Toolik: Upgrading my 12 year old Solar Power System

This discussion was created from comments split from: Ideas for back up inverters?.

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  • Toolik
    Toolik Registered Users Posts: 3
    I am upgrading my 25 year old 12v system, 1670AH Solar HUP1 batteries, 18 years old but still functioning very well, Outback 2812 with 2600w of solar.  I've got a Victron Quattro 48/5000 with 450AH Lithionic battery bank and will add/upgrade the solar.

    I have an offgrid homestead in Alaska with additions to the power system 400' from the inverter/battery. So I plan to move the old system to the other end where there is less power demand.  I would like to be able to transfer power between the two systems.  They would normal have no connection, but I thought to take power from AC out and connect to grid input of the other inverter should be a way I could do that. 

    Any potential problems anyone could forsee
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    Toolik said:
    I am upgrading my 25 year old 12v system, 1670AH Solar HUP1 batteries, 18 years old but still functioning very well, Outback 2812 with 2600w of solar.  I've got a Victron Quattro 48/5000 with 450AH Lithionic battery bank and will add/upgrade the solar.

    I have an offgrid homestead in Alaska with additions to the power system 400' from the inverter/battery. So I plan to move the old system to the other end where there is less power demand.  I would like to be able to transfer power between the two systems.  They would normal have no connection, but I thought to take power from AC out and connect to grid input of the other inverter should be a way I could do that. 

    Any potential problems anyone could forsee
    I suggest you start a thread. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    My first suggestion is usually to make one system and distribute the 120/240 VAC to the locations needed--Vs building out two power systems and having to try and move power between A and B. Generally easier to maintain one larger system.

    However, always up for a challenge. The first question is how far and how much power (Watts/Volts/Amps) do you want to move the power. The higher the voltage, the less losses and less copper ($$$) to transfer power.

    Will this be a one way or bi-directional power exchange?

    Have you thought of a "Micro Grid"-- Running 120 or 120/240 VAC around the property (your micro grid), and then connecting hardware to the micro grid that can do things like Grid Tied inverters, Hybrid inverters with batteries and backup genset, etc. (Sunny Island or simiilar concept)?

    If you choose an inverter with "generator support"--It is interesting... You could choose to send relatively low power/current from the old system to the AC input and program new AC inverter for a lower AC current like 10 amps. The new inverter would draw 10 amps maximum and move the energy to charging the local battery bank, sharing currenet with loads, etc... Basically treat the remote inverter system like a small genset.

    Check the Victron system's AC (genset) requirements. Some systems will take 120 only, others 120+240 (split phase power), or possibly 240 VAC only. Need to match the old Outback inverter with the new AC input requirements (could even use a transformer to step up from 120 to 240 VAC--And allow more power/smaller AWG cable for the 400 foot run).

    -Bill


    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    I hope you have planned for your Li batteries to be in a heated area,  Below 40F they have to be charged slower, and below 33F they cannot be charged at all.
    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 ,

  • Toolik
    Toolik Registered Users Posts: 3
    Thanks for the replies.  I was planning for occasional low power  transfers as you talked about Bill,<10A .  Programming the current limit to do that.  I didn't think it would be a problem.

    The Lithionics batteries will not be in a heated area, but they have silicone heater pads in the battery core.  The BMS turns on the heater at 35F, and will prevent charging below 32 and discharging below -4F.  I plan to turn off the heater when solar resources are low, and use the Quattro AC2 out, which only supplies power when Gen power is available, to power the heater with a 2000i Honda to preheat batteries before charging sources are turned on.
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    That scheme is going to take over an hour of generator run time to warm up the batteries, before charging even starts
    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 ,

  • Toolik
    Toolik Registered Users Posts: 3
    That's fine, using the AC2 in with the Honda 2000i does the heater and runs my house loads, then when the batteries have warmed ( I live in maritime Ak and temps usually are not that cold,( ave low temp in Jan is 30F ) I can charge with the Honda 5000 and solar.   The batteries charge at 52A 48v and the gen will warm the building so temps should be good for solar the rest of the day with out running the heater again, and I will only charge to 70-80% to make best use of expected solar that day.  I have 3600w of panels.