Low energy livestock water tank de-icer

[J.P.M.]

How much water do the animals need over, say, an 8 hr. period ? 24 hr. period ?

Solutions can depend on how complicated or involved you want to get. As I'm sure you know, min. involvement to maintain takes more time/$$ upfront or paying someone to haul your water.

Consider (daily or any period draw) X (some safety margin) and get a smaller tank sized for the design water use/draw with margin. In doing so, keep the open water surface area as small as possible/practical without spooking/confusing the animals. Insulate the sides and bottom of the tank if possible.

I'd avoid using fiberglass batts for insulation for possible animal health reasons (and maybe, come to think of it, avoid using wool or insulating material that looks like wool - sort of like walking toward a sheep while wearing Wellington boots, the sheep might get the wrong idea and think your intentions are less than honorable).

~ Minimum atmos. design temp. ? likely wind speeds ?

Before I went much further, I'd see "the engineer's toolbox", "heat loss from open water tanks", and figure out how much electricity it'll take to heat the water in the existing tank to keep it freeze free.

Basically, design for the minimum heat loss/degree delta T. at the minimum atmos. design temp. and max. sustained wind speed for a smaller tank with a smaller surface area. That min. loss is best achieved by the smallest tank that'll do the job. Then, get the smallest heater that'll meet a tank design heat loss low enough meet that demand for electricity you can tolerate and make sure the heating element has a thermostat. A lot of older mechanical thermostats could be "fooled" on temp. settings by screwing around with the mechanism. I'm not too sure about newer types. A poorer option is putting the heating element on a timer.

I'd also consider putting/floating/placing a smaller tank on top of or near the larger tank and seeing if that smaller tank with it's lower design and average heat loss are small enough to live with.

Another alternate that starts to get complicated: Build a (hopefully small) breadbox batch type water heater and elevate it above and near the above mentioned smaller stock tank. Put a small electric heating element in the batch heater and plumb/hose the water from the batch heater to the (Smaller ?) stock tank. Put a valve between them at the batch heater and maybe it won't freeze up.

Cover the batch heater at night. Electric use for the batch heater will be much less than for any stock tank, maybe by something approaching to an order of magnitude. With any luck, a bread box type batch heater will minimize the electricity or other non alternate energy required to keep the water for the sheep from freezing up.

Another possible option: Put a circulating pump on the stock tank and keep the water moving when the environmental temp./conditions warrant it. small circulator draw maybe < 40 W and with little head may flow about 3-6 GPM. Depending on tank shape and pump outlet location, that may produce enough turbulence to prevent complete freeze over most of the time. Bubblers might be another option here but their efficacy is probably also f(tank size, shape).

Also, Builidsolar.com has several ideas for insulated and solar heated stock tanks.

FWIW,

J.P.M.

[bcroe]

There used to be small propane heaters for cars or car engines, one of those might
be all you need. good luck, Bruce Roe

[Mike90250]

Wife (SWMBO) wants to not have to go out daily to carry hot water for "her" sheep. She wants an electric tank heater, which often run 400w and thermostat at 45F.
being off grid, that's a problem. Anyone come across any other solutions ? I've racked my brain for 2 years, and even dog dish deicers have a 40-45F thermostat. I'd be happier with a 35F stat, but maybe their sensors are not precise enough.
My thought so far is a sloping 1" hose, and fill the bucket in the AM from that, instead of hauling a bucket out through the muck .
No idea too outlandish ( except a radioactive waste as a heater )