Re: [RE-wrenches] Enphase excess solar for IQ system controller

[Jason Szumlanski via RE-wrenches]

With IQ8 series microinverters, there is an absolute limit of 64A connected
to the IQ Combiner input lugs of the System Controller. The DER port is not
for PV. It is for batteries that exceed the limits of the storage port. You
can have up to (8) 5P on the Storage lugs and (8) on the DER lugs. But
these will be power limited to the output of (4) 5P batteries per input. In
other words, this is a way to connect 80kWh of capacity to the system, but
you will only have 128A of power output even though the (16) batteries are
capable of 256A. Anyway, 64A is the PV limit for backup systems, and there
is no way around it with IQ8.

You CANNOT connect any additional IQ8 microinverters on the load side of
the System Controller when there is backup involved. All IQ8 must be
connected to the IQ Combiner lugs on the System Controller. The relay in
the system controller must be able to turn off the IQ8 micros. This relay
also disconnects the rooftop micros when the RSD switch is turned off.

The additional microinverters can be connected to the line side of the
System Controller (as a feeder tap or anywhere upstream of the System
Controller that complies with code). You do need a separate IQ Gateway,
because these microinverters need to be configured for grid-tie only. All
microinverters connected to the same Gateway must have the same mode. The
micros connected to the backup system will be set up as multi-mode.

Don't bother with a line filter unless it becomes truly necessary. There
are things that Enphase can do on its end to reduce the crosstalk by
establishing separate domains. They SAY you need a line filter, but this is
rarely the case. Don't listen to anything that Tier 1 customer service
tells you regarding powerline communications. That's their go-to response
when they can't figure something out.

As for the Sunlight Backup system, I don't have a single client that is
satisfied with this setup. It really needs at least one IQ Battery 5P to be
functional, in which case you can forget about the ridiculous limitations
of 8 x 120V or 4 x 240V circuits and the rigmarole of two load controllers
that Sunlight Backup requires, especially with that much PV. I would avoid
Sunlight Backup at all costs. It's not useful for anything but the smallest
loads during the best conditions

As for your crosstalk issues, here is what I would do. Have customer
service retire one of the IQ Gateways and all associated microinverters.
Provision the other IQ Gateway and get those microinverters working. Then
turn OFF power to the working Gateway and microinverters. Turn ON power to
the other Gateway and microinverters and have customer service unretire
everything. Reprovision using ITK. Once everything is working on the second
Gateway, turn the first one back on and all microinverters, and you will
probably be up and running without further issues.


I was really disappointed with the discontinuation of the IQ7 because of
this 64A hard limit of PV on a backup system. With IQ7 you could have 96A
of PV with the previous generation battery. The IQ8 was a step backward for
large backup systems. I provided this feedback to Enphase, and they were
working on a possible workaround to make something work, but I would not
hold your breath. I even wrote this article when the issue first came to
light:

https://floridasolardesigngroup.com/enphase-iq7-versus-iq8-microinverters/


Jason Szumlanski
Principal Solar Designer | Florida Solar Design Group
NABCEP Certified Solar Professional (PVIP)
Florida State Certified Solar Contractor CVC56956
Florida Certified Electrical Contractor EC13013208


On Wed, Sep 25, 2024 at 3:02 PM Dave Tedeyan via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> Hi all,
>
> All this talk about Enphase recently and I have a design question that I
> am having trouble getting a straightforward answer to. The IQ system
> controller can take up to 64A of PV AC output on the DER port (coming from
> the IQ combiner for example). When there is more solar on site, the
> question is what do you need to do with the rest of the solar.
>
> They have a system planning guide that talks about some of this and you
> can find it here:
> https://enphase.com/download/planning-enphase-energy-system-tech-brief
>
> Page 59 bullet point 6 says that with IQ8 micros, the excess PV must be
> split into a grid-tied system. I recently did this, got a separate IQ
> gateway, and a power line filter, and the system continues to have cross
> talk issues between the two gateways, and the microinverters will just not
> report properly no matter how many times tech support re-provisions the
> devices and prevents each gateway from looking for more devices.
>
> Then I noticed that with M series micros (page 62 bullet point 9) it says
> that microinverters exceeding 64A can be added to the main panel. In this
> scenario, there will be more than 64A of solar flowing through the IQ
> system controller, even though the DER port is limited to 64A. I would

Re: [RE-wrenches] favortie micro inverters?

[August Goers via RE-wrenches]

I've noticed that the Enphase compatibility calculator needs some work - it
called out microinverters as being compatible when clearly the operating
voltages or currents were outside of the ranges listed on the spec sheet.
Need to double check all of the voltage and currents at both high and low
ranges with the appropriate temperature corrections applied to make sure
they work! And, good point about modules losing a bit of max current and
voltage as they age.

August


On Wed, Sep 25, 2024 at 8:43 AM Jesse Dahl via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> I like enphase too. I live in northern MN and we see cold temps of -40 F
> in the winter and they hold up.
>
> Sent from my iPhone
>
> On Sep 23, 2024, at 10:09 PM, david quattro via RE-wrenches <
> re-wrenches@lists.re-wrenches.org> wrote:
>
> 
> I used Chilicon on a couple installs, and Enphase is far better.
>
>
>
>
>
> On Mon, Sep 23, 2024 at 9:05 PM greg egan via RE-wrenches <
> re-wrenches@lists.re-wrenches.org> wrote:
>
>> Good intel.  I believe their micros are rated to -40C/F.  If they quit
>> working at that temp it would be okay as long as they start back up when
>> if warms up.  Normally when it's that cold the sun is pretty scarce at
>> this latitude.
>>
>> Greg Egan
>> Remote Power Inc.
>> Fairbanks, AK
>>
>> On 9/23/2024 7:47 PM, MDElectricSolar wrote:
>> > Been around forever, good tech support, the products have been improved
>> and refined, easy to install, good monitoring platform. Not sure how they
>> would fare in Alaskan winters though…
>> >
>> > Maybe an sma installed indoors?
>> >
>> > Michael D Nelson
>> > MD Electric & Solar, Inc.
>> > 707-684-0064 mobile
>> > 707-884-1862 office
>> > www.mdelectricsolar.com
>> > www.facebook.com/mdelectricandsolar
>> >
>> >
>> >> On Sep 23, 2024, at 8:41 PM, greg egan 
>> wrote:
>> >>
>> >> Michael, thank you.  Any particular reason you like them best?
>> >>
>> >>
>> >> Greg Egan
>> >> Remote Power Inc.
>> >> Fairbanks, AK
>> >>
>> >>> On 9/23/2024 7:29 PM, MDElectricSolar wrote:
>> >>> Enphase…
>> >>>
>> >>> Michael D Nelson
>> >>> MD Electric & Solar, Inc.
>> >>> 707-684-0064 mobile
>> >>> 707-884-1862 office
>> >>> www.mdelectricsolar.com
>> >>> www.facebook.com/mdelectricandsolar
>> >>>
>> >>>
>> > On Sep 23, 2024, at 7:30 PM, greg egan via RE-wrenches <
>> re-wrenches@lists.re-wrenches.org> wrote:
>>  Esteemed wrenches,
>> 
>>  Have a client that is grid connected (not my usual client) and
>> looking to do solar without back up.  Has shading issues so I'm thinking
>> micros would work best for this application, plus take care of rapid shut
>> down without needing extra devices/wiring.  Problem is I have not ever
>> installed micros.
>> 
>>  Any recommendations on brands /models that have been reliable?
>> Decent tech support?  Customer just wants something that works and is
>> relatively simple to navigate the online monitoring.  Probably 4-5 kW so
>> not a huge system.
>> 
>>  Thanks in advance, I appreciate it!
>> 
>>  Greg Egan
>>  Remote Power Inc.
>>  Fairbanks, AK
>>  ___
>>  List sponsored by Redwood Alliance
>> 
>>  Pay optional member dues here: http://re-wrenches.org
>> 
>>  List Address: RE-wrenches@lists.re-wrenches.org
>> 
>>  Change listserver email address & settings:
>>  http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>> 
>>  There are two list archives for searching. When one doesn't work,
>> try the other:
>>  https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
>>  http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>> 
>>  List rules & etiquette:
>>  http://www.re-wrenches.org/etiquette.htm
>> 
>>  Check out or update participant bios:
>>  http://www.members.re-wrenches.org
>> 
>>
>> ___
>> List sponsored by Redwood Alliance
>>
>> Pay optional member dues here: http://re-wrenches.org
>>
>> List Address: RE-wrenches@lists.re-wrenches.org
>>
>> Change listserver email address & settings:
>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>
>> There are two list archives for searching. When one doesn't work, try the
>> other:
>> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>>
>> List rules & etiquette:
>> http://www.re-wrenches.org/etiquette.htm
>>
>> Check out or update participant bios:
>> http://www.members.re-wrenches.org
>>
>> ___
> List sponsored by Redwood Alliance
>
> Pay optional member dues here: http://re-wrenches.org
>
> List Address: RE-wrenches@lists.re-wrenches.org
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> There are two list archives for searching. 

Re: [RE-wrenches] favortie micro inverters?

[Jesse Dahl via RE-wrenches]

I like enphase too. I live in northern MN and we see cold temps of -40 F in the winter and they hold up. Sent from my iPhoneOn Sep 23, 2024, at 10:09 PM, david quattro via RE-wrenches  wrote:I used Chilicon on a couple installs, and Enphase is far better.On Mon, Sep 23, 2024 at 9:05 PM greg egan via RE-wrenches  wrote:Good intel.  I believe their micros are rated to -40C/F.  If they quit 
working at that temp it would be okay as long as they start back up when 
if warms up.  Normally when it's that cold the sun is pretty scarce at 
this latitude.

Greg Egan
Remote Power Inc.
Fairbanks, AK

On 9/23/2024 7:47 PM, MDElectricSolar wrote:
> Been around forever, good tech support, the products have been improved and refined, easy to install, good monitoring platform. Not sure how they would fare in Alaskan winters though…
>
> Maybe an sma installed indoors?
>
> Michael D Nelson
> MD Electric & Solar, Inc.
> 707-684-0064 mobile
> 707-884-1862 office
> www.mdelectricsolar.com
> www.facebook.com/mdelectricandsolar
>
>
>> On Sep 23, 2024, at 8:41 PM, greg egan  wrote:
>>
>> Michael, thank you.  Any particular reason you like them best?
>>
>>
>> Greg Egan
>> Remote Power Inc.
>> Fairbanks, AK
>>
>>> On 9/23/2024 7:29 PM, MDElectricSolar wrote:
>>> Enphase…
>>>
>>> Michael D Nelson
>>> MD Electric & Solar, Inc.
>>> 707-684-0064 mobile
>>> 707-884-1862 office
>>> www.mdelectricsolar.com
>>> www.facebook.com/mdelectricandsolar
>>>
>>>
> On Sep 23, 2024, at 7:30 PM, greg egan via RE-wrenches  wrote:
 Esteemed wrenches,

 Have a client that is grid connected (not my usual client) and looking to do solar without back up.  Has shading issues so I'm thinking micros would work best for this application, plus take care of rapid shut down without needing extra devices/wiring.  Problem is I have not ever installed micros.

 Any recommendations on brands /models that have been reliable? Decent tech support?  Customer just wants something that works and is relatively simple to navigate the online monitoring.  Probably 4-5 kW so not a huge system.

 Thanks in advance, I appreciate it!

 Greg Egan
 Remote Power Inc.
 Fairbanks, AK
 ___
 List sponsored by Redwood Alliance

 Pay optional member dues here: http://re-wrenches.org

 List Address: RE-wrenches@lists.re-wrenches.org

 Change listserver email address & settings:
 http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

 There are two list archives for searching. When one doesn't work, try the other:
 https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
 http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

 List rules & etiquette:
 http://www.re-wrenches.org/etiquette.htm

 Check out or update participant bios:
 http://www.members.re-wrenches.org


___
List sponsored by Redwood Alliance

Pay optional member dues here: http://re-wrenches.org

List Address: RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

There are two list archives for searching. When one doesn't work, try the other:
https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
http://www.members.re-wrenches.org


___List sponsored by Redwood AlliancePay optional member dues here: http://re-wrenches.orgList Address: RE-wrenches@lists.re-wrenches.orgChange listserver email address & settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.orgThere are two list archives for searching. When one doesn't work, try the other:https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.orgList rules & etiquette:http://www.re-wrenches.org/etiquette.htmCheck out or update participant bios:http://www.members.re-wrenches.org___
List sponsored by Redwood Alliance

Pay optional member dues here: http://re-wrenches.org

List Address: RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

There are two list archives for searching. When one doesn't work, try the other:
https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
http://www.members.re-wrenches.org

Re: [RE-wrenches] favortie micro inverters?

[jay via RE-wrenches]

The enphase MPPT voltage range seems low to me.

I reviewed a few of the newer string inverters and they are between 90-200v and 
500+
A range of about 2.5 -5.5.

Enphase is around 1.8X

AP systems is about exactly the same as Enphase. 

Hoymiles a newer company that now has full range of products is 16-60v MPPT 
range on its micro, 3.75X

Always lots to consider even with a micro.

Jay



> On Sep 25, 2024, at 7:29 AM, jay  wrote:
> 
> Hi Vince,
> 
> Your math looks correct of course, but I think you left out a variable in 
> that the panel won’t be operating at max power because the inverters are all 
> less than 400 watts rated. 
> Which means that the MPPT voltage will be pushed up to reduce power giving 
> you added room.  
> 
> From my understanding of how the Mppt works, but I don’t know specifically 
> about enphase, if its a good algorithm the inverter won’t go below its lowest 
> MPPT voltage.  
> The inverter will reduce power playing around with the IV curve to maintain 
> the MPPT within its range.  So it won’t ever get out of operating unless it 
> can’t even produce enough volts to make that voltage.  I’ve never seen a 
> curve of Enphase MPPT efficiency vs input voltage.  Would like to though. 
> 
> 
> 
> Jay
> 
> 
> 
> 
> 
>> On Sep 24, 2024, at 8:38 PM, Vince McClellan via RE-wrenches 
>> > > wrote:
>> 
>> Hello Wrenches List
>> I've recently become aware of an issue with micro-inverters that I would 
>> like to share. 
>> Be sure the solar module you're using is compatible with the microinverter 
>> for the solar module's full life. 
>> A good best practice is to design for the MPPT voltage range of the 
>> inverter. I only consider the operating range of the inverter when it won't 
>> affect the inverter during its operational time, such as when the solar 
>> module is at its coldest in the first few moments of sunlight when it hits 
>> max Voc. That will only happen for a few moments as the sun heats the solar 
>> module. High heat is different. If the solar module falls below the MPPT 
>> voltage window that will happen in the middle of the day when the solar 
>> array should be producing its maximum power for the day. If the voltage of 
>> the solar module falls below the MPPT voltage window during that time it 
>> becomes much less efficient at tracking the power or simply turns off. Some 
>> studies have shown a solar module degradation rate averaging up to 
>> 1.4%/year. 
>> 
>> Here is an example of what I'm talking about with weather data for Eugene OR 
>> and a roof-mounted Phono PS400M6H-18/VHB solar module. 
>> Vmp 30.85
>> Coe/°C = -0.28%
>> High-Temperature voltage calculation: 30.85 Vmp X [ 1-(32+30-25) X .0028] = 
>> 27.65 Vmp adjusted for 2% average high temp of 32°C
>> Here is my Enphase cheat sheet for quickly looking at design compatibility.  
>> Enphase M#   Operating Range MPPT Voltage Range  Commonly used module 
>> pairings   Phase
>> IQ8MC-72-M-US18-58 V 25-45 V 260-460 Wstc1
>> IQ8-60-M-US  16-48 V 27-37 V 235-350 Wstc1
>> IQ8PLUS-72-M-US  16-58 V 27-45 V 235-440 Wstc1
>> IQ8H-3P-72-E-US  16-63 V 28.5-45 V   320-540 Wstc3
>> IQ8M-72-US   16-58 V 30-45 V 260-460 Wstc1
>> IQ8A-M-US16-58 V 32-45 V 295-500 Wstc1
>> IQ8A-72-M-US 16-58 V 32-45 V 295-500 Wstc1
>> IQ8P-3P-72-E-US  16-63 V 35.5-53 V   380-640 Wstc3
>> IQ8H-208-72-M-US 16-58 V 36-45 V 295-500 Wstc1
>> IQ8X-80-M-US 25-79.5 V   43-60 V 320-540 Wstc1
>> So I'm good with three of the inverters on my list right? Not really. As the 
>> solar cells age the degradation of the cell drops the cells voltage. A good 
>> design practice is to drop the adjusted Vmp down 10% to make up for cell 
>> degradation.  So, 27.65 Adjusted Vmp - 10% would be 24.88Vmp. I would still 
>> feel comfortable using one of the inverters on my list. 
>> If I go to the Enphase compatibility calculator 
>>  it shows seven 
>> inverters that are compatible with the Phono PS400M6H-18/VHB solar module 
>> for my climate. 
>> 
>> Other than that issue, we try to use micro inverters only when they are 
>> reasonably easy to get to because we know we will be back at some point to 
>> replace inverters. 
>> Electronic components fail mostly based on temperature fluctuations over 
>> time. The area behind a solar array is both the hottest and coldest location 
>> at the installation site. I do like micro inverters for many applications 
>> where there are multiple roof angles and or moving shade to deal with on a 
>> client's roof. 
>> 
>> I would love to hear back from others if you think my calculations are way 
>> off. This kind of back and forth is how we grow as installers and I won't 
>> take offense if any of you slam my ideas. 
>> 
>> Thanks to all of you for contributing to our industry, 
>> 
>> Vince McClellan
>> President
>> NABCEP PV Professional
>> p: 54

Re: [RE-wrenches] favortie micro inverters?

[jay via RE-wrenches]

Hi Vince,

Your math looks correct of course, but I think you left out a variable in that 
the panel won’t be operating at max power because the inverters are all less 
than 400 watts rated. 
Which means that the MPPT voltage will be pushed up to reduce power giving you 
added room.  

From my understanding of how the Mppt works, but I don’t know specifically 
about enphase, if its a good algorithm the inverter won’t go below its lowest 
MPPT voltage.  
The inverter will reduce power playing around with the IV curve to maintain the 
MPPT within its range.  So it won’t ever get out of operating unless it can’t 
even produce enough volts to make that voltage.  I’ve never seen a curve of 
Enphase MPPT efficiency vs input voltage.  Would like to though. 



Jay





> On Sep 24, 2024, at 8:38 PM, Vince McClellan via RE-wrenches 
>  wrote:
> 
> Hello Wrenches List
> I've recently become aware of an issue with micro-inverters that I would like 
> to share. 
> Be sure the solar module you're using is compatible with the microinverter 
> for the solar module's full life. 
> A good best practice is to design for the MPPT voltage range of the inverter. 
> I only consider the operating range of the inverter when it won't affect the 
> inverter during its operational time, such as when the solar module is at its 
> coldest in the first few moments of sunlight when it hits max Voc. That will 
> only happen for a few moments as the sun heats the solar module. High heat is 
> different. If the solar module falls below the MPPT voltage window that will 
> happen in the middle of the day when the solar array should be producing its 
> maximum power for the day. If the voltage of the solar module falls below the 
> MPPT voltage window during that time it becomes much less efficient at 
> tracking the power or simply turns off. Some studies have shown a solar 
> module degradation rate averaging up to 1.4%/year. 
> 
> Here is an example of what I'm talking about with weather data for Eugene OR 
> and a roof-mounted Phono PS400M6H-18/VHB solar module. 
> Vmp 30.85
> Coe/°C = -0.28%
> High-Temperature voltage calculation: 30.85 Vmp X [ 1-(32+30-25) X .0028] = 
> 27.65 Vmp adjusted for 2% average high temp of 32°C
> Here is my Enphase cheat sheet for quickly looking at design compatibility.  
> Enphase M#Operating Range MPPT Voltage Range  Commonly used module 
> pairings   Phase
> IQ8MC-72-M-US 18-58 V 25-45 V 260-460 Wstc1
> IQ8-60-M-US   16-48 V 27-37 V 235-350 Wstc1
> IQ8PLUS-72-M-US   16-58 V 27-45 V 235-440 Wstc1
> IQ8H-3P-72-E-US   16-63 V 28.5-45 V   320-540 Wstc3
> IQ8M-72-US16-58 V 30-45 V 260-460 Wstc1
> IQ8A-M-US 16-58 V 32-45 V 295-500 Wstc1
> IQ8A-72-M-US  16-58 V 32-45 V 295-500 Wstc1
> IQ8P-3P-72-E-US   16-63 V 35.5-53 V   380-640 Wstc3
> IQ8H-208-72-M-US  16-58 V 36-45 V 295-500 Wstc1
> IQ8X-80-M-US  25-79.5 V   43-60 V 320-540 Wstc1
> So I'm good with three of the inverters on my list right? Not really. As the 
> solar cells age the degradation of the cell drops the cells voltage. A good 
> design practice is to drop the adjusted Vmp down 10% to make up for cell 
> degradation.  So, 27.65 Adjusted Vmp - 10% would be 24.88Vmp. I would still 
> feel comfortable using one of the inverters on my list. 
> If I go to the Enphase compatibility calculator 
>  it shows seven 
> inverters that are compatible with the Phono PS400M6H-18/VHB solar module for 
> my climate. 
> 
> Other than that issue, we try to use micro inverters only when they are 
> reasonably easy to get to because we know we will be back at some point to 
> replace inverters. 
> Electronic components fail mostly based on temperature fluctuations over 
> time. The area behind a solar array is both the hottest and coldest location 
> at the installation site. I do like micro inverters for many applications 
> where there are multiple roof angles and or moving shade to deal with on a 
> client's roof. 
> 
> I would love to hear back from others if you think my calculations are way 
> off. This kind of back and forth is how we grow as installers and I won't 
> take offense if any of you slam my ideas. 
> 
> Thanks to all of you for contributing to our industry, 
> 
> Vince McClellan
> President
> NABCEP PV Professional
> p: 541-485-8122
> a: 860 Conger St. Suite 12,. Eugene, OR 97402
> e: vi...@solarenergydesgin.com 
> w: SolarEnergyDesign.com
> CCB# 161672
> 
> 
> If you have received this email and are not the intended recipient, please 
> delete this email. Copying or using any part, content, or attachment of this 
> email is strictly prohibited.
> 
> 
> 
> On Tue, Sep 24, 2024 at 1:55 PM Jason Szumlanski via RE-wrenches 
>  > wrote:
> It's very curious how there are geographic preferences, and that is 
> definitely something to conside

[RE-wrenches] Enphase excess solar for IQ system controller

[Dave Tedeyan via RE-wrenches]

Hi all,

All this talk about Enphase recently and I have a design question that I am
having trouble getting a straightforward answer to. The IQ system
controller can take up to 64A of PV AC output on the DER port (coming from
the IQ combiner for example). When there is more solar on site, the
question is what do you need to do with the rest of the solar.

They have a system planning guide that talks about some of this and you can
find it here:
https://enphase.com/download/planning-enphase-energy-system-tech-brief

Page 59 bullet point 6 says that with IQ8 micros, the excess PV must be
split into a grid-tied system. I recently did this, got a separate IQ
gateway, and a power line filter, and the system continues to have cross
talk issues between the two gateways, and the microinverters will just not
report properly no matter how many times tech support re-provisions the
devices and prevents each gateway from looking for more devices.

Then I noticed that with M series micros (page 62 bullet point 9) it says
that microinverters exceeding 64A can be added to the main panel. In this
scenario, there will be more than 64A of solar flowing through the IQ
system controller, even though the DER port is limited to 64A. I would like
to do something similar to this for my system with crosstalk issues and get
rid of the second IQ Gateway.

I asked tech support why there was a difference in the planning document
for IQ8 and for M series and whether I could add the extra IQ8 into the
backed up subpanel (This is a Sunlight backup system). They did not give me
a fully complete answer, but they did say this, "You can add the panels up
to 64A into the system controller and exceeding PV can be connected to the
backup subpanel."

I fear that this was a level 1 tech and that they may not have completely
understood the situation. This is the answer that I wanted, but I am not
sure I trust it yet. Has anyone here tried something similar to this?

Thanks!
-Dave

-- 

[image: Logo] 
Dave Tedeyan, P.E.
Owner | Sungineer Solar
p: he | him | his
a: 1653 Slaterville Rd. | Ithaca, NY 14850
w: www.sungineersolar.com 
c: (607) 270-0370
___
List sponsored by Redwood Alliance

Pay optional member dues here: http://re-wrenches.org

List Address: RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

There are two list archives for searching. When one doesn't work, try the other:
https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
http://www.members.re-wrenches.org