Solar Oven using Recycled/Donated Material[edit | edit source]
For my Alternative Energy Class Final Project at Sierra Nevada College I built a solar oven with the provision of Ben Solomon’s shop and tools, and taught a sustainability lesson to middle school class from The Tahoe Expedition Academy with Celia. My inspiration for sharing my project with the youth comes from a quote in our library, “What we have done for ourselves alone, dies with us; what we have done for others... remains and is immortal”.-- Albert Pike.
The oven is great for my own household cooking needs, but the evolutionary aspect of my project to share sustainability with others, was the defining moment of my project’s completion. I will go over the innovation, the investigation, the investment, and conclude with the implementation of my solar oven project.
My innovation, the oven used almost all recycled and donated materials with the exception of screws, brackets, glue, and paint. Some of the materials I obtained from various dumpsters of local companies and local construction projects like the art building down the street. The plywood to construct the cooking box was donated to me from the Truckee Tahoe Lumber Company, and the rest of the materials were either donated by Ben Solomon or purchased from the local Ace Store.
The oven center box, made from plywood rectangles screwed together, has insulated walls and floor using cork board and is lined with sheet metal which I cut, installed with glue, and spray painted black to absorb the sunlight. The reflector shield was constructed using trapezoidal pieces of plywood which I cut with a skill saw, and screwed together using metal braces which I machined from a steel strap using a nibbler and drill press. Then I tried to cut mirrors with the trapezoid dimensions, and after failing to cut perfect trapezoids, I resorted to cutting squares and right triangles which i glued to the trapezoid plywood shield. The reflector shield sits into the oven box and a glass rectangle glazing which I cut to size, sits inside the reflector shield and on top of foam weatherstripping that lines the cooker box opening. The oven center in about 14 in. by 12 in. and is 9 in. deep. I use hook latches to hold the reflector shield to the cooker so it can angle down and be disassembled for easier mobility.
The angling mechanism i constructed is a gimbal mount using 2x6’s for legs and swinging on a pivoting bolt. I made holes on the sides of the cooker box to hold the angle when adjusted. The oven is a bit heavier than expected, which is what I would change if I built. another oven.
Over all the oven works great and has recorded temperatures close to 300 degrees F, which was my goal for the oven. The innovation took many adjustments and testing to acquire maximum efficiency, which was a great learning experience. “If at first you don’t succeed try, try again” -- Ben Franklin.
The investigation of the solar oven capabilities came first from what others had built, and second from the testing and adjusting the completed solar oven. Some things that i discovered, was that the cooking center should be just big enough to fit the cooking pot you wish to use, otherwise there is too much space to heat, taking away from cooking the food. I was going to make 4 square sides for reflection but after some investigation, I found that a full 360 degree reflector greatly increases the efficiency so I made trapezoid cuts rather than squares.
Another adjustment was putting a metal knob in the center of the glazing to concentrate the sunlight into the cooking center which improved the efficiency substantially. Spray painting the sheet metal lining black also made a huge difference, increasing the temperature. The investigation of trial and error was the great learning experience I hoped for when I began building the oven. I made changes based on observations, and tested the changes, either accepting or rejecting the change depending on the change of efficiency of the oven. Investigating is learning by doing.
The investment for the building materials of the solar oven was well under my estimated cost of $50, costing about $10 in new materials. However I did spend a lot more time than I expected, about 40 hours of construction and refining. My investment of time was well spent, because I got to see and learn first hand about how to capture the most possible sunlight by making small adjustments and tweaking the design slightly. Another small investment was gas for driving to collect materials from local sources and driving to work on the oven itself.
Overall the project probably cost me about $100 for new materials and gas for driving, but my investment of time, learning new construction techniques, and real life skills is priceless and outweighs the dollar cost of my oven. My investment of teaching a passive solar design lesson to the middle schoolers is also priceless and gave me another level of confidence, personability and self satisfaction. This is one investment that continues to give me positive returns whether its tasty food or gratification of giving back to the community.
The implementation of my solar oven consists of cooking food when it is appropriate ( very sunny)and continuing to share the ideas of passive solar technology and sustainability with the community. For the Evolution of solar technology I finished the project by sharing the concepts of solar energy through the educating a middle school class at the local Tahoe Expedition Academy, in order to further the exploration and passion for creating efficient communities that are symbiotic with nature.
This brought the project full circle and I was able to share all the things I learned during the design, construction, and use of the solar oven to provide the youth with early ideas of sustainability. I was so impressed by how much the students wanted to know and learn about living sustainably. It was overwhelming how many thoughtful questions and ideas were posed during the class session. We needed more time to share with youth, they were really forward thinking and engaged in the topic. This gave me the greatest feeling of completing the project, having sparked the imaginations of the next generation. Implementing the solar oven will provide me with a cooking source year round, using minimal resources, and be a catalyst for the encouragement and education of this generation and the next.
The solar oven was a huge success, achieving my goal of 300 degrees F and costing only $10 in new materials, while learning construction skills, techniques, and designs. On top of creating a recycled, durable, efficient oven which will be home’s sole source of cooking, educating a middle school class was the highlight of completion. Being able to share ideas of what living sustainably means and seeing that the kids just wanted to learn more, was the biggest success of implementing the oven in the real world. Overall this project has given me more than I had ever expected and all the struggles and barriers were well worth the work.
I feel renewed, rejuvenated, and empowered to design, build, and educate.