Sol-Ark 15K All in One Inverter Released.

[niktak11]

That is a 50a load, not a 100a, which makes this even worse.

Yeah I'm sure that the output voltage at the sol-ark load terminals was even worse during the startup surge. It dipped down to 178V at the pump house, but a lot do that was due to the long wiring run to get there.

 

[Wet1]

I have two Big Battery HSKYs that are rated for 130A each continuous and a big Lanni battery that can do 200A continuous. In that screenshot the battery voltage at the sol-ark terminals only sagged to 51.4V, still well above my cut-off voltage of 47V so I'd be surprised if it was that. Each HSKY is connected to my battery busbars with 6awg silicon wire. The Lanni is connected with 2AWG welding wire. From there there's about a foot of 2/0 to a SB350 connector then 3ft of 4/0 to get to the sol-ark terminals.

If I'm understanding this correctly, it looks like your wire sizes are limiting for the task at hand. The 6awg is only rated to 65a, the 2awg to 115a, 2/0 to 175a, and the 4/0 to 230a. Correct?

 

[Lt.Dan]

If I'm understanding this correctly, it looks like your wire sizes are limiting for the task at hand. The 6awg is only rated to 65a, the 2awg to 115a, 2/0 to 175a, and the 4/0 to 230a. Correct?

Depending on the wire

 

[niktak11]

If I'm understanding this correctly, it looks like your wire sizes are limiting for the task at hand. The 6awg is only rated to 65a, the 2awg to 115a, 2/0 to 175a, and the 4/0 to 230a. Correct?

The 6AWG is 200 degree C rated silicon which can do 160A (although I wouldn't want to use it for more than about 100A). All other wiring is rated for 105 degrees C. The 2 AWG can do 215A, 2/0 329A, 4/0 446A.

 

[Wet1]

The 6AWG is 200 degree C rated silicon which can do 160A (although I wouldn't want to use it for more than about 100A). All other wiring is rated for 105 degrees C. The 2 AWG can do 215A, 2/0 329A, 4/0 446A.

I don't doubt it's possible to flow that much if pushed hard enough, but with how much resistance and voltage drop? Silicone is used so the insulation doesn't catch on fire as quickly, the wire is basically the same though. If it were me, I would likely limit the configuration to the generally suggested safe limits of the weakest links (wiring, BMS, etc). I know you did the test just to check everything (and it's greatly appreciated that you shared the results!)

 

[niktak11]

I don't doubt it's possible to flow that much if pushed hard enough, but with how much resistance and voltage drop? Silicone is used so the insulation doesn't catch on fire as quickly, the wire is basically the same though. If it were me, I would likely limit the configuration to the generally suggested safe limits of the weakest links (wiring, BMS, etc). I know you did the test just to check everything (and it's greatly appreciated that you shared the results!)

The battery current was only around 50A through each short 6AWG wire so the voltage drop was minimal

 

[niktak11]

I think @Will Prowse received a 15k for testing. Maybe he'll be able to do a max load test to see if he has the same voltage problem.

 

[RayofSunshine]

Attached please find a PDF document with the answers to a bunch of questions (some posed in this thread) provided by Sol-Ark via a Zoom call set up by Ed Rosenberry of Enteligent (optimizer/RSD & bidirectional EV charger). There is a lot of info in it. I also attempted to be as precise as possible to prevent further confusion and/or questions. Hence the length. Sorry it took longer than expected.

 

[robby]

Attached please find a PDF document with the answers to a bunch of questions (some posed in this thread) provided by Sol-Ark via a Zoom call set up by Ed Rosenberry of Enteligent (optimizer/RSD & bidirectional EV charger). There is a lot of info in it. I also attempted to be as precise as possible to prevent further confusion and/or questions. Hence the length. Sorry it took longer than expected.

Thank you. You and I are pretty much the same in that we don't like surprises. You did your due diligence in making sure it will do what you want it to do.

As for Question Number 1
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1. If just DC coupling PV panels:
a. Can I configure the priority for wattage to go to battery or loads first, then the other, then excess
goes to grid?
i. Answer: realistically, unfortunately no. There is a feature to do this, but Sol-Ark has seen a
lot of issues with it, and it is not recommended. By default, it goes to battery first, then
loads, then grid feedback. I gave feedback that this is a feature that I would like to be able
to use.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++

I have also heard them mention some sort of bug with this feature but i have personally used it for months in Batt First Mode and then Switched it to Load First for the last 5 months and I have had no problems with it in Load first, as you can see it is still in that Mode. I cannot speak to AC coupled Panels or if the grid sell works properly.
I really preffer that it starts offsetting the Grid first thing in the morning. Once the PV climbs high enough (aprox 8am) the batteries start to charge on the excess power. This cut down about 1.5-2KWh of daily grid usage.

 

[Danke]

Attached please find a PDF document with the answers to a bunch of questions (some posed in this thread) provided by Sol-Ark via a Zoom call set up by Ed Rosenberry of Enteligent (optimizer/RSD & bidirectional EV charger). There is a lot of info in it. I also attempted to be as precise as possible to prevent further confusion and/or questions. Hence the length. Sorry it took longer than expected.

“The 15K has a max input of 19.5 kW of DC coupled PV panels (yes, the spec sheet says 17 kW, but he said that it is still 6500 per MPPT, for 19.5 kW). The max output from this DC coupled input is 15 kW (which includes any combination of output inverted to AC for loads/grid, and DC output to a battery ESS”

It can take input of 19.5 kW of DC, but only output 15kWs of it?

So is there no way to use all of the 19.5 kW, as in some DC charging batteries and some inverted to AC for load?

 

[RayofSunshine]

“The 15K has a max input of 19.5 kW of DC coupled PV panels (yes, the spec sheet says 17 kW, but he said that it is still 6500 per MPPT, for 19.5 kW). The max output from this DC coupled input is 15 kW (which includes any combination of output inverted to AC for loads/grid, and DC output to a battery ESS”

It can take input of 19.5 kW of DC, but only output 15kWs of it?

So is there no way to use all of the 19.5 kW, as in some DC charging batteries and some inverted to AC for load?

"It can take input of 19.5 kW of DC, but only output 15kWs of it?"
Correct.

"So is there no way to use all of the 19.5 kW, as in some DC charging batteries and some inverted to AC for load?"
No. But remember that the 15 kW output of the inverter can be split up in any combination of (DC) battery and (AC) load.

I tried to address this point just a few sentences later (the final one in that paragraph), to wit:

"We also discussed how the PV input specs in the spec sheets (for both the 12K & 15K) being higher than the inverter output represents the DC to AC ratio."

If you're not familiar with DC to AC ratio, I'll try to summarize as succinctly as I can. If I get this wrong, I'm sure there is someone here that can and will correct me. PV panel wattage ratings are given under ideal conditions, which - for all practical purposes - are rarely (if ever) reached. So inverters allow you to "oversize" your PV panel input to the inverter so that you can have the inverter maximize the available solar energy available without frying the inverter. This is where having an experienced solar engineer comes in quite handy. So, in this case (as long as you stick to the max voltage and amp limits per string), you can have as much as 19.5 kW of panels hooked up to the MPPTs to get to the 15 kW that the inverter can actually use. No matter how much you oversize your PV panel input to the MPPTs (up to the specified limits), if they happen to produce more than 15 kW of DC power, the MPPTs (Or is it the inverter electronics? It's one of the two.) "clip" the incoming power down to what the inverter can actually invert. I guess the most simple phrase that summarizes it is "real world wiggle room". Remember that experienced solar engineer I mentioned? He/she would take in all the factors of your installation (latitude, average high & low temps in all seasons, humidity, altitude, sq. footage available, required energy output, budget, etc.) and size the system with the right size, number, and output (etc.) of panels (and maybe batteries) so that you get as close to the required kWh on the worst day(s) of the year without clipping (wasting) too much panel wattage on the best day(s) of the year.

In all of my research so far, none of this is unusual. I could be wrong, but I think that about every inverter I've seen has a DC to AC ratio.

Bitte.

 

[robby]

Exactly right.
Having 19.5KWp of panels just guarantees that you will have a higher average PV input during the day. I have 10.2KWp on my 12K and on a typical day during peak solar hours I will see 9KW from the panels and that drops down to about 4KW by 4pm.

The Sol-Ark current limits the panels so even if your feeding in 30 Amps from the PV it will Clip it at exactly 26 Amps on the 15K

With 19.5KWp of panels you should on most days get at least 15KW of steady power during Peak solar production and in the evening you will probably get about 8KW at 4pm instead of maybe 6Kw if you had just the 15KWp of panels.

 

[Danke]

Not what I’m asking, I understand the limit of inverting 15kWs to AC, The question is, can it transform the DC to charge DC batteries. So if input is 19.5kWs of DC, can 4.5kWs or more go to charging batteries and the inverter doing DC to AC up to 15kWs?

 

[Wet1]

Not what I’m asking, I understand the limit of inverting 15kWs to AC, The question is, can it transform the DC to charge DC batteries. So if input is 19.5kWs of DC, can 4.5kWs or more go to charging batteries and the inverter doing DC to AC up to 15kWs?

I do not believe it has that capability based on a conversation I had with one of their TS reps about a month or two ago. Hopefully someone else can verify.

 

[RayofSunshine]

Not what I’m asking, I understand the limit of inverting 15kWs to AC, The question is, can it transform the DC to charge DC batteries. So if input is 19.5kWs of DC, can 4.5kWs or more go to charging batteries and the inverter doing DC to AC up to 15kWs?

Well, that's exactly the question I was trying to answer, but to answer it directly, No.

Perhaps we are getting hung up on the term "inverter".
Without knowing anything about the electrical or electronic design of the 15K, let me attempt to describe it in functional terms.
The MMPTs feed the "inverter module" (to coin a phrase). The "inverter module" decides what to do with the PV DC wattage coming in from the MPPTs (let's leave out AC coupled input for the moment for simplicity's sake).
The maximum AC or DC output that the "inverter module" can handle is 15 kW. So the max DC input is also 15 kW (plus maybe a % or 2 for conversion loss for AC inversion - I don't know the actual details). The "inverter module" can split it up any way you want between (DC) batteries and (AC) loads.
Whatever you specify for AC loads, the "inverter module" takes that portion of the DC input and sends it to the (HF) "inverter circuitry" (within the "inverter module" to invert to AC.
So let's just say that the MPPTs clip any (input PV DC) power in excess of 15 kW so as not to fry the "inverter module".
Lots of "inverters" (the complete boxes sold by Sol-Ark, Outback, Solar Edge, etc.) do this.

So, experts, do I have this about right?

 

[RayofSunshine]

Deleted.

 

[robby]

Not what I’m asking, I understand the limit of inverting 15kWs to AC, The question is, can it transform the DC to charge DC batteries. So if input is 19.5kWs of DC, can 4.5kWs or more go to charging batteries and the inverter doing DC to AC up to 15kWs?

No, it can only do 15KW. It can be supplying your house with 8KW while charging the batteries with 7KW. The sum total cannot exceed 15KW.
Now if you have AC coupled panels I think the answer changes.

 

[RayofSunshine]

No, it can only do 15KW. It can be supplying your house with 8KW and charging the batteries with 7KW but the sum total cannot exceed 15KW.
Now if you have AC coupled panels I think the answer changes.

Exactly. From the PDF doc I attached : "Again, additionally, one can AC couple PV panels up to a max of 19.2 kW. The total max combined AC output (of the inverted DC coupled panels and AC coupled panels) is 34.2 kW."

Actually, as I remember from the rep's description, that last sentence should have read "The total max combined output (of the inverted DC coupled panels and AC coupled panels) is 34.2 kW." (note that I removed "AC" from the phrase "combined AC output").

So, you can have a max total output of 34.2 kW AC (15 from DC inversion, and 19.2 from AC coupled). At the other end of the scale, you can have 15 kW DC sent to the batteries (from the PV DC input), and 19.2 kW to load (from AC coupled). Or you can split up that PV DC coming in from the MPPTs any way you want between batteries and loads, and still add that 19.2 from the AC coupled input to the loads.

So this gives a user with LOTS of roof (and/or ground) space a tremendous amount of flexibility in laying out their system. If you currently have panels AC coupled (via micros or a string inverter), and that array handles your daytime loads, but you want to add a (more efficient) DC coupled battery ESS, you can just hook up the existing AC coupled array to the gen input, and then add enough panels (or even re-purpose exiting panels) to be DC coupled to the MPPTs of the 15K. That way, the PV DC input to the MPPTs on the 15K can go directly to charge the battery ESS. (Or it could be sent directly to Enteligent's upcoming super whiz-bang bidirectional EV charger, which can charge your EV with DC current at - what they're calling - "Level 2.5").

 

[RayofSunshine]

Just BTW, or FYI, or whatever (to all, not any specific poster), I emailed a copy of my "meeting minutes" of our Zoom meeting to the Sol-Ark rep along with a few follow-up questions. Those "meeting minutes" were modified with the additional answers/clarifications supplied by him in response to my emails to become the PDF document I posted. I received NO comments or corrections from the Sol-Ark rep on my "meeting minutes". Whether that means that there were no errors, or whether the rep didn't have time to read my "meeting minutes", I can't say. But he did know that I was going to post all information to this thread (or at least this forum).

If anyone wants to verify any of this with their particular favorite Sol-Ark rep, please feel free. I welcome any corrections. All I'm trying to do here is to obtain and supply accurate info for my own purchase, and to return the favor to others doing the same.

 

[Balthazar-B]

"It can take input of 19.5 kW of DC, but only output 15kWs of it?"
Correct.

"So is there no way to use all of the 19.5 kW, as in some DC charging batteries and some inverted to AC for load?"
No. But remember that the 15 kW output of the inverter can be split up in any combination of (DC) battery and (AC) load.

I tried to address this point just a few sentences later (the final one in that paragraph), to wit:

"We also discussed how the PV input specs in the spec sheets (for both the 12K & 15K) being higher than the inverter output represents the DC to AC ratio."

If you're not familiar with DC to AC ratio, I'll try to summarize as succinctly as I can. If I get this wrong, I'm sure there is someone here that can and will correct me. PV panel wattage ratings are given under ideal conditions, which - for all practical purposes - are rarely (if ever) reached. So inverters allow you to "oversize" your PV panel input to the inverter so that you can have the inverter maximize the available solar energy available without frying the inverter. This is where having an experienced solar engineer comes in quite handy. So, in this case (as long as you stick to the max voltage and amp limits per string), you can have as much as 19.5 kW of panels hooked up to the MPPTs to get to the 15 kW that the inverter can actually use. No matter how much you oversize your PV panel input to the MPPTs (up to the specified limits), if they happen to produce more than 15 kW of DC power, the MPPTs (Or is it the inverter electronics? It's one of the two.) "clip" the incoming power down to what the inverter can actually invert. I guess the most simple phrase that summarizes it is "real world wiggle room". Remember that experienced solar engineer I mentioned? He/she would take in all the factors of your installation (latitude, average high & low temps in all seasons, humidity, altitude, sq. footage available, required energy output, budget, etc.) and size the system with the right size, number, and output (etc.) of panels (and maybe batteries) so that you get as close to the required kWh on the worst day(s) of the year without clipping (wasting) too much panel wattage on the best day(s) of the year.

In all of my research so far, none of this is unusual. I could be wrong, but I think that about every inverter I've seen has a DC to AC ratio.

Bitte.

It would be interesting to know why the asymmetric statements between the 12K and 15K, to wit:

12K:

The 12K has a max 13 kW input (6500 from each MPPT) from DC coupled panels, with a max 9 kW inverted to
AC to loads and/or grid, and an additional 3 kW DC output to a battery ESS...

15K:

The 15K has a max input of 19.5 kW of DC coupled PV panels (yes, the spec sheet says 17 kW, but he said that
it is still 6500 per MPPT, for 19.5 kW). The max output from this DC coupled input is 15 kW (which includes any
combination of output inverted to AC for loads/grid, and DC output to a battery ESS).

My reading of the above is that the 12K utilizes a greater percentage of the maximum input if one is feeding storage in addition to loads/grid, with a hard limitation of 9kW which can can be fed to the latter, while the 15K utilizes a smaller percentage of its maximum input, but loads/grid can get all of its 15kW of AC output, rather than just a subset of that output, and sliced/diced more flexibly (between AC and DC) if storage is in the mix.

If that's true, it represents a pretty significant functional difference between the two inverters, and I suppose it would be helpful to know why. Assuming there is instrumentation on the 15K that enables gathering metrics and reporting for input loads and output allocation, I hope someone will scientifically and rigorously verify the *actual* real-world maximum inputs on each MPPT and collectively, and the maximum AC and DC outputs, and level of flexibility for directing that output. As well as what happens when AC-coupled sources are added to the mix.

Understanding these things is really crucial to knowing what use cases this inverter can address, and how to plan accordingly.