Sol-ark 12k Pricing - Canada (and USA)???

[BenW]

Nice price, especially since it includes shipping.
Are you going to DIY your system or get someone to do it for you?

Doing it myself.

 

[robby]

Doing it myself.

That is what I did, the only part I left off was the final AC electrical hook up as I needed someone certified to sign off on it. Oh and my panels got put up by pros. There was no way I was going up on two floors on a 35 deg sloping Spanish tile clay roof. My wife did not even need to stop me on that one

 

[BenW]

That is what I did, the only part I left off was the final AC electrical hook up as I needed someone certified to sign off on it. Oh and my panels got put up by pros. There was no way I was going up on two floors on a 35 deg sloping Spanish tile clay roof. My wife did not even need to stop me on that one

I have the solar already installed. I just wanted the battery backup.

 

[Hedges]

So is that just as UPS?
Or rewiring PV panels to Sol-Ark?
Or AC coupling to existing GT PV system?

 

[BenW]

So is that just as UPS?
Or rewiring PV panels to Sol-Ark?
Or AC coupling to existing GT PV system?

I'm going to do AC coupling to an existing GT PV.

 

[Hedges]

I'm going to do AC coupling to an existing GT PV.

Your existing GT PV may implement "Arc Fault" protection and "Rapid Shutdown".
Arc fault should work the same with it connected to SolArk as to grid, so no issue there.

"Rapid Shutdown" is a feature for fireman safety, which disconnects between individual panels or drops their output voltage to reduce shock hazard. If you have a box per PV module with PV wires connected to those, then between the boxes, that could be rapid shutdown and/or optimizers.

If you have microinverters (e.g. Enphase), then no need to worry about preserving Rapid Shutdown because DC is already segmented to single panels.

Some GT PV string inverters support Rapid Shutdown by sending a "keep-alive" signal to the RSD boxes. When AC is disconnected by a switch or by main breaker to house, RSD activates to reduce electric hazard for firemen on roof. In this case, if you rewire your GT PV circuit on to battery backed SolArk, the hazard would remain.

I suggest determining if your system has Rapid Shutdown and ensuring it can still be activated by firemen. If it has a knife switch between GT PV inverter and breaker panel (or a separate RSD switch), that should take care of it. If GT PV inverter wires straight to breaker panel, then your adding SolArk could be a change such that main breaker no longer activates it.

 

[Hedges]

I'm going to do AC coupling to an existing GT PV.

I also have AC coupling, SMA Sunny Boy GT PV inverters connected to Sunny Island battery inverters.

Presently, you would have GT PV wired to same loads panel as the rest of your house. There are various ways to rewire so some or all loads are on output of SolArk. With some (or no) loads automatically backed up by it, you can manually use interlocks or transfer switch to power whole house.

It is possible loads draw more kWh/day than PV can produce, especially when cloudy. Loads can draw more than PV produces at a given time. GT PV can only deliver power if AC is up, and AC can only be up if enough charge in battery. This can lead to battery draining to the point of inverter of BMS shutoff and the "black start" problem.

My inverter won't even charge from grid unless it has enough battery SoC to create its own AC. Your SolArk may be different, allowing it to recover from grid or possibly generator.

"Black start" requires disconnecting loads and getting AC out from inverter. It is useful to have a way to shut off loads before battery gets so low that inverter can't turn on, and to start inverter (or keep it running until) sunrise. You don't want BMS to shut off due to low battery. Perhaps inverter low-voltage cutout can be set high enough that it can shut everything off, so you can manually disconnect all loads and restart inverter with just GT PV connected.

If you were to add some DC coupled PV, just a string of panels wired to SolArk's PV input, that would recharge battery enough eventually.

My system has a "load shed" relay controlled by a signaling relay in Sunny Island. If battery reaches 70% DoD, all loads (entire house) is disconnected, but GT PV remains connected. At 80% DoD Sunny Island would shut down, but the 10% difference is enough to keep inverter operating waiting for sunrise. Ideally, that "load shed" feeds important but not critical loads, and another load shed disconnects discretionary loads. For instance, I might power A/C only when surplus power available, battery above 80% SoC. Between 30% SoC and 80% SoC, important loads would still operate, sized so PV expected to always supply them 24/7.

 

[BenW]

Your existing GT PV may implement "Arc Fault" protection and "Rapid Shutdown".
Arc fault should work the same with it connected to SolArk as to grid, so no issue there.

"Rapid Shutdown" is a feature for fireman safety, which disconnects between individual panels or drops their output voltage to reduce shock hazard. If you have a box per PV module with PV wires connected to those, then between the boxes, that could be rapid shutdown and/or optimizers.

If you have microinverters (e.g. Enphase), then no need to worry about preserving Rapid Shutdown because DC is already segmented to single panels.

Some GT PV string inverters support Rapid Shutdown by sending a "keep-alive" signal to the RSD boxes. When AC is disconnected by a switch or by main breaker to house, RSD activates to reduce electric hazard for firemen on roof. In this case, if you rewire your GT PV circuit on to battery backed SolArk, the hazard would remain.

I suggest determining if your system has Rapid Shutdown and ensuring it can still be activated by firemen. If it has a knife switch between GT PV inverter and breaker panel (or a separate RSD switch), that should take care of it. If GT PV inverter wires straight to breaker panel, then your adding SolArk could be a change such that main breaker no longer activates it.

I have a Solaredge SE7600HD that has the rapid shutdown feature as well as a knife switch disconnect right by the meter. I do not plan on changing the GTI current hookup to my meter main panel.

 

[BenW]

I also have AC coupling, SMA Sunny Boy GT PV inverters connected to Sunny Island battery inverters.

Presently, you would have GT PV wired to same loads panel as the rest of your house. There are various ways to rewire so some or all loads are on output of SolArk. With some (or no) loads automatically backed up by it, you can manually use interlocks or transfer switch to power whole house.

It is possible loads draw more kWh/day than PV can produce, especially when cloudy. Loads can draw more than PV produces at a given time. GT PV can only deliver power if AC is up, and AC can only be up if enough charge in battery. This can lead to battery draining to the point of inverter of BMS shutoff and the "black start" problem.

My inverter won't even charge from grid unless it has enough battery SoC to create its own AC. Your SolArk may be different, allowing it to recover from grid or possibly generator.

"Black start" requires disconnecting loads and getting AC out from inverter. It is useful to have a way to shut off loads before battery gets so low that inverter can't turn on, and to start inverter (or keep it running until) sunrise. You don't want BMS to shut off due to low battery. Perhaps inverter low-voltage cutout can be set high enough that it can shut everything off, so you can manually disconnect all loads and restart inverter with just GT PV connected.

If you were to add some DC coupled PV, just a string of panels wired to SolArk's PV input, that would recharge battery enough eventually.

My system has a "load shed" relay controlled by a signaling relay in Sunny Island. If battery reaches 70% DoD, all loads (entire house) is disconnected, but GT PV remains connected. At 80% DoD Sunny Island would shut down, but the 10% difference is enough to keep inverter operating waiting for sunrise. Ideally, that "load shed" feeds important but not critical loads, and another load shed disconnects discretionary loads. For instance, I might power A/C only when surplus power available, battery above 80% SoC. Between 30% SoC and 80% SoC, important loads would still operate, sized so PV expected to always supply them 24/7.

Sounds like a nice set-up! Mine won't be as automatic as yours or at all! Good point about the black start. I do have a 240V split phase generator that I could transfer over to and power the house/charge the batteries as well as a small 120v inverter generator I could plug a 48v battery charger into and charge the batteries. My generator has auto start capability that the Sol-Ark can control if I ever want to go there.

 

[Hedges]

I have a Solaredge SE7600HD that has the rapid shutdown feature as well as a knife switch disconnect right by the meter. I do not plan on changing the GTI current hookup to my meter main panel.

Knife switch should do the trick. That's good.
Was required when I put my system in two decades ago, made optional later by my utility.

So Solar Edge will only charge battery of SolArk when SolArk feeds main breaker panel (as an interlocked "generator")?
i.e. SolArk will just be a UPS normally, until you flip switches to put Solar Edge on its output for AC coupling?

I think SolArk performs frequency shift to manage AC coupled inverters. I don't know whether SolarEdge varies power in response to frequency; that may be called UL-1741-SA frequency-watts. Without that, just UL-1741, it will bang offline, back online after a 5 minute wait, so battery cycles up and down.

Sounds like a nice set-up! Mine won't be as automatic as yours or at all! Good point about the black start. I do have a 240V split phase generator that I could transfer over to and power the house/charge the batteries as well as a small 120v inverter generator I could plug a 48v battery charger into and charge the batteries. My generator has auto start capability that the Sol-Ark can control if I ever want to go there.

Figure out if generator, SolArk, and discharged battery can be brought back to life.
For Sunny Island, there is an "emergency charge" procedure where AC is fed to output (rather than input) of inverter. Something I don't want to have to try.

 

[BenW]

Knife switch should do the trick. That's good.
Was required when I put my system in two decades ago, made optional later by my utility.

So Solar Edge will only charge battery of SolArk when SolArk feeds main breaker panel (as an interlocked "generator")?
i.e. SolArk will just be a UPS normally, until you flip switches to put Solar Edge on its output for AC coupling?

I think SolArk performs frequency shift to manage AC coupled inverters. I don't know whether SolarEdge varies power in response to frequency; that may be called UL-1741-SA frequency-watts. Without that, just UL-1741, it will bang offline, back online after a 5 minute wait, so battery cycles up and down.



Figure out if generator, SolArk, and discharged battery can be brought back to life.
For Sunny Island, there is an "emergency charge" procedure where AC is fed to output (rather than input) of inverter. Something I don't want to have to try.

I will! Thanks!