Have you ever thought about using the sun’s free energy to cook your food?
We use it to heat our houses and our water, but how about directly cooking food? A solar oven can create stews, soups, breads, meats, grains and vegetables without using fossil fuels.
Summer is a good time for beginners to experiment, since the days are long and the sun is high. You can use a solar oven year round, except for the coldest three months of the year at very extreme latitudes. The sun has powerful energy!
The principles of solar energy are the same in cooking as they are in building. Capture and collect the sun, and add some thermal mass (your pot of food) where heat can be stored. The stored heat cooks the food.
What is a solar oven?
A solar oven is similar to a slow-cooker. The heat is low, and foods cook slowly over a long period of time. You can’t overcook or burn the food, since temperatures do not get hot enough. Temperatures gradually build up to 300-350. Foods stay moist, since there is no drying air movement inside. Just like a slow-cooker, you can put your ingredients in the oven, leave for the day and come home to a prepared meal!
There are many solar ovens on the market at affordable prices, but it is a simple DIY project, too. It can be as simple as two nested boxes with insulation between the walls and the bottoms. Line the inner box with foil, and paint the bottom black. Make a clear plastic lid and add foil-covered reflectors on three sides (these could be the flaps of the boxes). That is the simplest idea for a portable oven.
Solar ovens in outdoor kitchens
A solar oven can also be a permanent addition to your outdoor kitchen on some sort of support. Surround it with an insulating material, such as mud, to keep the heat in. My partner and I have talked about building one into the south wall of our kitchen. It would be accessible from the outside for summer cooking to keep the house cool, yet in winter, the oven door would be in side, and we could let the heat come in the house. I’m eager to try this out!
Solar ovens are used in third world countries by peoples who have little fuel close by or where fuel has gotten too expensive. In some areas, where wood is scarce from over-harvesting, solar ovens have been employed to feed hundreds of people. There are many places in the world where there is no access to clean water, so solar ovens are also used for boiling contaminated water to remove bacteria.
Where else are solar ovens used?
Off-grid homes often employ solar ovens to reduce the load on the solar PV system. They are also great for camping and backpacking, since they can be portable. A solar oven is also a handy thing to have for power outages.
A school or camp group can build a solar oven from a pizza box. Children can learn about the environment, solar energy, building and cooking. What a great project! I once saw a young boy eat a chocolate chip cookie fresh out of a solar oven on display at a solar festival. He was enjoying his treat, but he was also in awe of what had just happened!
Whether you choose to purchase one or build one yourself, you are lowering your carbon footprint by using no fossil fuels. If your oven is built of recycled, non-toxic or sustainable materials, it is that much more eco-friendly. Cooking with solar in summer allows you to eat hot, nutritious meals without heating up the house, which calls for more energy and money to cool it. Solar cooking is a very green option!