Should I be concerned?

I’ve had solar for awhile, and recently 22 of my 40 panels had to be taken off for some roof work.

The remaining 18 panels seem to “cap out” on production at about 4281W but they’re 350W panels so I was anticipating more like 6300W (or in the ballpark of 6000).

Of course sun angles and obstruction would impact, but I was expecting that those factors would contribute on more of a smooth curve through the day. Instead, there’s a clear cap many days at that 4280W mark. See example below:

Is this an indication that my panels aren’t working properly? The native metering for the panels (Enphase) seems to roughly line up to output captured by Sense each day.

If your in the upper 1/2 of the US, your panels want see direct sunlight for a few months. Each month the sun’s angle is higher and higher until the peak (summer solstice) it won’t be 90 deg up. If you have fixed panels (in the US) they should be facing South and tilted at the angle that matches your Latitude. So if your location’s coordinates are 42.49882, 82.76878The panel’s tilt should be 42 1/degrees

I totally acknowledge i won’t get perfect output all the time, and at this time of year it would not be possible. BUT the part that seems bizarre is the cap (as seen in image provided) at 4281. Why a flatline there at my peak output each day? Why isnt that a more domed curve?

What’s the specs on your panels/ inverter. MPPT 4 might not be meeting the min voltage for it to come on. I didn’t see the wattages right on your one photo. Are those calculated or reporting from optimizers/ controllers?

Here’s what I know as far as specs:

The image from Enphase shows wattage per panel but that’s not really relevant to the question as it’s very lagged. The more relevant part is that the picture is oriented North to the top.

Those are micro-inverters. Is it like this ever day since you had the other panels down? I don’t think I would be worried at all, this time of the year for the upper states will have low PV production. I can’t imagine the one panel making 363 since the max is 350. The corner of array 3 looks like it’s got some shading in the right side and maybe the panel in the 4th array. I now my inverter’s reporting (sunny portal) will be several hours off some times. Like it will be dark out and show I’m still making 2500 watts but the totals for each day appear the same as sense.

I would just clean them off when if gets warm outside. Those are good modules and I doubt you’ll have many issues with them.

Just to be clear on the math, i have no expectation of 363W per panel. I am however expecting more like 320W per panel but i’m maxing out at 238W (4281W / 18 panels) per panel when i hit this upper flatline around 9:30am - 10:30am in the Sense screenshot provided.

Again - don’t try to use the Enphase data/image for more than orientation. It’s lagged by up to 6 hours and the sun doesnt hit the panels evenly in the early morning or afternoon

Normally flat lining with a string inverter is more of thing than with micro inverter. You have an inverter on each panel, so each panel’s output is independent of the others. I think the regular EnPhase IQ7 is has a max output of 320w. It looks like your in Massachusetts and your solar noon should have been 11:58am today and not 10am. The panels being (azimuth) 25-30deg off south just looses some production. You starting to drop at 10:45am I think is the bigger issue is with shading. Being that far North, being February and being 10am… the sun is low there. If you didn’t have any shading issues and had a cap issue. You would see that cap from 9:45- (peak= solar noon 11:58 and same as the sun sets) all the way to 1:57pm.

With your EnPhase monitoring, you would see a dead panel/ micro inverter very fast.

In a string inverter setup where you might have8 panels in a series. A mc4 connector could cap out that while array.

I think you’re kinda missing the point of the question. I took the screen capture at 10:59am so yeah maybe between 10:30 and 10:59 there were some clouds….

The IQ7 does not cap at 320W.

I think you are capping at the max the sun is giving out and your array can produce given the time of year and solar energy available. I have 18 panels total in my array. While later in the day than you, from 12 - 2pm, I was at about 4200w for the duration (with a few cloud dips).

I don’t remember how I got access, but I can see my system via Enlighten Manger, vs just the regular home owner view. In this view, you can actually look at power graphs per micro inverter. This may help you track down if / where you have an issue.
I’m sure its not this simple, but if you want to try, go to
replace the systemID with your ID number which you can find the in URL when you log into your “MyEnlighten” account.

Its also possible that your micro inverters are capping out due to line voltage issues. Once it updates with todays readings, can you grab a screen cap of your Sense Power Quality Screen? I’ve had it in the past where when the line voltage gets a little too high and we have good sun, the micro inverters will have a hard time keeping sync with the grid and seem to limit themselves and or turn off. I’m sure there is a much more technical description of that, but I don’t know what it is.

Also, can you try taking a screen shot of today’s flat line form the web power meter vs the mobile app just to see how “flat” it really is.

4281 watts/18 uinverters = 238 watt AC per inverter.
Given 8% conversion losses we are talking about ± 260 Watt DC from the 350 watt rated panels
Those specs are at 25C ambient temp and 1000 watts/m2 .
Currently I see about 80% of those values at my panels.
80% of 350 watt = 280 watt.

But more interesting is the spec of your IQ7 uinverters:
IQ 7 microinverters for solar systems | Enphase microinverters → technical specs
Screenshot from 2022-02-06 20-46-30

The micro inverter can never produce more than 240 VA (roughly watts) AC
I think I would have matched those panels with different microinverters:
IQ7+ 290VA continuous
IQ7A 340VA continuous
IQ7X 315VA continuous
You will imo never get the max out of the panels, it will be limited to the installed micro inverters


Awesome! Thanks Danny - this is exactly the math/info i wasn’t seeing. I’ve contacted my solar company and they’re going to contact Enphase to see what the options are. It sounded like (from an initial conversation) the IQ7+s aren’t compatible with the LG Neon 2 350Ws. He wasn’t sure about the IQ7A or the IQ7X but he didn’t think they were compatible either. So it seemed like a technical limitation basically locking my 350W panels at a max output of 240W. BUMMER.

He is going to try to get a better answer/investigate options and get back to me later today. He thought there might also be some limiting occuring at the software side based on local regulations and wasn’t sure if they applied to me/my location. I’m fairly close to Rhode Island which I guess has some stricter limits on these things.

@ben i tried that link, but it takes me to the same lame Enphase Enlighten views without any real detail of per-panel information or over time graphing aggregated any lower than 6hour increment. Sounds like there’s a much more useful interface that I dont have access to.

here’s the requested info. Power Quality seems pretty good (and always has when I’ve checked it.)

Here’s the power meter view. I indicated the period where the output pretty much locks in at 4281W. There are some instantaneous 4282W and 4280W moments but the output is nearly perfectly constant.

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Some online research makes me think the better spec micro inverters are actually compatible so I’ll be pushing on that a bit.

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Double check the module numbers.
I found these:
Screenshot from 2022-02-07 07-02-32
I assumed some temperature limits

In that case the IQ7X won’t work

I have the LG350N1K-A6’s according the the paperwork filed with my Utility company.
-15F to 102F was the range for the record high and low in my town so should be safe there

Looks like the ideal would be the IQ 7+ and if that’s for some reason not an option the IQ 7A would be better than what I’ve got.

Solar panel specs sure are confusing.
The NMOT of those panels is 42+/-3C at 800 W/m^2 and ambient temp of 20C, wind speed of 1 m/s, Spectrum AM 1.5.
At NMOT Max Power is 262W
With 8% conversion loss doesn’t that put it at 240W?

I’ve never taken a Fluke to a panel in Arizona cranking away (or anywhere for that matter) but I assume at 1,000 W/m^2 a cell temperature of 25C is pretty rare. Maybe high altitude and some wind? Anyway, shouldn’t you go by the NMOT spec for real world conditions?

@ixu If i follow (which is definitely questionable) the actual Max Power output from my panel (given a lot of environmental variables) is something like 265W.

Although that’s a bit frustrating since they call them 350W panels some internet research seems to tell me a similar story. So the fact that I’m getting 238W out of these is actually indicative of a really good output, and the Enphase person’s offer to up the settings to allow 250 VA instead of the current limit of 240VA is really likely to remove that hard cap I’m seeing.


Were you not seeing a 10,000w cap before on when you had 14,000w setup? Isn’t EnPhase reporting that some of the panels are producing 270-280w at 11am? I’m thinking you might actually have the 350w IQ 7 … actual model (IQ 7A.) Which does have a max continuous ac power output of 349va and a peak of 366va. I wouldn’t be surprised if all the IQ7’s show up as just IQ7 in the system info screen. Im assuming that the 2 arrays are off your roof and this should be easy to check.

I think its much more likely that you were just caping out for being that far north and 10am in feb than someone pairing 250w micro-inverters on 350w panels

Sadly - no. The Enphase App is REALLY dumb what it’s showing on the panel is not 270W at 11am. It’s instead showing that for that day, that panel has produced 270wh. It only gets updated data every 6 hours or so and so it’s just showing a total output for the day amount.

It looks like as mentioned above, there’s an upgraded version of Enlighten (enphase app) and it’s either $9.99 / month or a $250 one time cost. I’m going to try it for a month to see if it has more useful info.

I’m certain I don’t have the IQ 7As as well. I did check that from the enlighten app / serial numbers and SKU.

As far as a 10,000W cap - Sorta. When all the panels were on and running in the summer i had gotten wemm into the 12,000W mark, but only during install. After the install days i was capped then at about 9,600W. So i think this is the 240VA limit from the microinverter that can be increased by 250VA by just asking hahaha.

In the end, seems like a 350W panel really puts out like 265W max.

Screen Shot 2022-02-07 at 11.48.28 AM
Screen Shot 2022-02-07 at 11.48.48 AM
Screen Shot 2022-02-07 at 12.07.02 PM
Screen Shot 2022-02-07 at 11.55.41 AM

@rlavorgn, as far as I understand panels, the sun and the weather AND what physics & marketing dictate, the STC (Standard Test Conditions) are there to essentially stress-test the panel at maximum output (and to look good for marketing). When you burrow into these things IMO it’s as much about getting a “Linear Warranty” on output covered by an installer as it is about “Maximum Output”.

That said there is good reason to have a little buffer (I assume) in your inverter so probably what @dannyterhaar said is a good call. Then again, switching working inverters only makes sense if you know the gain will be significant enough. Then again again, at similar max peak output a more efficient inverter can give you generation gains. :man_shrugging:

I would love to hear from Solar industry/installer types on this sort of thing.