Backup Solar Power

BKY2003BKY2003 Registered Users Posts: 7
Will this support my well (9amp @230v) for backup power?
XW4024
6- 4v Surrette 546 Ahr (4cs17ps)
I am concerned the battery bank is to small, any thoughts would be appreciated.

Comments

  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Backup Solar Power
    BKY2003 wrote: »
    Will this support my well (9amp @230v) for backup power?
    XW4024
    6- 4v Surrette 546 Ahr (4cs17ps)
    I am concerned the battery bank is to small, any thoughts would be appreciated.
    Welcome to the forum.

    Your inverter can handle the running load of the pump. I don't know if it can handle the startup surge, that depends on the specific pump.

    9 amps at 230 volts AC will cause an approx 90-110 amp DC draw from your batteries. That's a heavy draw for a 546 ah battery bank. You can probably get away with it for a minute or two.

    How often and for how long do you backup power for your pump? Perhaps a generator would be a more cost effective solution.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • BKY2003BKY2003 Registered Users Posts: 7
    Re: Backup Solar Power

    I was going to use it for power outages, so I don't know how long (2 minutes to 2 weeks to 2 years).
    So if this did not cut it I was going to go with XW6048 and 48v Bank. But man the cost.

    I also already have a 10 kw grid tie system and fm80, but I was going to get some imput to make sure I did the rest right.
    Thanks for the reply.
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Backup Solar Power
    BKY2003 wrote: »
    I was going to use it for power outages, so I don't know how long (2 minutes to 2 weeks to 2 years).

    If this battery system is just to pump water for power outages, a generator makes most sense. If you are trying to keep the lights and the fridge on during frequent outages, batteries may make more sense. But you will still need a generator. Why not buy the generator first. If you find yourself using it too much, then buy batteries.
    BKY2003 wrote: »
    So if this did not cut it I was going to go with XW6048 and 48v Bank. But man the cost.

    Don't forget that the most expensive part of the system (batteries) you will get to buy several times over the years. They will need replacement even if they're never used.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • BB.BB. Super Moderators, Administrators Posts: 28,851 admin
    Re: Backup Solar Power

    There are things you can do to reduce the power used by the pump... There are VFD (Variable Frequency Drive) controllers--which control surge and can adjust pump RPM (slow down over-sized pumps). There are also pumps that (in well, surface) that are designed with VFD internal to the pump or even have the ability to take multiple power sources (AC, solar panels, battery bank, backup generators, etc.--obviously not cheap at ~$2,000 or so).

    Some types of pumps are less efficient (jet pumps) than others... It is generally less expensive to spend money on conservation vs building/buying a larger system to generate the higher power levels.

    Solar pumps

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: Backup Solar Power
    BKY2003 wrote: »
    I was going to use it for power outages, so I don't know how long (2 minutes to 2 weeks to 2 years).
    So if this did not cut it I was going to go with XW6048 and 48v Bank. But man the cost.

    I also already have a 10 kw grid tie system and fm80, but I was going to get some imput to make sure I did the rest right.
    Thanks for the reply.

    most opt for 2 or 3 days ftr, but sometimes even 2 hrs fills the bill depending on circumstances.

    the inverter surge is in the manual. it said,
    "The Xantrex XW Series Inverter/Charger handles surges of over twice its rated output power with
    only a minimal drop in output voltage."
    only question remaining is the time duration of such a surge, but is more than likely enough for the pump.

    that answers the question of the inverter, but not your wires. can they take that much current? 8kw peak/24v=333.3a. will they need to and if not then how much? hard to say what your specific pump will require to go into this aspect, but you can be sure the wires will be quite large in thickness.

    another question is will the battery bank provide a huge surge like that? probably not for long. would it survive a surge from your proposed pump? most probably as my guess would not be in the 10x the draw area for the surge, but it will still be appreciable. it's hard to speculate with any real certainty though.

    you could've bought the xw4548 at the same cost. higher voltage, but current requirements would've been roughly cut in half as there is a tad more power available from the inverter. this represents more cost in batteries only because there will be more batteries, but the current rating of each battery would not be required to be at your current capacity choice. maybe around 3/4 of that capacity would suffice. again some speculation.
  • BKY2003BKY2003 Registered Users Posts: 7
    Re: Backup Solar Power

    Will this work as the VFD (Schneider electric Soft start ATS01N109FT). My pump is a Franklin electric 1HP 9.8volt @230 single phase. Thanks for any input.
  • BB.BB. Super Moderators, Administrators Posts: 28,851 admin
    Re: Backup Solar Power

    It looks like it should work/help... Unfortunately, I do not have much experience with VFDs. There are some threads here with some more discussion about options:

    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

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BKY2003BKY2003 Registered Users Posts: 7
    Re: Backup Solar Power

    I purchased the xw6048 from wind & sun and the manufacture date is almost 2 years old. Will this be a problem (firmware) and should new xw6048 be that old. Thanks.
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,354 ✭✭✭✭✭
    Re: Backup Solar Power

    1.07.00 BN 3 is the latest. For offgrid the only problem with any of the firmware has been the use of non inverter type generators in my opinion. I would like to hear how your VFD works. I am starting to get interested in the VFD that Gould makes for their houshold water pumps.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • BKY2003BKY2003 Registered Users Posts: 7
    Re: Backup Solar Power

    Thanks for the reply, I abandoned the VFD idea because I put an amp meter on the water pump and the surge amps were 15 amps (@ 3600 watts) running amps at 9 (@ 2160). I felt like the xw6048 and a 546 Ahr batttery bank would do the trick without the VFD.
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