Has there been a study as to how much more efficent a kiln would be if it could rotate one revelution per 24 hours and present the broadside to the sun, for all of the day lite hours. Say a kiln mounted on the turn table of a track hue. would it be worth concidering.

I don't know if you need a study for that. I'm sure it would make a significant difference. More so the farther north you go. Pretty cool idea.

JJ, sorry for the crazy delayed response. It would definitely make a difference - there are rotating mounts used for photovoltaics already. However, I think it wouldn't be worth the effort and defeats the premise of a solar kiln. Simplicity is one of the greatest benefits of a solar kiln. Adding a way to rotate the kiln would greatly raise the cost. Once you get to $4k or $5k then you might as well go with a dehumification kiln (assuming you have power at your site).

I think the bigger option to consider (and one that hasn't been talked about much in the solar kiln world) is simply increasing the collector size for a given number of bdft. The VT kiln is designed to ensure oak won't be dried too quickly. There are lots of woods that can be dried much, much faster than oak. With a larger collector, these other woods can be dried much more efficiently. I think that's the basis behind the Timbergreen kilns and their ability to dry through the colder months. I"ve also thought about some sort of reflectors used in the winter months, but I haven't really worked it out.