Solar water heater for farm water trough?

heynow999
heynow999 Solar Expert Posts: 80 ✭✭✭✭
Another trade show question, we are doing a farm show and we get farmers asking for a way to keep the water trough out in the field from freezing. I don't really know how this can be done economically with PV because they need the electricity exactly when the available sunlight is the lowest. I was thinking some thermal set-up as it is so much more efficient? They only need to keep the water from freezing.

Any ideas?

Comments

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Solar water heater for farm water trough?

    A flat plate thermal collector, and a small PV & recirc pump ? But even if you got the tank heated up to spa temps at 4pm, a bit of a breeze and cold weather, you will have ice in the AM.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Solar water heater for farm water trough?

    How cold it gets will make a difference of course.

    But here's one man's answer: http://www.builditsolar.com/Projects/WaterHeating/SteveTank/SteveTank.htm

    Another similar design: http://highmountainhorse.blogspot.com/2009/11/insulated-water-trough.html

    And I know there's a commercial version because I've seen it - 30 years ago. But I can't find one on line now! It had floating balls on the top which kept ice from forming on the surface. Livestock could just nuzzle them out of the way to get at the water.

    EDIT: found it; http://www.jfc.ie/InsulatedWaterTroughs.html
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Solar water heater for farm water trough?

    A completely different tack. Heat line makes submersible semi-conductor heat tape in both 12 vdc and 120 ac configurations. Couple this to a agua-stat so that they draw no current until the water temp reaches a prescribe degree of cold,,say +.5C or 33F. A few watts of heat tape running only as needed might work just fine.

    http://www.heatline.com/kompensator.htm

    I have also installed a number of horse waterers with built in heat systems in them. They are self filling so they only hold ~ 1 gallon of water so the heat requirement to keep them above freezing is pretty small. The harder trick is keeping the water lines to them from freezing given how little water they use.

    Tony
  • System2
    System2 Posts: 6,290 admin
    Re: Solar water heater for farm water trough?
    heynow999 wrote: »
    Another trade show question, we are doing a farm show and we get farmers asking for a way to keep the water trough out in the field from freezing. I don't really know how this can be done economically with PV because they need the electricity exactly when the available sunlight is the lowest. I was thinking some thermal set-up as it is so much more efficient? They only need to keep the water from freezing.

    Any ideas?

    Thought this may help you:
    http://www.gearsolar.com/SolarPacTS2400.aspx

    Low cost all in one unit. No pumps needed. We sell them to Farm Users all the time and are always looking for Dealers.

    Cecil
  • SolarLurker
    SolarLurker Solar Expert Posts: 122 ✭✭
    Re: Solar water heater for farm water trough?

    Would a circulating pump keep it from freezing.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Solar water heater for farm water trough?
    Would a circulating pump keep it from freezing.

    A lot depends on how cold it gets where the trough is located. In some cases circulating would work. In fact they sell "circulators" to keep the water from freezing around docks:
    http://www.thepondreport.com/dock-bubbler-deicer.shtml