Combining Victron with Fronius inverter

[1201]

I have an off grid system (fully operational using string inverters) with a Multiplus, so AFAIK, unless the microinverter has a stand-alone mode it won't work connected to the MP AC in. (I've tried it with a cheap micro inverter, and my searches in the Victron haven't revealed a work-around).

Edit for clarification: Note that I understand that the micro inverter can just be plugged into the AC out side of the multiplus but you have to install a separate meter to determine how much power you're getting from the array and take other steps to integrate it into the rest of the Victron system

If the microinverter could connect through the AC input, the multiplus would keep track of it without more equipment and integration.
I am just exploring how and if micro-inverter driven panels could be integrated.

Have you ever come across a device that would provide a low-power reference AC to the micro inverter so that it would produce stand-alone AC.
Is this even a good idea?

I think you should read the ess manual

 

[DaveF]

I think you should read the ess manual

From the manual.
When not to use ESS

• Off-grid systems - either with or without generator.
• Marine systems.
• Automotive systems.
• Inverter priority, also known as 'Intentional islanding“ or 'Ignore AC' input systems.

 

[1201]

From the manual.
When not to use ESS

• Off-grid systems - either with or without generator.
• Marine systems.
• Automotive systems.
• Inverter priority, also known as 'Intentional islanding“ or 'Ignore AC' input systems.

So in an off grid system, no grid tie inverter will ever work on the ac input. There is no signal that it can synchronize to. You connect it to AC out so that the battery inverter can provide the signal to wake up the grid tie inverter. No, you don't need an additional meter to make this work.

You say you have an off grid victron system with a string inverter. Obviously you have it connected to ac out. What additional meter did you need?

 

[ctsit]

I don't know for certain how your Fronius works in grid down but grid tie inverters will shut down when grid power is lost. If the Quattro is after the Fronius AC connection, the Fronius will shut down when grid power is lost.

When wired according to the Victron diagram in my previous post you quoted, the inverter supplies AC power when grid power is down and the grid tie inverter will not detect a grid down situation and will not shut down. The Quattro will control export to grid power both when grid power is available or when grid is down by not allowing export.

You don't want the grid tie inverter feeding in before the Quattro but after it. With a grid down situation and power coming from grid tie PV to the Quattro AC output, any loads will be powered by the grid tie power coming in, any excess will be used by the Quattro to charge batteries. If PV can not supply enough power, the Quattro will supply power by drawing from the batteries.

I see what you mean, however this can't be an option since the management and cutoff of power must be regulated by fronius. This is the basis of the permit I received from the grid management company. When grid is down PV point on the fronius is activated so I will still get power to the quattro, just not as much. Furthermore, victron will also have it's own PV array, which although small, will contribute to the battery charging and providing power to the loads.
So on this basis is it doable ?

 

[ctsit]

for some reason the posts where not visible to me and just saw them.
In a nutshell I understand that I can only combine the fronius on the Ac out.
Of course mine is the GEN24 Plus which I am not sure if it operates as the rest of the Fronius.
If this is really the case then I can't use the Victron. Based on the electrical diagrams and the agreement I signed, only Frojius handles the feeding back to the grid. One of the clauses of the agreement stipulates that in case of grid outage the fronius will cut feeding to the grid within 5 seconds (or something like that), I can't risk Victron doing something else. As I said initially the whole concept I wanted to have with the victron was to act like a UPS for the entire house. While receiving power from fronius or grid. If power would to go out then the house would continue having power because of victron batteries and victron PV array. I guess this is not feasible the way I imagined.
Let me know if there is anothe way of doing it.

 

[1201]

for some reason the posts where not visible to me and just saw them.
In a nutshell I understand that I can only combine the fronius on the Ac out.
Of course mine is the GEN24 Plus which I am not sure if it operates as the rest of the Fronius.
If this is really the case then I can't use the Victron. Based on the electrical diagrams and the agreement I signed, only Frojius handles the feeding back to the grid. One of the clauses of the agreement stipulates that in case of grid outage the fronius will cut feeding to the grid within 5 seconds (or something like that), I can't risk Victron doing something else. As I said initially the whole concept I wanted to have with the victron was to act like a UPS for the entire house. While receiving power from fronius or grid. If power would to go out then the house would continue having power because of victron batteries and victron PV array. I guess this is not feasible the way I imagined.
Let me know if there is anothe way of doing it.

It's very feasible. With fronius on ac out or ac in. Either way is not a problem

2. System design

www.victronenergy.com

There are two options when connecting the grid-tie inverter:

• in parallel with the Multi or Quattro.
• on the AC out.

When connected on the AC out, the factor 1.0 rule must be adhered to. There are no exceptions to this. Also use the factor 1.0 rule in countries where the utility grid rarely fails; and also when connecting a Fronius grid-tie inverter on the AC out, and employing 'Zero feed-in'.

 

[1201]

ESS always requires anti-islanding. This is also true for a No feed-in-system.
For several countries the built-in anti-islanding in our products can be used. For example the MultiGrid in Germany, and the MultiPlus in the United Kingdom. See certificates on our website for details.
In case there is no certified product available for the country of installation, install external anti-islanding.
More details here: VEConfigure: grid codes & loss of mains detection.

 

[ctsit]

@1201 thank you, I will talk to my local installer based on your recommendations.
I really appreciate everybody's feedback.
I am located in Athens Greece. Indeed the power rarely goes down I just want to better utilise the power production from my investment in the Net Metering system. As I said on average I produce around 20kwh and my consumption is around 15kwh so I though why not have a supplementary system for the extra 5kwh

 

[1201]

@1201 thank you, I will talk to my local installer based on your recommendations.
I really appreciate everybody's feedback.
I am located in Athens Greece. Indeed the power rarely goes down I just want to better utilise the power production from my investment in the Net Metering system. As I said on average I produce around 20kwh and my consumption is around 15kwh so I though why not have a supplementary system for the extra 5kwh

is it cheaper to add the victron or just add the fronius backup board?

 

[ctsit]

is it cheaper to add the victron or just add the fronius backup board?

Good question, however the requirement is not just Back up (which is indeed cheaper going with Fronius) but also to better utilize the existing infrastructure.
I am trying to consume as much power as I can during the day (direct consumption) but still there is on average 5kwh to 10kwh going to the grid.
The options to address this is to get more battery modules, but BYD goes for 2000 euros per module of 2.73kwh
So
2 X 2.73 BYD = 4000Euros (without installation which has to be done by the installer otherwise I will have problem with the warranty)
1 X Fronius back up circuit breaker panel + installation = About 1500euro 2000euro and the backup can take up to 35s.
So a total of about 6000 euros.
I thought that if the scenario of adding a Victron is feasible maybe for about the same money I could get much more functionality.
But seems that this will not be possible

 

[Zwy]

Adding batteries doesn't help if the consumption isn't there. If you are on net metering and it is 1:1, there isn't any incentive to add a battery system other than backup power. If net meter isn't 1:1 or the grid tie is something like TOU or export at a lower price than retail with buyback at retail, then a battery system would make sense.

 

[ctsit]

Adding batteries doesn't help if the consumption isn't there. If you are on net metering and it is 1:1, there isn't any incentive to add a battery system other than backup power. If net meter isn't 1:1 or the grid tie is something like TOU or export at a lower price than retail with buyback at retail, then a battery system would make sense.

Net Metering in Greece does not work with Tariffs but with power credit.
the system sends extra power to the grid as a credit and at a later time if Battery reaches minimum SOC I can tap of that credit.
However I am always paying the back and forth of power. This is what you save through Batteries.
One more thing to point out is that the Batteries CANT be charged from Grid. Fronius has been parameterized in such way that the batteries are only charged from the PV.
So in summary extra batteries will reduce my feed in to the grid and will increase the self consumption therefore eliminating the fees for power management. Another aspect of increased battery capacity is that the existing battery will not reach its lowest SOC very often. This will prolong battery life. As it is today I am reaching 20% almost every other day which makes sense since all the family is at home after midday.

 

[1201]

Good question, however the requirement is not just Back up (which is indeed cheaper going with Fronius) but also to better utilize the existing infrastructure.
I am trying to consume as much power as I can during the day (direct consumption) but still there is on average 5kwh to 10kwh going to the grid.

Your fronius doesn't do self consumption from battery or the battery gets full and you have to export?

.
But seems that this will not be possible

Why not?

 

[ctsit]

Your fronius doesn't do self consumption from battery or the battery gets full and you have to export?

Why not?

The whole thing works as follows:
1. Direct consumption which means that evwr is produced is first allocate to the loads
2. Battery charge, the surplus that is not consumed from the loads is allocated to charge the battery
3. If battery is full the surplus from the load goes to the grid.

Incase the loads are higher than the current production the battery contributes the difference unless it is 20% soc in which case the grid contributes.

Regarding the feasibility of using a Victron, I have to use it between the fronius /grid and the house loads so that the house gets power only through the Victron. It can not be in parallel and the victron interacting directly withe grid. (So I the fronius can't be in the out of the victron).
Victron has to work as a UPS concept

 

[1201]

The whole thing works as follows:
1. Direct consumption which means that evwr is produced is first allocate to the loads

Got it

2. Battery charge, the surplus that is not consumed from the loads is allocated to charge the battery

Got it

3. If battery is full the surplus from the load goes to the grid.

Copy.
Sounds pretty standard for a system so far. I don't understand if you already have this in place or you need some more items from fronius and batteries? Sounds like this would do exactly what you're trying to to do. Is the victron cheaper or something?

Regarding the feasibility of using a Victron, I have to use it between the fronius /grid and the house loads so that the house gets power only through the Victron. It can not be in parallel and the victron interacting directly withe grid. (So I the fronius can't be in the out of the victron).
Victron has to work as a UPS concept

Ok . If you say so.

 

[ctsit]

Got it

Got it


Copy.
Sounds pretty standard for a system so far. I don't understand if you already have this in place or you need some more items from fronius and batteries? Sounds like this would do exactly what you're trying to to do. Is the victron cheaper or something?

Ok . If you say so.

The Fronius battery combo is already in place, I was thinking of the Victron as an add on, to supplement and recover instead of feed back to the grid, some of the extra energy I am producing.

But I have to have the Fronius on the Acin do you think that this is possible ?

 

[1201]

The Fronius battery combo is already in place, I was thinking of the Victron as an add on, to supplement and recover instead of feed back to the grid, some of the extra energy I am producing.

But I have to have the Fronius on the Acin do you think that this is possible ?

You don't have the fronius on the ac in. The ac in of the victron would connect to the grid in parallel-the same grid the fronius is connected to

The fronius would keep doing it's thing, unaware of the victron, and the victron would do it's thing, unaware of the fronius.

The victron will use current transformers. If it sees current being pushed back to the grid, it charges the battery. If it sees a load on the line, it discharges the batteries, it's that simple-in theory at least

 

[Brucey]

Hope it's ok to resurrect this thread.

Here in upstate NY there are plans afoot to get rid of net metering and go to some other complicated calculation that will basically be worse. Right now one can choose to opt in to the worse plan, but it seems like inevitable all new install will be forced to that.

I am assembling an off grid 48V Victron system. My thought is seperate from that, get a small Fronius grid tied inverter, throw some panels on it, no problems with UL listing and approvals etc. Then I can build up credits with net metering that I'll need during the winter months. And then post inspection, connect the Fronius and the Quattro with a Cerbo gx, looks like Fronius and Victron work pretty seamlessly together, and then be able to use the batteries connected to the Victron, while the Fronius remains battery free.

Looks like the Fronius Primo UL would be the one to get for US 120V?

AC-coupled PV with Fronius PV Inverters [Victron Energy]

www.victronenergy.com