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Enphase Backup Storage - DIY Self-Installer Hurdles

solar8484 said:
It's highly unlikely UL1741SB will resolve Enphase problems that exist with UL1741SA. UL1741SB basically adds communication (for use by POCO's) requirements over UL1741SA.
Click to expand...
Yeah, I was aware of that part (POCO control and visibility, same as with SA’s control improvements). I got interested in SB more when the additional capabilities were mentioned upthread.

Is the interop testing mentioned in the PowerPoint deck I found about testing between POCO and the inverter? It mentioned local communications, which I guess could mean from the smart meter.
 
zanydroid said:
Is the interop testing mentioned in the PowerPoint deck I found about testing between POCO and the inverter? It mentioned local communications, which I guess could mean from the smart meter.
Click to expand...

They only test for utility grid conditions. Unfortunately, even the best consumer grade off-grid or hybrid inverters are significantly weaker than even the weakest utility grid in the US in terms of dynamic stiffness.
 
solar8484 said:
They only test for utility grid conditions. Unfortunately, even the best consumer grade off-grid or hybrid inverters are significantly weaker than even the weakest utility grid in the US in terms of dynamic stiffness.
Click to expand...
Yeah, that is for basic anti islanding. I was referring to the three DER protocols that SB smart inverters are supposed to speak. And how many of those APIs are local and accessible for use by users. Just as frequency/watts was for POCO but the proletariat appropriated the means for themselves.

Theoretically you should be able to grant yourself access. If you have proper ownership rights of your own equipment. Ofc that is dicey in this day and age.
 
zanydroid said:
Yeah, that is for basic anti islanding. I was referring to the three DER protocols that SB smart inverters are supposed to speak. And how many of those APIs are local and accessible for use by users. Just as frequency/watts was for POCO but the proletariat appropriated the means for themselves.

Theoretically you should be able to grant yourself access. If you have proper ownership rights of your own equipment. Ofc that is dicey in this day and age.
Click to expand...

For Enphase, owners are unlikely to ever get access to the SB protocol comms or related control functions. There needs to be more competition in the market.
 
zanydroid said:
Yeah, that is for basic anti islanding. I was referring to the three DER protocols that SB smart inverters are supposed to speak.
Click to expand...

The equipment approved for later installations is supposed to support more features including communication. But no requirement yet that it be connected. Know if there is a plan to force networking of systems that were deployed without Ethernet or whatever connected?

The TriPower I was going to use (with a 3-phase converter) was rejected for not having the required Phase II Communications and Phase III Functions. So I'm going to use a current model Sunny Boy which does.

But I'm wondering if they will get their fingers into my business beyond Frequency-Watts (which doesn't hurt me much, and I can always operate offline.)

TriPower no Phase II Comms Phase III functions.jpg
 
Hedges said:
The equipment approved for later installations is supposed to support more features including communication. But no requirement yet that it be connected. Know if there is a plan to force networking of systems that were deployed without Ethernet or whatever connected?
Click to expand...
No clue. I saw April 1 as the start date for a new level of inverter requirements in california on a random website.

I would guess they want it to talk to the local wireless protocol on the smart meter. Zigbee? The smart meters are usually equipped with futureproof hardware platform in case utilities want to or allowed to get more into your stuff.

TBH I’m a little skeptical of user oriented functions being part of the required functionality here. HECO and CEC don’t really have a mandate or priority to impose that, vs imposing things to help grid and utility. I found an early PG&E document for 2030.5 <-> Rule21 that actually said the scope was focused on utility to DER and not other stuff.

I would appreciate specific reference to the required profiles and access for users.
 
All I know are the column headings from spreadsheet on CEC's website, highlighted in snapshot above when PG&E rejected my inverter.
(Things like frequency-watts and volts-watts are clear, and volts-var I vaguely understand)

Interconnection applications received starting 6/22/2020 are required to use Smart Inverters that have Phase II Communications, and Phase III - Function 1, 2, 3 & 8 solar smart inverters on their “Solar Equipment Lists” website, as indicated with a “Y” or “N” in the column labeled “UL 1741 SA Disable Permit Service Limit Active Power SA17-SA18”, “Common Smart Inverter Profile Conformance CSIP” and “Monitor Key Data Scheduling Attestation” on their “Grid Support Inverter Lists”

Solar Equipment List - CA Energy Commission

solarequipment.energy.ca.gov solarequipment.energy.ca.gov


Download Excel file
 
Interesting list and interesting snapshot why the specific Tripower SMA inverter was rejected. There are inverters that are SB compliant but do not support SA. Are they acceptable? All Y's in the compliance columns would be a safe bet for an inverter and a Y in the battery column would be best.

Compliance testing is targeted for utilities to control DER equipment. Interoperability using open standards falls into the scope of SunSpec. There are additional regional organizations and efforts to promote interoperability, like EEBus and SEMP.
 
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I thought I read that all SB comply with SA.

Probably some or all of the "Y" my TriPower had were required, and they highlighted the "N" that needed to be "Y"

I pasted heading and two TriPower lines together (I think some columns to right are misaligned.)
Left 10 columns detail different features between my STP 30000TL-US-10 and later model
STP 33-US-41

Manufacturer NameModel Number1Hybrid Inverter2UL 1741 Supplement SB CertificationUL 1741 Supplement SA TestingUL 1741 SA13 Volt-VarUL 1741 SA
Freq-Watt
Volt-Watt		UL 1741 SA
Disable Permit Service
Limit Active Power		Common Smart Inverter Profile ConformanceMonitor Key Data
Scheduling		DescriptionMaximum Continuous Output Power at Unity Power FactorNominal VoltageWeighted Efficiency
UL 1741 (3rd Ed.) Supplement SB
Certification​
UL 1741 Supplement SA
Certification (SA8-SA13)5​
UL 1741 SA13 Volt-VarUL 1741 SA
Freq-Watt
Volt-Watt		UL 1741 SA
Disable Permit Service
Limit Active Power
Inverter CSIP Conformance6​
Monitor Key Data
Scheduling
Attestation		NotesBuilt-In MeterMicroinverterNight Tare LossPower Rating, Continuous, 40 deg CNight
Tare Loss, 40 deg C		Voltage MinimumVoltage NominalVoltage MaximumPower LevelPower LevelPower LevelPower LevelPower LevelPower LevelEfficiency @Vmin,Efficiency @Vmin,Efficiency @Vmin,Efficiency @Vmin,Efficiency @Vmin,Efficiency @Vmin,Efficiency @Vmin,Efficiency @VnomEfficiency @VnomEfficiency @VnomEfficiency @VnomEfficiency @VnomEfficiency @VnomEfficiency @VnomEfficiency @vmaxEfficiency @vmaxEfficiency @vmaxEfficiency @vmaxEfficiency @vmaxEfficiency @vmaxEfficiency @vmaxGrid Support Listing DateLast Update
PV and Battery3rd EditionSA8-SA13RPP3SA14-SA15SA17-SA18CSIP4Attestation(kW)(Vac)(%)Certifying EntityCertificate Date [mo/day/yr]Certifying EntityCertificate Date [mo/day/yr]Firmware Version(s) TestedListing Date (mo/day/yr)Certificate Date [mo/day/yr]Listing Date (mo/day/yr)Issuing EntityDocument Date (mo/day/yr)Listing Date(W)(kW)(W)(Vdc)(Vdc)(Vdc)10% (kW)20% (kW)30% (kW)50% (kW)75% (kW)100% (kW)10% Pwr Lvl (%)20% Pwr Lvl (%)30% Pwr Lvl (%)50% Pwr Lvl (%)75% Pwr Lvl (%)100% Pwr Lvl (%)Wtd (%)10% Pwr Lvl (%)20% Pwr Lvl (%)30% Pwr Lvl (%)50% Pwr Lvl (%)75% Pwr Lvl (%)100% Pwr Lvl (%)Wtd (%)10% Pwr Lvl (%)20% Pwr Lvl (%)30% Pwr Lvl (%)50% Pwr Lvl (%)75% Pwr Lvl (%)100% Pwr Lvl (%)Wtd (%)
SMA AmericaSTP30000TL-US-10 [480V]NNYYYNNNSunny Tripower TL-US 30 kW, 480Vac, 3-phase, Transformerless Grid Support Utility Interactive Inverter3048098No Information SubmittedNo Information SubmittedUL[7/6/2017][2.03.04.R]10/15/18[7/6/2017]No Information SubmittedNo Information SubmittedNo Information SubmittedNo Information SubmittedYN1.225007208003.0016.0029.00315.00522.507530.0196.58897.71697.92697.9897.83897.62297.8114897.58898.44898.6998.60298.53898.32898.5166897.02698.0698.45298.38698.28298.0898.25288/1/2018########
SMA AmericaSTP 33-US-41 [480V]NYYYYYY*Y33.3 kW, 480 Vac, 3-phase, transformerless, Grid Support Utility Interactive Inverter33.348097.5UL[11/08/2018]UL[11/08/2018][01.09.03.R]12/17/18[11/08/2018]1/13/2020UL12/16/20191/13/2020NN5.433306838003.336.669.9916.6524.97533.394.25996.33796.70596.64496.4696.00396.41194.70796.75597.30397.64797.69497.71997.4720395.73197.62698.04498.22998.11997.98898.0063812/17/2018########
 
hedges: Great detail! Clearly shows what was required to get approved.

UL 1741 SB certification includes UL 1741 SA. I think the SB column is there to highlight support for the SB additions or supplements.
The column header says SB Supplements, not SB compliance, wasn't clear when I first saw the spreadsheet.
 
I wonder what that April Fools Day adoption by California means for my NEM 2.0 application with PG&E.
Does it matter whether I get it through by April 14th, or by March 31st?

The 30kW TriPower I was going to use had "N" in this column, while newer model 33kW had "Y"
It looks like the single phase Sunny Boy still has "N"

That is just SB; does that mean something beyond the individual features of other columns?

"Inverter manufacturers choose which Supplement (SA or SB) to certify their equipment to as they deem appropriate and as the market requires. The intention of the Supplement SB revision document is to result in a common understanding and application of the new requirements to maximize consistency in DER response to grid events."

"Market" meaning adopted regulations, not purchasers?

SMA AmericaSB7.7-1SP-US-40 [240V]NNYYYNNN7.7 kW, 240 Vac transformerless Grid Support Utility Interactive Inverter
SMA AmericaSB7.7-1TP-US-40 [240V]NNYYYNNN7.7 kW, 240 Vac transformerless Grid Support Utility Interactive Inverter with revenue grade energy meter
 
UL 1741 SB is ok where UL 1741 SA is required, but if UL 1741 SB is required you need a "Y" in the SB Supplement column.
SB covers direct power controls via one of 3 options, see post #56

IEEE 1815 DNP3
IEEE 2030.5
SunSpec Modbus

Just received a Hoymiles HMS-2000 microinverter with UL 1741 SB certification and ModBus support.
Will try ModBus power control over the weekend!

ModBus has been around for years to perform power control, see WattNode

https://ctlsys.com/wp-content/uploads/2016/10/WattNode-Modbus-Brochure.pdf

WattNode is popular to implement export control with inverters like Schneider XW's and others.

Or you can look at CHINT. I have been using CHINT DIN mounted controls for a few years!
They also have a great selection of inverters plus 500kW utility-grade inverters:

https://chintglobal.com/categories/grid-tied-pv-inverter-7-1198
 
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Hedges said:
I wonder what that April Fools Day adoption by California means for my NEM 2.0 application with PG&E.
Does it matter whether I get it through by April 14th, or by March 31st?

The 30kW TriPower I was going to use had "N" in this column, while newer model 33kW had "Y"
It looks like the single phase Sunny Boy still has "N
Click to expand...

Oh, that was the -40; -41 has "Y" for those features. But "N" for Supplement SB

Manufacturer NameModel Number1Hybrid Inverter2UL 1741 Supplement SB CertificationUL 1741 Supplement SA TestingUL 1741 SA13 Volt-VarUL 1741 SA
Freq-Watt
Volt-Watt		UL 1741 SA
Disable Permit Service
Limit Active Power		Common Smart Inverter Profile ConformanceMonitor Key Data
Scheduling
PV and Battery3rd EditionSA8-SA13RPP3SA14-SA15SA17-SA18CSIP4Attestation
SMA AmericaSB7.7-1SP-US-41 [208V]NNYYYYY*Y
SMA AmericaSB7.7-1TP-US-41 [208V]NNYYYYY*Y
 
zanydroid said:
Do we know how widespread cross-vendor AC coupling actually is?

Given the risk of damage when the GT inverters overproduce before curtailment kicks in, I kind of wonder if vendors will stop wanting to support it. Or, perhaps the design rules that they give out (kW-AC coupled vs kW-inverter and kWh battery) are enough to cover their butts.

It would be great if 1741SA has something about safety during AC coupling (maybe it does, I presume it doesn't b/c it's primarily a smart inverter standard for protecting the grid, but I'm not about to read a few hundred pages of UL spec on the web) to help with this. I'm not sure how much we can trust UL to get into the business of making sure inverters interoperate with each other. That feels more like a SunSpec thing (as alluded to about 10 posts ago)

Ideally maybe there would be a standard PLC way of setting GT inverters into an off grid profile that is easier to handle. Instead of only proprietary standards for this.
Click to expand...
I mean enphase has $$$ reasons not to support it.
 
I can report back now that we have great weather to test.

Setup:
Outback Skybox with 4.6kw of DC solar
7.5kw of AC coupled solar on the critical loads side using Enphase IQ7+ with profile CA Rule21 201902 VV VW FW

Conditions:
300ah battery was fully charged
2.7kw of power from DC array
3.8kw of power from AC coupled array (~16A)
Selling 5kw of power to the Grid
DC + AC power - 5kW = house consumption
60.0Hz as measured with a fluke meter

Test:
Fluke meter measuring the AC Frequency at the Load out breaker
AC power out from Enphase combiner using clamp meter
Turn off grid input to Skybox

Result:
Lights flickered briefly
Envoy did not go offline
AC current from Enphase combiner measured 2.6A (624W)
DC solar array reported 1.7kW
Battery was charging 1.4kW
AC Frequency measured 60.67Hz

I would call this a success but i didn't have time to start turning on different loads and checking that the AC frequency would go up and down. I feel better knowing that the Enphase IQ7 micros will continue to provide the power i need during blackout or rolling power outages that we sometimes have during the summer.
 
ImAnIdiotPleaseBePatient said:
I mean enphase has $$$ reasons not to support it.
Click to expand...
If you are talking about AC coupling, Enphase does not have a choice. AC coupling from the perspective of the grid following inverter is driven by the response dictated by CA Ule 21 And UL1741SA. My experience is it is the grid forming inverter that that usually has the issues.
 
Ampster said:
If you are talking about AC coupling, Enphase does not have a choice. AC coupling from the perspective of the grid following inverter is driven by the response dictated by CA Ule 21 And UL1741SA. My experience is it is the grid forming inverter that that usually has the issues.
Click to expand...
Oh you may be totally correct. Was just pointing out that enphase has some incentive to get you to pay megabucks for their backup solution instead of working out how to work with other company's systems.
They also have a different incentive to work well with other companies, because customers like that kinda stuff. I am sure their higher ups decide which incentive makes them more money :)
 
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