Black Pots and Deeper Parabola
Looking at your photo of the hot dogs and beans being cooked, I can't help but think it would go much faster with a black-bottomed pot/pan to absorb more reflected sunlight. Also, I heard shallow reflective cookers that focus above the rim have caused accidental fires. Why not have a deeper parabola with a focus below the rim. It would be more efficient (more light concentration and less breeze cooling) and would also be safer.
Thank you for your questions and concerns.
You are very observant and bring up some good points.
Yes, If one can find some "heavy gauge" metal cooking pans that are also dark in color then that would be great to use with the solar parabolic cooker.
Yes, it would give you a bit extra advantage by absorbing some more of the focused rays of the sun.
I have used both kinds, both dark and bright metal, I just happen to have access to more of the standard bright metal cookware (heavy gauge steel)
Because the Solar Burner generates such intense heat I have not experienced much by way of reduced efficiency and effectiveness when using bright cookware cooking on the Solar Burner Parabolic. I am still able to cook, deep fry etc. as quickly as I would on a standard range top, even with the bright steel pots.
And, you are right when you state that a "deep dish" parabola keeps the focal point below the rim.
This particular model, The Solar Burner, just happens to be manufactured with the shallow dish parabola and is very effective in its own way.
The deeper the dish (parabola) the more you spread out your focal point, covering the sides of a cook pot as well as on the bottom, whereas a shallow dish will focus mainly on the bottom of the pot.
We carry parabolic cookers that use both the shallow and deep dish and will soon have another added to our lineup of cookers that will have a deep dish.
Yes, If one were to store a parabolic with no protective covering next to a wooden, grass or thatch structure you can run a risk of starting a fire.
Most people if they are instructed properly on care and use of a parabolic cooker they can avoid such possibilities or incidences.
So yes, you bring up some very valid points with regards to cooking and safety with a parabolic cooker.