Sol-Ark 15K installation and PV production monitoring quandary....

[Msg822]

CURRENT SETUP:

• I have 7.92 kW grid-tied array running thru a Fronius Primo 7.6 DC inverter selling any excess production back to utility
• This system sends the AC power that it outputs to a 100 amp subpanel in a barn, about 150 feet from the 200 amp main panel
• The subpanel is connected to a 100amp breaker in the 200amp main panel which is in the house basement. So the solar production goes from inverter to subpanel to main to grid.
• The 100 amp barn subpanel also has a bunch of other stuff that it is powering: barn lights, tools, pool pump, etc...
• There is also a 30amp generator hookup in the barn that feeds to a 30amp breaker in the main panel (I turn off the main breaker and use the interlock to ensure no power flows to grid in an outage). Currently, this is how we get power when the grid goes down, which it does 3 or 4 times per year. This generator also is tied to a relay so that when it is running it does not allow power to backfeed to the subpanel and inverter.

NEW SYSTEM INSTALLING NEXT WEEK:

• Sol-Ark 15K with 15kW of Signature Solar batteries in a server rack
• Plan/thought is to Wire it this way: Meter directly feeds to GRID connection on Sol-Ark. LOAD connection on Sol-Ark connects to main 200amp breaker. Move the 30 amp wire from the generator from the 30amp breaker on the main and TO the GEN connection on the Sol-Ark.
• My goal is to eliminate and/or reduce the need to use the generator and instead seamlessly switch to battery provided power in an outage. I also will want to use the batteries to power the house at night and then re-charge when the solar array is producing...the classic sort of management that people are doing with the Sol-Arks. In the case of a prolonged power outage I'll fire up the generator and recharge the batteries that way.

WHAT I NEED TO SOLVE FOR:
Because the Fronius inverter and the 100amp subpanel are so far from the main I can't directly bypass the Fronius inverter and run the solar DC lines directly to the Sol-Ark's MPPT inputs. So I don't see any way to directly measure or monitor the PV outputs thru the Sol-Ark app or software. Right now I use the Fronius app to measure realtime and historical PV output, but it is just information only and not a management tool.

Any ideas on how to overcome this shortcoming?

Thanks in advance.

 

[timselectric]

There is also a 30amp generator hookup in the barn that feeds to a 30amp breaker in the main panel

What size wire is this. Could it be repurposed for the Fronius? This would allow it to be connected to the gen input and be monitored. A transfer switch could allow it to still be used for the generator. Or move the generator closer. So that you can use both, on those rare occasions.

 

[Msg822]

What size wire is this. Could it be repurposed for the Fronius? This would allow it to be connected to the gen input and be monitored. A transfer switch could allow it to still be used for the generator. Or move the generator closer. So that you can use both, on those rare occasions.

Not sure which wire you're asking about. The wire from the gen to the main is XHHW 2.

 

[Danke]

Not sure which wire you're asking about. The wire from the gen to the main is XHHW 2.

XHHW 2 is a type. He is asking for size or gauge. Probably good to know whether it’s copper or aluminum too.

 

[timselectric]

Not sure which wire you're asking about. The wire from the gen to the main is XHHW 2.

Yes, that wire.
#2 aluminum or copper should be large enough to do what I described. If that's what it is. Look for AWG size.

 

[Msg822]

XHHW 2 is a type. He is asking for size or gauge. Probably good to know whether it’s copper or aluminum too.

2 AWG

 

[Msg822]

Yes, that wire.
#2 aluminum or copper should be large enough to do what I described. If that's what it is. Look for AWG size.

So you're suggesting taking the AC feed from the Fronius, pulling it off the 100amp subpanel and then running that to the generator feed and connecting it and then running that directly to the GEN port on the Sol-Ark? Interesting idea, and with a transfer switch I could switch back and forth between generator to Sol-Ark OR Fronius AC output to Sol-Ark via the GEN port. Is that correct? BTW, the wire size is 2 awg AL.

 

[timselectric]

So you're suggesting taking the AC feed from the Fronius, pulling it off the 100amp subpanel and then running that to the generator feed and connecting it and then running that directly to the GEN port on the Sol-Ark? Interesting idea, and with a transfer switch I could switch back and forth between generator to Sol-Ark OR Fronius AC output to Sol-Ark via the GEN port. Is that correct? BTW, the wire size is 2 awg AL.

Yes, and that wire is big enough to do it.

 

[mgdean]

So here is an idea the Fronius inverter is basically acting like an ac coupled system, you will need to update your 100 amp panel to a 200 amp with pass through to your main in your house. Put the sol ark and batteries in the barn and back feed through that panel.

 

[wheisenburg]

So you're suggesting taking the AC feed from the Fronius, pulling it off the 100amp subpanel and then running that to the generator feed and connecting it and then running that directly to the GEN port on the Sol-Ark? Interesting idea, and with a transfer switch I could switch back and forth between generator to Sol-Ark OR Fronius AC output to Sol-Ark via the GEN port. Is that correct? BTW, the wire size is 2 awg AL.

 

[wheisenburg]

Yes, and that wire is big enough to do it

So you're suggesting taking the AC feed from the Fronius, pulling it off the 100amp subpanel and then running that to the generator feed and connecting it and then running that directly to the GEN port on the Sol-Ark? Interesting idea, and with a transfer switch I could switch back and forth between generator to Sol-Ark OR Fronius AC output to Sol-Ark via the GEN port. Is that correct? BTW, the wire size is 2 awg AL.

This should work as far a monitoring, there is another benefit to this design. The sol-ark also uses the relay on the gen input to control the power coming from the PV array. If a large A/C load suddenly stops, it takes time for the frequency shifting to kick in. If the batteries are full then there is no place to dump the excess power. The sol-ark can then use the relay to disconnect the PV array giving the frequency shifting time to work. While you can A/C couple the PV on the load, it gives the sol-ark less ability to control the PV power and is not recommended. If you still want the ability to use a generator, you should install a transfer switch between the PV and the Generator. You should never run PV and Gen at the same time. You might need to reconfigure the Gen port if you move from PV to an Actual Generator.