My in-laws use electric water
heaters, but I've helped with some other farms here. The electric water heaters are REALLY popular up here, even for sites that are somewhat off-grid.
We get lows of -10 F routinely, -30 occasionally at night up in the hills here. (that's about -25 to -35 C, in round numbers)
I have seen bigger troughs stay unfrozen longer, especially with a good-sized herd sharing the same trough so the water is added more often. Goats and sheep seem to keep the ice broken up pretty well. A lot of the farmers I work with will do 1 heated and 1 spare water trough, so there's a fallback if the unheated one freezes. Some places will bucket water from 1 heated storage tank to 3 or 4 different stock-watering areas, all unheated. Seems like at that point, if electric is not your thing, you could do the same with a single, freeze-protected water source in a house or
greenhouse.
Just adding fresh/warm water to the chicken pan daily seems to be enough for most flocks. (I would bring a bucket of warm water out, wash out the heated pan, refill, then pour the leftover warm water into the unheated pan to melt the ice, or dump out the ice if it looked grossly dirty. Extra pans seemed like it let all the girls get a good drink while it's fresh, and then the heated pan inside the coop was the main access point for the rest of the day.)
I have an idea, untested, but let me know if anyone tries something similar:
- The simplest solar water heaters are a clear case over a black pipe or tank, with insulation anywhere that's not actively collecting heat.
I wonder about using a big shallow rubber pan or bin, maybe just start with the oversized oil-change pans that people already seem happy with, and use a piece of Plexiglass to cover 2/3 of the pan. (A broken windshield from an ATV, or a Pyrex pan of the right size, could work fine - just something a little tougher than window glass, to take some abuse from the birds.)
Insulate the outside or bury it in dry earth, to avoid unnecessary heat loss out the sides.
Leave in a sunny location, with the water available through the last 1/3 opening.
Consider a floating, insulated, evaporation barrier on the drinking side, to further reduce evaporation losses (something like an empty plastic bottle or hip-flask, that would be too smooth and boring to peck apart, but could be pushed under water/out of the way to get a drink.) A string, hinge, screen, or bars between the drinking and supply sides might be needed to keep the drinking-side cover in place.
If it freezes, can always kick the ice out of the rubber pan and start over, as most people are already doing.
If it works well enough to be interesting, could be built into a box, with added features.
Make sure the clear lid is airtight as possible, except where it's open for drinking. Condensing water would be a good sign, that means you're recovering some of the evaporative heat loss.
Consider making the solar-heated end deeper, for a larger water supply that will hold heat longer into the night (using
pond liner or something). A larger trough or bin could be used, with screen or bars to keep the birds from accidentally falling down into deeper water under the cover. Or it could be a standard tank-type self-watering trough, with a pan at the bottom and replacement water overhead, an airtight lid, and good insulation. With the self-watering kind, seems like a glass airtight lid might be technically tricky to make, and keep the access easy. So I'd lean toward a black tank (can blacken other colors with food-grade oil and soot), and build the clear-topped, insulated box for solar collection around the whole thing.
Black, or any dark color, is most likely to be effective at heat collection.
It would be smart to cover it with insulation during the night, if it's convenient (if you're already visiting the birds morning and evening).
The sun collection could be expanded with tin-foil covered reflector panels, like a solar
oven... an insulative cover with reflective foil facing the tank could serve both functions, with a keeper chain at the right angle to catch some extra sun at the end of the day. (Two or three panels will get you near-total coverage from morning to evening...)
Although if the birds are half as smart as they seem to be, they'll start sitting on the cover and sunbathing. I suppose a chicken tanning-bed would not be a bad accidental side effect, if it keeps them happy.
Mad science .... FOR THE CHICKENS!!
Let me know if anyone gives it a try.
-Erica
(aren't you proud that I didn't suggest a
rocket stove water heater?)
It sounds like one of the main purposes for such a contraption would be to increase the number of days the flock can go without attention.
If you're visiting morning and evening to open/close a lid on the solar water tank, there's not much difference to just hauling a bit of water out twice a day.
If you have larger flocks, or your winter water access is difficult (trucked or moving hoses around), I could see where you might find it worth building several water contraptions so you can run the refills less often, say once a week.
As an occasional farm-sitter for neighbors, I suspect that finding a compatible human who can be trusted to check your beasts while you're gone, and swapping flock-sitting for fresh eggs on the occasional winter absence, will probably be the most
permaculture solution in the long run.