Enphase IQ8 - islanding

So per Enphase, the IQ8 inverters will intentionally island and allow homeowners to power some devices when the power goes out.

My question is - where does the grid isolation take place?  Obviously they're not going to get any approvals if they backfeed the grid during an outage, which means there has to be a disconnecting/sensing means that implements UL1741.  What is it?  It is a breaker they remotely trip somehow?  A relay box in series with that line?  Something on the line side of the meter?

Comments

  • PhotowhitPhotowhit Solar Expert Posts: 4,879 ✭✭✭✭
    I've been wondering the same thing. The demonstration at the show said it was seamless, Since it's on it's own breaker, somehow it has to have something in line that senses a grid shutdown and turns off the grid feed while allowing the instant transfer to the array. I can see a transfer switch like this, the trick being that the individual inverters are designed to shut down if they don't sense the grid and it's suppose to be backward compatible back to IQ6...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,422 ✭✭✭✭✭
    edited November 2018 #3
    Look up Curtailment! Forget transfer switches and think frequency shift or AC coupling. This is not new or, it is new for Enphase :)

    I did not see any demo so I am just winging it. The thought of solar panels on a roof is bad enough for me. Installing electronics up there is even worse.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • SolarKingsSolarKings Registered Users Posts: 1
    Dave, having MLPE on the roof is the DG way (described by Sunnova's John Berger).  Low-voltage DC conversion using microinverters is the safest, most reliable way, and offers the highest longevity @ 25 years.  High-voltage string inverters are dinosaurs, non-PID free, prone to DC arc faults as system ages, etc.  Enphase's IQ8 microgrid codenamed "Ensemble" will be accompanied with an Automatic Transfer Switch as described in their Analyst Day 2018 presentation (http://files.shareholder.com/downloads/AMDA-H4G6H/6350916243x0x983454/F9801B72-AC2F-45BB-BDEE-20623B222E37/AnalystDay-_Final.pdf) (see p.42).  Also read Sun on Run's CEO Jim Jenal's "mind blowing" report on an actual demonstration of the solution in action around the time of Enphase's annual shareholder meeting this past May.   (https://runonsun.com/~runons5/blogs/blog1.php/residential-solar/what-i-saw-at-enphase-mind-blown)


  • Dave AngeliniDave Angelini Solar Expert Posts: 4,422 ✭✭✭✭✭
    You are free (just as I do not based on decades of experience) to believe that electronics up on a roof is going to help longevity of electronics.  I have seen alot of my installation wrench buds give up microinverters after a brief romance. Much easier to replace a string inverter and much more comfortable surroundings. 

    Most of the failures are Enphase. Maybe they will get better,  I really could care less but good luck !
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • clockmanfranclockmanfran Registered Users Posts: 44 ✭✭
    edited November 2018 #6

    On a RE forum in Australia a few folk have been developing the small stand alone Inverter that can feed the loads direct without the needs for a battery back up to start things rolling.

    'Warpseed' is a retired toroid engineer and has some working examples now that match output to load, without using a toroid....... see .... https://www.thebackshed.com/forum/forum_posts.asp?TID=10432&PN=3  ....

    However there are load limitations when you start getting into Power Electronics.  

    Regards AC coupling yes its the way forward for many reasons the biggest being saving on costs. But upping the frequency to control GTI's when AC Coupled can cause irreparable damage to domestic appliances if the frequency shifting is not controlled properly, especially when you may have DC coupling and other charging sources present.    Here, At this time, we are constantly matching PV, Wind Turbine, etc,  Input to Load Output required, without using the batteries but back charging the batteries depending on what they require.

    We here use PWM control of the PV array before it goes to the GTI, or simple but fast voltage comparators with appropriate hysteresis if using a multitude of AC coupled GTI's. 

    I now find that many Soar and Inverter machines manufactures seem to have got wickedly complicated with the electronics and this limits the life of the machine when particular components fail. Sad to say there is allot of fake component's out there and overrated tech specs on even the humble capacitor.

    Me I am all in favour of keeping it simple, make it Robust, and importantly keep it cost effective.

    Is Enphase really doing something new, ?  its possible.  Is the price good, ? quality good,?  support good, ? ....  time will tell, we will see when the product goes to market.


     

    Everything is possible, just give me Time.

    The OzInverter man. Normandy France.

    3off Hugh P's 3.7m dia wind turbines, (10 years running).  ... 5kW PV on 3 Trackers, (5 years) .... 9kW PV AC coupled using Used/second hand GTI's, on my OzInverter created Grid, and back charging with the AC Coupling and OzInverter to my 48v 1300ah batteries. 

  • Dave AngeliniDave Angelini Solar Expert Posts: 4,422 ✭✭✭✭✭
    SMA inverters have been using their 'secure power" as a way to power 1500 watt loads in an outage from their TL series and up grid inverters for 7 or so years in North America. Nothing new here, maybe in France it is different?

    Enphase is doing this because it is cheap, easy to install, gives module data, and sounds good to marketing folks.

    Reliability is a warranty thing that they have been dealing with since this started. Most grid people do not care about this, yet.
    Most installers want up front money to troubleshoot and repair devices up on a roof. This has been a problem in a few cases that I know of.

    Enphase & others have been doing this for quite some time and the support has been questionable from what I hear from my compatriots.

    Nice once again to be offgrid and not have to think about doing something like this, ever!   ;)


    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • PhotowhitPhotowhit Solar Expert Posts: 4,879 ✭✭✭✭
    SMA inverters have been using their 'secure power" as a way to power 1500 watt loads in an outage from their TL series and up grid inverters for 7 or so years in North America. Nothing new here, maybe in France it is different?
    I don't think the SMA system is seamless, I think someone actually has to be there to throw a transfer switch. I guess this could be automated in some manner? and at some level, but I see there would be great interest from people needing to flee an area could count on their freezers and fridges to have power during afternoons. That would be enough to maintain safe temps for foods. A sizeable array could also provide afternoon cooling running a window air after a hurricane took out power. 

    I think others are seeing a big potential here as well. As the first quarter approaches, there stock has been on an upswing during the current instability.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,422 ✭✭✭✭✭
    My Brother has an SMA  TL and whatever is plugged into that outlet will get up to 1500 watts while the sun is shining. It wont start a normal refrigerator. It does start his LG inverter fridge. He does have to plug it in as the secure outlet only gets power in an outage.

    I know a few people at the Petaluma office of Enphase. One wrote and said the prototype does need a subpanel to power while the grid is disconnected. He would not say how it will do with a surge or what percentage of the solar will translate into useable AC power. The first quarter of next year is the target. 

    It sounds like a good idea until the sun goes down ;)

    They are planning to sell a 10kwh battery for it.......

    I still do not like the idea of more thermal cycling of electronics used in a high reliability application like offgrid.
    For the Grid folks why not, it is good for business. :)
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • PhotowhitPhotowhit Solar Expert Posts: 4,879 ✭✭✭✭
    I still do not like the idea of more thermal cycling of electronics used in a high reliability application like offgrid.
    For the Grid folks why not, it is good for business. :)
    I'm not a fan either, Brother has had 2 failures of Enphase 215(?) on his roof in about 8 years of service.

    I'm off grid an ground mounted array, So when I got caught in Florida for 7 weeks last Christmas... I came home in the middle of the night, grabbed a Marie Callender Pot Pie out of the freezer and popped it in the microwave. I'd just like our grid tied brethren to be able to do the same if they have to bug out... 

    I understand Enphase does batteries in Australia(?).
    My Brother has an SMA  TL and whatever is plugged into that outlet will get up to 1500 watts while the sun is shining. It wont start a normal refrigerator. 
    I can again see the use of a small/tiny Lithium battery pack just for those starting issues. I'm sure it could be worked out easily, much like starting capacitors...

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,422 ✭✭✭✭✭
    edited November 2018 #11
    My supplier has had them here for over a year. Pretty wimpy but it might heat a Pie :)


    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • littleharbor2littleharbor2 Solar Expert Posts: 1,287 ✭✭✭✭
    My supplier has had them here for over a year. Pretty wimpy but it might heat a Pie :)

    As opposed to baking it?

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • Dave AngeliniDave Angelini Solar Expert Posts: 4,422 ✭✭✭✭✭
    I would bake it during the day. At night, if I was hungry, I probably would do what Photowit did.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • PhotowhitPhotowhit Solar Expert Posts: 4,879 ✭✭✭✭
    I would bake it during the day. At night, if I was hungry, I probably would do what Photowit did.
    Uh-oh, What did I do now? I'm guessing being off grid...lol.

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • BB.BB. Super Moderators, Administrators Posts: 29,009 admin
    Microwave leftovers?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • PhotowhitPhotowhit Solar Expert Posts: 4,879 ✭✭✭✭
    BB. said:
    Microwave leftovers?
    Image result for Marie Callender Pot Pie
    ...I actually do know there's a restaurant but never have been in one...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • mike95490mike95490 Solar Expert Posts: 8,240 ✭✭✭✭✭
    10 oz pies have no leftovers, and all 3 pieces of meat are shown in that photo.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • clockmanfranclockmanfran Registered Users Posts: 44 ✭✭
    mike95490 said:
    10 oz pies have no leftovers, and all 3 pieces of meat are shown in that photo.


    I had to laugh when i saw the meat pie, laughed some more when i saw mikes reply.  .... Sadly even in France nowadays we play spot the meat in a meat pie, but then we do not sell many meat pies.  I am in London, England tomorrow where the pies marketing has no connection with what is inside. lol.


    Direct feed Inverters without batteries............... As I said earlier it is possible to have PV directly controlled and direct to a suitable load. As far as I am aware the clever guys seem to manage about 1.8Kw then other issues arrive, but they are working on fast paralleling and a master control.

    Above 3KW Inverter electronics can start to suffer with 'shoot through' and magnetics start to raise their ugly heads, so tuneable/variable  chokes are required, and we shift into power electronics where the normal 50mm x 50mm PCB SMD boards architecture start misbehaving as it isn't normal electronics anymore.

    Everything is possible, just give me Time.

    The OzInverter man. Normandy France.

    3off Hugh P's 3.7m dia wind turbines, (10 years running).  ... 5kW PV on 3 Trackers, (5 years) .... 9kW PV AC coupled using Used/second hand GTI's, on my OzInverter created Grid, and back charging with the AC Coupling and OzInverter to my 48v 1300ah batteries. 

  • bill von novakbill von novak Solar Expert Posts: 843 ✭✭✭✭
    Dave, having MLPE on the roof is the DG way (described by Sunnova's John Berger).  Low-voltage DC conversion using microinverters is the safest, most reliable way, and offers the highest longevity @ 25 years.  High-voltage string inverters are dinosaurs, non-PID free, prone to DC arc faults as system ages, etc.  Enphase's IQ8 microgrid codenamed "Ensemble" will be accompanied with an Automatic Transfer Switch as described in their Analyst Day 2018 presentation (http://files.shareholder.com/downloads/AMDA-H4G6H/6350916243x0x983454/F9801B72-AC2F-45BB-BDEE-20623B222E37/AnalystDay-_Final.pdf) (see p.42).  Also read Sun on Run's CEO Jim Jenal's "mind blowing" report on an actual demonstration of the solution in action around the time of Enphase's annual shareholder meeting this past May.   (https://runonsun.com/~runons5/blogs/blog1.php/residential-solar/what-i-saw-at-enphase-mind-blown)

    Thanks.  The "automatic transfer switch" looks like it does the job - and what was missing from the earlier descriptions I heard about.

    To reply to a few other comments here:
    (Dave A) Most of the failures are Enphase. Maybe they will get better,  I really could care less but good luck !
    I would add that on other forums I am seeing a significant failure of the Solaredge optimizers.  They are simpler than inverters, but are still "electronics on the roof."  I tend to agree that unless there's an overriding issue (i.e. unavoidable shading) you are better off with a string inverter.

    (photowit) I don't think the SMA system is seamless, I think someone actually has to be there to throw a transfer switch.

    Yeah, I think there's just a simple "enable" switch that switches the inverter from grid to "secure power" operation.  It's usually wired as a 120V wall switch but I think it's low voltage DC.

    (Dave A) My Brother has an SMA  TL and whatever is plugged into that outlet will get up to 1500 watts while the sun is shining. It wont start a normal refrigerator. It does start his LG inverter fridge. He does have to plug it in as the secure outlet only gets power in an outage.

    There are a lot of people who really want backup power, from the discussions I have heard both from solar people in person and on other forums.  Perhaps it's due to the more significant weather events, or the sort of intentional blackouts we are seeing here in California during fire season.  It also seems like most people don't want the hassle/expense of a full hybrid system.  I've been recommending the SMA system with an off the shelf UPS for nighttime power.  Plug the UPS into the secure power outlet, run critical loads (cellphone charger, a light, a fan) into the UPS, run the rest of the loads off the regular secure power outlet.  It's not a great solution (those UPSes don't have the best inverters, and they charge slowly) but it's very cheap - they are $69 on sale at the local big box store.  And when it fails, return it/recycle it and buy a new one.

  • Peter_VPeter_V Solar Expert Posts: 226 ✭✭✭
    I wouldn't recommend Enphase even if they were giving away their equipment.  I've had 70% of my micro-inverters fail in 8 years, and now I can't get them replaced.   Enphase has horrible customer support, they won't even talk to consumers anymore except for automated replies to talk to a "Professional Installer", however the installers are tired of putting up with Enphase's crap when it comes to replacing equipment.  None of the installers in my area will even return my phone calls.
    I agree that putting electronics on roof tops is probably a bad idea; however, in my case, the inverters aren't on my roof.  My panels are on trackers with the inverters behind them so they are always in the shade with LOTS of airflow.  Not only that, buy where I live it rarely get's over 100 degrees F, maybe 4-5 days a year.  Most of my failures happen when it's not even particularly hot out.
    Enphase builds crappy products and lies about how reliable they are, and now they are screwing their customers by not honoring their warranty.  Sure they'll claim it's not their fault that the installers refuse to service their products, but Enphase are the ones that set up the situation that ensures their customers can't get support. 
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,422 ✭✭✭✭✭
    You comments are what I have heard from my Solar Wrench buddies, too many times.
    What tracker Peter?

    There are lot's people who want storage Bill, there is an even greater number who want MORE  ;)
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • cow_ranchercow_rancher Solar Expert Posts: 115 ✭✭✭
    And I've had 0% of my micro-inverters fail in 7 years, I couldn't be happier.  Remember you solar panels are electronics.

    Rancher
  • PhotowhitPhotowhit Solar Expert Posts: 4,879 ✭✭✭✭
    Peter_V said:  I've had 70% of my micro-inverters fail in 8 years, and now I can't get them replaced.   Enphase has horrible customer support, they won't even talk to consumers anymore except for automated replies to talk to a "Professional Installer", ….
    I have to interject this has NOT been my brothers experience, though he has had failures in his 7-8 year old system. The 2 failure happened close together and he contacted Enphase, they talked with him and sent 2 replacement units and even a little money to have them professionally replaced ($30-40 each as I recall). IT IS TRUE no installer had any desire to even quote my brother on replacing the inverters! and that was before he told them it was on a 2 1/2 story roof. He did it himself, he has climbing gear from spelunking.



    He thought he had another failure recently, it turned out the unit was reporting low voltage and it turned out being a a burnt diode in the panel. He didn't mention a hard time talking with them.

    I do think they do an unfair comparison in their advertising, when they suggest their inverters are more reliable than string inverters, I would suggest if an install with 20 micro inverters has failures the system has failed, though they appear to be comparing 20 micro to 1 string inverter. 
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • Ralph DayRalph Day Solar Expert Posts: 885 ✭✭✭✭
    I thought I had my first Enphase failure after 8 years...but it got better!  Wasn't reporting, no reason found, but the next day it was reporting again.  That's the kind of warranty I like!  The system is running at the highest possible AC voltage allowed and designed for.  The local feed would be over 250vac sending the inverters into fits of "out of frequency out of voltage range".  Once programmed for the higher voltage limit no more problems.

    Still have fingers crossed that they'll last.  I'm ignoring the Enphase sales emails for updated inverters, or inverter/panel or inverter battery mixes.  If it's not broke (at least not yet) don't fix it.

    Ralph
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