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Grid Tie to Off Grid Conversion

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  • Grid Tie to Off Grid Conversion

    Hi All, We have an existing 15Kv grid tie with 3 - Sunny Boy 5.0 which supply our business with 3 phase 208V. I would like to convert to off grid but I do not know if the SB 5.0 will work in this application. Any suggestions?

  • #2
    The Sunny Boy inverters can be converted to off-grid operation by using a technique called AC Coupling. Go purchase three SMA Sunny Island inverters and a large 48 volt battery bank and wire it all up..

    The Sunny Islands will cause your normally grid-tied Sunny Boy's to make power as if the grid was still connected. You'll need three of the Sunny Island units.


    • #3
      If you are abandoning the grid connection, you will also need a large generator that can run the business AND recharge the batteries in bad weather. And with a generator over 50hp. many locations require Air Quality permits and inspections
      Powerfab top of pole PV mount (2) | 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



      • #4
        We have a 22kv generator currently backing up the system. My problem is that even though we installed a 15Kv PV grid tied system, we still pay meter charges and demand even though in 8 months we back fed 15Mw back to the grid. I spoke with my utility and they said that we never get paid for the banked MW so we will always have to pay about $200 in meter charges and demand.