Hi. I have an odd situation I need some help resolving. About 12 years ago, we installed a grid-tie solar PV installation with 36 LG 175w panels and a Fronius IG 5100 inverter. This system, has worked well, but never completely eliminated my energy bill as we have a few computer servers and now with 4 kids, burn a lot of energy. But it's saved a ton of money (and the roof has never leaked!), as here in the SF Bay Area, PGE charges an arm and a leg when you get into their band 4 or 5 pricing. The panels are all on the same 2nd story roof and point almost exactly due south, and on a clear day the system generated about 4700W in mid day.
The IG 5100 recently failed, and in discussions with Fronius, it became clear it was going to be better to replace it with a new inverter than repair the old one, esp since the old one didn't have monitoring. The company that installed it is no longer in business on top of it all. So I got a new fronious primo 5000, and even though its pretty easy to replace myself (the inverter is in the garage, and has an ac disconnect at the panel and a separate dc disconnect next to the inverter), I like to stay compliant with code so I called an electrician to replace it.
The electrican really didn't want to deal with the inverter programming and such,. and referred me to a solar installer that also does repairs. The issue is apparently that the wiring I have to the panels is not double insulated, which was common a decade ago, but is no longer code with a transformerless inverter like the primo. Furthermore, it appears that you can't find inverters in the 5 KW class anymore, and to redo the wiring to and between the panels would be very expensive, and I should probably replace the panels at the same time if I did that. He said the new primo would work fine if installed, but that it could not be compliant with code, so he wouldn't do it, but agreed it would probably be easy for me to do it.
So now I am thinking about executing the original plan, and swapping out the inverter myself, which gives me pause as I like to be compliant with code, or basically redoing the entire system and installing new panels, which might be good in terms of reducing my electric bill even more.
I'd love some advice on how to proceed, and have a few specific questions:
1) Why is it needed to use double insulated wiring with a transformerless inverter like the primo?
2) If I do install a new set of panels, does the 30% federal tax credit still apply if I am just replacing an existing system instead of installing one for the first time?
3) How much cheaper would replacing the panels and wiring cost over a new installation, and could the existing roof mounts be reused? I know a more powerful system would need a bigger inverter, so I would have to factor that in as well.
4) With 36 panels, I don't think I need to go with an expensive panel like the X21, but I the LG 315W panels seem like a good fit. Do folks have any advice for me in terms of special things to consider if I do go with new panels in a situation like mine?
Thanks!
Mike
The IG 5100 recently failed, and in discussions with Fronius, it became clear it was going to be better to replace it with a new inverter than repair the old one, esp since the old one didn't have monitoring. The company that installed it is no longer in business on top of it all. So I got a new fronious primo 5000, and even though its pretty easy to replace myself (the inverter is in the garage, and has an ac disconnect at the panel and a separate dc disconnect next to the inverter), I like to stay compliant with code so I called an electrician to replace it.
The electrican really didn't want to deal with the inverter programming and such,. and referred me to a solar installer that also does repairs. The issue is apparently that the wiring I have to the panels is not double insulated, which was common a decade ago, but is no longer code with a transformerless inverter like the primo. Furthermore, it appears that you can't find inverters in the 5 KW class anymore, and to redo the wiring to and between the panels would be very expensive, and I should probably replace the panels at the same time if I did that. He said the new primo would work fine if installed, but that it could not be compliant with code, so he wouldn't do it, but agreed it would probably be easy for me to do it.
So now I am thinking about executing the original plan, and swapping out the inverter myself, which gives me pause as I like to be compliant with code, or basically redoing the entire system and installing new panels, which might be good in terms of reducing my electric bill even more.
I'd love some advice on how to proceed, and have a few specific questions:
1) Why is it needed to use double insulated wiring with a transformerless inverter like the primo?
2) If I do install a new set of panels, does the 30% federal tax credit still apply if I am just replacing an existing system instead of installing one for the first time?
3) How much cheaper would replacing the panels and wiring cost over a new installation, and could the existing roof mounts be reused? I know a more powerful system would need a bigger inverter, so I would have to factor that in as well.
4) With 36 panels, I don't think I need to go with an expensive panel like the X21, but I the LG 315W panels seem like a good fit. Do folks have any advice for me in terms of special things to consider if I do go with new panels in a situation like mine?
Thanks!
Mike
Comment