Simplest AC coupling for backup power on an existing SolarEdge system?

[gvl]

Solar Edge means optimizer per panel.
To move the PV panels over to an AIO, you have to remove the optimizers and possibly rearrange string.

It appears SolarEdge has their own AIO solution, which presumably is compatible with their optimizers, but I have not researched into it at any depth:

https://investors.solaredge.com/news-releases/news-release-details/solaredge-unveils-next-generation-all-one-home-solar-storage

And finally, SolarEdge may have a much higher failure rate than other brands. Not all models or installations do, but we've seen some reports. A reason to consider replacing with a hybrid/AIO.

The original SE 11kW inverter that was put in service in 2015 lasted only about 5 years. Got it replaced under warranty with a newer "Home Wave" 10kW unit, it's a much more compact unit that runs much cooler which bodes well with better reliability. The optimizers, apart from one which was DOA, were solid all these years.

 

[gvl]

My question about availability of more of a "shrink-wrapped" AC-coupling solution remains. Do systems from companies like EcoFlow or Bluetti support AC coupling with existing PV inverters?

 

[1201]

My question about availability of more of a "shrink-wrapped" AC-coupling solution remains. Do systems from companies like EcoFlow or Bluetti support AC coupling with existing PV inverters?

If they do it will exceed your budget, I'm sure.

 

[gvl]

If they do it will exceed your budget, I'm sure.

Yeah, but still would be interesting to know just as a point of reference.

 

[solar8484]

My question about availability of more of a "shrink-wrapped" AC-coupling solution remains. Do systems from companies like EcoFlow or Bluetti support AC coupling with existing PV inverters?

The Anker Solix F3800 supports AC coupling on-grid only. None supports AC coupling off-grid. A main challenge is that hybrid inverters need large battery banks to safely AC couple with common home solar system size. For example, 10kWH battery bank to support 5kW grid-tied solar but that much battery is heavy (>200lbs) and bulky for mobile systems and not something a typical person can easily lift or move.

 

[gvl]

The Anker Solix F3800 supports AC coupling on-grid only.

Meaning it cannot form a grid-tie system with an existing PV inverter in case of a power outage, such as the Schneider unit, and charge the batteries?

 

[Hedges]

It appears SolarEdge has their own AIO solution, which presumably is compatible with their optimizers, but I have not researched into it at any depth:

https://investors.solaredge.com/news-releases/news-release-details/solaredge-unveils-next-generation-all-one-home-solar-storage

Yes, or an earlier "StorEdge" which might be a drop-in replacement.

Of sorts; unless this is just for peak shaving, need either a transfer switch or move protected loads downstream.
I think StorEdge offered an auto-transformer for about 30A of protected 120/240V loads.

The new one might be more fully integrated, not sure.

Catch is proprietary batteries will break the bank.

There is a BMS emulator on GitHub to translate from entire EV packs to HV inverter.
That is a DIY project, and an incendiary device.

A liquidation priced battery inverter from Schneider or SMA, or a moderate priced hybrid, for 48V VRLA batteries and used with LiFePO4 might be best way to go. Either AC or DC coupled. Just be sure you know what you're doing safety and Voc wise before doing anything with PV strings.

 

[gvl]

A liquidation priced battery inverter from Schneider or SMA, or a moderate priced hybrid, for 48V VRLA batteries and used with LiFePO4 might be best way to go. Either AC or DC coupled. Just be sure you know what you're doing safety and Voc wise before doing anything with PV strings.

Yeah, seems that the Schneider-based solution is the closest to what I had in mind as I don't really want to mess with the existing PV inverter and the strings.

Anyone knows if Schneider is going to offer a replacement model for the XW Pro or they decided to pull out from this market completely?

 

[solar8484]

Meaning it cannot form a grid-tie system with an existing PV inverter in case of a power outage, such as the Schneider unit, and charge the batteries?

Technically it will try but will fail quickly and potentially get damaged. Unlike Schneider inverters, It doesn't have frequency shifting capability when off-grid so it has no ability to control excess power from grid-tied PV inverters.

 

[ASword]

Anyone knows if Schneider is going to offer a replacement model for the XW Pro or they decided to pull out from this market completely?

Strangely neither — they’re removing their old low-frequency transformer-based XW Pro product (20+ years on market in various versions), and replacing it with a high frequency product that is considerably different (notably with proprietary high voltage a batteries, iirc). The new product is much more inline with other HF products on the market, but they’re dropping a fairly unique and robust product that had the respect of many. Its main shortcoming was its firmware, which would be fixable with investment that Schneider was unwilling or unable to make. My completely unsubstantiated and weakly thought through pet theory is that the price of copper has made the huge transformer too expensive, plus staff turnover probably means their LF experts have gone and been replaced by engineers who grew up on HF designs.

 

[gvl]

My Inverter is actually rated at 10kW and I have 30x300W panels for a total of 9kW DC. These days, however, I never see more than 7kW AC output, likely because of panel degradation and soiling (I never clean them). Technically I need to use 2x XW Pros to satisfy their PV inverter sizing requirement of 125% of 6.8kW for PV inverter power, given I connect enough batteries. How bad of an idea is it to proceed with just 1 XW Pro?

 

[SplitUniverse]

XW Pro max charging capacity is 140A, at 50V that's 7KW. So it can absorb the 7KW of AC production you currently have (even with no loads whatsoever), AS LONG AS THE BATTERIES DON'T "OBJECT". There's a good chance you can get away with it if you have enough batteries and make sure it starts "curtailing AC coupling" while still at a about 80% SOC (the chances of "charging limitations" grow with the SOC).

P.S. Coincidentally that's a good SOC point to keep your batteries at in the long term.

 

[gvl]

XW Pro max charging capacity is 140A, at 50V that's 7KW. So it can absorb the 7KW of AC production you currently have (even with no loads whatsoever), AS LONG AS THE BATTERIES DON'T "OBJECT". There's a good chance you can get away with it if you have enough batteries and make sure it starts "curtailing AC coupling" while still at a about 80% SOC (the chances of "charging limitations" grow with the SOC).

P.S. Coincidentally that's a good SOC point to keep your batteries at in the long term.

It's interesting but they don't mention the charging rate of the XW Pro as input for the PV Inverter sizing decision, only XW Pro inverter's power of 6.8 kW or battery charging power. But sure, batteries can't charge at a higher rate than the XW Pro battery charger allows.