diy solar

diy solar

Sol-Ark 15K All in One Inverter Released.

Danke said:
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.
Click to expand...
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.
 
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?
 
Danke said:
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?
Click to expand...
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.
 
RayofSunshine said:
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.
Click to expand...

So next question, if one has two Sol-Arks, can the standby gen feed one, and the AC PVs the other?
 
Danke said:
So next question, if one has two Sol-Arks, can the standby gen feed one, and the AC PVs the other?
Click to expand...
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.
 
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.
 
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.
 
robby said:
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.


.
Click to expand...
This is a great explanation.
I agree there must be balancing in the panels as well.
Thanks Robby.
 
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.
 
Danke said:
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.
Click to expand...
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.
 
Last edited:
RayofSunshine said:
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.
Click to expand...
Yep, they said no. Both paralleled inverters have to be wired the same. So it looks like gen would be on the ATS.
 
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.
 
robby said:
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.
Click to expand...
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.
 
niktak11 said:
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.
Click to expand...
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.
 
Mahendra Gomanie said:
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.
Click to expand...
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.
 
Would there be any issues with AC coupling the 15K (through the GEN input) while tied to the grid and using zero export, or off grid, if batteries were installed and not at 100% SOC, with no DC coupled panels installed?
 
Wet1 said:
Would there be any issues with AC coupling the 15K (through the GEN input) while tied to the grid and using zero export, or off grid, if batteries were installed and not at 100% SOC, with no DC coupled panels installed?
Click to expand...
What do you mean by "any issues"?
 
Wet1 said:
Can it be done without causing any issues, like it won't limit export to grid, it can't be done w/o DC panel input, etc.
Click to expand...
My understanding: By default, any excess AC coupled power is exported to grid. However, specifically setting to zero export should prevent exporting.

In the attachment on (my) post #408 in this thread is an example where I specifically asked Sol-Ark about a (15K) setup with only AC coupling of panels through the gen input; no DC panel input (in the numbered list of questions, it is question #2). The Sol-Ak rep made no statement that it couldn't be done. He gave answers for the 3 sub-questions.
 
I vaguely remember something being said that with AC coupled panels it has a hard time bringing the PV input to an abrupt stop (like if you had an 8kw load that abruptly turned off). It had something to do with wild frequency shifts and the inverter didn't like it, which is why exporting to the grid helps because it has somewhere to send that (now) excess PV. I cant remember exactly though...
 
AC Coupling is a broad term. To answer the specific question of @Wet1 about AC coupling with zero export or off grid the issues are going to be the battery size that the Sol Ark needs to use as a buffer and the size of the AC coupled solar. There probably is a maximum kW of solar that can be AC coupled and a minimum kWh size battery pack. SolArk may specify these in their documentation. This is not as subject that I would attempt without clear documentation from SolArk and/or some actual user experience in the field with that particular inverter.
 
Lt.Dan said:
I vaguely remember something being said that with AC coupled panels it has a hard time bringing the PV input to an abrupt stop (like if you had an 8kw load that abruptly turned off). It had something to do with wild frequency shifts and the inverter didn't like it, which is why exporting to the grid helps because it has somewhere to send that (now) excess PV. I cant remember exactly though...
Click to expand...

The use case that he specified included batteries that aren't at 100% SOC, so, unless the 15K has a bug, I figured that the battery ESS would be able to absorb that power.
 
Last edited:
Ampster said:
AC Coupling is a broad term. To answer the specific question of @Wet1 about AC coupling with zero export or off grid the issues are going to be the battery size that the Sol Ark needs to use as a buffer and the size of the AC coupled solar. There probably is a maximum kW of solar that can be AC coupled and a minimum kWh size battery pack. SolArk may specify these in their documentation. This is not as subject that I would attempt without clear documentation from SolArk and/or some actual user experience in the field with that particular inverter.
Click to expand...
Max AC coupling for the 15K is 19.2 kW.
The 15K manual has tons of info about batteries, including the "Batt Capacity" setting in the "Batt Setup" page of the inverter config. It is specified in Ah. They give no minimum.
The "Battery-Communications-Integration-Guide-V2.6" (dated June 1, 2022, available on Sol-Ark's support web page), has a ton of info as well. It does not list the 15K (IOW, the specs given are for the 5K, 8K, and 12K). Again, no mention of minimum battery capacity.
Any info I volunteer is either from official documentation (or Sol-Ark videos), or direct communication with Sol-Ark. As I have stated before, I encourage verification.

I agree that "AC coupling" is a broad term (electrical theory in general, PV panels, battery ESS, etc.), which is why I have previously stated that I would prefer people specify how they are using the term. But from @Wet1's previous posts, it was clear to me that he was talking about AC coupling of PV panels through the gen input of the 15K.
 
Last edited:
Wet1 said:
Would there be any issues with AC coupling the 15K (through the GEN input) while tied to the grid and using zero export, or off grid, if batteries were installed and not at 100% SOC, with no DC coupled panels installed?
Click to expand...

Unless something has changed from earlier models (and I'm only going by what was said by others, I'm not a SolArk user),
AC coupled PV is recommended to be on the GEN port so it can be disconnected. Probably because the high-frequency SolArk can't deal with the load-dump case of suddenly having excess AC power and no where to put it.

And, recommended to have DC coupled PV in excess of AC coupled. I presume that is so DC input can be curtailed down to zero, then AC abruptly disconnected and DC ramped up fast to replace the lost AC coupled power, then DC further ramped down if needed. More direct control of DC than of AC, which requires frequency to change but can't change too fast.

With battery able to accept the power, could pull down the excess. But that is limited to a certain number of watts. And there is the question of how well the inverter transitions between direction of AC <--> DC and HV <--> LV.

In other words, if you don't get assurances from documentation or the manufacturer, you will be the Guinea Pig.
 
Hedges said:
Unless something has changed from earlier models (and I'm only going by what was said by others, I'm not a SolArk user),
AC coupled PV is recommended to be on the GEN port so it can be disconnected. Probably because the high-frequency SolArk can't deal with the load-dump case of suddenly having excess AC power and no where to put it.

And, recommended to have DC coupled PV in excess of AC coupled. I presume that is so DC input can be curtailed down to zero, then AC abruptly disconnected and DC ramped up fast to replace the lost AC coupled power, then DC further ramped down if needed. More direct control of DC than of AC, which requires frequency to change but can't change too fast.

With battery able to accept the power, could pull down the excess. But that is limited to a certain number of watts. And there is the question of how well the inverter transitions between direction of AC <--> DC and HV <--> LV.

In other words, if you don't get assurances from documentation or the manufacturer, you will be the Guinea Pig.
Click to expand...
The reason I was given (directly from a Sol-Ark rep, as a side note in answering another question) for AC coupling via the gen input was so that the inverter can measure/record/report the input more accurately.

For the 12K, the reason given (in one of the 4 "Sol-Ark University" on-demand webinars found on their Web site here - I think it was "SA-201") for having more DC coupled PV input than AC coupled PV input was that the inverter operated more efficiently that way. And the best efficiency is 13 kW DC with 3 kW AC (see attached screen shot). I don't know what the most efficient combination is for the 15K (which has max 19.5 kW DC input to MPPTs, max 19.2 AC coupled input, max output of 15 kW inverted from DC (PV and/or battery), and max combined output from AC and DC coupled input of 34.2 kW).

I agree that getting confirmation from Sol-Ark on these points - preferably in writing (e.g., email) - is best, since the current documentation doesn't seem to provide this information. In interacting with Sol-Ark, I would also suggest you request that they add any such answers to their documentation; either in the manual, or some sort of design/installation/integration guide. I suggested this to them, pointing out that if they gathered all the answers their support reps researched and provided to customers and added it to some form of documentation, it would save them customer support expense and improve customer support response metrics by preventing having to answer the same questions multiple times.

BTW, this page on Victron's Web site gives some interesting information on these topics (including minimum battery sizing for AC coupled PV panels), and serves as an example to Sol-Ark on how to provide such information. I think Sol-Ark is a promising young company with some really good tech (which currently is the most promising contender for the core system to install on/in our house), but one area where it can definitely improve is in product documentation.
 

Attachments

  • Sol-Ark 201 screenshot.png
    Sol-Ark 201 screenshot.png
    1.5 MB · Views: 22
You must log in or register to reply here.

Similar threads

W
Sol-Ark 15k confusion
Replies
2
Views
294
glandpuck
G
M
Order of Operations: Adding first battery to Sol-Ark 15k system
Replies
6
Views
554
Mr.Hyde
M
M
1st Gen Sol-Ark 12K with Cummins ATS
Replies
6
Views
575
DIYrich
D
D
Sol-Ark 15K for Partial Backup
Replies
1
Views
250
DIYrich
D
S
Is there a market for used Sol-Ark 15k???
Replies
13
Views
803
Theory_N
Theory_N

diy solar

diy solar
Back
Top