My Solar system 8.4 kW only producing 5.5 kW

[stok1232]

I had my system on for the last couple weeks with many sunny days and the highest I've seen it produce is around 5.5 kW. Is this normal to be this much off or should I give Tesla a call? Also, when my system was installed they turned the system on for me right away. Were they not suppose to?

 

[h2ofun]

What is your inverter size? You will never get your panel specs!, Every!! And the sun angle is also dropping production off now

 

[jsmay311]

I had my system on for the last couple weeks with many sunny days and the highest I've seen it produce is around 5.5 kW. Is this normal to be this much off or should I give Tesla a call? Also, when my system was installed they turned the system on for me right away. Were they not suppose to?

5.5/8.4 = 65.5%

I’m also in Chicagoland. Over the last 2 weeks the highest output I’ve gotten is 77% of my panels’ nameplate rating. (My microinverters are rated for 80%.)

But I also have a pretty ideal setup from a roof geometry standpoint, with all of my panels facing due south and a ~25 degree roof angle.

So, yeah, your numbers seem a tad low, but could be explained by inverter clipping if you have a small-ish inverter or by the layout of your roof/panels if they’re not angled optimally.

 

[stok1232]

What is your inverter size? You will never get your panel specs!, Every!! And the sun angle is also dropping production off now

This is what I found from my documents.

 

[jjrandorin]

I had my system on for the last couple weeks with many sunny days and the highest I've seen it produce is around 5.5 kW. Is this normal to be this much off or should I give Tesla a call?

This comes up every so often as a question.

This is likely normal, and for a very TL ; DR (too long, didnt read) version, as was already mentioned in this thread, the system size number is "in a lab, if everything was perfect including roof pitch, angle to the sun, etc".

For a bit more than that you can review a couple of other threads on this topic:

7.2 kw system generates only 4 kw

I am from San Diego. Have enough sunlight but my 7.2 kw system generates only 4 kw rarely generates 5 kw. Appreciate any tips to maximize production.

teslamotorsclub.com

Solar roof production before PTO vs after PTO

Hello, this is my first post here after discovering this forum. Looks like lots of super knowledgeable members! My solar roof is finally ready for PTO and Tesla is trying to get me to pay my invoice before activating. But I have some concerns and want them resolved before I pay or I may never...

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[ucmndd]

Lots of good explanations above. Another relevant question, are all of your panels facing the same direction, on the same roof plane?

Per the docs you posted you have a 7.6kw inverter, so your peak output will never be higher than that.

 

[stok1232]

Lots of good explanations above. Another relevant question, are all of your panels facing the same direction, on the same roof plane?

Per the docs you posted you have a 7.6kw inverter, so your peak output will never be higher than that.

Here is the layout

 

[Matt-FL]

I second the last request, what is your layout, direction, shading and angles?

You will never see more than your inverter max (there are claims of over-driving, but that only works on partly cloudy days for short bursts. On a clear day, you get a consistent 7.6kw max from the inverter. I have seen my two inverters burst to 8.6 each as the sun peeks out, but as of yet I've not seen it hold that for more than a minute before it drops back to 7.6.

 

[jjrandorin]

Here is the layout

Based on what you have posted, and your location, I think there is nothing wrong with your system.

 

[gaswalla]

if you are in the southern part of the country with no clouds and panels facing the sun, then you will generate the max stated

 

[ucmndd]

Here is the layout

So with panels facing 3 different directions, I'd say with 99% certainty your system is functioning as designed.

Your panels will not all hit peak production at the same time given the varying orientation, rather it will be spread out throughout the day. Remember that "area under the curve" is more important than peak production.

 

[stok1232]

So with panels facing 3 different directions, I'd say with 99% certainty your system is functioning as designed.

Your panels will not all hit peak production at the same time given the varying orientation, rather it will be spread out throughout the day. Remember that "area under the curve" is more important than peak production.

Thanks for the explanation. I never considered the layout to be the reason.

 

[C DM]

Thanks for the explanation. I never considered the layout to be the reason.

Typically the installers would cover explaining details like that, or at least mention that not all panels would be able to produce what they are rated for.

 

[gaswalla]

explanations, customer service, someone to reach with questions ---> nonexistent with Tesla Solar

 

[Matt-FL]

In my experience, the installers were fantastic. Very knowledgeable and went through the entire system, cabling, panel setup and app configuration with lots of detail. (I did buy them lunch both days they were installing, plus coolers full of waters and sodas - so a little bit of brown-nosing)

It is the follow-up support that has been a bit painful.

 

[rzn89]

Im in NY my, 6.8kw system on a 7.6 inverter hit 6.6 kw/h in August mostly it never went above 5.5. Since September rolled around even full sun im maxing out at 21kw a day in early August I was doing 32.

 

[stok1232]

I did get this reply from Tesla. "Powerwall+ has a 7.6kW inverter attached to it. The reason you are seeing less than peak performance is your system is in self-consumption. Self-consumption mode is a software feature we created that purposely limits the inverter output between installation and receiving final approval from the utility. You don't have final approval from ComEd so your system isn't allowed to send them additional energy. This feature allows customers to take some advantage of what is installed while we are working on final approval."

 

[jjrandorin]

I did get this reply from Tesla. "Powerwall+ has a 7.6kW inverter attached to it. The reason you are seeing less than peak performance is your system is in self-consumption. Self-consumption mode is a software feature we created that purposely limits the inverter output between installation and receiving final approval from the utility. You don't have final approval from ComEd so your system isn't allowed to send them additional energy. This feature allows customers to take some advantage of what is installed while we are working on final approval."

I dont think your instant production numbers are going to change much after PTO. That depends on what your house load is, vs production etc. You are never going to see anything larger than 7.6kW number though since thats the size of the inverter, and based on your layout, you wont see 7.6kW peaks either (and thats fine).