Here is my existing equipment. 50 * 415w panels with enphase iq7a microinverters (~21KW), sungoldpower 18kw pure sine wave inverter, 48v LiFePo4 battery bank in an offgrid configuration providing 240v split phase power. Currently have/had 10 panels directly wired to the sungoldpower inverter’s onboard mppt
My inverter decided it wanted to be on fire and the replacement boards they tell me will take months. Unacceptable. So exploring my options.
What I am looking for:
240v split phase power
Frequency shifting to control production on the enphase panels
Charging and powering off the 48v bank
Ability to source 240v power from the grid and/or generator but does not necessarily need to be automatic transfer
Ability to backfeed/sell excess solar production to the grid if I want.
Nice to haves:
Parallel/stacked/whatever inverters so if I have an inverter failure I can at least limp along supplying critical loads at a reduced load and/or dropping to a single 120v leg. I’m fine with this scenario requiring manual reconfiguration.
Automatic generator start up as needed
Automatic transfer from grid if grid tied and grid power fails.
Caveats:
If I can’t support the entire 50 panels whether they are directly tied to the inverter, all enphase powered, or some combination that’s fine but I would like to support as many as is possible/feasible.
Can someone point me in the right direction? Single large 15k 230v with an auto transformer?
Multiple 120v inverters? Can they be arranged such that I can both have split phase and desired power while still supporting frequency shifting to control the enphase microinverters?
For ac coupled you should follow the 1:1 rule. So if you have 20k of solar you need 20k of inverter.
Convert some (like 5k to dc mppt with a 450/100) which is also a good move for ac couple systems and black start purposes, this will also allow a drop to 15kVa if that covers you peak load needs still.
Frequency shifting will only happen off grid.
There is not official enphase integration but enphase say they have so they will be your line of support. There are few posts here on the forum and the old kne and a git hub repository where a kind fellow shared his integration.
I don’t have experience with the 240/120 split phase set up. So I hit ETC at that point.
Since it is a fairly large system it will be worth contacting someone close to you for some specific advice on your system design. https://www.victronenergy.com/where-to-buy
Thanks! I’m already in touch with my local dealer, just gathering all the info I can! Local dealer primarily installs on yachts so my situation is a unique system for him and we’re trying to get it sorted out.
You didn’t say where you were, but since you’re looking for split-phase 120/240V I will assume you are in North America.
Victron does NOT support grid interactivity in North America. Victron provides no grid codes along with the required UL listings for any kind of sell back to the utility. There are no products coming anytime soon that will support this, and top Victron leadership says grid-tied features are not on the roadmap for us in N.A.
Because of this you have two options: Use Victron equipment attached to the grid for power backup only (no sell back) OR choose a different brand.
You can easily AC couple your Enphase system to the output of Victron’s inverters. But any excess power created by the micros will not be fed back into the grid. You’ll need to decide how important it is to you to feed excess into the grid.
You could put the Enphase system in parallel to the grid input of the Victron inverters and sell excess power made by the Enphase system back to the grid, but if the utility fails the Enphase system will shutdown, leaving only the Victron inverters to provide power to loads connected to them.
In summary, determine if feeding back excess power is important. If it is, use different products.
You are welcome to have your local dealer contact us if they would like some pointers. I’m happy you are supporting your local dealer!
Sell back to the grid is a nice to have but not critical. I’m not grid connected now so at present it’s irrelevant. Since I’ve got more micros and panels on hand than the victrons can support or my battery bank can store it sounds like I could just put excess micros on the AC input side of the victrons if grid connected so they AC couple to the grid and back feed, and just go down in a grid failure?
Correct. Two Quattro 10kvA inverters can handle it, though as LX said, you should have some DC-coupled PV for black start purposes if your batteries shutdown due to low SoC. Good luck with your project!