Low energy livestock water tank de-icer

[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 )

[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

[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.

[chrisski]

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


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

Could not find the website. I got "builidsolar.com cannot be found

"

I looked at builditsolar.com, but nothing on livestock.

[J.P.M.]

Could not find the website. I got "builidsolar.com cannot be found

"

I looked at builditsolar.com, but nothing on livestock.

I made a typo that got past my usual error checking which itself is less than perfect.

I apologize for my error. Looks like you figured out the site is "Builditsolar.com".

About 5-6 items are in there on ways to use solar to add heat to keep water in stock tanks from freezing. Keep snooping.

[PNPmacnab]

Not sure what you are calling off grid. Sometimes these tanks are even too far away from your home. 45F is not a bad temperature. The tank is storage for heat which the heater may not be able to accomplish when it finally gets cold. If I had a remote tank 65F is where I would set it to store as much heat during the day. PV solar may be low enough with used panels. Here is a system that will heat at power point without a battery. It can even operate off existing charge controller array raw voltage in parallel with a charge controller. A heater with a small chimney arrangement would circulate water to keep a small opening from freezing. Production still is often poor when you need it most.
HW_BOARD_new.jpg

[Mike90250]

Is that heater controller a kit, product, or totally DIY ? Any source info about it ? What sort of power can it handle, 48V or 12V ???

[bcroe]

Sure tell us about it. I think the proposal is heat water directly from solar panels,
running at MPPT? Not very effective under clouds or if panels are covered with snow.
I see no inductor to allow setting up MPPT efficient power operation. Bruce Roe

[PNPmacnab]

There is no need for an inductor. It is PWM duty cycle from a capacitor bank with arc interruption. This design has been used around the world for several years. It should go into production next year. Very similar to this https://actii.pl/knowledge/?p=14

[bob-n]

If PV can work, why not consider directly heating water with black pipes? It should be much more efficient and perhaps cheaper. There are lots of solar hot water systems out there. You could either use a heat exchanger from the pumped fluid or directly run the tank water through the heat collector. The heat exchanger concept allows you to use an antifreeze in the pumped fluid.

[bcroe]

There is no need for an inductor. It is PWM duty cycle from a capacitor bank with arc interruption. This design has been used around the world for several years. It should go into production next year.

You said it works at POWER POINT, does that mean MPPT? No inductor required for PWM,
but efficiency will be much poorer. Bruce Roe

[PNPmacnab]

There are many variations of MPPT. All have their advantages and disadvantages. This uses the thermal coefficient of the panel to change the power point voltage. Not ideal for shade, but if you go into bypass you won't be heating much anyway. This method does allow you to parallel the water heater with the charge controller to harvest excess energy not needed for charging. It uses the principal of adiabatic capacitor charging and it is quite efficient >97%. One user in Australia says energy production is right in line with his grid tie system. He mounts the temperature sensor to his tin roof as it gets about the same sun. I don't bother with temp tracking at my camp since a portion of my array is always in shade. A seasonal adjustment is all that is necessary with excess production doesn't occur to any degree till the panels are warm.

[bcroe]

This method does allow you to parallel the water heater with the charge controller to harvest excess energy not needed for charging. It uses the principal of adiabatic capacitor charging and it is quite efficient >97%.

Better do your research. Adiabatic capacitor charging might be only 50% efficient. It IS NOT MPPT,
which can approach a theoretical limit of 100% efficiency. Bruce Roe

[DanS26]

Here is the ultimate low energy freeze proof sheep waterer.....in fact it uses no energy........

https://www.horsedrinker.com/product/sheep-goat-automatic-waterer/

I've used this waterer for my sheep for over 10 years and never failed.

[DanS26]

Mike......Google "BAR-BAR-A Sheep / Goats Automatic Waterer"