Victron and Fronius off grid setup

[Cmiller]

Settings.

Here are some screenshots of my settings.


Note that as I recall, the virtual switch must be disabled in order to be able to use assistants. Although I believe you are currently using ESS assistant, so I'm sure you are aware of this already.


I'm pretty sure that I'm using the default values for the frequency shift numbers, as those work quite well with the Fronius. I have the Fronius configured for MG60 (micro grid/ 60Hz). Having it set to that will help with keeping frequency shift working smoothly.

I did have a little bit of issues (mostly a mild annoyance) of one or 2 lights flickering at times when Fronius production was within a few hundred watts of power consumption. Fronius told me to adjust a setting that controls the response time for the Fronius, and that greatly improved the issue! I do think the lights that flickered were partly responsible for the issue, but was impressed that I was able to mostly clean up that issue!

The biggest drawback of this setup (for me specifically) is that my solar is all AC coupled, therefore if the batteries run low enough to shut down the Victron inverters, the only way to get solar out of a deadlock is to either get a gen charging via the Victrons or reconfigure the low battery shutdown voltage with all load breakers off to get AC power back on for the Fronius.

It would be beneficial to at least have some solar just going to a charge controller, and I believe I don't use a high enough portion of my solar directly as it's produced, to be ahead in terms of efficiency. I only use ~30% directly, so ~70% goes through inverters to battery, then back through inverters to loads.

 

[sunshine_eggo]

@Cmiller

Since this was well off-topic in the other thread (at my request), I requested the mods make it into its own.

Thanks again!

 

[sunshine_eggo]

Just to confirm, that's the only assistant you have installed. You have no direct interaction between the two except for the frequency shifting, i.e., no Fronius connection to the Cerbo.

Since I already have up to 6kW of DC PV, with this sort of performance, I'm leaning heavily towards a Fronius due to their lower cost.

What model and firmware level Fronius do you have?

 

[Cmiller]

Just to confirm, that's the only assistant you have installed. You have no direct interaction between the two except for the frequency shifting, i.e., no Fronius connection to the Cerbo.

That is the only assistant that I have installed.

Now for monitoring purposes, I do have the Fronius and the Cerbo GX connected to the same network, and then I got the Cerbo GX to find the Fronius. I will add some screenshots of the menu items and how to get there.



As you can see, after "finding" the Fronius (or other brand of compatible GT inverter, see my note at the bottom*), you can configure where in the system that the GT inverter is located (in off-grid it will always be on the "AC Output" of the Victrons), the phase type (single phase, Split-phase, or multi-phase L1, L2 or L3) which in my case is Split-phase (US 120/240V).

The "Show" selection is, I believe to select whether or not to display the Fronius production on the main home screen of the GUI. However, that is one thing that I have not been able to get to work. All historical data shows correctly, such as loads, PV production, Generator input totals etc. However, I have not been able to see realtime data on the home screen, that includes PV. When I am charging the batteries via PV, my loads show as 0W. In my first screenshot of this reply, you can see that the actual realtime production shows up in the menu, next to "Fronius 7.6", but I will add a screenshot showing home screen during charging.



As you can see, all load numbers show 0. I have found other people online with similar setups, that have full realtime data showing on the home screen. I have tried using both wifi, and hardwired ethernet connection via a network switch, with no success. Sometime I plan to delete the Fronius and attempt a start from scratch approach to see if it can be resolved that way.

*Edit, by delete, I am referring to within the Venus OS menu.

Since I already have up to 6kW of DC PV, with this sort of performance, I'm leaning heavily towards a Fronius due to their lower cost.

Another great benefit is an efficiency gain for any direct-use loads!

What model and firmware level Fronius do you have?

I have the Fronius Primo 7.6-1 208-240 running firmware: fro34310.upd

*A note on GT inverter monitoring via the Victron Venus OS. Venus OS does support "monitoring" a few different brands of GT inverters. The brands that I remember off-hand are Fronius, SMA, Solaredge and ABB. Of those, I believe Fronius and possibly ABB are the only ones that have the option of using ESS assistant to do a grid-tie with self consumption setup. In that scenario, the GT inverter is also connected to the load side of the Victron system, and the Venus OS controls the power output of the GT inverter via communication on LAN and limits the PV production to avoid selling out past the Victron system to the grid.

I have no experience with the ESS setup, so I really don't know how well it works (or doesn't work).

I will try to add another comment with a link to Victron's documentation page on GT inverter integration.

 

[Cmiller]

Just to be clear, even though I do have communication established between the Venus OS and Fronius, all power control is done via frequency shift. I could shut down my home network and the frequency shift control would continue working exactly as it is now, I just would lose the VRM records of PV production, as well as being able to see the Fronius in my Venus OS menu.

 

[sunshine_eggo]

many thanks!