The fact that on a sunny hot day you can cook fried eggs on stones without much difficulty has long been known. But people did not stop there and came up with a solar furnace. It is much more functional and effective than hot stones. If you are traveling in the sultry southern countries, a solar oven is sure to come in handy.
Solar stoves can be of the most diverse design. Some stoves can be the size of a box and have the shape of a box. Others are commensurate with cabinets and can be equipped with a lens system for additional concentration of sunlight. Despite the different appearance, such stoves operate on the same principle and serve for cooking.
The most elementary option of such a stove is a box glued with foil. Food is prepared in a black saucepan. The solar stove is covered with a glass lid, through which rays penetrate into it and are delayed. And it’s best to make a stove of such a plan from sheet metal.
The advantages of solar furnaces are: compact design, the use of only solar energy, successful heating, not only under the influence of direct rays, but also scattered. An indisputable advantage is the fact that making a solar furnace is cheap and simple. If mirrors and lenses are used to concentrate heat, then in such an oven pies are successfully obtained. And the water in them easily and quickly boils.
A significant disadvantage of them is the inability to heat food if the sun has disappeared. Any dish during the day will be cooked for at least several hours. If you prefer fried foods, then a solar stove is not an option.
The thermal power of such a furnace depends on the amount of solar radiation, on the area of the heat-absorbing surface, as well as the thermal efficiency.
In most cases, reflex furnaces have a larger working surface than drawer ovens. From this it follows that their power is higher. So, you can boil more water and cook more food in a shorter time interval.
In countries with tropical and subtropical climates, clear weather and good lighting last for almost a year.Thermal power, due to the most intense total solar illumination, increases by noon.
With cloudiness or rain, solar radiation decreases dramatically. And in such conditions, a solar oven is only suitable for storing already cooked food in a warm form. It remains only to use traditional means: firewood, a kerosene or gas burner.
When using a solar oven, do not forget about one simple rule: the color of the dishes should be black. Light walls of the dishes will repel heat. The body of the solar furnace is best covered with insulation. With proper observance of all the requirements for the manufacture of such furnaces, it is easy to achieve a temperature of 90 degrees in them. For cooking ordinary plain food this is enough.