Modified Panel Solar Cooker

by Dr N K Srinivasan
(Palo Alto,CA, USA)

Modified Panel cooker

Hi Nathan Parry!
I made a small panel cooker using cardboard with back panel size 15in x 12 in and side panels of the same size.
I realized while using this cooker at Palo Alto, (30 deg N) a lot of radiation was reflected back to the sky. I tried using a small top panel --again about 12inx12in with aluminum foil--to cover the top. Since I intend using the cooker in early mornings and late afternoons at this latitude, I made the top panel a sloping one ---like a sloping roof,by making cuts at the side panels to fix this top one.

The performance improved significantly--the cooking time was reduced by 30% compared to the cooker without the top panel. I tried cooking potatoes--the usual vegetable I use for trial measurements which took about an hour on 30th Jan 2011.
With this modification, this panel cooker appears almost like a Telkes solar oven tilted vertically or any solar oven sans the glass chamber for the pot. I used a blackened cooking pot ,set on a black can to raise the level for maximum capture of the radiation.
I hope that this modification of panel cooker would be adopted by cooker designers for panel cookers at higher latitudes.


___________________________________________

Greetings, Dr. NK,

Thank you very much for this excellent and helpful information. This is an issue that is quite common with a variety of solar cookers; lost energy due to bouncing and out-reflecting rays, and especially so with many panel style solar cookers.

I am sure many people will find your information very helpful in their own solar cooking efforts.

Thank you for including a photo of your cooker as well.

Nathan
Admin.