Sol-Ark 15K All in One Inverter Released.

[RayofSunshine]

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

12K:


15K:


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.

Well, first point: I pushed hard on these specs during our call because a) they were important to me, and b) it was clear to me that they are important to others on this forum. So it was clear to the rep that I wanted clarification. And actually, on the 19.2 kW (PV DC input) limit, he volunteered that info. I read off the "17000W" number from the published spec sheet, and he said, "Actually, it's 19.2: 6500W to each MPPT."

Next point: Yeah, they operate differently; they're different hardware. Regarding the "why", usually, when proposing a new product (software or hardware), an enterprise takes input from Sales/Marketing (what the customer wants), Engineering/Research (what is technically achievable), and Accounting (what is "reasonable", usually with input from Engineering as well). So they have to decide whether to use "off the shelf" ICs, PCBs, and other components, or to design, engineer, and manufacture their own. So it's entirely reasonable that percentages could be different. The specs could be the result of any combination of the above inputs (and more). Also, I look at the differences from another (more "glass half full") perspective. People complained that the name of the product didn't reflect the max AC output to loads, so it has a more representative name. It has 50% more PV DC input to MPPTs than the 12K, 66% more inverter output (combined AC & DC, split up any way you want), 100% more AC coupling, and 114% higher max combined output from simultaneous DC and AC coupling of panels).

As I have said previously, I welcome verification, be it from other Sol-Ark reps or real-world data ac and analysis (which, by the way, I used to do for various auto racing teams). If anyone determines that the specs I forwarded are incorrect, I urge them to contact Sol-Ark for clarification or correction of their specs/documentation.

I fully agree with your final sentence. That is what drove my quest for verification.

 

[Mahendra Gomanie]

I really like these but I came across two utube videos where these appears to have a load balancing issue on its L1 and L2 legs

 

[robby]

I really like these but I came across two utube videos where these appears to have a load balancing issue on its L1 and L2 legs

Ignore both of them.

The First video is done by a nut job.
Where the hell did he get a single phase LRA 90 Well pump. Almost every large well pump is split phase. And did he really expect a 12K Sol-Ark to withstand 66 Amps on one phase? That test was never going to work period. He could have started a split phase well pump but that single phase well pump was designed to make the Sol-Ark fail. This guy is just trying to get noticed.

The second test is the same mistake David Poz made. You can see the battery indicator blinking yellow just before the Inverter shuts down. None of these guys spend the time to read the manual and they are not use to working with Inverters that have setting for the Maximum Battery bank size. So they leave it at default which I think is 100A and then they wonder why it trips.

There is a huge post on the Second video where it was revealed that David Poz was lent that Inverter by Signature Solar in order to basically make it look bad. It had the original Firmware on the unit that was designed to trip out at a low imbalance level because Sol-Ark wanted to be conservative while the unit was just out of Beta (David knew this and deliberately did not want to update it).

The second issue was that he also had not not set the battery bank capacity level and that's why you see the Error light on the battery go yellow just before it tripped out. The third thing was that he never contacted Sol-Ark even once during those test. If he had they would have simply told him to update the firmware. Lastly he already had a Autotransformer in his panel box. If he wanted to prevent it from happening all he needed to do was turn it on. The second video he made after he got so much flack on that one, he switched on the transformer and the problem was gone. That first video is why his channel has gone belly up.

If you don't want to spend a few minutes balancing your panel box or if for some reason you really are expecting to push one phase to the Max while the other is kept low then just get a $400 Autotransformer and the phase imbalance problem is solved. It will eat down your batteries a bit quicker, but it's up to you.


.

 

[Danke]

Hmmm, maybe have to rethink my setup, was gonna do all DC to DC, but might mix in some micro inverters. I doubt I’d ever push the Sol-Ark with just the DC setup, but something to think about.

 

[RayofSunshine]

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").
...

I reworded the sentence in question with a more precise description and replaced the attachment in post #408 with the updated PDF.

 

[RayofSunshine]

Hmmm, maybe have to rethink my setup, was gonna do all DC to DC, but might mix in some micro inverters. I doubt I’d ever push the Sol-Ark with just the DC setup, but something to think about.

And if you think micros might be for you because:

1. You might now or in the future have PV panel capacity well over 15 kW, and/or
2. You don’t plan on using the gen input for a backup generator (remember that you can add a whole house backup generator with a separate ATS wired into the grid input), and/or
3. You have some shading and/or orientation issues, and/or
4.You need or want panel RSD capabilities

Then you might want to check out Sol-Ark’s new micros. From the comparison charts shown in Tom Brennan’s Alt-E conference webinar YouTube videos, they look price competitive with Enphase and Tigo (for the 4 panel M2000 model). As we now know, you just have to ignore all the talk about “doubling your output by adding only micros”.

I would consider AC coupling just enough PV panel wattage (real world wattage for your particular location and installation) to cover your daytime AC loads. Then DC couple the rest of your panels to the MPPTs to charge the (DC coupled) batteries more efficiently. Remember the answers to all those specific questions I asked of Sol-Ark: if the AC loads are met and there is extra AC coupled PV input, the inverter will invert it back to DC to charge the batteries; and if the batteries are charged and there is extra DC input, the inverter will invert the excess and send it to the loads.

 

[Danke]

I do have a standby gen, can I hook up the AC panels to one of the MTTPs? Or would I be back to the limit of 15kW with that configuration?

 

[RayofSunshine]

I do have a standby gen, can I hook up the AC panels to one of the MTTPs? Or would I be back to the limit of 15kW with that configuration?

Nope. The MPPTs take DC current only. Your AC coupled panels have to come in through either the gen input (preferred so the inverter can monitor it more accurately) or on the load side. See the 15K user manual for suggested wiring diagrams.

 

[Danke]

Nope. The MPPTs take DC current only. Your AC coupled panels have to come in through either the gen input (preferred so the inverter can monitor it more accurately) or on the load side. See the 15K user manual for suggested wiring diagrams.

So next question, if one has two Sol-Arks, can the standby gen feed one, and the AC PVs the other?

 

[RayofSunshine]

So next question, if one has two Sol-Arks, can the standby gen feed one, and the AC PVs the other?

From the suggested wiring diagrams in the 15K manual, it looks like the answer is no. But, unless someone else has a definitive answer, I'd say email or call Sol-Ark support.

 

[Danke]

Ya, I emailed them, I’ll post their response.

BTW, every time I call tech support, I wait on hold, then eventually get sent to voicemail.

 

[niktak11]

I asked customer support if a large voltage drop is expected when running the 15k off-grid and here is their response:

"This is very normal behavior for voltage output when testing off-grid scenarios. Under heavy load the internal resistance from the battery bank and internal components of the sol-ark will increase causing a voltage drop. A transformer will keep voltages within nominal range under heavy load and the sol-ark is grid following, meaning it will match voltages seen from utility when connected. Because we are transformerless inverter technology, we will see this voltage drop."

I am glad that this is expected and that I don't have to have mine serviced/replaced. I responded to them asking if they can provide a chart of expected output voltage vs load power.

 

[Mahendra Gomanie]

Ignore both of them.

The First video is done by a nut job.
Where the hell did he get a single phase LRA 90 Well pump. Almost every large well pump is split phase. And did he really expect a 12K Sol-Ark to withstand 66 Amps on one phase? That test was never going to work period. He could have started a split phase well pump but that single phase well pump was designed to make the Sol-Ark fail. This guy is just trying to get noticed.

The second test is the same mistake David Poz made. You can see the battery indicator blinking yellow just before the Inverter shuts down. None of these guys spend the time to read the manual and they are not use to working with Inverters that have setting for the Maximum Battery bank size. So they leave it at default which I think is 100A and then they wonder why it trips.

There is a huge post on the Second video where it was revealed that David Poz was lent that Inverter by Signature Solar in order to basically make it look bad. It had the original Firmware on the unit that was designed to trip out at a low imbalance level because Sol-Ark wanted to be conservative while the unit was just out of Beta (David knew this and deliberately did not want to update it).

The second issue was that he also had not not set the battery bank capacity level and that's why you see the Error light on the battery go yellow just before it tripped out. The third thing was that he never contacted Sol-Ark even once during those test. If he had they would have simply told him to update the firmware. Lastly he already had a Autotransformer in his panel box. If he wanted to prevent it from happening all he needed to do was turn it on. The second video he made after he got so much flack on that one, he switched on the transformer and the problem was gone. That first video is why his channel has gone belly up.

If you don't want to spend a few minutes balancing your panel box or if for some reason you really are expecting to push one phase to the Max while the other is kept low then just get a $400 Autotransformer and the phase imbalance problem is solved. It will eat down your batteries a bit quicker, but it's up to you.


.

This is a great explanation.
I agree there must be balancing in the panels as well.
Thanks Robby.

 

[niktak11]

I'd like to see the first guy repeat that test with the 15k. Based on the specs it should be able to handle it easily.

 

[robby]

Ya, I emailed them, I’ll post their response.

BTW, every time I call tech support, I wait on hold, then eventually get sent to voicemail.

Yes same here, I am told that they are literally guiding the Installers step by step through each 15K install right now.
I am hearing that some CSR are tied up all day on just one or two calls. I guess all the Pro Installers are 15K Virgins and need guidance.

If you leave your name and phone number they do get back to you within a few hours. This pileup will probably go away in a few weeks as installers get a better handle at installing the 15K.

 

[Danke]

From the suggested wiring diagrams in the 15K manual, it looks like the answer is no. But, unless someone else has a definitive answer, I'd say email or call Sol-Ark support.

Yep, they said no. Both paralleled inverters have to be wired the same. So it looks like gen would be on the ATS.

 

[niktak11]

I hope one of the interfaces adds support for more complicated ToU schedules. The time of use plan I'm switching to in a few days is different Monday-Friday, Saturday, and Sunday. It seems like I can only select one set of days that it is "on" for and I can't have multiple groups of days with different schedules on at the same time.

 

[Mahendra Gomanie]

Yes same here, I am told that they are literally guiding the Installers step by step through each 15K install right now.
I am hearing that some CSR are tied up all day on just one or two calls. I guess all the Pro Installers are 15K Virgins and need guidance.

If you leave your name and phone number they do get back to you within a few hours. This pileup will probably go away in a few weeks as people get a better handle of installing the 15K.

Yes there is one in my country that was installed by a guy with no such experience.
From what he told me they literally walked him through the installation on the phone.
The only issue that remained was the imbalance of the legs which I suspected had some other factor.
The guy did not do a firmware upgrade.

 

[robby]

I hope one of the interfaces adds support for more complicated ToU schedules. The time of use plan I'm switching to in a few days is different Monday-Friday, Saturday, and Sunday. It seems like I can only select one set of days that it is "on" for and I can't have multiple groups of days with different schedules on at the same time.

No you can't but it would be a nice feature.
They did add seasonal changes for TOU about 5 updates ago. This was probably a highly requested feature as Winter days are so much shorter than summer days.

 

[robby]

Yes there is one in my country that was installed by a guy with no such experience.
From what he told me they literally walked him through the installation on the phone.
The only issue that remained was the imbalance of the legs which I suspected had some other factor.
The guy did not do a firmware upgrade.

It's really a shame when an installer won't take the time to balance the loads.
The really big one is the Kitchen. Any worthwhile electrician will make sure the Microwave, Toaster, Convection Oven and Appliance plugs are connected for optimal phase balancing. A good Installer will double check all this stuff and just shift the breakers up or down a slot to make sure it's done properly. I did this stuff myself with an Amp meter and a sheet of paper. I think I had the whole house done in less than an hour. My Inverter has never tripped and I am using over 50KWh per day even if the Grid is down.