System Management - Generac Solar, but question in general.

[oregon_phil]

I respect your decision. Getting to root cause is always fraught with numerous questions.

[Rade]

Please post the wiring diagram if possible. Obscure any private information (like name, address, etc.) before posting.

Thanks in advance.

I appreciate the input but I am going to say no. Our system was designed by a reputable system architect, installed by a licensed electrician for Generac and then inspected by our Town electrician, also licensed and finally approved by our regional electric service provider. The system has a substantial warranty and is fully monitored and managed by Generac. If something breaks, I have one phone number to call.

This diagnostic discussion is getting too in the weeds for me.

Thanks, everyone.

Rade

[oregon_phil]

After even more digging, I found the Generac installer tool set. The PVLink sizing tool can be found by searching "cce-installer-resources/system-sizing-tools" on the Generac website.

I ran just the PVLink sizing tool for Maxeon 3 410 420 W panels using 420 as a guideline. See the attachment Generac Sizing tool. When panel Voc is entered, the PVLink sizing tool shows an error (Chose another panel). Panel Voc too high for SnapRS. PVLink is meant for use with 60, 72, 96 cell solar panels. This particular Maxeon 3 solar panel is a 112 cell solar panel.

I'm thinking your installer did not run the Generac sizing tool kit and/or assumed all Maxeon 3 panels are the same cell count. My cursory web review of Maxeon 3 cell counts range from 104 to 128. I have yet to find a Maxeon 3 with a cell count of 96 or lower. I'm trying to say, so far, I can't find a Maxeon 3 solar panel that will work with the PVLink sizing tool without throwing an error.

[oregon_phil]

I am glad that you are contacting Generac to follow up on system voltages being higher than specification voltages. Generac set the max voltages for a reason.

One additional request please. Please post the wiring diagram if possible. Obscure any private information (like name, address, etc.) before posting.

I assume you have one battery cabinet. The inverter has 4 DC inputs for batteries and solar panels. One input is taken up by the battery cabinet.

Somehow your installer configured your six strings into the three DC inputs remaining at the inverter. Your installer may or may not have paralleled strings together before the PVLink.

It's important to understand how the strings are configured so we can see if paralleling and amp limitations are being followed for all devices.

Also show which string/PVLink is causing you grief on the drawing.

Thanks in advance.

[Rade]

a) SnapRS Max Voc allowed of 75 Vdc is being violated. Maxeon Voc 80.5 Vdc is greater than Snap RS Max Voc of 75 Vdc.

Using a string length of 6 as an example:

b) PVLink max Voc limit of 420 Vdc is being violated. 6 x 80.5 Vdc = 483 Vdc. 483 Vdc > 420 Vdc (Panel Voc may increase in winter due to temperature coefficient).

c) PVLink Mppt range of 60 to 360 Vdc is being violated. 6 x 67.7 Vdc = 406.2 Vdc

Of course I could be totally wrong because maybe Generac posted the wrong specs on their website. This is the brochure I used: "pwrcell_consumerbrochure_202212_digital.pdf" .

If I am not mistaken, then eventually Generac is going to say the system violates the three items I mentioned above. Since this is a new system, if it were me, I would get Generac to validate the system one way or another in writing just in case you have warranty events in the future.

Thank you for that! The problem is that this one PVLink is situated on an area of our roof that, for a period of time each day, gets intermittent sun due to the proximity of a cypress tree usually blowing in the wind. According to the Generac technicians, that rapid intermittency in the power spike causes the inverter to think the array is malfunctioning, and it throws the Ground Fault. Generac (once again - 4th time!) adjusted the parameters on the PVLink to accommodate those environmental issues.

The other thing I need to take into consideration is that - this is a new system - these components are under full warranty by Generac. I cannot adjust many of the parameters beyond what is covered in the Owners Manual. If I touch the code, I can void the warranty. But I will relay the above to my local authorized service team.

[J.P.M.]

You can say that again....
My journey in solar was probably the worst case scenario. Everything that could go wrong did go wrong.

After a lot of work on my part and a reset in expectation, I did get to a point where I am happy with the system though....

OK, Sounds like you didn't get what you wanted or what you agreed to pay for.

Sometimes you get stuck with bad karma.

When running engineering projects back in the day, and always for reasons I could not understand, but 1X/awhile a project would go south for unfathomable reasons (and usually unexplainable even at the project autopsies), and it turned into a magnet for weird problems to the point where there was the devil to pay to get it back on track for cost, schedule and startup.

[scrambler]

Sounds like you didn't get what you wanted or what you agreed to pay for.

You can say that again....
My journey in solar was probably the worst case scenario. Everything that could go wrong did go wrong.

After a lot of work on my part and a reset in expectation, I did get to a point where I am happy with the system though....

[oregon_phil]

32 - Maxeon 3 solar panels, 410-420w. 2 arrays of 4 panels, 4 arrays of 6 panels. Batteries are Generac PWRCell - 6-3kW batteries (total 18kW), Inverter is Generac PWRCell. All in all the system works well, the problem we hit (TODAY) is that the intermediary technical/roofing crew is getting stonewalled by Generac technical support on repairing the installation. Physical parts in hand, Generac told them they were not approved to install, instead Generac did a code update (that failed before). We have on Photovoltaic link (PVLink) that keeps tossing out errors since the array was first powered up. Back to "Observe and report"...


Our array.
Array.png


When the weather is cooperating, we ARE able to bank about 100kW a week in power above what the house consumes. Batteries are able to sustain the house until around 1AM, then we swap over to grid power until sunrise.

I would like to offer the following comments below, but please realize that I am not a solar installer. I am a retired Mechanical Engineer with process and design experience in the high tech industry. I am interested in solar power and like to help whenever possible. I downloaded the latest specifications from the Generac website and found the following:


1) One or more component specifications are being violated.

Component Specs

Maxeon 3 panels (420W used as example)

Voc = 80.5 Vdc
Vmpp = 67.7 Vdc

PVLink APKE00010

Voc Max when Cold = 420 Vdc
Mppt range = 60 to 360 Vdc

SnapRS APKE00011

PV Module Max Voc = 75 Vdc

a) SnapRS Max Voc allowed of 75 Vdc is being violated. Maxeon Voc 80.5 Vdc is greater than Snap RS Max Voc of 75 Vdc.

Using a string length of 6 as an example:

b) PVLink max Voc limit of 420 Vdc is being violated. 6 x 80.5 Vdc = 483 Vdc. 483 Vdc > 420 Vdc (Panel Voc may increase in winter due to temperature coefficient).

c) PVLink Mppt range of 60 to 360 Vdc is being violated. 6 x 67.7 Vdc = 406.2 Vdc


Of course I could be totally wrong because maybe Generac posted the wrong specs on their website. This is the brochure I used: "pwrcell_consumerbrochure_202212_digital.pdf" .

If I am not mistaken, then eventually Generac is going to say the system violates the three items I mentioned above. Since this is a new system, if it were me, I would get Generac to validate the system one way or another in writing just in case you have warranty events in the future.

[Rade]

It does take a while to learn all the intricacies of a Hybrid battery system.
And it takes a while to iron out all the little bugs...

It took me 18 months on mine, and I had to give up on many of the perks the system was supposed to have. But ultimately, I have the system running and fulfilling the basic needs, and I mostly run a monitoring report from the downloaded numbers on a monthly basis to make sure all is in order.

Thank you for that. In my mind I kind of suspect it will take a good year for the kinks to work out of the system. We're overall happy with it.

[Rade]

Are you using the SnapRS rapid shutdown devices? Those are known to be problematic and could be causing the PV Link errors you have seen. BTW, in case you are didn't know, SnapRS is part of multiple ongoing lawsuits against Generac.

No, we caught that YouTube video about the problems with those and checked with the rep before the installation. This is just one... fussy... PVLink.

[solardreamer]

We have on Photovoltaic link (PVLink) that keeps tossing out errors since the array was first powered up.

Are you using the SnapRS rapid shutdown devices? Those are known to be problematic and could be causing the PV Link errors you have seen. BTW, in case you are didn't know, SnapRS is part of multiple ongoing lawsuits against Generac.

[J.P.M.]

It does take a while to learn all the intricacies of a Hybrid battery system.
And it takes a while to iron out all the little bugs...

It took me 18 months on mine, and I had to give up on many of the perks the system was supposed to have. But ultimately, I have the system running and fulfilling the basic needs, and I mostly run a monitoring report from the downloaded numbers on a monthly basis to make sure all is in order.

Sounds like you didn't get what you wanted or what you agreed to pay for.

[scrambler]

It does take a while to learn all the intricacies of a Hybrid battery system.
And it takes a while to iron out all the little bugs...

It took me 18 months on mine, and I had to give up on many of the perks the system was supposed to have. But ultimately, I have the system running and fulfilling the basic needs, and I mostly run a monitoring report from the downloaded numbers on a monthly basis to make sure all is in order.

[Rade]

What Brand, model and wattage panels did you get with your system?

And how are your 6 arrays arranged?

Which inverter did you get?

32 - Maxeon 3 solar panels, 410-420w. 2 arrays of 4 panels, 4 arrays of 6 panels. Batteries are Generac PWRCell - 6-3kW batteries (total 18kW), Inverter is Generac PWRCell. All in all the system works well, the problem we hit (TODAY) is that the intermediary technical/roofing crew is getting stonewalled by Generac technical support on repairing the installation. Physical parts in hand, Generac told them they were not approved to install, instead Generac did a code update (that failed before). We have on Photovoltaic link (PVLink) that keeps tossing out errors since the array was first powered up. Back to "Observe and report"...


Our array.
Array.png


When the weather is cooperating, we ARE able to bank about 100kW a week in power above what the house consumes. Batteries are able to sustain the house until around 1AM, then we swap over to grid power until sunrise.

[oregon_phil]

So question to the folks who have been long-term Solar adopters - How much time do you spend having to manage your system?

I feel like I am spending an inordinate amount of time managing our system with daily configuration inspections and revisions.

We are 4 months into our full, Generac installation. 32 Panels (6 arrays / 13.2kW), inverter, 18kW battery backup. Either I discover that something has gone offline and I have to place a service call, or Generac decides to change the inverter configuration parameters that just don't work for our region. For the most part, our system is working well and we are learning a lot about what our home is doing (it's a frickin' power hog!) and when, and how to improve our overall energy usage. Banked some decent energy credits for use this coming winter. I am running our system in what they call "Self Supply" mode - charge the batteries and use the grid to power the house during the day, use the grid for when the batteries have depleted. When the grid starts producing more than 1kW of power, currently around 7AM, the arrays are able to sustain the house while starting the trickle of power to recharge the batteries. Full charge is somewhere late in the 10AM hour. When the batteries reach around 90% charged, power starts to trickle back to the grid and into our power "bank". Huzzah.

On the first issue - We have one PVLink (of 6) that has been problematic since installation. We are at the 4th incident where it went offline and we lose power from that array. Our regional rep opens a problem ticket and it's usually resolved with an OTA system fix. Finally, on this last outage Generac is sending a roofing crew to hopefully swap it out this week. That should repair it once and for all. But that said, when I am observing (obsessing?) over the PWRView app (what our system is producing at the moment), and the number just don't add up for where the sun is over the arrays, I head to our utility basement and go through the configuration panels to see if something got knocked off line (that PVLink keeps popping a Ground Fault error). OR Generac pushed a software update and the panels did not all come back online (this has happened a few times).

The second issue - I am constantly having to review and change is the low battery threshold. The inverter setting that determines how low the inverter will allow the batteries to deplete before switching over to Grid power. We live along the coastline in Rhode Island. We get a LOT of morning fog and related overcast that does not burn off until late morning. If that low-battery threshold is set to 20% remaining, then it takes a better part of the day for the batteries to fully recharge. Depending on the weather forecast for the coming week, I have been keeping that low battery threshold set between 30 and 50%. I discover that a couple times a week, that setting is changed back to a "Generac Summer Season" setting of 20%. Thankfully, I am learning to catch these changes before turning in for the night while the batteries are still relatively charged. My understanding from the Generac information is that their "Summer Season" lasts from May 1 to September 30, so I expect these annoying configuration changes will cease after this month.

Background into the ASK: I am retired after 36 years in Information Technology. I know code, I know networks, I know cyber security. I know problem determination. I am a geek. I had thought this was simplifying life by reducing our homes obligations to fossil fuels and installing "state of the art" technology. I feel that if I were not so in-tune to these things, our solar installation just does not seem to as robust as expected. I also got a really good education on our system configuration from the crew that installed the system. They were kind to my shoulder surfing and questions - I don't suspect that happens a lot.

So my ask to this board is: Is this degree of system management normal?

What Brand, model and wattage panels did you get with your system?

And how are your 6 arrays arranged?

Which inverter did you get?