An Enphase Ensemble Installation

svetz

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... I know my array is a lot smaller than yours, so my numbers might not be impressive... This is just 16 300 watt panels. So if we do this in raw "sun hours" In November 2020, I am getting about 3.85 x my DC panel rating of 4,800 watts. Back in May 2020 (my best month yet) I was getting over 30 KWH a day, or 6.25 sun hours. And that is after all of the inverter losses and even with some clipping in the 240 watt inverters.
That's plenty impressive! We've been so wet/cloudy since June the numbers have been dismal, a little abnormal for here (probably would have gotten more power with wind 😉 due to all the storms). Today might be the first day I produce more power than I used since April.
2UGzPR7rHlbSkAqWSaKBmXn_iyMXQIiR5G4AlBmBnOk.jpg
 

svetz

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I know most won't have any sympathy that this is the first time this
winter... but it serves as a great example why electrical heating is a
bad idea. We're definitely acclimatizing... When we lived in Colorado
the thermostat daytime high was 68°, here it's 70° (of course, more
humidity here too).
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svetz

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In another thread there was a question about the IQ7s and the rapid shutoff requirement, which I answered (flipping the IQ7 breaker disconnects them and they go into RSS mode). But, I didn't know what should be done with the batteries, esp. as how to take off the Encharge covers off to access the DC switch isn't obvious. Here's a bit of the response from Enphase:

Opening the Encharge storage breaker inside the Enpower smart switch will disconnect the battery from the rest of the house electrically and the rest of the house won’t have electricity from the battery. To turn the battery off, the DC switch on it needs to be turned off after removing the cover. There is no rapid shutdown requirement for battery storage systems in the NEC code. It is only for the PV systems (which are on the roof).
 

svetz

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Happy New Year Everyone!

Thank you to all the forums members for posting their hard-won knowledge here and throughout the site. I've really appreciated all the help I've been given and am wishing you all the best for healthy and prosperous 2021.

What a year!

End of the month so I updated the OP with system numbers and SAM users might be interested in the update to post #31 (SAM was within 2% for the year), interesting to see the accuracy of the software and how much difference weather makes. Below is the power usage/generated, the two purple spikes on the right end are where the days the heat kicked on, and the temperature didn't even dip below 50°F.

1609505854664.png
I had been expecting the green trend line to go over the purple (net positive) in October...but rain. That and we consumed more power than expected (heat).... Looks like I need another couple of kilowatts on the roof. More/better insulation would be nice, but more panels is probably cheaper and more practical (no attic to blow insulation into).
 

svetz

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Just noticed there was a update pushed this morning to Enpower (1.2.2278_release/20.39) and Encharge (oddly two at are 1.2.2883_release/20.34 and one at 1.2.2944_release/20.39, both have today as the created date). grid_profile_name: "IEEE 1547:2015-WHB".
The Envoy is still from 11/11/20. The IQ7s were updated recently too: 520-00082-r01-v04.27.04 Updated 21/01/2021
 

svetz

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Typically I'm seeing "grid instability" followed by a reset. No clue what's causing it and probably not the grid since it's one here one there. At least it's only one panel at a time and 5 minutes.
 

GXMnow

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When my iQ7's were set to "Rule 21 f/w" and my system would switch to the inverter, I would have a few panels go offline with a "Grid frequency out of range" error, but it would not clear. Even hours later, still locked out like that, even when I put them back on grid. When I did my power failure test, I was able to get each panel back online, only by covering the panel and then letting the sun hit it again. The DC had to quit to make it reset. This last time under a real power failure, I got them to log in remote, and they changed the profile to "IEEE 1547 mainland alternate" and as each panel updated, it came back online and started making power again. I am having an odd problem with Enphase installer toolkit. I am not able to log in, like the password is wrong, or something. On the older version, it was popping up on my phone that I am no longer on the network with the Envoy, even though I can see the data behind the pop up updating in real time. I can't do anything though as I have to click "OK" and once I do, it disconnects and reloads again, and the pop up comes back. Wow, I just tried it again now, and it's working again, Nice.

So I logged in, and my iQ7's are still showing running image: 520-00082-r01-v04.18.02 Updated 10/04/2019 3:43 PM

The big rain storm did a nice job washing off the panels. My production has topped 20 KWH's a few days now. That is better than 4 sun hours in January.
 

Hedges

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Sounds typical. Consumers are the beta testers.
Response to frequency/voltage deviation and grid failures out to be wrung out well during development and testing.

I think SMA had all that working well for several generations of systems, but some of the functionality got left out of the logic at one point. It was SB 10000TLUS-12 that I bought because it was on the compatibility list. With "grid backup" mode it did allow wider frequency range but didn't do frequency/watt. That feature was in the code and enabled for "island", but but probably a simple logic statement failed to reference the other mode.

Enphase ought go back, evaluate all state-machine states, all transitions between states, and make it robust. They should be able to exhaustively consider all possibilities. A state diagram ought to fit on a single sheet of paper.


Do your IQ7 now have a mode other than "Rule 21 f/w" that does everything desired?
 

svetz

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... Wow, I just tried it again now, and it's working again, Nice....
Woot!
So I logged in, and my iQ7's are still showing running image: 520-00082-r01-v04.18.02 Updated 10/04/2019 3:43 PM
Updates are supposed to be automatic... I wonder why you haven't been updated? Possibly your internet was down when they attempted and you're no on some naughty list? You might open a support ticket with them to request an update.

...a mode other than "Rule 21 f/w" that does everything desired?...
Is there any explanation for those rules that anyone knows of anywhere?
 

Hedges

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Is there any explanation to those rules that anyone knows of anywhere?

The following links have graphs showing out of spec ride through for frequency & voltage (e.g. up to 62 Hz, don't disconnect for 299 seconds, do disconnect by 300 seconds), also power ramping down with increasing frequency.

The exact numbers for ride through (full power being output) seem clearly defined. The frequency/watt ramp has generally been vague or not defined.

SMA now has "Rule 21" on their inverters, but doesn't detail how/what implemented. Their original implementation of frequency/watt for off-grid was well documented.


 

svetz

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There are a number of rules around UL-1741 (e.g., CA Rule 21, Hawaii (HECO 14h?), Peurto Rico (PREPA/PECO))... figuring out which one to use is a mystery. Even Canada has a version of it adopted nationally.

There are probably a 100 or so profiles available on the Envoy... they all have short names that are vaguely descriptive (e.g., AC Coupling FW83pct/Hz PEL 100 REC5s, CA Rule 21 201709, CA Rule 21 201709 w/VW, IEEE 1547-2015 - PECO, PREPA 2107 FW83) but not enough to tell you what the difference is between them. AFAIK, we havent' adopted UL 1741 yet, but it'd be nice to know if I was using the best one.
 
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GXMnow

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There are certainly a lot of grid profile choices. Just under CA Rule 21 there are 6 options. Only one ends with FW which I believe is "Frequency Watt" which is what I should be in to allow the XW inverter to curtail the output by shifting the frequency. But that is also the profile that locked me out. I am trying to find out more info from Enphase about which grid profiles work well with battery backup. There are a bunch for off grid and AC coupling, but none of them are for USA. I think they are all Puerto Rico or Virgin Islands. I want to be legal in Cali, but I also want it to work. Hope Enphase gets this worked out.
 

svetz

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Saw the battery discharging today (right image)... turns out it was smart... yesterday (left image) there was a wind advisory and Storm Guard automatically boosted the battery charge to 100% (I leave it at 60% over the winter, see this thread for why)

1612294150743.png 1612294273201.png
 

svetz

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Inq720's thread What is a cycle and how many of micro-cycles can I get? has me questioning the 60% SoC over winter strategy.

At 60% the system fluctuates a bit, so sounds like micro-cycles to me. According to the 2013 paper each one adds a bit to the voltage memory.

A full recharge will erase the "memory" effect that builds up, but only if it is higher than the memory voltage. At 60% the voltage is 13.15V, at 100% 13.6V; so less than 1/2 volt. Probably the memory voltage wouldn't build up fast enough and via Storm Guard there are full charge cycles in the winter (which is also good for cell balancing). Probably need to research more.
msf4vpdl-1_14.jpg
 
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GXMnow

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I had never heard of anyone talking about memory being a problem in Lithium batteries. So when I saw your post, I did a few searches. I found this article.


They were actually searching for problems that a partial charge/discharge use could cause, and were able to show some memory effect. And in this case, it was with LFP cells. The effect does seems to be pretty small, but if they can extend the life even further by having the BMS work around the issue, that could be a very good thing. This build up of memory from short cycles may actually be part of the cause of the end of life of the batteries. If this issue can be reduced or corrected, we may have longer life batteries than we once thought. I am looking to see if there is something similar in NMC cells, but have not found anything yet.
 

Inq720

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Saw the battery discharging today (right image)... turns out it was smart... yesterday (left image) there was a wind advisory and Storm Guard automatically boosted the battery charge to 100% (I leave it at 60% over the winter, see this thread for why)

View attachment 35643 View attachment 35645
Are you saying, this thing allows me to set a narrow range during storage times say between 40% and 60% SOC while I'm gone and it will get info from weather services and decide it needs to store 100% to ride out a few days of no sun? :oops:

Does it also "learn" your habits... even on a seasonal level? Input types solar, wind, water, etc? Sounds very interesting!
 

svetz

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Are you saying, this thing [Enphase's Storm Guard] allows me to set a narrow range during storage times say between 40% and 60% SOC while I'm gone and it will get info from weather services and decide it needs to store 100% to ride out a few days of no sun?
Turning on Storm Guard just overrides your default SoC setting (not a range, just the maximum). So, if the national weather service (NWS) says to batten down, yes it automatically lets the batteries charge to full in advance of bad weather.

Does it also "learn" your habits... even on a seasonal level?
No, it doesn't learn them (just as well, I don't have any good habits). As I typically only use the LiFePO4s during outages they don't really get cycles on them so at first I left them at 100% all the time. Then I learned about degradation from them always being at 100% charge and decided to manually set the SoC for our seasons. Given Storm Guard, they only need to be full enough such that I can get to a full charge before the bad weather hits. Outages during good weather typically don't last that long so it's no hardship to be at a lower SoC. Also, if the grid's out, it also automatically reverts to 100% SoC, so if it was a long duration outage (days), the panels would still charge the batteries to full without me needing to lift a finger.

I don't think it would be hard to program an NWS scanning program to adjust the SoC on the fly. I've done similar things in a companion program to figure out if I need to clean my panels.

Input types solar, wind, water, etc?
Just solar on my system.
 

Inq720

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Turning on Storm Guard just overrides your default SoC setting (not a range, just the maximum). So, if the national weather service (NWS) says to batten down, yes it automatically lets the batteries charge to full in advance of bad weather.


No, it doesn't learn them (just as well, I don't have any good habits). As I typically only use the LiFePO4s during outages they don't really get cycles on them so at first I left them at 100% all the time. Then I learned about degradation from them always being at 100% charge and decided to manually set the SoC for our seasons. Given Storm Guard, they only need to be full enough such that I can get to a full charge before the bad weather hits. Outages during good weather typically don't last that long so it's no hardship to be at a lower SoC. Also, if the grid's out, it also automatically reverts to 100% SoC, so if it was a long duration outage (days), the panels would still charge the batteries to full without me needing to lift a finger.

I don't think it would be hard to program an NWS scanning program to adjust the SoC on the fly. I've done similar things in a companion program to figure out if I need to clean my panels.


Just solar on my system.

OMG! You just opened a brain storm.

My cells (when they finally get here) and I have an Overkill BMS waiting... I read it has a programming API via Arduino... I could easily do what you're suggesting with fairly trivial programming on a ESP8266 device. As you pointed out above... could also do a counter of micro-cycles and do a clearing, full-charge every so often to wipe out any memory effect!

Oh! This could be fun!
 
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