Safety First
Be cautious when handling scissors or a cutter, and always wear sunglasses when handling the solar cooker in direct sunlight. Be aware that the cooking pots get as hot as in any kitchen – use gloves not to burn your hands.
Activity Description
1. Find a piece of cardboard big enough for the planned reflector or combine several bits of cardboard to get the surface needed.
2. Copy the shape of the reflector to the cardboard (by hand).
3. Use white glue diluted with some water to stick the aluminium foil to the cardboard. Use a very soft cloth to gently press the foil to the cardboard, in order to avoid without creating wrinkles.
4. Finish the reflector according to the plans you chose.
5. Find a cooking pot of a dark outside colour and with a lid. Find also a wind shield which can be a high-temperature plastic bag (‘chicken bag’ or ‘turkey bag’ from a supermarket) or a glass bowl slightly bigger than the pot.
6. Learn how to orient your cooker and get used to solar cooking. Start with simple recipes and small quantities. You can find more information and tips to these topics in the activity ‘Solar cooking’.
NB:This text mainly refers to the model ‘CooKit’, a panel-type solar cooker. You can also choose to build another type of solar cooker, you find a huge list of plans in the link on the right side. We also recommend the Copenhagen cooker or any box cooker.
Exploring the Science Behind
Panel-type solar cookers efficiently concentrate sun rays, i.e. solar energy, onto a relatively small area, using reflective aluminium as a mirror. A black pot placed in the solar cooker absorbs this energy and turns it into heat. This heat is used to cook the food within the pot, with nothing more but sunlight.
From a scientific point of view, the reflector must be as shiny as possible to reflect sunlight, while the object to be heated (the cooking pot in our case) must be as dark as possible in order to absorb the sunlight and transform it’s energy into heat.
Additionally, the efficiency of the solar cooker can be increased if it is insulated or protected from the wind, since heat is naturally lost (‘transferred by convection’) to the air. A windshield is normally made out of a heat-resistant plastic bag or by covering the cooking pot with a glass bowl.
The history of the specific model ‘Cookit’ ist described in the following text from Solar Cooking International SCI: “In 1994, a volunteer group of solar cookers and engineers associated with Solar Cookers International developed and produced the CooKit, based on a design by the French scientist Roger Bernard. Sleek and deceptively simple in appearance, it's an affordable, effective and convenient solar cooker. With just a few hours of sunshine, CooKit makes tasty meals for five to six people at mild temperatures, cooking foods and locking in nutrients without burning or drying them out. Solar cookers also allow some essential processes, such as pasteurization and sterilization.
Did you know… Solar cookers can significantly reduce firewood consumption, benefiting rural communities. Although solar cookers cannot replace other cooking methods entirely, they offer a sustainable alternative during daylight hours.
Still, solar cooking is not reserved to poor communities, it can be done by anybody having access to a sunny spot! It is a fun activity, it can open our eyes to other forms of ecological actions, it makes us observe the weather and much more. In a school or university context, building a solar cooker can be combined with reflections about climate, physics, cooking and development work in communities.
Evaluation
Explain how the solar cooker works based on energy transformations during cooking.
Reflection Questions:
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The cooking pot gets hot in a solar cooker. But how about the reflector, does it get hot, as well? Why? Or why not?“
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How can solar cookers contribute to addressing environmental and energy challenges in our community?
- What obstacles can we imagine to using a solar cooker? Why does not everybody on this planet uses one already?
Additional Solar Chef Activities:
- Cooking adventure with family and friends: Put your Solar Chef skills to the test by preparing a delicious meal for your family or friends using the solar cooker! Start with simple recipes like heating water to make tea or coffee. Gradually challenge yourself with more complex dishes like cooking rice or vegetables. Share your sustainable cooking creations and the benefits of solar cooking with your loved ones.
- Explore solar recipe collections: Discover a world of solar cooking possibilities by exploring various solar recipe collections online or in cookbooks. Seek out recipes specifically designed for solar cookers, and experiment with a wide range of cuisines and flavours. Challenge yourself to create a diverse menu using your solar cooker.
- Design your own solar recipes: Unleash your creativity and design your unique solar recipes! Experiment with different ingredients, cooking times, and flavour combinations. Document your creations and share your innovative solar recipes with others who are interested in sustainable cooking.
- Solar Cook-Off Challenge: Organize a friendly solar cook-off challenge with friends or family. Each participant can choose a recipe and prepare it using his/her solar cooker. Share your culinary masterpieces and evaluate each other's dishes based on taste, presentation, and sustainability. This fun competition can inspire everyone to explore further solar cooking.
- Optimize solar cooker design: Get hands-on with solar cooker design by altering elements of it. Test how different configurations affect cooking efficiency. You can try out other reflector materials, reflector shapes, better insulation, wind shields, the size of the elements, etc. Record your observations and discuss your findings with fellow Solar Chefs.
- Solar cooking outreach: Share your knowledge and passion for solar cooking with your community or school. Organize a solar cooking workshop to teach others how to build and use solar cookers. Spread awareness about the environmental and social benefits of solar cooking and inspire others to adopt sustainable cooking practices.
