[Greenbuilding] Fresnel lenses box solar cooker

[Topher]

On 6/2/2013 3:13 PM, sanjay jain wrote:
> http://www.ebay.com/itm/Made-in-USA-plastic-Plexiglas-3D-Fresnel-Lens-Collapsible-Solar-Oven-Cooker-/251281362842?pt=LH_DefaultDomain_0&hash=item3a81894f9a

I am confused about how it works at all...

1) Are those small lenses? Mirrors?  Convex or concave?  What would 
EITHER do to improve performance?
2) What good could fresnel lenses on the BOTTOM do?  Are they 
reflective?  (hard to tell from pictures)
3) Solar Microwave?  Pseudo-science alert.
4) Insulation?  What temperature do you expect a plastic box with a pan 
hot enough to cook pizza in it to be?
5)Typography is another scam alert.

General design considerations for a solar oven.  1) Largest solar 
aperture possible.  Forget about ambient light.
2) Insulate the rest.  3) Reflect any light not absorbed by the pan, 
back for another try.

Thank You Kindly,

Corwyn

-- 
Topher Belknap
Green Fret Consulting
Kermit didn't know the half of it...
http://www.GreenFret.com/
topher at greenfret.com