Sol-ark - eating their own dog food?

[robby]

I can tell you my gen will start in a grid outage and I believe I have my SA15 operating the way you describe. Night on battery as sun comes up PV ramps up charging batteries but also covers my loads until batteries are full then it’s grid sell the excess. Reverse process in the evening/night. I do grid charge in the early AM usually when rates are low. I have gen charge unchecked at the moment but usually both gen charge and grid charge boxes are all checked for all time periods.

So explain this to me in a little more detail.
If you have both boxes ticked how does it select which one to use or does it default to Grid first?
Or is it based on the Minimum SOC rate that you set under each source?

 

[629658]

So explain this to me in a little more detail.
If you have both boxes ticked how does it select which one to use or does it default to Grid first?
Or is it based on the Minimum SOC rate that you set under each source?

Minimum SOC rate.

 

[629658]

I've heard of time-of-day rates, but never heard of a place where they published new prices daily. Interesting that you can arbitrage electricity during the day. The local utility in Albuquerque explicitly prohibits that, though I don't see why. If they have surplus at night and a shortage in the day, why should they care if you store it for them?

I think while absolutely possible with the Sol Ark they would frown on me selling stored battery power back to them at a higher rate. Theoretically it would be difficult for them to discover me doing it I am content to use some of their cheap grid power to put my batteries close to 100% and then grid sell my PV production back to them at full retail. I won’t say I’d never do it (on rare occasions we will see 22-44 cents per kWh for an hour or two) if I had an opportunity to buy at 2-3 cents and sell at 35 cents it would be tempting. The best thing about the Sol Ark is it’s flexible enough to operate to my benefit in almost any rate environment.

 

[robby]

I think while absolutely possible with the Sol Ark they would frown on me selling stored battery power back to them at a higher rate. Theoretically it would be difficult for them to discover me doing it I am content to use some of their cheap grid power to put my batteries close to 100% and then grid sell my PV production back to them at full retail. I won’t say I’d never do it (on rare occasions we will see 22-44 cents per kWh for an hour or two) if I had an opportunity to buy at 2-3 cents and sell at 35 cents it would be tempting. The best thing about the Sol Ark is it’s flexible enough to operate to my benefit in almost any rate environment.

Yes and you can absolutely charge from the grid and then sell back whenever you need to.
The power companies will know what your up to but with so few people doing it they probably think stirring up the Pot is not worth any potential bad press and public interest that might arise.

One company I worked for use to ignore anything, including user manipulation so long as it was affecting less than 5% of their revenue.
Anything over 5% would start alarms ringing and meetings were held to stop or curtail the practice.
Anything that reached 10% was considered and act of war that required all hands on deck.

 

[Think About It]

Your Welcome and I am glad if I can help people with issues.

Ok well this is beyond me as to why it is working that way.
I can only address the Battery First vs Load First issue with how mine has been working.
Here are Graphs of When I had it in Battery First and then When I realized I was wasting grid power and I switched over the Load First

Battery First at 7:20am

View attachment 130668


Load First at 7:20am.
View attachment 130667

Yours seems to be working. Mine isn't. What version of the firmware are you on?

 

[robby]

Yours seems to be working. Mine isn't. What version of the firmware are you on?

6.2.1.0 which is over 2 month old or 6 updates ago, which is embarrassing. No new features have come along that Interested me until 10 days ago when they released the latest which has some big changes to the GUI.

 

[Llaves]

No new features have come along that Interested me until 10 days ago when they released the latest which has some big changes to the GUI.

have you found a place on the Sol-Ark website that lists the changes in the firmware so a user can decide if the update is important enough to adopt.

 

[robby]

have you found a place on the Sol-Ark website that lists the changes in the firmware so a user can decide if the update is important enough to adopt.

LOL Nope it does not exist.
Because they keep on releasing so many updates I have begged for one, but all I ever hear is that "It Will Soon Be Coming".
I get my info from a few of the Techs and even then they don't remember everything, just the more salient features of the update.

 

[Llaves]

Because they keep on releasing so many updates I have begged for one, but all I ever hear is that "It Will Soon Be Coming".

when I asked I got more of a "why would you want that" sort of answer.
So what are these GUI changes? Anything that struck you as important or useful?

 

[robby]

when I asked I got more of a "why would you want that" sort of answer.
So what are these GUI changes? Anything that struck you as important or useful?

I don't know, I only hear that changes were made to how things are laid out.
Some of the things really do need a change so that could be a good thing.
I plan to update next week.

 

[629658]

when I asked I got more of a "why would you want that" sort of answer.
So what are these GUI changes? Anything that struck you as important or useful?

I think some of your issues are because in your present configuration the only way your batteries can charge is through PV. Now I think another issue you definitely are having or will be having is accurate SOC. If you are short charging frequently (you are) your SOC readings on your Sol Ark will/are drift off and becomes inaccurate unless your closed loop communication. So you could potentially show 50% SOC and you’re actually on zero. This would explain why you’re seeing some grid usage. No PV and no batteries = grid usage. So my best advice is to make sure your batteries get a 100% SOC at least every couple of days. This is beneficial for several reasons but it allows the inverter to reset its SOC and it allows your batteries to top charge and cells equalize. This would also explain why you cannot predict the grid usage. If your SOC is low it is going to go on grid and charge your batteries anytime you get below 5% the way you have it set and there is nothing you can do about it or predict it. If you keep your batteries fuller you then can have control over when you will charge and what you will charge with grid or Gen. I suspect you are discharging your batteries below the 5 % often. The inverter automatically charges once the 5% is hit and then recharges to 15% and off and you get into this loop and grid usage you have zero control over. That is why I mentioned you could use more storage as it would smooth things out for you.

 

[Think About It]

I think some of your issues are because in your present configuration the only way your batteries can charge is through PV. Now I think another issue you definitely are having or will be having is accurate SOC. If you are short charging frequently (you are) your SOC readings on your Sol Ark will/are drift off and becomes inaccurate unless your closed loop communication. So you could potentially show 50% SOC and you’re actually on zero. This would explain why you’re seeing some grid usage. No PV and no batteries = grid usage. So my best advice is to make sure your batteries get a 100% SOC at least every couple of days. This is beneficial for several reasons but it allows the inverter to reset its SOC and it allows your batteries to top charge and cells equalize. This would also explain why you cannot predict the grid usage. If your SOC is low it is going to go on grid and charge your batteries anytime you get below 5% the way you have it set and there is nothing you can do about it or predict it. If you keep your batteries fuller you then can have control over when you will charge and what you will charge with grid or Gen. I suspect you are discharging your batteries below the 5 % often. The inverter automatically charges once the 5% is hit and then recharges to 15% and off and you get into this loop and grid usage you have zero control over. That is why I mentioned you could use more storage as it would smooth things out for you.

Yes I agree with your assessment. I'm on closed loop. I have also been on Voltage and percent. The problem with percent is that the inverter has to continually "relearn" the SOC.

Tomorrow I'm going to try a few things. First, a complete reboot - which I hate to do. I'm tired of setting the oven and microwave clocks. LOL Even though I have a transfer switch to take the Sol-Ark out of the loop, my mains are tapped and to cut grid I have to kill power entirely to the home.

The second thing is that I'm going to change my SOC to 20% in my TOU. My theory is that the SOK batteries may be reporting that they are at cutoff at 17% causing the Sol-Ark to charge them. What doesn't make sense is that I have "Grid charge" disabled, so the grid should never charge the batteries.

 

[Think About It]

I don't know, I only hear that changes were made to how things are laid out.
Some of the things really do need a change so that could be a good thing.
I plan to update next week.

I'm on 7.2.2.2, which is about 2 weeks old. I didn't notice any changes. It supposedly fixed a bug whereas the RSD button was not dropping the RSD power. I have that wired but keep forgetting to test it. On the list for tomorrow.

Is anyone running firmware newer than 7.2.2.2?

 

[Think About It]

If you're willing to go with an external device but want a more turnkey solution, the Victron 700 series monitors can be used to start/stop a generator. From my reading of the manual (I don't have one), you can program the both the start and stop SoC. It does not appear to offer the "run for fixed time" of the PLC solution, and switching between "run to %" vs. "run to full" would require resetting parameters.

Until I get this fixed, I could wire a 240 volt relay to the grid and have it do the 2-wire start - probably best to use a time delay relay to avoid momentary loses from starting the gen. Perhaps the Generac has a built in delay to compensate for momentary outages.

On second thought, I could simply disable the 2-wire start on the Generac and go back to letting the generator auto start. I still have N1, N2 and T1 connected to my transfer switch. I neutered the switch by disconnecting +12, -12, and x-fer leads and, removing the wires to the transfer coils which are spade connectors. I did it this way so that I could easily remove the Sol-Ark, reconnect my generator, and send the Sol-ARk back to them for repair, replacement or refund.

 

[robby]

I'm on 7.2.2.2, which is about 2 weeks old. I didn't notice any changes. It supposedly fixed a bug whereas the RSD button was not dropping the RSD power. I have that wired but keep forgetting to test it. On the list for tomorrow.

Is anyone running firmware newer than 7.2.2.2?

7.X.X.X I believe is for the 15K model. I am using a 12K which is 6.X.X.X

 

[Think About It]

I have Solar Assistant attached also but I use Power view to change my settings. While I could use Solar Assistant to make changes I find Power view easier. Solar Assistant just shows the information better for you. If you want the gen to auto start and charge you will need to check gen charge for all time periods and set it lower than your grid charge settings. I think once you familiarize yourself with it you will find it much easier to set a grid charge period get your batteries at 100% then work off your batteries. Otherwise you will be endlessly checking on your system to get what you want. If you let the Sol Ark do its thing you almost never have to mess with it unless something happens out of the ordinary. I check mine once a day usually to set up which 2 hrs of the day I will charge. I find we work well in the 40-100% SOC range but can go much lower if we have a grid outage. I also grid sell our excess. I have never used load priority but from your post I think I can do everything you are asking for. On my attachments yesterday we had power for $2.5 cents per kWH from 2300-0400. I elected to charge my batteries and stay on grid for those hours. These are the settings I used to do that. At 0400 we went back on battery and off grid. I figured with cheap power might as well use it.

I'm curious why you are using "Limited to home". I've gotten conflicting information about this from Sol-Ark. The more experienced techs have stated that I should be "Limited to Load" for my use case. They explained that I only would use "Limited to Home" if my Sol-Ark was wired as a sub-panel off my main load center.

 

[robby]

Yes I agree with your assessment. I'm on closed loop. I have also been on Voltage and percent. The problem with percent is that the inverter has to continually "relearn" the SOC.

Tomorrow I'm going to try a few things. First, a complete reboot - which I hate to do. I'm tired of setting the oven and microwave clocks. LOL Even though I have a transfer switch to take the Sol-Ark out of the loop, my mains are tapped and to cut grid I have to kill power entirely to the home.

The second thing is that I'm going to change my SOC to 20% in my TOU. My theory is that the SOK batteries may be reporting that they are at cutoff at 17% causing the Sol-Ark to charge them. What doesn't make sense is that I have "Grid charge" disabled, so the grid should never charge the batteries.

Percentage mode sucks. It drifts a lot unless you get up to 100% SOC at least every 2-3 days
If it is in closed loop the Inverter is not learning the SOC, it is taking the batteries reported SOC and averaging out the SOC for all the batteries connected. I highly suggest you look at all of the LCD screens and see if the Average SOC is adding up to what the Sol-Ark is reporting. It is very easy for one battery in the string not to be communicating with the Sol-Ark due to a bad cable or dip switch setting.

The second issue is that the BMS suffers from the same problem as the Sol-Ark just in a slower way.
If the BMS does not get a full charge every week or so it will start to drift and the accuracy will go off.
YMMV depending on the quality of the Batteries and BMS.

The third issue is that you cannot use SOC with so much precision!
The head engineer of Fortress Power told me this after I tried some 5% Increments in my settings. He said that he recommends no less than 10% increments if you want to make sure there are no long term issues with TOU or other settings that are using SOC.

 

[Think About It]

It is very easy for one battery in the string not to be communicating with the Sol-Ark due to a bad cable or dip switch setting.

Is there a way to see if the Sol-Ark is communicating with all of the batteries on the CANbus? or does it treat the array of batteries as one battery?

 

[Llaves]

Is there a way to see if the Sol-Ark is communicating with all of the batteries on the CANbus? or does it treat the array of batteries as one battery?

I suspect that it may depend on whether the batteries communicate with each other using the CANbus protocol or some other.

For my batteries (MeritSun), the batteries communicate with each other over an RS-485 connection, and the Sol-Ark sees the four batteries as a single unit through the CANbus connection. The BMS reports the average SoC of the four batteries. It's supposed to report the sum of the charging capacity but it's not doing that, which rules out the closed-loop control in my case. My battery vendor supplies software for monitoring the batteries so I'm able to verify that each battery is communicating with the one that is connected to the inverter.

On the other hand, I reach 100% SoC most days, so the drift isn't a real issue.

 

[629658]

I'm curious why you are using "Limited to home". I've gotten conflicting information about this from Sol-Ark. The more experienced techs have stated that I should be "Limited to Load" for my use case. They explained that I only would use "Limited to Home" if my Sol-Ark was wired as a sub-panel off my main load center.

When I went through the manual Limited to home offer more options than limited to load and it better fit my needs. I do have an interconnect agreement so we do grid sell our excess. After reading through it again my settings may not apply to limited to load. I read it to say limited to load reduces inverter output to match the loads so that is limiting your PV production to only what you need. No excess will be grid or home sold. So that means your PV production is being throttled back to make your loads only. I am wired to my load center and not a sub panel. Works great and when I said I am doing what you want I am.