Fishing for suggestions for inverter replacements..

Hi all..

We've had a GT setup since late '07 -- a 6kw system installed by Premier Power in the Sacramento,CA area (we're down in the LA area -- they subbed the job out at the time).. Anyway, we've got two strings of panels (using 176 of the Sharp's ND-62RU1 modules) that feed into two Fronius IG3000 inverters. It's been a good system so far but has, in my opinion, had more failures than I believe a system ought to have at this point in its life :
  1. One inverter failed about 3-4 years ago -- replaced under warranty
  2. the other inverter fried a GFCI type of board (I don't recall the exact terminology off the top of my head) about 2 years ago
  3. the same inverter fried another board about a year ago
  4. today I found out that the inverter mentioned in the first bullet needs to be replaced again as it has not been putting out any power for a week

So, to me it is apparent that the Fronius inverters -- at least these models, are short lived at least when used on the So-Cal Edison grid and I can expect a failure every year or at most 2.. None of the times we've had major power glitches (downed lines,outages,etc) did any of the inverters skip any beats -- they fired right up once the power was restored. The failures on all of these occasions are at seemingly random times. Also, I should note that Fronius told me this morning that my warranty runs out in 2017.. only 5 years left for free fixes. I've also discussed swapping in other inverters (e.g. Sunny Boy) with Premier Power and they claim they can't (more likely -- wont) do it -- seems an odd stance since it costs them $$ to send technicians out to swap hardware on a regular basis.. :confused:

So, with that in mind, I'd like to plan for the future since I realize this job will cost me out of my own pocket (probably).. What are considered to be very stable & reliable grid-tie inverters by todays standards? I realize what may be today's good inverters may not be the case 4+ years from now but if I can at least get an idea of pricing I can start budgeting for the replacements.. I think that the Fronius IG3000's go for somewhere in the $1500/ea range.. Right now I've heard nothing but good things from the Sunny Boy stuff which is what Premier Power switched to sometime after our installation was done in late '07 due to problems with the Fronius stuff. Are they about as good as they get?

P.S. I will be checking w/ Premier Power when my warranty is closing out to see if I'm completely on my own at the 10 year mark -- even though the Sharp panels have the standard 25yr warranty.. Not sure how that angle will play out.. Perhaps they might offer me an extension of sorts for $X or something..

Comments/suggestions? Thanks!!

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Fishing for suggestions for inverter replacements..

    At this point--SMA/Sunny Boy would/will be my next choice to try when the current one fails out of warranty.

    In any case, most electronics/power supplies/inverters are on "borrowed time" after 10+ years (in my umble opinion).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • osx-addict
    osx-addict Registered Users Posts: 7
    Re: Fishing for suggestions for inverter replacements..

    Thanks.. By the way.. For a typical grid-tie install, what is an average time between inverter issues in a system that is well under 10 years old? Are my issues out of the norm for a 5 year old (or under for the early failures)? Just curious..
  • osx-addict
    osx-addict Registered Users Posts: 7
    Re: Fishing for suggestions for inverter replacements..

    Another few questions if you don't mind that popped into my head.. In looking at the SunnyBoy inverters, it seems like their SunnyBoy 3000-US or their 3800-US would be good replacements for our Fronius IG3000's.. In looking at the specs, either SunnyBoy model seems like it would take the existing capacity without issue (unless I missed reading something -- the original Fronius specs can be found here and the specs for the SunnyBoy are here) -- is that a fair assessment?

    Also, in the off chance we decide to put up a wind-tower (something similar to a pacwind or similar) is it a bad idea to oversize the inverter to handle more capacity than we currently have? I realize that the two Fronius inverters we've got now are very much tied to our existing system size (on the upper end for our 6KW system - IMHO).. Perhaps it'd be better to just add another inverter when the time comes (and if it comes) to add more generation to the equation..

    Also, on the SunnyBoy's, how are the remote monitoring items? Something tells me that they're not cheap but I didn't check -- some of them seem for larger scale setups.. In our current system I've got the fronius hardware that allows me to monitor the inverters outputs, check wind speed, temps,etc.. Nice but it requires the use of their custom software which is a pain..
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Fishing for suggestions for inverter replacements..

    Probably vender and Mfg dependent.

    My first inverter went over 5 years without problems. Vender replaced unit after 5 year warranty period with new and improved unit which fails in less than 1 year.

    Replaced for free with 5 year old spare... Still working.

    Solar array failed after about 6 years. Vender replaced for $500 labor.

    Still working.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • osx-addict
    osx-addict Registered Users Posts: 7
    Re: Fishing for suggestions for inverter replacements..

    Thanks Bill.. I guess I won't expect too much in terms of units not having issues from time to time.. I might have to start tracking these failures though.. I didn't take notes at the time.. Ugg..
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    Re: Fishing for suggestions for inverter replacements..
    osx-addict wrote: »
    We've had a GT setup since late '07 -- a 6kw system installed by Premier Power in the Sacramento,CA area (we're down in the LA area -- they subbed the job out at the time).. Anyway, we've got two strings of panels (using 176 of the Sharp's ND-62RU1 modules) that feed into two Fronius IG3000 inverters.

    Hi,

    Something doesn't add up with the info above. Firstly, those are 62W panels, x 176 = 10.9kW, but you only have 6kW of inverter? The Voc of each panel is 10.8V, if you have only 2 strings, then that's 88 panels in series for a combined Voc of 950V well over the fronius' input limit. So, I'm going to guess it's actually 2 strings per inverter, ie. 4 x 44 panels in series.

    Plugging this info into the sunny design tool, shows that 2 x SB5000US would be the optimum solution, giving you 10kW of inverter.

    Attachment not found.

    Don't know if the extended warranty is available in the US, but over here in euro land you can buy an extend the SMA warranty up to 25 years.
  • osx-addict
    osx-addict Registered Users Posts: 7
    Re: Fishing for suggestions for inverter replacements..

    Ok.. You got me.. I had to go back and check the papers.. We don't have 176 panels (not sure why that stuck in my head) but we have 98 of them -- taking up a claimed 450-500SF of roof space. I'll try their design tool later when I'm at home. Thanks!
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    Re: Fishing for suggestions for inverter replacements..

    A bit tricky because the Froniuses (Fronii?) have a lower acceptable voltage input than the sunny boys. The SMA software has come up with the following configuration using 1 x SB3000US and 1 x SB2500HF

    Attachment not found.
  • rollandelliott
    rollandelliott Solar Expert Posts: 834 ✭✭
    Re: Fishing for suggestions for inverter replacements..

    3KW inverters tend to be more expensive than a single 5kw or 6kw inverter.

    call up SMA and give them your specs and they will email you a potential scenario of how your current panels might work with their inverters. Dont' be afraid to "overpanel" the inverter a little bit.
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    Re: Fishing for suggestions for inverter replacements..
    3KW inverters tend to be more expensive than a single 5kw or 6kw inverter.

    Yes, but with those panel specs and number of panels they can't fit into a single 5kW inverter with 1 MPPT tracker. They need to be on 2 MPPT trackers, and the dual tracker sunny boys in the 5kW range aren't available in the US.