforests, Renewable Energy, Renewables, Solar energy, Solar Heating, Solar hot water, solar panel, Solar Panels
Finding an appliance which needs absolutely no fuel and costs nothing to run is difficult to say the least. However, solar cookers and ovens require only sunlight as their energy source. The advantages of such contraptions are being embraced by humanitarian groups as a means of helping poverty-stricken communities cook food without having to rely on fossil fuels such as wood and coal. Solar cookers also minimize the risk of forest fires due to the fact that they do not require fire for the creation of heat. 10,000 solar cookers have already been donated to various refugee camps in Darfur.
Solar cookers work by concentrating sunlight using mirrors or other highly reflective materials, such as certain types of metal. Concentrating the sunlight into a smaller area concentrates the energy and allows the area to heat up more quickly. In order to maximize the amount of heat created by the concentrated sunlight in the cooker, the cooking pot within the oven is usually black in colour and made of a highly conductive material - black objects will usually absorb most (or all) of the sun’s light and turn it into heat. It is vital that the air within the solar cooker’s glass or plastic cover is isolated from the air outside. This is because the cooker works much like a greenhouse: once the light is absorbed by the pan and converted to heat, this heat is effectively trapped inside the cover. This is a huge advantage because it means that the solar cooker can also be used on cold or windy days. Below is a list of the various types of solar cookers with brief descriptions of each.
Box Cookers: A box cooker is literally a box (big enough to hold a cooking pot) with a transparent glass or plastic window at the top. They usually have reflective panels that extend vertically from one or two sides of the box which allows sunlight to be reflected more effectively through the window. This type of solar cooker can reach temperatures of 150 degrees Celsius.
Panel Cookers: This type of solar cooker uses panels lined with a reflective material (such as aluminium foil) to direct sunlight towards a cooking pot that is enclosed in a plastic bag. These are cheap to make and can be produced from everyday materials found around the house such as cardboard, foil and regular plastic bags.
Solar Kettles: Solar kettles use vacuum solar glass tube technology to capture, accumulate and then store solar energy within the kettle itself. They can often store enough energy to keep the liquid contained inside hot throughout the night.
