by Dr Samuel Alexander, co-director of the Simplicity Institute and a lecturer with the Office for Environmental Programs, University of Melbourne.
I was at the salvage yard the other day and saw some cheap mirrors, so I bought them. Not so that I could look at myself. From my typical appearance it is clear that I do not do that nearly as often as I should. Rather, I thought I could use them to make a good solar oven, and it turned out I could.
As you will see from the pictures, a solar oven works by concentrating the sun’s rays toward a central tub which heats up and thus functions as an oven. My solar oven consists of four mirrors, two cardboard sheets which I covered with tin foil, a black tub (a good colour for heat absorption), and the glass from a picture frame. Within the tub I placed a closed cooking pot with a glass lid. Total cost of these salvaged materials: $38.
I set it up at 10:30am and much to my surprise the cooking pot was too hot to touch in about half an hour. This was all the more surprising because the temperature in Melbourne today only reached 22 degrees (C) and there was scattered cloud for parts of the day. By mid-afternoon I had successfully cooked beetroots and carrots from the garden, as well as a bowl of red lentils. I chose beetroots and carrots due to their natural sugars, which were enhanced during the slow cook. Dee-licious. I look forward to experimenting with different foods (e.g. bread, pasta sauces, potatoes, cakes etc.) especially as we enter summer days reaching heats into the 30s and 40s.
Solar ovens are hardly a means of giving up your indoor oven. The sun is not always shining, and some foods probably won’t work so well. But when the sun is out and temperatures are moderate to high, solar ovens provide an easy, fun, and cheap way to reduce electricity or gas consumption in cooking. If everyone used such a device once or twice a week during the warmer months, fossil fuel consumption could be significantly impacted.