powernovice: Off grid PWS Pump and Panel Questions

This discussion was created from comments split from: buying panels.

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  • powernovicepowernovice Registered Users Posts: 7 ✭✭
    I am sooo new to this and sooo confused. We decided to go solar with a deep well pump for livestock. The well is 300' and the solar kit is a PWS pump, 0.7hp, 48v DC which has a max flow rate of 9gpm with a max total head of 390'. The power is 540 watts. Also comes with the MPPT controller.
    I couldn't find the 4x 200w, Vmp: 36v panels that were recommended.
    I settled on 4x150w mono 12v instead. I just got everything delivered yesterday and am now in a panic that this may not be sufficient. BUT hope that my saving grace is that we only require a drip system in the long term or a timer for once a day short flow.
    Does anyone know if this will be sufficient or do I need to increase my panels?
  • BB.BB. Super Moderators, Administrators Posts: 31,082 admin
    Powernovice,

    Welcome to the forum. I have moved your first post to its own thread. This way the discussion will focus on your Q&A.

    Is this the kit?

    https://www.plumbingsupplystore.org/pws-48v-540-watts-stainless-steel-316-submersible-solar-water-well/

    Do you have any information on the MPPT controller (I guess the LCB--Linear Current Booster equivalent)?

    In general, to answer your question, need the detailed specifications for the MPPT controller.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • powernovicepowernovice Registered Users Posts: 7 ✭✭
    BB
    Yes that is the kit but I have the JS3-2.1-120 pump kit and the following is all the info I have on the MPPT:

    • MPPT CONTROLLER: The solar water pump controller drives the high efficient brush-less DC pump motor, utilizing the latest MPPT technology to ensure maximum flow is delivered under all light conditions. It also protects the submersible pump from frequent start up in low light conditions, overheating & running dry.
    Just from the description.
  • EstragonEstragon Registered Users Posts: 4,478 ✭✭✭✭✭
    My guess is the recommended panels were to be wired as 2 series strings of 2 panels for rated array voltage of 72v and current of ~11a.  

    If 
    this is the case, and assuming the 12v panels have a Vmp of ~18v, you could wire them in a single string for about the same voltage and ~8a.  Before trying this though, you need to confirm the panels Vmp and Voc spec, and get the controller max input voltage (maybe from a spec label on the unit?).
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • mcgivormcgivor Solar Expert Posts: 3,559 ✭✭✭✭✭✭
    edited August 2019 #6
    According to this link https://watergardenstore.com/pws-48v-540-watts-stainless-steel-316-submersible-solar-water-well-pump-kit-js3-2-1-120/ there are dual MPPT controllers with a 100VOC.

    Being that the pump is 540w, the 4 × 150W panels would likely not provide enough power assuming ~80% rated or 480W total, using 6 × 150W would be  required for a total of 270W at 80% rated, 2 strings of 3 series would be approximately 60VOC



    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • powernovicepowernovice Registered Users Posts: 7 ✭✭
    Mcgivor, that is the pump kit but I ordered it from Amazon and I pretty sure there is only one that came in the kit. Ok, check Vmp and Voc and max voltage for the MPPT and if that's not quite right, add two more panels. Got it! Thanks! I may have more questions...do you mind?
  • EstragonEstragon Registered Users Posts: 4,478 ✭✭✭✭✭
    If I'm right in my guesses, adding two more panels may not help much. 

    With six panels in two strings of three, string voltage would be ~18Vmp x 3 = 54v. A pretty skinny margin to buck to 48v, more so on a hot still day.

    If I'm understanding how the system works, with less pv current but ok voltage (as would be the case in low light), the pump will pump, albeit more slowly.  With too low string voltage, it may not pump at all?

    If this is right, and flow is insufficient, you'd need to add a second string of 4 x  ~18Vmp panels

    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • powernovicepowernovice Registered Users Posts: 7 ✭✭
    Estragon, right now I only have one horse in two open pastures. We plan to put a slow drop system in and set out three troughs so that the any overflow would flow to the next trough and any excess will flow into the creek. This is in prep for cattle.
    With that said, the slower the better for right now.
  • mcgivormcgivor Solar Expert Posts: 3,559 ✭✭✭✭✭✭
    Here is another link to the same pump,  it says    Solar panels required: 4x 200watts Vmp:36V panels, each 2 panels connected in series, 2 strings in parallel. https://egypt.desertcart.com/products/105300913-pws-48-v-540-watts-stainless-steel-316-submersible-solar-water-well-pump-kit-js-3-2-1-120

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • jonrjonr Solar Expert Posts: 1,384 ✭✭✭✭
    Stop guessing and try it.   Put all 4 of your 12V panels in series.  Expect lower than rated flow, which is good (the pump will last longer).

    I am available for custom hardware/firmware development

  • powernovicepowernovice Registered Users Posts: 7 ✭✭
    Mcgivor, my original post says that I couldn't find the recommended 200w, 36v panels.

    Jonr, going to be checking on everything today, thanks.
  • mcgivormcgivor Solar Expert Posts: 3,559 ✭✭✭✭✭✭
    Personally I would recommend what the design calls for, but that's just me, I would also  recommend pumping into a holding tank as there are limitations to the hours of sunlight, average over a time period of time. The pump comes with high/low switches for a holding tank so why not use them?
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • powernovicepowernovice Registered Users Posts: 7 ✭✭
    Mcgivor, the well is on the opposite side of a 45 acre tract if land. Three large troughs will be in place in a step down pattern. The troughs are food grade tanks that have been cut in half with a large valve at the bottom for draining and cleaning purposes. I also live in the south where sunshine is not normally a problem. Usually during rainy days the sun is shining close by. The well is a total of 300' deep and 6" in diameter, but the water level is at 23' down, so I have thought that to drop the pump to 100 - 150 ft, set a timer at mid-day for approx. 15-20 minutes with a lower than rated flow, it should be plenty for one horse. If anything, once more livestock are added, I can increase the timer for a longer length of time.
    I know that most of you are probably off-gridders. We are not off-grid but have the right location to be able to go hydro, turbine, and or solar. I am a novice as far as electric/solar but have been living in a house built of tires for 14 years with very little need for heat or a/c. We built the house ourselves. Only outside help was pouring the concrete foundation.
    Please bare with me on the solar.
  • jonrjonr Solar Expert Posts: 1,384 ✭✭✭✭
    edited August 2019 #15
    Please let us know how it works and holds up over time.   Some lower depth (131 feet) solar pumps are now $210 on Amazon.  That's attractive if they last.

    I am available for custom hardware/firmware development

  • powernovicepowernovice Registered Users Posts: 7 ✭✭
    Jonr, I will let you know but it will be a few more weeks before we get to that project. I posted here early in case I needed to order more or other panels and would have time to get them in before we were ready to install. Just more info...the troughs will be set approx. 30 ft up a hill from the well and the troughs will be on the other side of the hill downward. Thanks for all the help!! Greatly appreciated!
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