Beginning Search for Solar Well Pump System

CrystalCrystal Solar Expert Posts: 121 ✭✭✭
We are just starting our research for a solar well pump system that will fit our needs.
Our plan is to pump water from our 165' well located just 50' from our home.
We will fill a cistern inside the house (not sure how many gallons yet). We also will need to fill 3 outdoor tanks equaling 1000gallons for a drip irrigation system for market garden. These tanks are about 250' from the hydrant.
Anyone that has experience with solar pumps, panels, and pump controllers, or even an entire system ready to install, please share what might work in our situation.
Any suggestions are greatly appreciated!
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Comments

  • BB.BB. Super Moderators, Administrators Posts: 31,077 admin
    Re: Beginning Search for Solar Well Pump System

    Freezing weather? Deep Freeze? That may affect the sizing/design of your tanks and/or limit to three season use and affect cycling time for the pump (i.e., large tanks a couple times a week in spring/summer. Small in-home tank in winter).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CrystalCrystal Solar Expert Posts: 121 ✭✭✭
    Re: Beginning Search for Solar Well Pump System

    Yes, we live in MN, so it will definitely deep freeze. We will need to fill the indoor cistern year round. However, the outdoor tanks will need to be filled only during the summer season when it does not freeze.
  • mike95490mike95490 Solar Expert Posts: 9,036 ✭✭✭✭✭
    Re: Beginning Search for Solar Well Pump System

    It's a tough call, I eventually went with a conventional well pump, and ran 240vac to it.
    (I had to dig a trench for the water lines anyway)
    I had the battery & solar PV system, and argued with myself for months,
    solar MPPT pump that nobody knows how to repair, or
    conventional pump that has parts at the local store.

    so far, I'm happy with my choice.

    Remember, the pump curve charts are your friend!
    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
    gen: http://tinyurl.com/LMR-Lister ,

  • BB.BB. Super Moderators, Administrators Posts: 31,077 admin
    Re: Beginning Search for Solar Well Pump System

    If you have a well person local that you use... See what this would recommend. I would suggest researching a VFD (Variable Frequency Drive). Works very well with three phase well pumps and pretty nicely with single phase AC pumps with a remote starting capacitor. The VFD is just an AC Inverter that starts at zero Hz (frequency) and ramps up to 60 Hz. You can also adjust the frequency for optimum pumping for your needs ("soft start", and some have variable inputs that could, for example, adjust pump RPM depending on the pressure--during irrigation season, raise pump RPM to support higher water flows). There is a good chance that your existing pump is a single phase with a "well head" capacitor--perfect candidate for a VFD.
    BB. wrote: »
    Some discussions about VFD (Variable Frequency Drives)... Basically a variable frequency inverter with (typically) three phase output. Used to soft start motors (handy for 3 phase well pumps, or pumps with well head starting capacitor) and can also turn an AC motor into a variable speed motor (very handy for pumping applications).

    WELL PUMP and Inverter QUESTION

    Wind/solar for large scale pumping etc (out of my depth!)
    could use knowledge - using Gould jet pump - transfering from 230vAC to ? DC (new link/thread 10/27/2012)
    Help required to design off grid system (information on possibilities to connect "standard VFDs direct to solar panels) (new link 1/13/2013)

    I wish I knew more/had more experience. VFD's are not very expensive and they can make motors much more flexible and "solar" friendly. But it is a tough topic to start from zero knowledge.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • tmarchtmarch Solar Expert Posts: 143 ✭✭
    Re: Beginning Search for Solar Well Pump System
    Crystal wrote: »
    We are just starting our research for a solar well pump system that will fit our needs.
    Our plan is to pump water from our 165' well located just 50' from our home.
    We will fill a cistern inside the house (not sure how many gallons yet). We also will need to fill 3 outdoor tanks equaling 1000gallons for a drip irrigation system for market garden. These tanks are about 250' from the hydrant.
    Anyone that has experience with solar pumps, panels, and pump controllers, or even an entire system ready to install, please share what might work in our situation.
    Any suggestions are greatly appreciated!

    It can be a bit complicated and confusing, but basically to do this with 1 system isn't that bad. Are all the tanks on the same line? If so then you will need to put a pressure float system on the each tank except the highest with a electric shut off float on that one.
    Is the cistern inside the house located in the basement? If so you will need a pump from it to your water lines running to the point of use, faucets etc.
    If I was doing it from scratch I'd go with a pressure tank system in the house and a seperate line for the gardening cisterns. Doing this you could eliminate the extra pump for the house if your pressure tank is big enough to supply your needs for a time when there is no sun.
  • CrystalCrystal Solar Expert Posts: 121 ✭✭✭
    Re: Beginning Search for Solar Well Pump System

    Thank you much for the information.
    The three outdoor tanks are on the same line. We'll run a garden hose of the hydrant (eventually trenched underground, so we don't have to drive over it) to fill these 3 tanks. I don't quite understand why I would need a pressure float system on each tank, since they are already piped together and they all fill at the same time. So, wouldn't a shut off float on just one tank work?
    The cistern inside the house will be located on the main floor. We plan on using a DC diaphragm pump to pump from cistern to sinks, toilet, etc. We thought about the pressure tank idea and may go ahead and install a smaller pressure tank that is filled with the diaphragm pump from the cistern. I think this will prolong the life of the diaphragm pump, since it won't run each time the faucet is on, toilet is flushed, etc.
    Many different options, just trying to figure out what will work best in our situation.

    Any suggestions on DC submersible pumps? We want one that we won't have to replace anytime soon. We looked at the Simple Pump which has the option of hand pumping, but don't know if it will work in our MN winter.
    Thank You!
  • BB.BB. Super Moderators, Administrators Posts: 31,077 admin
    Re: Beginning Search for Solar Well Pump System

    Grundfos pumps are very nice--But not cheap at $2,XXX or more (inflation is raging now). The SQ-Flex can take 120/240 VAC power, battery power, direct to solar panels, and even backup generator power. Very flexible and "off grid" friendly.

    A smaller three phase pump with a VFD may be a lot cheaper and easier for your well guy to service (assuming you are not servicing your pump yourself).

    Using a smaller DC pump from your in-house cistern is probably a good solution. Ideally, the pump should be below the water level in the tank. Mounting pumps above the water level can cause pumping problems (small air leaks, clogged screens/filters, cavitation, etc.) as you are drawing a vacuum. Note that if you have the DC pump in a pit, you may need a water leak alarm and/or drainage to keep the pump from being flooded.

    Cavitation
    - Wikipedia, the free encyclopedia


    When pumping from the well, you can dump the water into the tank directly, or pump into a pressure tank (to maintain ~45-60 PSI system pressure).

    Dumping into the tanks directly saves you energy if you do not need 50 PSI water pressure in the system (pump water up well, thru piping, and then the "cost of 60 psi pressure" for water fixtures/sprinklers). Note that low pressure water flow needs larger diameter pipes to efficiently move water (i.e., a water hose will pass ~5-10 GPH from a ~60 PSI water system).

    In any case, you have several options for controlling water flow... Valves at each water outlet. When the tank (or parallel tanks) are full, the valve closes and a pressure switch + small pressure tank, stops the well pump. Or an electric float switch to control the pump. Just depends on how automatic you want. Note, you don't want to leave the pump on without some sort of control (flooding, wasted energy, etc.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • tmarchtmarch Solar Expert Posts: 143 ✭✭
    Re: Beginning Search for Solar Well Pump System
    Crystal wrote: »
    Thank you much for the information.
    The three outdoor tanks are on the same line. We'll run a garden hose of the hydrant (eventually trenched underground, so we don't have to drive over it) to fill these 3 tanks. I don't quite understand why I would need a pressure float system on each tank, since they are already piped together and they all fill at the same time. So, wouldn't a shut off float on just one tank work?
    The cistern inside the house will be located on the main floor. We plan on using a DC diaphragm pump to pump from cistern to sinks, toilet, etc. We thought about the pressure tank idea and may go ahead and install a smaller pressure tank that is filled with the diaphragm pump from the cistern. I think this will prolong the life of the diaphragm pump, since it won't run each time the faucet is on, toilet is flushed, etc.
    Many different options, just trying to figure out what will work best in our situation.

    Any suggestions on DC submersible pumps? We want one that we won't have to replace anytime soon. We looked at the Simple Pump which has the option of hand pumping, but don't know if it will work in our MN winter.
    Thank You!

    IF the 3 tanks are level then you would only need one float, but if they are not level that's where you need a float on the lowest and on up so the water will fill the highest tank. Otherwise the lowest tank will over fill and the highest may only get some water.
    Does your well have a pitless unit installed? If so that's 1 less item of concern.
    How about the static water level and recovery rate? If the well is in use now and working well the new pump can probably use the existing pipe and possibly the existing wire.
    Grundfos or Lorentz are my choice of pumps for this and they can be sized for your application easily by the installer or if you are going to install it yourself. Either can be set up for DC or AC in case you need water when there isn't enough sun.
  • CrystalCrystal Solar Expert Posts: 121 ✭✭✭
    Re: Beginning Search for Solar Well Pump System

    Well has a submersible ac pump right now.
    Static level is 56'
    Now sure of the recovery rate, but can keep up with 100gpm right now with the ac pump.
    It's a new well...had it drilled 2 years ago.
    Would like to be able to keep existing pipe that runs into house...however, it's 1'. Will this pose a problem? I was reading that with low flow pumps you should have smaller pipe.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Beginning Search for Solar Well Pump System
    Crystal wrote: »
    The three outdoor tanks are on the same line. We'll run a garden hose of the hydrant (eventually trenched underground, so we don't have to drive over it) to fill these 3 tanks. I don't quite understand why I would need a pressure float[?] system on each tank, since they are already piped together and they all fill at the same time. So, wouldn't a shut off float on just one tank work?

    If all of the tanks are at the same level and same height (not sure what you meant by "on the same line"), then you can use a float switchon one of them. But you have to be very confident that the flow to the tank with the switch cannot be accidentally cut off.
    You cannot use a float valve on one tank unless all of the water for the three tanks comes in through that valve. BB. was allowing for the tanks to be at different heights or to fill at different speeds. The latter could happen if the inlet pipe is larger than the pipe connecting the tanks, for example.
    A pressure switch would just turn off the pump when all three float valves had closed off their tanks.
    SMA SB 3000, old BP panels.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Beginning Search for Solar Well Pump System
    Crystal wrote: »
    I was reading that with low flow pumps you should have smaller pipe.
    The only reason that I can think of for using a smaller pipe for the lower flow would be to keep sediment from accumulating at the bottom of the pipe since the water is not moving as fast. But with sediment-free water or filters in the right place I cannot see it as a problem.
    SMA SB 3000, old BP panels.
  • tmarchtmarch Solar Expert Posts: 143 ✭✭
    Re: Beginning Search for Solar Well Pump System
    Crystal wrote: »
    Well has a submersible ac pump right now.
    Static level is 56'
    Now sure of the recovery rate, but can keep up with 100gpm right now with the ac pump.
    It's a new well...had it drilled 2 years ago.
    Would like to be able to keep existing pipe that runs into house...however, it's 1'. Will this pose a problem? I was reading that with low flow pumps you should have smaller pipe.

    If there is a solar pump that will pump 100 gpm, that's a tremendous amount of water and will take more than a few panels. Most house wells are in the 10 gpm range.
    The 1" pipe is standard and shouldn't create a problem, most of the solar pumps I sell are helical rotor pumps that can handle more sediment than a conventional submersible pump.
  • Texas WellmanTexas Wellman Solar Expert Posts: 153 ✭✭
    Re: Beginning Search for Solar Well Pump System

    2 Questions:

    What is your budget? Honesty goes a long way here.

    Is there A/C power available at the site?
  • CrystalCrystal Solar Expert Posts: 121 ✭✭✭
    Re: Beginning Search for Solar Well Pump System
    2 Questions:

    What is your budget? Honesty goes a long way here.

    Is there A/C power available at the site?

    Our budget: $4000
    Only A/C power is Honda genny, which we use right now to fill small pressure tank in home, troughs for livestock, and
    irrigate market garden (in summer).

    Five years ago we purchased raw land, built a small house, hauled water, outhouse...the whole works. Over these past 5 years we've paid for a well, septic, and small solar electric system (more than enough power for us). The next step is pumping water without the use of genny.

    I realize that the route we are taking isn't less expensive, but it is priceless (for us) to be self-reliant.
  • tmarchtmarch Solar Expert Posts: 143 ✭✭
    Re: Beginning Search for Solar Well Pump System

    For $4000.00 you can come close to a full system including pipe for a short run, but NOT a 100 GPM system. I just priced a system for a customer today at less than $3500.00 with 2 panels and at 100 feet of head it will produce approximately 10 GPM. This is basically for a self install, with assistance from me, but no well rig costs involved.
  • CrystalCrystal Solar Expert Posts: 121 ✭✭✭
    Re: Beginning Search for Solar Well Pump System
    tmarch wrote: »
    For $4000.00 you can come close to a full system including pipe for a short run, but NOT a 100 GPM system. I just priced a system for a customer today at less than $3500.00 with 2 panels and at 100 feet of head it will produce approximately 10 GPM. This is basically for a self install, with assistance from me, but no well rig costs involved.

    That's great! We should have no problem making this happen! We definitely won't need 100gpm...that's just what the A/C submersible pumps right now (w/ generator running). Still trying to figure out how many gallons we will need though. 10GPM seems like a good number.

    Our pipe is already installed to the house (it's 1" but should be ok?). We'll use garden hose (which we already own) to fill the garden cisterns. We'll someday install permanent underground piping to garden cisterns.
    Won't need to purchase a mounting system, we can build ground mount for pretty cheap.
    Well is already drilled. That wasn't cheap, $6000 after it was all done.
    We'll install the system ourselves, with many questions for all you here on the forum. : )

    Really leaning toward the Grundfos SQFlex w/ the IO 101 control. That should cost around $2500, right?
    Just not sure what model Grundfos to get. Any suggestions?
    Also, not sure if we should go with 12v or 24v. What are the pros and cons of each?

    Thanks Again!
  • tmarchtmarch Solar Expert Posts: 143 ✭✭
    Re: Beginning Search for Solar Well Pump System

    The Grundfos pumps are a good pump, and there is also Lorentz. Lorentz is more modular, meaning that the pump end and motor are separate so if 1 fails you can replace just that part, not both. Price is not a lot different, but the Lorentz AC adapter is more expensive.

    For either I would suggest a top of pole mount close to the well. They are pre fabricated so all you would need to purchase is a schedule 40 steel pipe 8' long for each rack of panels. That I've found is better than most straight ground mounts for keeping things elevated for mowing etc. I only use 2 panel racks to prevent excess wind load, but not sure how much wind you get.

    With either pump I would go with 2 190 watt panels with which will produce somewhere in the 80 volt range and the 10 101 control will have a AC cord and plug to connect your generator.
    I use mostly the Grundfos 11 SQF-2 which should produce 10-11 GPM at that total dynamic head.

    If you need pictures of some installs or any other advice feel free to PM me here.
  • stephendvstephendv Solar Expert Posts: 1,571 ✭✭
    Re: Beginning Search for Solar Well Pump System
    Crystal wrote: »
    Over these past 5 years we've paid for a well, septic, and small solar electric system (more than enough power for us). The next step is pumping water without the use of genny.

    So you already have some solar kit, including inverter? Then you could spend the budget on beefing up that system and then using a variable frequency drive (VFD) with a 3-phase well pump. As Bill mentioned earlier, VFDs are not that expensive and 3 phase pumps are sometimes cheaper than their single phase equivalents. What you gain from the VFD is a much smoother startup current, so your inverter doesn't have to be 3x the pump rating in order to start it. My 1.5kW pump on a VFD has a peak of 2kW when starting up over a 10 second period. Lengthen the period and will probably be even less.

    Would definitely avoid the expensive solar-only pumps like the grundfos SQflex if you already have an existing off-grid system that you can use to power the pump. Doubly so for the Lorentz, because you can't power it with AC power- for that you need their AC connection box which costs upwards of $700.
  • CrystalCrystal Solar Expert Posts: 121 ✭✭✭
    Re: Beginning Search for Solar Well Pump System

    Ok, so in my research we came across the Simple pump, which has the hand pumping option. Might be nice to have this option, just in case we don't have access to fuel and the sun isn't shining.
    Has anyone here had experience with the Simple pump?
    Is the Simple pump well made or are we going to have to replace it in the near future?

    Not ruling out the Grundfos or Lorentz...just looking at all our options. : )
    Any info about the Simple pump is greatly appreciated!
  • CrystalCrystal Solar Expert Posts: 121 ✭✭✭
    Re: Beginning Search for Solar Well Pump System
    stephendv wrote: »
    So you already have some solar kit, including inverter? Then you could spend the budget on beefing up that system and then using a variable frequency drive (VFD) with a 3-phase well pump. As Bill mentioned earlier, VFDs are not that expensive and 3 phase pumps are sometimes cheaper than their single phase equivalents. What you gain from the VFD is a much smoother startup current, so your inverter doesn't have to be 3x the pump rating in order to start it. My 1.5kW pump on a VFD has a peak of 2kW when starting up over a 10 second period. Lengthen the period and will probably be even less.

    Would definitely avoid the expensive solar-only pumps like the grundfos SQflex if you already have an existing off-grid system that you can use to power the pump. Doubly so for the Lorentz, because you can't power it with AC power- for that you need their AC connection box which costs upwards of $700.



    Our existing system is very small.
    2-210 watt evergreen panels
    4-T105 Trojan batteries
    350 watt inverter
    (as well as the other components: charge control, meter, battery charger)
    When planning this small system we installed bigger cables/wire so that is would be easier to beef it up in the future.

    Our well driller will buy back the A/C submersible pump, if we end up going with D/C. So that's a bonus.

    Thank you for your suggestion Stephendv. So many options to consider...it's seems more difficult to decide than to actually figure out the installation.:confused:
  • FernwehFernweh Registered Users Posts: 5
    Re: Beginning Search for Solar Well Pump System

    Just for your info:

    the Grundfos SQF pumps are not solar-only.....you can run those from 30 - 300VDC and 90 - 240 VAC. That means with a simple manual transfer switch (HomeDepot $118.00) you can switch the pump from your solar panel array to a generator/grid power when the "solar day" is over.
    Grundfos recommends a voltage >120V for best efficency. You can find all the data needed at the Grundfos website - just go past the simple brochures.

    I have attached a pdf.file created by Grundfos Support for my project in La Paz, BCS using a 11SQF2 solar pump.Attachment not found.

    BTW you can find those pumps heavily discounted on the internet
  • tmarchtmarch Solar Expert Posts: 143 ✭✭
    Re: Beginning Search for Solar Well Pump System
    Crystal wrote: »
    Ok, so in my research we came across the Simple pump, which has the hand pumping option. Might be nice to have this option, just in case we don't have access to fuel and the sun isn't shining.
    Has anyone here had experience with the Simple pump?
    Is the Simple pump well made or are we going to have to replace it in the near future?

    Not ruling out the Grundfos or Lorentz...just looking at all our options. : )
    Any info about the Simple pump is greatly appreciated!
    The simple pump might be an option for inside your house, but it's not what I would call real conductive for your well pump. Much easier to store a few containers of water than to pump it into containers by hand and pack to the house. Many of us that live "in the sticks" store a few 5 gallon containers in case the power goes out. Realistically it's better to store enough for a limited time and with solar + a generator it shouldn't be take much.
  • Texas WellmanTexas Wellman Solar Expert Posts: 153 ✭✭
    Re: Beginning Search for Solar Well Pump System

    My vote goes for the Grundfos SQ Flex. It will work with your current set-up, but I recommend getting at least 2-3 200 watt panels to power it . The SQFlex really like voltages above 90v, but can run on anything 30-300VDC or 90-230VAC. I seriously doubt you are getting 100 gpm from your well pump you have now-that would require at least a 2-3 HP motor and about 8KW minimum. Maybe more, I would have to look at the chart and know the pumping level.

    Use ~30V panels wired in series, about 90VDC and 600 Watts. I'm not exactly sure how you would wire it in with your existing set-up but Grundofs has about 6 or so interface boxes. We use the simple on/off or the generator interface.

    I have no information about the simple pump etc. so post up what you find.
    Crystal wrote: »
    That's great! We should have no problem making this happen! We definitely won't need 100gpm...that's just what the A/C submersible pumps right now (w/ generator running). Still trying to figure out how many gallons we will need though. 10GPM seems like a good number.

    Our pipe is already installed to the house (it's 1" but should be ok?). We'll use garden hose (which we already own) to fill the garden cisterns. We'll someday install permanent underground piping to garden cisterns.
    Won't need to purchase a mounting system, we can build ground mount for pretty cheap.
    Well is already drilled. That wasn't cheap, $6000 after it was all done.
    We'll install the system ourselves, with many questions for all you here on the forum. : )

    Really leaning toward the Grundfos SQFlex w/ the IO 101 control. That should cost around $2500, right?
    Just not sure what model Grundfos to get. Any suggestions?
    Also, not sure if we should go with 12v or 24v. What are the pros and cons of each?

    Thanks Again!
  • stephendvstephendv Solar Expert Posts: 1,571 ✭✭
    Re: Beginning Search for Solar Well Pump System

    The disadvantage of the SQFlex in an off-grid setup is that you'll have 2 solar arrays, 1 for the pump and 1 for the house. So on a bad solar day when you really need power to the house, but don't need to pump water, the pump array will be wasted. Instead if you had 1 single big array with a bigger inverter and more solar panels, you can then choose where to spend your solar energy, and you have the luxury of a much bigger array for your house needs, so less generator run time.

    The SQFlex is by all accounts a really great pump, and it's very well suited to remote pumping stations in the middle of nowhere that have no power going to them. But if you already have or need to have power near it, then in my opinion it's cheaper, simpler and more versatile to get a more conventional pump and invest the difference in a beefier power system for the house.
  • Texas WellmanTexas Wellman Solar Expert Posts: 153 ✭✭
    Re: Beginning Search for Solar Well Pump System

    Why can't you tie it into your existing array? You can tie it directly into the panels or come off the inverter, the pump doesn't care. I'm not sure which interface you'd have to use but it could be done.

    Solar panels right now are costing $200-300 for a 180-200watt panel. Even if you used a seperate array you're only talking $600-1000 more.
    stephendv wrote: »
    The disadvantage of the SQFlex in an off-grid setup is that you'll have 2 solar arrays, 1 for the pump and 1 for the house. So on a bad solar day when you really need power to the house, but don't need to pump water, the pump array will be wasted. Instead if you had 1 single big array with a bigger inverter and more solar panels, you can then choose where to spend your solar energy, and you have the luxury of a much bigger array for your house needs, so less generator run time.

    The SQFlex is by all accounts a really great pump, and it's very well suited to remote pumping stations in the middle of nowhere that have no power going to them. But if you already have or need to have power near it, then in my opinion it's cheaper, simpler and more versatile to get a more conventional pump and invest the difference in a beefier power system for the house.
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Beginning Search for Solar Well Pump System

    One advantage to having a separate power system for the pump is with regard to lightning. When your well is any distance from your house, the ground potential between the house ground and the well ground can be 1000's of volts, and this can destroy a pump. If your power system is at the well and grounded to the well, the lightning problem is mitigated.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • CrystalCrystal Solar Expert Posts: 121 ✭✭✭
    Re: Beginning Search for Solar Well Pump System

    Now you really have my wheels turning.
    So, if I beef up the existing system, would I be able to run the existing AC pump? I don't have all the specs (I'll call well guy tomorrow), but I do know that it runs off of 220v round plug. Are there inverters that take this kind of plug?

    What is a 3-phase well pump?

    Would I need a bigger battery bank since I would be adding panels?
    Our existing battery bank consists of 4-T105 Trojans.

    Loving all of your different ideas. Best to know all of our options, so we can figure out what will work best in our situation.;)
  • BB.BB. Super Moderators, Administrators Posts: 31,077 admin
    Re: Beginning Search for Solar Well Pump System
    Crystal wrote: »
    Now you really have my wheels turning.
    So, if I beef up the existing system, would I be able to run the existing AC pump? I don't have all the specs (I'll call well guy tomorrow), but I do know that it runs off of 220v round plug. Are there inverters that take this kind of plug?

    Crystal, if you can, please put your basic system information in your signature (aaa Watts of solar panels, B.B kW 120 VAC Xback CC Volt @ DDD AH battery bank, E.E kW inverter, 5 kW backup genset, etc.).

    But, there are two basic ways of getting 240 VAC power (really around 220/230/240 depending on local grid/off grid components). One is to use a 120 to 240 VAC transformer. A second is to have an inverter (or pair of inverters) that output 120/240 VAC.
    What is a 3-phase well pump?

    There are two main power standards. single phase (the normal 120/240 VAC power to your home) and three phase power for industrial/larger power installations.

    Single phase power cannot create a "rotating" magnetic field. So, when we work with standard AC Motors, there are all sorts of methods to create a rotating magnetic field through the use of starting capacitors (a second set of coils is offset from the first and the capacitor offsets the coil current in time--causing a rotating field to get the motor turning). Once the motor is turning, only one set of power lines is required (single phase) to keep the motor running.

    Three phase power would use (a minimum) of three coil pairs in the motor and the three "hot wires" will create a rotating field "naturally". So, 3 phase motors are more rugged (less parts to go bad, capacitors, switches, etc.) and a bit more efficient.

    You almost for sure, do not have a 3 phase pump in your well. What you probably have is a pump that uses (hopefully) a starting capacitor that is installed at the well head (i.e., controller box with capacitor inside).

    This type of motor has two advantages for you... This type of motor is "easier" to start (needs less current) and can be run with a VFD (Variable frequency drive).

    If the motor is a "two wire" + ground motor (capacitor is usually in the well with the motor)--You cannot use a VFD.

    A VFD is a combination of an AC inverter which has a 2 or 3 phase output (two phase can replace the starting capacitor, or three phase to run a three phase motor).

    And, the Grundfos SQFLEX line of pumps (I am guessing here--but it is close enough for our needs) is a high quality three phase motor with permanent magnets in the rotor. A PM motor is simply more efficient than an induction motor. But, normally, needs some electronics like a VFD to get turning properly (induction motors "slip", PM motors are "phase locked"--Sort of the difference between an automatic transmission on a car vs a stick shift with a stuck clutch--if that makes sense).

    Anyway, the Grundfos SQFLEX has a PM three phase motor with a VFD built in. The VFD output takes care of starting and running the motor, and the VFD input can take a wide range of AC or DC power (most digital type power supplies convert all input power to DC then convert the output to what is needed).

    The neat thing about the SQFLEX is that the VFD can take solar power directly and the internal electronics figure out the Pmax=Vmp*Imp directly and figure out how much energy is available to turn the pump motor at the correct RPM (VFD--Variable Frequency Drive--I.e., 60 Hz = 1,800 RPM, 30 Hz = 900 RPM, etc.). It saves you from all the complexity of MPPT charge controllers, batteries, AC inverters, etc...

    So--Sorry for the long detour--But understanding what you have and what your options are is important.
    Would I need a bigger battery bank since I would be adding panels?
    Our existing battery bank consists of 4-T105 Trojans.

    I would suggest starting with your loads "today", size of array, inverter model/size, etc.

    The typical SQFLEX pump (if that is your choice) can consume ~1,000 watts under full load with enough available power.

    So, if you operated the pump for 5 hours per day at 10 gallons per minute--Could take upwards of 1,000-2,000+ of solar panels to run it.

    5 hours * 60 minutes per hour * 10 gallons per minute = 3,000 gallons per 5 hours of pumping.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • stephendvstephendv Solar Expert Posts: 1,571 ✭✭
    Re: Beginning Search for Solar Well Pump System
    Crystal wrote: »
    So, if I beef up the existing system, would I be able to run the existing AC pump? I don't have all the specs (I'll call well guy tomorrow), but I do know that it runs off of 220v round plug. Are there inverters that take this kind of plug?

    There is definitely an inverter out there that will run your existing AC pump, the question is whether it's cost effective or not. Imagine a sliding scale of putting money towards your household system or putting that some money towards your pump, the scale would go something like:
    1. Install a BIG split phase inverter for your house that has enough surge power to start your pump as is: Big money for the inverter and no money for the pump.
    2. Smaller split phase inverter or single phase inverter + transformer and VFD for pump, and perhaps a new 3 phase pump (if your current pump can't be used with a VFD: Some money towards inverter and some money towards pump + VFD.
    3. Keep your existing household system and buy a grundfos SQLFlex: no money for the household system and big money for the pump.

    Can't tell how big an inverter you need until we know the pump specs and the generator specs. And you could ask your well guy whether that pump will work with a 3 phase VFD or not. As an example, the magnum inverters have split phase output 120/240V: http://www.solar-electric.com/maenms4040wa1.html it has a 5 second surge rating of 5.8kW which might be enough to run your existing pump.
  • CrystalCrystal Solar Expert Posts: 121 ✭✭✭
    Re: Beginning Search for Solar Well Pump System
    stephendv wrote: »
    There is definitely an inverter out there that will run your existing AC pump, the question is whether it's cost effective or not. Imagine a sliding scale of putting money towards your household system or putting that some money towards your pump, the scale would go something like:
    1. Install a BIG split phase inverter for your house that has enough surge power to start your pump as is: Big money for the inverter and no money for the pump.
    2. Smaller split phase inverter or single phase inverter + transformer and VFD for pump, and perhaps a new 3 phase pump (if your current pump can't be used with a VFD: Some money towards inverter and some money towards pump + VFD.
    3. Keep your existing household system and buy a grundfos SQLFlex: no money for the household system and big money for the pump.

    Can't tell how big an inverter you need until we know the pump specs and the generator specs. And you could ask your well guy whether that pump will work with a 3 phase VFD or not. As an example, the magnum inverters have split phase output 120/240V: http://www.solar-electric.com/maenms4040wa1.html it has a 5 second surge rating of 5.8kW which might be enough to run your existing pump.

    Here's the specs for the AC submersible pump that we have installed right now:
    Franklin AC pump
    1/2 hp
    10 gal/minute
    5A running, 6A startup
    230v
    max load startup 960w, running 670w
    Single phase
    Red, Yellow, and Black wire running through it...Red wire carries 0A, Yellow 6A, and Black 6A (don't know exactly what this means, but thought it might be helpful)

    Our well guy said that it would run a VFD and suggested a Franklin mono-drive (don't know if this will work or not).

    Generator Specs:
    Honda em5000sx
    5000w
    120/240AC

    At this point we're are leaning towards making the AC pump work and beefing up the house solar system.
    1500 more watts in panels, 1500w inverter, and more batteries should do it?
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