from off grid to grid tie in

blue Registered Users Posts: 35 ✭✭
I have 15 x 100 watt panels in an off grid configuration with 8- 114 ah 12volt batteries. I plan to switch eventually and get more panels and go to grid tie in. Can I still use these 15 renogy panels with a grid tie in system. I know it is more practical to use 300 watt panels that have micro inverters. But what do I do with the 15 -100watt panels?


  • BB.
    BB. Super Moderators, Administrators Posts: 33,404 admin
    Guessing you are in Florida...

    GT Solar can be highly location specific... Both building permits and utility. So the first question is can you use the present array (will the inspectors accept the array, or will they require you to bring up to present code--If it presently does not comply). And are the panels UL/NRTL Listed? You have to have to match the series/parallel configuration to whatever GT Inverter you will choose (1.5 kWatt GT inverters are getting fewer these days; either larger inverters or micro inverters--and the micro inverters may not be "Listed" for use with these panels/configuration).

    New "value" of these panels is probably much less than $1 per Watt, and you can purchase new panels at less than $1 per Watt... So the issues of trying to keep these panels on a GT system may not be worth it...

    If you have the room to keep the older panels... A 1,500 Watt array with an 800 AH @ 12 volt or ~400-800 AH @ 24 volt battery bank (10% to 5% rate of charge)--You could have a nice backup power system (for just the price of maintaining a battery bank)... How reliable is/will be your power?

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Photowhit
    Photowhit Solar Expert Posts: 6,001 ✭✭✭✭✭
    The good news is that these are likely 12 volt nominal panels, so they might find a new home with the RV crowd or even boating crowd. Stick them on Craigslist for 50-75 cents a watt and see if anybody is interested. If you have a charge controller that you used with them, it may be good as well. Florida doesn't have a lot of scrap dealers, but still lead acid batteries look like they go for 20 cents a pond (assuming your batteries are dead) at 60 lbs (best guess) that's $12 a piece.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former, 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • blue
    blue Registered Users Posts: 35 ✭✭
    Thanks I don't really care about backup. It is not worth the trouble for the little time the power goes out. Guess I need to sell it and start over. I want to go up to 3500 watts.