Hi william Here is possibly another option
The sma 50 and 62 kw tripower core 1 have operating Mppt voltages down around 125-150vdc. I don’t know how the system is wired: combiners and sub combiners? What about installing the inverters in place of the combiners, then AC runs to the main AC buss via hanging wire trays. This eliminates the combiners, uses newer technologies, is probably a cheaper option buying time Until a full repower with new modules/ inverters can happen. Those 50 kw units are $4500 each. Which is of course the other option in my mind, full rebuild. The repair + parts kit puts you close to $200k in the hole with ancient inverters and 10+ year old panels. I don’t know if they can push more KW, but that array could probably be upgraded to double what it is now. With 125 kw string inverters, no combiners could be an option. There are going to be a lot of these issues in the future Let us know what option you figure out. Jay > On Sep 8, 2021, at 5:14 PM, William Miller <will...@millersolar.com> wrote: > > > Friends: > > I learned a new buzzword recently: “Re-powering.” It means replacing > inverters on an existing PV system of ten or more years old. Due to the high > number of systems of this vintage it appears that re-powering has become > somewhat of a sub-industry. The big problem is these systems are all 600 > Volt limited PV panels, combiners and re-combiners and there are no 600 volt > utility grade inverters being manufactured. > > I am working on a utility scale system built about 14 years ago that fits the > description above. There are two 250KVA Xantrex GT250 inverters and one has > failed. The question of the moment is: Repair or replace? > > Repair: If we fix these inverters, can we count on support in the future? > We can negotiate a service contract with Schneider at a cost yet to be > revealed. This requires we buy a spare parts kit for about $100K. There are > a few other companies that claim to offer repair services on these inverters > but none has followed through. > > Replace: The PV plant is built with panels and BOS all limited to 600 VDC > max. There are no more 600 volt input utility scale inverters being built, > or at least none that I have found. If we install a 1000 or 1500 volt > inverter we may have to replace the entire PV array and BOS. It may be > possible to convert the output of the existing panels to a higher voltage > with DC-DC converters. > > Here are the options I see: > > Optimizers: One purveyor of optimizers is Solar Edge. Solar Edge offers a > 100 KVA inverter. This inverter requires DC input of 850 volts. The > inverter requires optimizers to obtain this voltage. The question: Do the > optimizers isolate the PV from the higher string voltages in the case of a > catastrophic failure of one or more of the optimizers? > > Repower with outboard DC-DC voltage converters, such as provided by Alencon > Systems. Solectria has successfully done this. Here is a paper on the > subject. > > If anyone has dealt with this issue before I would sure appreciate any wisdom. > > Here is a link to a web-page I built for this project. > > Thanks, > > William Miller > > Miller Solar > 17395 Oak Road, Atascadero, CA 93422 > 805-438-5600 > www.millersolar.com > CA Lic. 773985 > > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org >
_______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
