Peak output vs actual

[Bobup]

Solar Edge system
15 300kw panels plus 4 400kw panels
The 15 facing south with no obstruction
The 4 panels are facing East with no obstruction
= 6100kw ? potential
Every day the app peaks at 5kw with production around 22kwh
so my question is...why does it peak at 5kw
TIA Bob

[J.P.M.]

For starters, those are "W", not "kw".
"kW" = 1,000 W.
You have a 6.1 STC kW system.
The most you will get from either portion of the system is about 0.85 of the STC output for that portion.
Those peaks will come at different times due to different orientations of the larger and smaller portions of the system.
Given two different array orientations, that 5 kW peak output sounds about right, depending on your location and weather and maybe happening slightly before solar noon (which is most likely not at 12:00 noon civil time).
Download a free copy of "Solar Power Your Home for Dummies" for explanations of the above.
Then download and get familiar with a user-friendly design program called "PVWatts" which will model your system and provide you with information about expected system performance.
After the self-education and homework, come back and ask questions to fill in any knowledge gaps your self-education creates.

[davidcheok]

Maybe you should list out the nameplate output for the inverter first?

[solar pete]

Solar Edge system
15 300kw panels plus 4 400kw panels
The 15 facing south with no obstruction
The 4 panels are facing East with no obstruction
= 6100kw ? potential
Every day the app peaks at 5kw with production around 22kwh
so my question is...why does it peak at 5kw
TIA Bob

Sounds like you have a 5kW inverter mate

[J.P.M.]

Sounds like you have a 5kW inverter mate

And I'd suggest if the other provided information is reasonably correct, that's probably about the right size.

[Bobup]

So here is a pic of the inverter label.
if I'm reading this correctly...it has a max output of 5000w
so my system has the potential to do more , 6100w, but the inverter is holding it back.
so the next question(s) is, is it worth upgrading the inverter? And can I do it or is paying someone else the better choice?
Thanks again for the insight and knowledge that is shared here, Bob

[J.P.M.]

So here is a pic of the inverter label.
if I'm reading this correctly...it has a max output of 5000w
so my system has the potential to do more , 6100w, but the inverter is holding it back.
so the next question(s) is, is it worth upgrading the inverter? And can I do it or is paying someone else the better choice?
Thanks again for the insight and knowledge that is shared here, Bob

You are partially correct. Your inverter is limiting your maximum power output to 5kW.
However, it's pretty unlikely your system will ever achieve its 6.1 kw STC rating except under unusual conditions of high irradiance or if extra irradiance hits the arrays either from bright surroundings of the intentional placement of highly reflective materials.
In any case, your inverter is likely limiting your output, but that doesn't mean it undersized because the most you're likely to get out of the array is something like 5 kW or so and that's likely to happen only a few hours of the year., if that much.
Read the Dummies book for reasons why.

[Bobup]

Dummies book has been ordered...awaiting it's arrival. TY

[J.P.M.]

Dummies book has been ordered...awaiting it's arrival. TY

NOMB but FWIW, I'd cancel that order.
What you need is in the 1st ed. and it's a free PDF download for some snooping around on the net as is PVWatts. Just read ALL the help screens before you do any runs. and get the inputs as close to reality as possible. You'll need separate runs for each array orientation. use the hourly printout option , then add the results together for combined output on one of the spreadsheets.

[azdave]

if I'm reading this correctly...it has a max output of 5000w
so my system has the potential to do more , 6100w, but the inverter is holding it back.
so the next question(s) is, is it worth upgrading the inverter?

No. If you upgrade to a 6000W inverter now, you would likely never recover what it will cost to purchase and install it, even if you sold the used 5K inverter to someone else to help you recoup some of the upgrade costs.

The small amount of energy you are not converting only occurs during the peak of the solar day and only when conditions are perfect. That little bit extra you might collect with a new inverter will never be significant enough to matter compared to what you will spend to get it. Your 5K inverter appears to be working as planned and again, there is only a brief time period in the day where a 6K inverter could take full advantage of what your panels output during that daily peak production that occurs around solar noon. As your panels age, and they naturally lose some efficiency, you might not see any clipping. I believe a 5K inverter is a perfect choice now and in the future. In my opinion, your panels and inverter were chosen properly by the installer. The cost difference to install a 6K inverter back when the system was new probably would have moved the ROI point several more years down the road.

[Just starting]

I have a similar, but slightly different situation. I recently had a 14.58 KWp system installed. It consists of 36 405W panels facing in an easterly direction. The inverter is a Solis 10KW string inverter. The system has been operational for approximately a month now. When I got access to the Solis app (after I fully paid for the system), I noted that over half of the days I am seeing clipping at 10KW from the inverter. Looking at the graphs, it appears to the uneducated eye, the ramp up should well exceed the 10KW level. I questioned the system supplier about the inverter limitations and why an additional inverter was not used, they claimed: 1-the clipping will only a very minimal impact—only about 0.3% during first year of operation, which is negligible and an industry standard, 2-Having only one inverter has less opportunity for failure, 3- I am making up for the lost energy by picking up more energy in the early part of the day with the eastern exposure, 4-Clipping will only occur occasionally and will not significantly affect your system’s performance or savings.

From my biased perspective, purchasing a 14.5 KWp system should be limited by sun exposure and efficiency only. It feels, again to me, that they are avoiding the added expense to them to increase my collection capacity. I should add, that originally, I was quoted a 12.1 KWp system that would not achieve my requested 100% system coverage.

Can any of you with expertise provide me with your thoughts on should this system be expanded inverter wise or is this truly an "industry standard". I absolutely do not want to pursue a potential legal solution if I am being unreasonable in my expectations for a quoted sized system. Below is an example of its performance on a more sunny day.

image.png

[solar pete]

Hi Just Starting,

Everything sounds fine with your system, you always over panel your inverters as much as you are allowed too, in Australia we are allowed to over panel by 33% when no battery is used and when a battery is installed with the system we can typically over panel by 50% or more in some cases, this is the norm and how it should be done and how it has always been done here.

The way your looking at it is just typical of people new to solar. So the other way to look at it is say you went with a bigger inverter say a 12K or 15kW inverter the price would be say 1K to 3K more and you would make make a little bit more power on sunny days for a couple of hours a day and never get that extra money back, remember panel's degrade over time, you typically drop between 1% and 2% in the first year and it settles down to about .5% each year after that, so all up no need to stress or change anything all is good, hope that helps, cheers

[Just starting]

Thank you for the response, solar pete. I hated to see energy go to waste and was just surprised to see the inverter being the limiting factor. Appreciate the guidance!