What degrees of the panel should we put to make the solar panel reflect heat efficiently?
Heavens Flame cooker
Should it be 120????????????
Your answer could work, depending on the size of your solar oven and the size of your panels.
Here is some advice and information from another website source:
The angle of a reflector should be no more than 22.5 degrees from perpendicular to the glass. If the reflector is taller than the glass is wide I would go with 20 degrees off perpendicular. That means the reflector will be between 112.5 degrees and 110 degrees.
And here is one more person's answer:
The angle usually works with the length of the reflector. So a longer reflector will have a more acute angle, and a shorter reflector will have a shallower angle.
The angle is usually chosen so that when the cooker is pointed right at the sun, a point of light falling on the upper edge of the reflector will just touch the far side of the glazing (glass).
Something like a 45 (135) degree angle is used with the Heaven's Flame oven. More typical is the 60 (120) degree angle used with the Global Sun Oven. The advantage of the shallower angle is that less reflective material is needed. The advantage of the sharper angle is that the edges can be joined together to form a very solid structure.
And, here is a great website page from a friend of mine on how to determine reflector panel size and angle: http://rimstar.org/renewnrg/how_design_solar_cooker_sun_reflector.htm
I hope this is helpful.