recommend a direct pv pump solution

solarsquirralsolarsquirral Solar Expert Posts: 54
hi guys
thanks in advanced for your input

im trying to set up a off grid solution to pumping water from a tank at my spring to another tank 250 vertical through 600 feet of one inch poly pipe

i have 8 12 volt panels that i could wire to 24volts or perhaps 48volt that are rated at 4.5 amps 75watts each

what pump would you recommend
ive heard good things about the slow pump

the panels would have to be 100 feet away to get the maximum sun so wire run voltage drop is an issue
any suggestions???


  • BB.BB. Super Moderators, Administrators Posts: 31,684 admin
    Re: recommend a direct pv pump solution

    How much do you want to spend? How much water per day (winter/summer) do you want to pump?

    Any issues with sand? Can the spring be "pumped dry"?

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • solarsquirralsolarsquirral Solar Expert Posts: 54
    Re: recommend a direct pv pump solution

    well to get the water up the hill it looks like im gonna have to go with a slow pump

    id like to spend under 1000 dollers(wishful thinking?)

    ive got the panels already 8 sp75 12 volt panels

    i found a slo pump for 600$
    filter and low current booster,dry run swith add 300
    after taxes its already 1000+

    spring flows year round
    gets down to .5gallon per minute at lowest
    plan to capture and run through two filters then into 300 gallon tank then up the hill via pump

    figured the tank would refill at night and be full and ready for pumping as the light hits the panels in the morning

    have a growing orchard and more water in the upper tank the better (fire protection)
    would require more water in summer

    any other options you can see
  • tmarchtmarch Solar Expert Posts: 143 ✭✭
    Re: recommend a direct pv pump solution

    Solar won't work at night so it will only be pumping during the day. A tank to collect the water at the spring would refill overnight then could be pumped directly to the daytime usage using solar. Possibly a bigger tank or two tanks connected located at the spring?
  • solarsquirralsolarsquirral Solar Expert Posts: 54
    Re: recommend a direct pv pump solution

    kinda a big investment for me right now but i should have thought of that before planting a rather large orchard ,and after filling barrels in my truck for a summer i said enough
    im thinking of using this old tracker rack that someone gave me along with a lcb and going with 24 v system

    anybody have experience with these pumps. ive heard all the issues with filtration so i got the inline filter set and will add an additional lava rock filter to catch the first particals before the tank

    the didnt have the lcb in stock any suggestiongs on a good lcb
  • BB.BB. Super Moderators, Administrators Posts: 31,684 admin
    Re: recommend a direct pv pump solution

    You should pick a supplier (and/or installer--if needed) and talk with them.

    I can give you some ideas on specifications and possible issues--But talking with somebody that actually sells/installs/supports the product (like our host NAWS, or others) will be very helpful.

    Grundfos is a great high end submersible pump. They have ones that soft start on AC (SQ), and others (SQFLEX) (more expensive) that can run on almost anything (solar, battery, genset) within their specifications.

    Sun Pumps, Lorentz Pumps are also good pumps. Shurflow are less expensive and simpler pumps that work pretty well too. I think somebody here has used Advanced Power's "Ranch Pump".

    Pumps with brushes/commutators (universal) motors, are usually less expensive, but not great for 24x7 operation (brushes may last 6-8 months). Electronic commutated motors are really nice--But certainly cost more.

    Would be better off replacing/rebuilding a $200+ pump every couple years, or $2,000 pump every 10+ years? Something I cannot answer.

    Having a pump mounted outside the tank and below water level is nice (easy to service, no issues with water leaks into the motor). Pumps mounted above the water level tend to be less efficient and can have issues with clogging filters/air leaks/cavitation. Good Submersible pumps can solve a lot of issues--But tend to be very pricey.

    And it sounds like you will end up with two pump/solutions. One remote at the spring that uses a pump that can direct connect to a solar array (no battery, no inverter)--Do you need gasoline engine backup? And a second pump at the cistern where you will have a pressure pump for home and farm. Perhaps a small/simple 12 or 24 volt DC pump for house (Shurflow), and what(?) for irrigation (do you need higher pressure for sprinklers/drip irrigation, or just flood irrigation, etc.).

    Pumping against pressure take power--Nice to have a 100 PSI to a sprinkler, but if you can flood irrigate with just a few PSI, you will save lots of power.

    And understanding your GPH needs... That will eliminate many pumps.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • hemmjohemmjo Solar Expert Posts: 90 ✭✭
    Re: recommend a direct pv pump solution

    According to my figures you need 110 PSI just to overcome the 250' lift.

    We are using a SHURflo 8000 12 volt pump to lift about 1 GPM about 70 feet vertical over 500 feet away. Took about 30 hours to fill our 1-350gal and 2-675 gallon tanks. Fortunately they are never empty. The pump runs about 4 hours each day. Ours easily runs on the system described below.

    Our pump is rated for 60 PSI, have you ever considered a second pump mid way up the line? It has been running for over a year with no problems. The solution is so simple and inexpensive we can afford to have a spare pump on the shelf.

    Good Luck,

    Two systems in the Dominican Republic
    installed Feb 2014 at 19.796189° -70.893594°, Classic 150 + WBJR, KISAE SW1210, MN Battery Monitor, IOTA DLS 55/IQ4,  4- Solar World 275w, 4-6v x 225ah Trace Batteries
    installed Feb 2015 at 19.795733° -70.893372°, same components  as above
    Honda PowerMate PC0497000, 7000/8750w generator - powers the well and chargers maybe once a week

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