Navigating cloud cover

by James Wampler
(Shelbyville, Ky. USA)

Happy post-Halloween!

Halloween marks the beginning of cloudy weather for the Louisville area. We still have sunny days, but November can be a cloudy month.

This will give me more time to tinker with other designs, which will be helpful when presenting information to students on the pros and cons of each system.

My evacuated cylinder has turned out some decent results with a ad-hoc aluminum foil/posterboard reflector. Right now I am looking into materials that would give me the best compromise between reflectivity, resiliency and cost. I would love to hear from anyone who has done some of this research themselves!

I have been looking at types of mirror sheeting, aluminum coated mylar and some stuff I had lying around from a past project called monokote, which shrinks when you apply a heat gun to it. In a future post, I would like to try out reflectors from the various materials and see if there are significant temperature changes in the solar ovens.

I am also trying to find the best way to obtain internal temperatures of the evacuated cooker. My current plan is to drill a hole in the silicone stopper that I can slide the probe through - - I wouldn't imagine that doing so would alter the performance, but it is always good to think something through before you drill into anything :)

Ideally, i would like to model it after successful designs that can be found here like the GoSun stove. Keep in mind, a large part of my job is tinkering and playing around with variables in an effort to teach students to problem solve on their own. In regards to time invested and product outcome, people are probably better off saving up for a commercial unit.

I'll post pictures as soon as I begin experimenting in earnest! For now, enjoy pictures of the latest cookies from the tube! Solar ovens and evacuated tube ovens tend to deal with clouds a little better than parabolic cookers.