Morris Dovey wrote:
dpb wrote:
Morris Dovey wrote:
dpb wrote:

My guess is there's not enough solar heat density to make it
practical in size anyway, just wondered if you'd looked into it.

I have, but not for a while - because (in my ignorance) I thought it
a solved problem.

The approach I had been working on involved using a solar-powered
pump to pump solar-heated _air_ through an immersed tube in an
insulated stock tank.

I think it can be made workable, so if you have a little time to
collaborate, you're invited to e-mail me directly...

OK, later on I may do that. Will have to guesstimate what heat load
would have to be to have a relatively low level of icing given a tank
size. You have any idea what kind of power level you might be talking?

It's fairly difficult for me to do much estimating without a handle on
your weather conditions and some info on tank/stock dimensions - for
example, I don't have any idea how far a steer can (or is willing to)
"reach" for a drink, and that'll be a determining factor for the
thickness of insulation that can be used around the tank.

The way to approach his kind of problem is to assume that all the power
needed is available, and then design to use it as efficiently as
possible - and size the collector to capture whatever turns out to be
needed.

....

Well, they'll reach as far as they can if thirsty, just like they reach
under a fence for that delectable blade of grass...

About 3-ft is probably practical limit--but you have to count for the
water level dropping as they slurp it down, too. Even in cold weather
they'll average 3-5 gal/day/head. So far all we've used are the round
metal tanks--typically 12-ft diam are convenient to handle/haul and one
or two are enough for each location.

Not sure the best estimates for weather to try to use as I think of this
more. The problem as I see it on further consideration is that the
coldest weather is when the pita factor kicks in the most as that's when
if the heaters go out the tanks freeze fastest and thickest so both
longer time w/o water and more waste and more trouble. Yet to design
for the 0F/30-mph condition would probably be way over what could be
practical. I'll have to think some more, Morris and take this offline...

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