Is choice of pump the basis for all well planning?

bmetbmet Solar Expert Posts: 630 ✭✭
In trying to decide which way to invest in a solar-powered well, I'd like to get an opinion on what the priorities should be. We have a traditional AC pump, 230 volts, 2 HP, but want to replace it some day with solar. Our well is quite deep, but we draw water at about 160 feet.

Should all specs be based around choice of submersible pump? If not, then what is the most critical decision to be made with DC pumps? I understand the flow rate will be much less, but the ability to continously pump during daylight hours would ultimately equalize AC's higher flow for short spurts.

Comments

  • mike95490mike95490 Solar Expert Posts: 9,047 ✭✭✭✭✭
    Re: Is choice of pump the basis for all well planning?

    How much water you need, and if you can store any above ground, should dictate type/size of pump.
    5 hours of 0.5 gmp pump will give you 150 gallons. In summer you may need more for gardens, in winter less . Come up with a number, and then you select a pump.

    Mike
    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

    solar: http://tinyurl.com/LMR-Solar
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  • wild01wild01 Solar Expert Posts: 97 ✭✭✭
    Re: Is choice of pump the basis for all well planning?

    If you are on-grid house water, don't bother you won't save any money and you won't save the planet. If you want emergency water to be available put in a couple 80 gallon pressure tanks.

    if it's for low pressure like irrigation etc. then a low pressure high voltage dc submersible might be a good idea, because low prussure pumps use less energy. (don't go with a low voltage pump your well is to deep, you would end up having to run welding cables to avoid voltage drop. )

    if you are planning a whole house offgrid system (which I assume you are not since you are using a 220 ac pump currently) then I highly recommend a grundfos sq as you will already be inverting power for other things and grundfos sq pumps have an almost zero surge start.

    Bottom line though if you have grid power solar is a waste of money. if you are looking for a more reliable water source ie water during power outages, you can usually add above ground storage for far less than a solar setup will run you. (for non-pressure irrigation a large holding tank will do and for house pressure a couple 80 gallon pressure tanks)
  • bmetbmet Solar Expert Posts: 630 ✭✭
    Re: Is choice of pump the basis for all well planning?

    You are correct that we aren't planning for off-grid on the home, but we do want to reduce our reliance on infrastructure for survival needs (such as water). I had already decided on 24v system, but was curious how much voltage drop would be at 160+ feet run of #10 AWG cable.

    I've read the specs on a couple of the solar pumps sold by this forum's host, and seen diagrams with a controller. Is this a DC-DC controller?
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Is choice of pump the basis for all well planning?

    For what you pay to convert your existing pump system, a pretty good emergency generator can be had. That in turn can do all manner of other tasks the rest of time. If you are worried about short term (hours/days or limited weeks) grid failure I think it a better alternative. If you are worried about armageddon then water might just be the least of your worries, IMHO.

    Tony
  • bmetbmet Solar Expert Posts: 630 ✭✭
    Re: Is choice of pump the basis for all well planning?
    icarus wrote: »
    For what you pay to convert your existing pump system, a pretty good emergency generator can be had. That in turn can do all manner of other tasks the rest of time. If you are worried about short term (hours/days or limited weeks) grid failure I think it a better alternative. If you are worried about armageddon then water might just be the least of your worries, IMHO.

    Tony

    It isn't about armageddon so much as it's about getting tired of the local utility controlling the water use from my own well.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Is choice of pump the basis for all well planning?
    bmet wrote: »
    It isn't about armageddon so much as it's about getting tired of the local utility controlling the water use from my own well.

    you have my curiosity on how the utility is controlling your well water use or is it simply a case of you need electric to bring the water forth?

    as to the voltage drop with a 160ft run of #10 it would be dependent on the current drawn. the voltage drop calculator can be used for this purpose as well and it isn't just for solar applications as anytime a current goes through a wire there is a voltage drop due to the resistance of the wire. the v drop isn't dependent on the voltage of the system, but the voltage drop percentage is. for example 1v drop at 120v is less than 1%, but at 20v is 5%. this also means that a v drop % at 12v will be cut in half at 24v.
  • BB.BB. Super Moderators, Administrators Posts: 31,090 admin
    Re: Is choice of pump the basis for all well planning?

    Water rights are quite different across regions and states... I have seen areas where the water rights are owned by down stream (Colorado was famous for this--old water user rights trump new property owner rights--cannot legally collect rainwater from your own building roof as the water is "owned" by somebody way down the river basin--although I think this has been changed recently).

    I have seen neighborhoods where the local utility/gov agency owns the water rights (check the tittle).

    And I have read about at least one area where they have placed water meters on private wells to charge for water use (I don't remember if this was a conservation forcing measure or a water rights issue)...

    For large agricultural areas--over pumping aquifers has been a nightmare--ancient underground water that was left from the last ice age and/or have slow recharge rates--almost like pumping a non-renewable resource (like oil). Has cause water levels to drop hundreds of feet (new/redrill wells) and land dropping by 10's of feet in the last century from over pumping.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bmetbmet Solar Expert Posts: 630 ✭✭
    Re: Is choice of pump the basis for all well planning?

    I get your point. For our small 'ranch', there is a daily quota for irrigation which my family could never use in 6 months. It's a very small property with a dozen or so head of cattle. Still, the electric bill needed to keep pace with pond evaporation in the summer easily overwhelms the fixed-incomes involved. Yes, a generator may be more practical, but we are looking at the long haul. Being remote, the infrastructure is unreliable(who needs Armageddon?), we've had a leaking transformer on our property now for years, the 'co-op' is taking its time to replace it.

    All things combined, we see solar as a solution we could live with. We have two 4-ring cisterns to hold water, plus troughs for cattle. If need be we could add more.
    BB. wrote: »
    Water rights are quite different across regions and states... I have seen areas where the water rights are owned by down stream (Colorado was famous for this--old water user rights trump new property owner rights--cannot legally collect rainwater from your own building roof as the water is "owned" by somebody way down the river basin--although I think this has been changed recently).

    I have seen neighborhoods where the local utility/gov agency owns the water rights (check the tittle).

    And I have read about at least one area where they have placed water meters on private wells to charge for water use (I don't remember if this was a conservation forcing measure or a water rights issue)...

    For large agricultural areas--over pumping aquifers has been a nightmare--ancient underground water that was left from the last ice age and/or have slow recharge rates--almost like pumping a non-renewable resource (like oil). Has cause water levels to drop hundreds of feet (new/redrill wells) and land dropping by 10's of feet in the last century from over pumping.

    -Bill
  • bmetbmet Solar Expert Posts: 630 ✭✭
    Re: Is choice of pump the basis for all well planning?
    niel wrote: »
    you have my curiosity on how the utility is controlling your well water use or is it simply a case of you need electric to bring the water forth?

    We need the electricity. Too deep for a hand pump :(
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Is choice of pump the basis for all well planning?

    I am missing something. Does your utility mandate when you can pump? Does it charge a time of day rate that is different at various times of day? Does it limit the volume you can pump in a given period?

    How is pumping your water from your well via a generator of Pv going to change that?

    Just curious.

    Tony
  • bmetbmet Solar Expert Posts: 630 ✭✭
    Re: Is choice of pump the basis for all well planning?

    The pump doesn't work without electricity. Electricity is supplied by the co-op. The co-op raises its rates at the peak of summer. The co-op won't change out the leaky transformer so we get plenty of brownouts.
    icarus wrote: »
    I am missing something. Does your utility mandate when you can pump? Does it charge a time of day rate that is different at various times of day? Does it limit the volume you can pump in a given period?

    How is pumping your water from your well via a generator of Pv going to change that?

    Just curious.

    Tony

    To B.B.

    Our daily water quota-allowed is a ridiculously excess amount, but it's intended for Ag much, much larger than ours.
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Is choice of pump the basis for all well planning?

    I was just curios to know more about your situation. I still don't understand what your "water quota" is. Is that the amount you are permitted to pump on some basis?

    The bottom line is, almost every grid tie application is much cheaper to maintain grid tie. The cost of a PV solar is likely to be way more expensive on a KWH basis than simple grid tie. This is most especially true if your usage for water pumping is fairly small.

    Tony
  • BB.BB. Super Moderators, Administrators Posts: 31,090 admin
    Re: Is choice of pump the basis for all well planning?

    The reason we are asking (or at least me)--First solar is very expensive--so we want to understand if this can be a solar panel + pump--Or if you were going to need solar+battery+pump so that you could pressurize your home (for example).

    Also, there are people from all over the world here--and it is interesting to hear about how other areas manage complex issues--such as water rights.

    A solar only (sunny day) pumping setup will be much less expensive (no batteries) and much less maintenance (check battery charge, replace water, replace batteries, more solar panels because of battery losses, etc.).

    I am certainly no solar pump expert--but the documentation (such as for the Grundfos pumps) is pretty straight forward. How much water per day you want, how deep, and how much sun do you have (perhaps checking by season). The charts will tell you how large of pump motor and how many watts of solar panels you will need.

    The motors support a pretty wide range of DC (and for some models) AC voltages. In general, if you need, for example, 600 watts of solar panels--you are better off running the panels at the higher voltage range vs a lower voltage--to reduce current and voltage drop (allows you to use smaller awg wiring).

    And, you might want to leave enough room to install ~25% more solar panels if it turns out that you need more water than you planned on (or have stretches of bad weather).

    Also, how much grit is there in your well water--some types of pumps will not tolerate very much sand in the water...

    The limits of my skills here are probably asking the questions and helping to read the tables for your needs (and we can look up for the hours of sun per day by month for you with PV watts or somewhere else).

    Finding a pump dealer (or dealer/installer) to help you with the details is probably a good idea. I certainly don't have the experience to advise you on the details of your purchase.

    Note that some pumps (and controllers) do include hardware to support solar panels directly--and other need linear current boosters or a battery bank to work well.

    And there are options where you could go with solar + batteries and use a 3 phase AC pump (or a 3 wire single phase AC pump) with a VFD (variable frequency drive). It can allow you to use your current pump (or less expensive AC pump) instead of the very expensive DC type pumps.

    There are lots of options out there (and they are not usually cheap from what I have seen). So--if you can let us know your flow rate per day, well quality, and roughly where it is (to look up solar irradiation data), we can start narrowing down some of the options.

    Sorry for taking your thread off topic.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bmetbmet Solar Expert Posts: 630 ✭✭
    Re: Is choice of pump the basis for all well planning?

    I see. The amount of water I can pump is governed by a municipal board. Our county is highly agricultural, so Ag use is allotted acre-feet for irrigation and livestock. Our ranch is small, so we don't pump high volume.

    The lousy quality of our electric, and the ever rising rates are the major complaints I have. Solar, once installed, could serve our needs for several years before requiring major service.

    Our pump house is in a open plot of land, so there's plenty of room inside and out for a solar package.
    icarus wrote: »
    I was just curios to know more about your situation. I still don't understand what your "water quota" is. Is that the amount you are permitted to pump on some basis?

    The bottom line is, almost every grid tie application is much cheaper to maintain grid tie. The cost of a PV solar is likely to be way more expensive on a KWH basis than simple grid tie. This is most especially true if your usage for water pumping is fairly small.

    Tony
  • bmetbmet Solar Expert Posts: 630 ✭✭
    Re: Is choice of pump the basis for all well planning?

    Thank you B.B.

    I was trying to learn the differences between the extremes of pump systems sold by NAWS. On one end there is the Shur Flo which has the numbers on paper, but doesn't include very much support documentation. On the other hand, the Grundfos product tells you everything you need, but I need a Windows-based pc for their interactive forms.

    I didn't want to bother NAWS with probing questions about solar pumping IF I am not ready to purchase. I won't be ready to purchase before I can research it thoroughly. I come here to research the Solar Water Pumping forum, and am asked why I want to pump water with solar.

    sheesh
    BB. wrote: »
    The reason we are asking (or at least me)--First solar is very expensive--so we want to understand if this can be a solar panel + pump--Or if you were going to need solar+battery+pump so that you could pressurize your home (for example).

    Also, there are people from all over the world here--and it is interesting to hear about how other areas manage complex issues--such as water rights.

    A solar only (sunny day) pumping setup will be much less expensive (no batteries) and much less maintenance (check battery charge, replace water, replace batteries, more solar panels because of battery losses, etc.).

    I am certainly no solar pump expert--but the documentation (such as for the Grundfos pumps) is pretty straight forward. How much water per day you want, how deep, and how much sun do you have (perhaps checking by season). The charts will tell you how large of pump motor and how many watts of solar panels you will need.

    The motors support a pretty wide range of DC (and for some models) AC voltages. In general, if you need, for example, 600 watts of solar panels--you are better off running the panels at the higher voltage range vs a lower voltage--to reduce current and voltage drop (allows you to use smaller awg wiring).

    And, you might want to leave enough room to install ~25% more solar panels if it turns out that you need more water than you planned on (or have stretches of bad weather).

    Also, how much grit is there in your well water--some types of pumps will not tolerate very much sand in the water...

    The limits of my skills here are probably asking the questions and helping to read the tables for your needs (and we can look up for the hours of sun per day by month for you with PV watts or somewhere else).

    Finding a pump dealer (or dealer/installer) to help you with the details is probably a good idea. I certainly don't have the experience to advise you on the details of your purchase.

    Note that some pumps (and controllers) do include hardware to support solar panels directly--and other need linear current boosters or a battery bank to work well.

    And there are options where you could go with solar + batteries and use a 3 phase AC pump (or a 3 wire single phase AC pump) with a VFD (variable frequency drive). It can allow you to use your current pump (or less expensive AC pump) instead of the very expensive DC type pumps.

    There are lots of options out there (and they are not usually cheap from what I have seen). So--if you can let us know your flow rate per day, well quality, and roughly where it is (to look up solar irradiation data), we can start narrowing down some of the options.

    Sorry for taking your thread off topic.

    -Bill
  • BB.BB. Super Moderators, Administrators Posts: 31,090 admin
    Re: Is choice of pump the basis for all well planning?

    That is why understanding and adjusting your needs is so critical... You can easily have a 4:1 or greater range in the cost of a solution depending on how you answer the questions (daylight only, pressurized vs free flow, sand in well, long term operation vs few minutes a day, etc.).

    And, there is always the two roughly equivalent pumps:

    Grundfos SQFlex Submersible Solar Well Pumps
    Price: $1,848.90

    Vs Sunpumps which range from $1,700 to $2,100 list and a:

    Shurflo 9300 Submersible Solar Water Pump
    Price: $695.00

    And they have their differences in mechanical construction and where they each would be a cost effective solution.


    Personally, I do what you are doing--find a company that has good documentation and study the heck out of it.

    I have even taken charts from such a company, then attempt to plot the limited information from less well documented components (as a design engineer) to understand where other options/products fall on the spectrum.

    Then I can ask direct and on-point questions of the retailer or manufacturer to see if I understood the trade-offs.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Is choice of pump the basis for all well planning?

    Just a note on the shurflo 9300. I think it is a good pump for what it is designed for, and the price. I have one in the water and it has worked perfectly for about 3 years. That said, we are a family of 2 and our water needs slight, maybe 100 gallons a day tops. I think that if you are looking for much more quantity for irrigation etc it is too small.

    Tony
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