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.