Solar house generator I started DIY back in 2000 - My path from Trace to Xantrex (on FLA battery) to XW Pro inverters on Tesla Model S batteries

[dougbert]

But why?
I don't see the goal/purpose.

When the battery runs low, why not just let the grid power your loads and let the battery sit low overnight?

that is what I want to do. Run on battery all the time except when the battery gets too low, then the grid takes over the loads with ByPass and the battery is charged by the solar panels during the day. But with my limited time with the Pro, I cannot determine just how to do that.

Every time I turn on the grid, it goes to ByPass, charges the battery. When the battery reaches the Bulk target, the charger turns off and the grid stays in ByPass running the Loads. aka UPS mode

I want to run the house from the battery all the time - until it gets too low. From March to November I RARELY had (under the Xantrex inverter) the battery discharge so low to cause a Grid ByPass. Very sunny during those times. Late November to early February we get rain/snow storms.

I leave my system connected to the grid all the time. Solar supports loads and charges the battery most of the time. I have set the "grid support voltage" to about 60% SOC, meaning if the power goes out I'll always have at least 60% of my battery capacity to make it through even the hottest nights.

how do you do that? how to get the grid OUT of ByPass?

Once the battery discharges to 60% it just sits there. I might buy 2 or 20 kWh, but I'll only buy the power I actually used. PV can recharge tomorrow, or not if the weather doesn't cooperate.

maybe it is because I don't understand "grid support voltage" - the manual SUCKS in explaining it

Seems like with your plan, any time you run the battery down, you'll be buying XX kWh, even if you only needed 100Wh to make it through the night. You might even buy enough that you have excess solar the next day, past what the battery can hold.

In sunny times, the battery fills full and the H2O heater diversion kicks in. When all the water is hot, then yes, the solar is wasted. I do not do NetMetering. Even if I wanted to, the local grid circuit is maxed out and they are NOT allowing any more Netmetering connections.

 

[dougbert]

@400bird did you imply that you can run on battery with grid on, but no bypass?
trying to understand what you meant

 

[400bird]

I tried to sit down at the computer this weekend to get some screenshots of the settings, but I couldn't make it happen.

Yes, when there is enough battery capacity, it does support the loads while connected to the grid.

You need to enable grid support, set the voltage as the low voltage where you want your reserve/stop grid support.
This line isn't a hard limit, I think the XW will pull below this number if it thinks the battery will recover to this voltage. But, normally it follows this lower limit really well.

I believe you said you can't sell back to the grid? In that case I'd leave the sell timers set so it runs 24 hours a day and put the sell current at 0 amps

Charge voltage needs to be at least 0.5 volts below grid support voltage. I have this set to a full volt below grid support.

If battery voltage is above the grid support voltage setting, the battery will support your loads.

If the battery voltage is at or below the grid support voltage setting, the grid supports loads.

The XW won't discharge the battery past 0.5 volts above the charge voltage setting (if set to 50.0 volts, it will stop discharging at 50.5) this means that when on grid, it shouldn't engage the XW as a charger.

I believe both of these settings are ignored when there is no AC detected on the input.

 

[dougbert]

thank you, this is helping my old brain

I tried to sit down at the computer this weekend to get some screenshots of the settings, but I couldn't make it happen.

Yes, when there is enough battery capacity, it does support the loads while connected to the grid.

You need to enable grid support, set the voltage as the low voltage where you want your reserve/stop grid support.

"set the voltage" refers to which setting? The "Grid Support Voltage" I assume.
There are so many "voltage setting" I try to fully specify its full name and which section (ie Grid Energy Management (Grid Support))

This line isn't a hard limit, I think the XW will pull below this number if it thinks the battery will recover to this voltage. But, normally it follows this lower limit really well.

I believe you said you can't sell back to the grid? In that case I'd leave the sell timers set so it runs 24 hours a day and put the sell current at 0 amps

I have both Export Power Block Start and Export Power Block End set to midnite. Does that enable or disable it?

manual does not give Operational overview, just crytic low level info on that.

Charge voltage needs to be at least 0.5 volts below grid support voltage. I have this set to a full volt below grid support.

I assume "Charge voltage" refers to "Battery Settings Section: Bulk/Boost Voltage Set Point", is that correct?

If battery voltage is above the grid support voltage setting, the battery will support your loads.

If the battery voltage is at or below the grid support voltage setting, the grid supports loads.

The XW won't discharge the battery past 0.5 volts above the charge voltage setting (if set to 50.0 volts, it will stop discharging at 50.5) this means that when on grid, it shouldn't engage the XW as a charger.

I believe both of these settings are ignored when there is no AC detected on the input.

okay, here are my settings on my first attempt:

SECTION:Setting​	VALUE​
Controls: SELL ENABLE	Enabled
Battery Settings: Bulk/Boost Voltage Set Point	45.2v
Battery Settings: Absorption Voltage Set Point	45.2v
Battery Settings: Bulk Termination Voltage	45v
Battery Settings: Low Battery Cut Out	38.4v
Grid Energy Management: Grid Support	Enabled
Grid Energy Management: Grid Support Voltage	41v
Grid Energy Management: Export (Sell) Power Block Start	12am
Grid Energy Management: Export (Sell) Power Block End	12am
Grid Energy Management: Maximum Export Sell Amps	0

So in English, these values do the following:

When the charger engages, it will do a 2-stage charge cycle of the battery to 45.2 volts.
During the charging, Grid will supply the loads in ByPass.
When the battery reaches the target voltage, the charger will stop.

Whereas Grid Support voltage is at 41v, the inverter will take over supplying the loads and ByPass will stop.
This will be the steady state, until the battery reaches 41v, when ByPass will engage again, supplying the Loads and the battery enters an idle state, no charge (by the inverter) and no discharging to loads.
The DC MPPT controllers will charge the battery when the sun shines


before setting the values in the above table, Grid IN was on, charger off, ByPass operating
after setting the above:

Grid IN is on, and the battery is inverting at this moment, battery is at 47 volts, charger off

seems like a WIN at the moment

now I will work on "Charger Settings: Recharge Voltage", as to where I want it

 

[400bird]

Yup, that's why I wanted to get time to sit in at the computer and get screen shots.
"Recharge voltage" is what I as referring to. The XW will not discharge to 0.5 volts above this setting. So, 49.8 for me.
Recharge voltage is when the charge cycle starts. If your battery doesn't drop below recharge voltage the XW won't start a charge cycle.




My grid support settings.
The way it works for me is that I push 1 amp to the grid during peak rate hours.
I just verified this, I set max sell amps to 0 and grid usage was single digit watts.
After peak rate is over, it continues supporting loads, but allows about 100 watts of feed in from the grid (after 9:02 pm)
I think I see so much grid power feeding load because my night time loads are pretty imbalanced. All the bedrooms ended up on L1. I really should go swap around breakers.

I believe if you have the start and stop time set to midnight it allows that function 24 hours a day.


You can ignore the SOC settings, I don't have SOC control enabled. I am using battery voltage only.

 

[dougbert]

well things went nicely....until they didn't

All day I was watching the system operate just fine, then at 4:44PM I got 5 massive SELL events to the grid, pushing 5kw of power, here is the battery display



Then zoomed in on that region



I don't like unexpected events like that.

My smart service meter is NOT programmed for netmetering, so I don't know what that will do, or report

the sun was down, and power was flowing from the battery to the grid on the Dashboard Power Flow, and the inverter was humming very loudly.
so I turned OFF Sell and Grid Support for now.

more research on this inverter operation

 

[400bird]

That's almost exactly what mine did on the current firmware (1.11 build 49) with EPC enabled. If you're on current firmware, I'd recommend disabling EPC or rolling back to the previous firmware.

You might try peak load shave, that may do what you want also.

Are you tracking grid home load? Did this really all go to the grid?

 

[dougbert]

That's almost exactly what mine did on the current firmware (1.11 build 49) with EPC enabled. If you're on current firmware, I'd recommend disabling EPC or rolling back to the previous firmware.

firmware is 1.11 build 49

EPC is disabled
and I moved the two slider settings to 0 as well, just in case

You might try peak load shave, that may do what you want also.

will read up on

Are you tracking grid home load?

what/how do you mean?

Did this really all go to the grid?

I was watching the Power Flow display at the time and the moving dots moved from Battery to Inverter to Utility

 

[400bird]

Here's where I started to see a similar issue with 1.11
No idea why I posted this in GXMnow's thread, but at least I was able to find it.

Post in thread 'Adding storage to my Enphase system' https://diysolarforum.com/threads/adding-storage-to-my-enphase-system.10797/post-465639

firmware is 1.11 build 49

EPC is disabled
and I moved the two slider settings to 0 as well, just in case

I know what I'd do, roll back to the previous firmware.

will read up on

Basically it limits how much you pull from the grid to your setting.
"Peak Load Shave" in amps = max amperage pulled from the grid.
But it may also limit your AC charging from the XW.

what/how do you mean?

You answered it below, I was asking about where the AC energy was actually going, loads or the grid.

I was watching the Power Flow display at the time and the moving dots moved from Battery to Inverter to Utility

 

[dougbert]

Here's where I started to see a similar issue with 1.11
No idea why I posted this in GXMnow's thread, but at least I was able to find it.

Post in thread 'Adding storage to my Enphase system' https://diysolarforum.com/threads/adding-storage-to-my-enphase-system.10797/post-465639

ok, I see the similarity

after reading your post and sliding the EPC scales to 0, I re-enabled Sell and Grid support
in 40 minutes, I got another single spike to 5kw draw down on the battery with an accompanying voltage drop

I know what I'd do, roll back to the previous firmware.

I will see if I can find it

Basically it limits how much you pull from the grid to your setting.
"Peak Load Shave" in amps = max amperage pulled from the grid.
But it may also limit your AC charging from the XW.

You answered it below, I was asking about where the AC energy was actually going, loads or the grid.

 

[dougbert]

what is the firmware version that you are using?

and which versions do you have at this time?

Nevermind, I found your post https://diysolarforum.com/threads/adding-schneider-xw-pro.19090/post-552204 where you indicate v1.11.00

Can I get that from you?

cancel that, I found a dealer that has the v1.11.00 BD0028 and downloaded it


I have locally now:

v1.03.00 BD0003
v1.11.00 BD0028
v1.11.01 BD0049

In Release notes for 1.11.01 BD 0049, it lists the following history of firmware versions

Release 120-240V Firmware 01.11.01 Build 0049
Release 120-240V Firmware 01.11.00 Build 0028
Release 120-240V Firmware 01.09.00 Build 0009
Release 120-240V Firmware 01.06.00 Build 0386
Release 120-240V Firmware 01.04.00 Build 0353
Release 120-240V Firmware 01.03.00 Build 0003
Release 120-240V Firmware 01.02.00 Build 0005
Release 120-240V Firmware 01.01.00 Build 0233
Release 120-240V Firmware 01.00.00 Build 0020

with changes listed for each version

but references I find on the web, all point back to the current FIRMWARE DOWNLOAD page at SE, which has the latest, so hard to locate older firmwares.

Seems like something to collect - lol

 

[400bird]

I'm glad you both filled in the missing part of the firmware # I forgot and found a source to download it.

After that situation, I too, started saving any firmware vs the old habits of deleting the prior version.

 

[dougbert]

Reflashed the firmware to 1.11.00 BD0028

turned back on Grid Support and Sell to Grid (with 0 amps) settings, we'll see if we get any more of those 5kw Battery to Grid sell surges - hope not

 

[dougbert]

Looking at the Energy Comparison tab on InsightLocal, yesterday, when the sell surges occurred, 725wh went out to the grid - oh my!
today after doing what I described in the last post, 19watt-hrs have gone out to the grid so far today

I assume the inverter is doing some real-time protocol hand shaking. Will the utility notice such small "Sells"? or the larger one yesterday?

again, my Smart meter is not enabled for netmetering, just normal operation

 

[400bird]

I don't know your utility.
Most won't care about you "selling" less than a kWh. Because in reality, you probably paid them for that kWh as if you used it.

I highly doubt 19 watt hours for an entire day would be noticed. Did you purchase any power?
If not, you might want to try switching to peak shave and set it to the lowest number that isn't 0, play with that setting some. I'll bet you can get it so you buy a very small, nearly constant amount of power. Maybe 15 watts constant thought the day?

The biggest issue for the inverter is actively adjusting output to cover things like loads starting and stopping. It might be take a cycle or 3 for it to adjust when the refrigerator turns off. So you're pushing 100 watts out to the grid for 3/60th of a second? Larger numbers if a larger motor stops. Like the AC, to go from 4,000 watts down to my base load of 400 watts can't be instant.

More importantly, I think it sounds like rolling back the firmware did the trick for the random max grid sell spikes.

 

[dougbert]

For reference use for future readers (and myself)"

I re-found the following Schneider conference session on the XW Pro, namely Voltage Control and SoC Control.
These deal with Grid Support Voltage, Recharge Voltage and LBCO Voltage

it makes more sense this time around, after working with these settings.

Op-Ed: I think Schneider could add far more explainations on this important operations mode. This video segment on this is very short - or I am dense

 

[dougbert]

I want to thank @400bird for helping me understand the features of the Conext XW Pro which I failed to understand

In a prior post I mentioned that the XW Pro didn't have the same features as my older Xantrex SW+ inverter. Still true BUT it has similar features in an expanded manner

Like the Xantrex, the XW Pro continues to have the UPS mode of operation, which is to charge the battery, then turn off the inverter and power the loads by the Grid, basically Grid ByPass. The battery becomes a backup resource of power for when the grid goes off.

Using a new feature, that allows for Enable/Disable setting, called Grid Support, the unit can be toggled between UPS mode (Grid Support disabled) and expanded operations using the Grid when Grid Support is Enabled.

I will explain more in detail how and what those operations are in future posts

Again just wanted to express my thanks to him

 

[400bird]

Glad to help!
I hate that the settings in the XW are confusing, but I don't have any ideas how to type up two sentence explanation for the manual.

I can explain it over about 7 posts here ?

 

[dougbert]

Okay time to add more info

There is regular UPS mode as I mentioned, where when Grid is added, the battery is charged, then the system goes into Grid Pass Through or Bypass operation.

Control is performed by use of the InsightLocal web interface

On the Top Menu Bar: Select "Devices" and a list of devices on the Xanbus is presented.
Click on the Inverter device and a Status display for the inverter is presented.
Click on the next Menu Bar on "Configuration"

Enabled Advanced menu presentation

Look for and click on:

Grid Energy Management (Grid Support)​

The first setting is "Grid Support" toggle - Enabled/Disabled state

This must be enabled to allow operation of all the Grid features and operations

There are 3 sub-settings that are key for selecting various operations:

1. Grid Support Voltage (located in the Grid Energy Management subsection, here)
2. Recharge Voltage (located in the Charger Settings subsection)
3. Low Battery Cut Out (located in the Battery Settings subsection)

These 3 voltage setting and the current voltage of the battery, determines what happens, like grid bypass or inverting or battery charging or Load Shave Mode.


Here is the first instructions of Grid Support of the manual, page 78 (this manual has 233 pages and just 2-4 pages on this important topic):

XW Pro 6848 NA
Operation Guide
990-91227D-01
June 2022


Grid Energy Management (Grid Support) Settings

The Grid Energy Management (Grid Support) Settings menu contains configuration
options for grid-tie operation. To enable these settings, Grid Support must be enabled
in the Grid Energy Management (Grid Support) menu. Individual grid-interactive
features such as PLS and Sell are enabled individually.

In grid support mode, the XW Pro supports the utility grid by limiting the power drawn
from the utility to close to zero. This mode is desirable for using excess energy from
auxiliary DC sources like PV, while still maintaining a charged battery bank. No power is
sold to the utility in this mode.

NOTE: Grid support and sell functions are modes of operation that are subject to local
and/or national grid interconnection requirements in most jurisdictions. It is the
responsibility of the installer and system operator to ensure that all applicable procedures
and technical requirements are complied with before turning on either of these modes.
The interconnect codes and standards with which the XW Pro complies are listed in
Specifications on page 137.

NOTE: Upon startup, the XW Pro does not enable grid support functions for five minutes
(300 seconds). During this period the XW Pro connects to AC input and determines
whether the utility grid voltage and frequency are stable and within nominal range. If
Grid Support is enabled, the inverter information panel also displays a 300 second
countdown during this period. For more information, see "Islanding Protection" on
page 27.

NOTE: In grid support mode, the XW Pro should not draw a large amount of current from
the grid. If the XW Pro is drawing more than expected, it is important to note that it cannot
distinguish between real power and reactive power. Large current draw will only affect
reactive power and not real power, and utility companies generally only charge by real
power consumed.

Its a start

 

[dougbert]

The TWO things about Grid Support Voltage that I did NOT understand at first, is (1) that when the battery voltage is ABOVE Grid Support Voltage, then the battery is used via the inverter to support the loads.

and (2) when the battery voltage is BELOW Grid Support Voltage, then various Grid operations and features become operational.

(If I am wrong on certain things, please point them out and I will correct, thanks)