Roxie Peters — Solar ovens are not objects of the future or of the past but an alternative increasingly used in every country in the world to cook without using other energy than the sun. The first solar cooker was invented in 1767 by a Swiss named Horace de Saussure, who made numerous experiments on the greenhouse effect and invented the first solar oven equipped with reflectors to concentrate sunlight.
Today there are thousands of models of solar ovens, and more recently, they invented concentration models that are based on the concentration of solar radiation at a point where you can place a pot, using a parabolic reflector.
What is a solar cooker?
A solar cooker is a device which uses sun to cook food or boil water. The vast majority of the solar cookers are not expensive devices and you can easily find solar cookers plans online. Generally they don't need fuel and cost nothing to operate, many NGOs are showing how they work worldwide to help reduce energy costs for poor families.
Using solar cookers also reduce desertification, caused by use of firewood for cooking. Cooking with a solar oven is a form of outdoor cooking and is often used when it is dangerous to cook because of high risk of accidental fires. If you like travelling, it’s a good product to put in your bag!
Solar cooking in the world
In Europe, only a privileged few who have a south facing terrace can enjoy solar cooking, but these cooking equipments are also used increasingly in countries where solar radiation is constant throughout the year and where resources for cooking are limited and have an impact on the environment.
In Africa, for example, they are essentially cooking with charcoal and firewood. It is good to remember that more than half of the world population has only this solution to cook every day, increasing deforestation and desertification in some areas.
This cooking solution has several impacts besides being expensive for these populations: Firewood collection is a very hard work and requires time that could be used to develop other activities in many homes and the smoke of this cooking medium each year causes many health problems for people.
According to a study made by the Food and Agriculture Organization (FAO), an inhabitant of Africa consumes between 1 and 1.5 kg of firewood each day to cook, which represents about 500 kg of firewood per year and per person. If we calculate the impact on global warming, this represents 670 kg of CO2 per person per year.
The solar oven being a thermal box designed to capture solar energy and keep warm inside, reduces the risk of burns, avoids the possibility of fire, prevents food from burning and loss of its nutritional value, and allows doing other activities while cooking food. Moreover, excluding the materials needed for the manufacture of a solar oven that can represent some kilos of CO2 emitted, the big advantage is that it doesn’t pollute and it doesn’t need any additional energy than sunlight.
Are there disadvantages of cooking with a solar cooker?
Yes, there are some disadvantages: solar cookers are less usable in rainy weather but it has a fuel-based backup heat source in these conditions.
Also, solar cookers take longer time to cook food than fuel-based cookers. Using a solar cooker requires to start several hours before the meal for a cake. However, it requires less attention, so this is often considered a reasonable solution.
Data source: The Solar Cooking Atlas
Solar Cooking Atlas is a good website that aims to inform about solar cooking projects and worldwide solar cooking associations. It has numerous articles, photos, videos and solar cooking recipes available online.