Low energy livestock water tank de-icer

[bcroe]

As delta V gets smaller, it becomes more efficient.

Based on comments and a couple pics, I am going to try and define just what
we are talking about here. If this is not it, let us see your detailed explanation.
PVtoHeater.jpg
Here is what I make of the discussion. The panels are allowed to charge the
cap to the MPPT voltage. As that is slightly exceeded, the MPPT switching
control closes the switch and allows current to flow through the water heater
element. With heater current exceeding panel current, the capacitor voltage
will drop slightly below MPPT and the switch will be opened. This continuous
action will keep the cap voltage close to MPPT.

This system I concede to be approaching the theoretically possible 100%
efficiency of other MPPT controls such as used for charging batteries. There
are a few practical considerations to actually making it effective.

The control should be as close to the heater as possible. Otherwise, the wiring
will be an antenna for interference generated by the switched current. The
inductance of long leads could also develop severe ringing voltages. The
resistance of the heater should be high enough to limit peak on current, or
losses will build up in the wiring, the switch, and the cap equivalent series
resistance.

Not shown here is the max water temp shutdown input.

I would not describe the above as adiabatic capacitor charging, I thought that
was charging a cap by connecting it directly to a voltage source. The blackboard
exercise never happens in the real world, things like resistance and inductance
prevent a cap current pulse of infinite amplitude and zero time. Load dump
comes to mind. Bruce Roe

[PNPmacnab]

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

I guess it is too late to get your money back for your education. As delta V gets smaller, it becomes more efficient. HWBnew65W_17ms.jpg
Just an old image I grabbed. This is a 5% hysteresis from a test hey can be much smaller. It is adorable that you think you have any knowledge you could offer me.

[Mike90250]

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.

Awesome, I like that. Now to keep the waterline feeding it from freezing.

[DanS26]

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

[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.

[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

[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]

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

[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.

[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

[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

[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 ???

[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

[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.

[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.