Solar Well newbie

SystemSystem Posts: 2,511 admin
Greetings from Alabama!
I've been lurking here on this great website for a few days, reading existing threads and trying to learn the basics of solar water pumping. I've learned alot, but I still have many questions.

Our recently drilled well is 300 feet deep. The well is drilled through almost solid limestone after the first 25 feet of top soil/clay. The static water level is approximately 35 feet. Water enters the well through several fissures in the limestone. The water entering the well flows at 5 gallons a minute. The casing is 6 inch PVC, and 40 feet in length.

I would like to use a solar water pump to pump well water into two 350 gallon water storage tanks (connected to each other), and then use a small booster pump to push water from the storage tanks into a 40 to 60 gallon pressure tank. All of this would be located inside the "pump house" (water well, storage tanks, and pressure tank).

I've looked into the Shurflo 9300 solar pump, the Coenergy Solar Slowpump, and the Grundfos 11-SQF-2.

I like the Grundfos the best, but the cost of the solar panels necessary to run the pump make it more expensive than my water well budget can stand.

My second choice is the Coenergy pump, but I'm not sure this pump would work in our situation. Everything I have read about these pumps seems to suggest that they can "push" water from a shallow well, much better than "siphon" water from a deep well. Would this type of solar pump draw water from a depth of 150 feet?

That leaves the Shurflo 9300. Is this pump heavy duty enough to run for five or six hours continuously without wearing out the pump? Would it be possible to run this pump using 24vdc from a 24 volt power supply (150 watts, 6 amps) instead of solar panels? For instance, going from a 24 volt power supply, to a 902-200 Shurflo DC Pump Controller, to the Shurflo 9300 pump.

More info:
We currently have, and use city water. This is a farm, and the well would be used for farm animals, and for the house also. Our total water usage currently is 500 cubic feet per month, I think that equals about 3500 gallons a month.

Thanks in advance for any help!

Jbear

Comments

  • mike95490mike95490 Solar Expert Posts: 9,047 ✭✭✭✭✭
    Re: Solar Well newbie

    It's not clear in your post, where the water level is, 300' or 35'.
    Where do you want to hang your pump ? 80'? The shallower you keep the pump, the less work it does.
    3500 gl / month, = .49 GPM @ 4 hours of solar daylight/day. (30 days) Which is not a lot of water being pumped, if my math is correct. [ 7200 minutes to pump 3500 gl ]
    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 ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

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  • System2System2 Posts: 6,290 admin
    Re: Solar Well newbie
    mike90045 wrote: »
    It's not clear in your post, where the water level is, 300' or 35'.
    Where do you want to hang your pump ? 80'? The shallower you keep the pump, the less work it does.
    3500 gl / month, = .49 GPM @ 4 hours of solar daylight/day. (30 days) Which is not a lot of water being pumped, if my math is correct. [ 7200 minutes to pump 3500 gl ]

    Thanks for the quick reply mike90045. The well is 300 feet deep. The water level in the well is 35 feet from the surface. Using a large wooden spoon attached to a 50 foot section of rope, the spoon touches the water 35 feet from the top of the well casing.

    I'm not sure exactly sure how deep I would hang the pump. The well has a flow rate of 5 gallons a minute. It seems like the solar pumps I am considering deliver 2 gallons or less per minute. I guess somewhere between 60 to 100 foot depth for the pump?

    Do you know if it is possible to run the Shurflo 9300 from a 24 volt power supply instead of a solar panel?

    Thanks,
    Jbear
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Solar Well newbie

    there is more than just pvs to pump water with.
    http://www.windmills.biz/
  • kd7irmkd7irm Solar Expert Posts: 39 ✭✭
    Re: Solar Well newbie

    Check out this pump http://www.solar-electric.com/sdsosupu.html , we have 2 of these that replaced old windmills, I installed last year. With one panel there is no need for a controler and they install no more than 50 foot deeper than static water level or your expected draw down level. We have a grundfos solar at another well but only because of the depth of the water, the cost involved with a grundfos set up was vastly more than the sunpumps. For the money, the sunpumps are hard to beat in that application.

    (Old tread but wanted to share my experience with these pumps, hope it helps some one)
    Outback MX60 charge controller, Outback VFX3524 inverter, Deka 95-25 1140 Ahr (8hr rate) 24v batteries, Champion 3.8kw generator, and about 2000 panel watts. (Honda EU6500is inverter generator in for repair) 
  • KeithWHareKeithWHare Solar Expert Posts: 140 ✭✭✭
    Re: Solar Well newbie
    jbear wrote: »
    Thanks for the quick reply mike90045. The well is 300 feet deep. The water level in the well is 35 feet from the surface. Using a large wooden spoon attached to a 50 foot section of rope, the spoon touches the water 35 feet from the top of the well casing.

    I'm not sure exactly sure how deep I would hang the pump. The well has a flow rate of 5 gallons a minute. It seems like the solar pumps I am considering deliver 2 gallons or less per minute. I guess somewhere between 60 to 100 foot depth for the pump?

    Do you know if it is possible to run the Shurflo 9300 from a 24 volt power supply instead of a solar panel?

    Thanks,
    Jbear

    There are several factors that determine where you should hang the pump.
    • The deeper the pump, the larger the water reserve above the pump. This is important if you can pump faster than the well refreshes. One consideration is whether you have the same flow rate year round. Another is whether some near by drilling, excavation, etc. will affect the flow rate and static level.
    • The deeper the pump, the heavier the pipe when you install it and remove it later. How critical this is depends on the equipment you have available.
    • The deeper the pump, the heavier the wire you need to minimize voltage drop.

    The majority of the power needed to pump water is for the vertical distance from the static level to the tank.

    The power needed to pump from the pump level to the static level is pretty minimal because of the weight of the water outside the pipe & pump.

    Without knowing anything else, I would lean towards hanging the pump at 100 feet or more. That gives you 65 feet of reservoir above the pump.

    The formula for volume of a cylinder is Height * pi * r**2 cubic feet. So, with a 6 inch (inside diameter) casing, the calculation is:
    65 feet * 3.14 * (.25 feet * .25 feet) = 12.75 cubic feet.

    There are 7.48 US gallons per cubic foot, so this gives you a reservoir of 95.4 gallons.

    Keith Hare
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