We’ve previously reported on Barbara Kerr’s solar wall ovens for home use. They’ve been a favorite of mine for over a decade. Yesterday I just came across a larger version of this concept – a commercial size solar wall oven by Gregor Schaper over at Inhabitat.com. The cookers can reach temperatures up to 1,020C and save 16 gallons/month of fuel. His company Trinysol sells the cookers for $4,000 to $5,000. These ovens would work well for restaurants, school cafeterias, eco-resorts and other similar commercial applications.
Related: Wolfgang Scheffler solar ovens (We’ve talked about these solar ovens that feed thousands of people.)
Wish to see it
Carroll:
I think I can explain it for you.
The large dish covered with mirrors concentrates the sunlight and reflects it through a hole or small window in the wall of the kitchen. The big mirror dish is gradually shifted by a mechanical clockwork mechanism to track the sun and keep the light aimed correctly at the hole in the wall.
Once the concentrated light passes through the wall it is reflected upward by a secondary mirror to heat the cooking vessel.
This video shows the whole system fairly clearly. Even if you can’t read the language, the pictures pretty much tell the story.
http://www.youtube.com/watch?v=XszAGwLgYJA
The system is very effective. However, it does have some potential safety hazards. Cooks looking down into a cooking pot or griddle need to be extremely careful to not look down into the secondary mirror and blind themselves. With light that concentrated even just a few seconds of exposure could cause blindness. There also is a significant risk of getting the worst sunburn one has ever experienced. Also, the area between the big dish and the wall needs to be kept clear of people, particularly children. Serious burns could result by someone walking between the dish and the wall even though the dish won’t be completely in focus at that point somewhat diminishing the potential temperatures at that location.
Also note that the wall is made from masonry. That is critically important. If (WHEN!!) the clockwork mechanism that keeps the dish aimed correctly fails or doesn’t keep good time, the mirror can possibly heat a spot on the wall. If that wall were constructed out of flammable materials … better call the fire department. All machines eventually break down, including mechanical clocks. That’s why it’s important to design the wall to withstand the heat from the dish if it gets mis-aimed. Eventually the wall will get blasted by the solar heat beam. Best to make the wall able to withstand high temperatures.
I’d like to see some kind of a metal plate to set the cooking pot on that completely blocks the light from getting into the eyes of the cooks or causing sunburns while stirring the stew. The metal would still conduct heat into the pot without letting light pass. The small reduction in efficiency would be worth the increased safety in my opinion.
This is a very cool idea. I wonder how mirror would work? Any ideas Owen?