Converting older system to Grid tie

Hi, 9 years ago I installed a set of panels (8x120watt), a Trace sw4048 system with 16 batteries (2 series of 8 -L16s) and used the Grid only to charge and equalize. Now Alas the batteries are shot and I find that while my Trace once supported the Grid tie spec, the spec has changed. As I really don't want to buy a new set of batteries and I also don't want to let my PV panels go unused - what is the cheapest way for me to get this system grid tied? (the system runs at 48V). My PV charge controller is a Power Advantage 302 from FireWind and Rain (would that be used in no batteries are involved?) Not sure if relevant, but I live in New Hampshire - thanks


  • GunnyDGunnyD Registered Users Posts: 5
    Re: Converting older system to Grid tie

    I would rewire the panels into a single string. Sell the inverter and charge controller on ebay and buy a 1kw grid tied inverter with the disconnects. Might even have some money left over.
  • RoderickRoderick Solar Expert Posts: 253 ✭✭
    Re: Converting older system to Grid tie

    You can probably find an older inverter like a PVP1100 for a song.

    Look for someone who had a small system, finally decided they want more, and is selling the old inverter. Maybe scan Craigslist or eBay?

    If you want new, maybe Arizona Wind & Sun still sells a small grid-tied inverter.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Converting older system to Grid tie

    be sure your 8 12v pvs in series will meet the voltage needs of any inverter you choose as these will usually be in the hundreds of volts.
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    Re: Converting older system to Grid tie

    The lowest GT inverter input voltage I have seen is around 150 VDC... Typically, they are around 200-220 VDC minimum input voltage from the panels.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Converting older system to Grid tie

    yeah 115V seems to be the lowest I have seed - I can't reach that even - So in order to make use of my panels I would need to add more panels to bump up the voltage and do as described above or buy more batteries and don't grid tie. Xantrex used to sell the GTI to upgrade systems like mine - they discontinued it, however some dealers may still have one - $427. take while to get a payback on that. Thanks
  • icarusicarus Solar Expert Posts: 5,433 ✭✭✭✭
    Re: Converting older system to Grid tie

    Another option would be to sell the panels you have, and find some higher voltage panels. The 12volts are big sellers on e-bay, if sold by the each the tend to get ~$5watt, then sell the inverter and the cc, but a couple more panels with the difference. If you don't need to be free of the grid, a grid tie will buy you way more panels/efficiency.

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