New System Running Correctly???

[tidalforce]

My contractor installed a 13kW system using #40 Hanwha Q Cell Q.Peak 325 panels. It appears that they installed completely different panels without my knowledge/consent (Solaria PowerXT-360R panels). From what I've read, the Solaria panels are actually better (feel free to correct me if I'm wrong) so I'm fine with that. My question is if they installed higher wattage panels (325 vs 360) shouldn't my system be higher than 13kW? Also, I've had my system for about two weeks and my current power has never been higher than 10kW despite having a lot of really sunny days. Just wondering if my system is running correctly (I've read that systems are only 80% efficient and that 13kW number is basically in lab testing conditions). One panel was having some issues so they are replacing the optimizer. Just wondering if there is anything else possibly wrong with the system.

Thanks,
JC

[SunEagle]

What is the inverter that is installed with your panels? There might be some type of clipping if your inverter is no bigger then 10kw or if you are using micro inverters then they are limited to a specific wattage output even with higher wattage panels.

Also are all the panels oriented in the same direction? If not then while your total wattage may be 13kw your peak production would be less if you had and East & West panel orientation.

[tidalforce]

My system is east/west and is using a Solar Edge SE11400H-US inverter. It says the max AC output is 11400@240v or 10000@208V (I've attached the specs as I am not very well versed in all this terminology). Should they have installed a different inverter?

Thanks,
JC inverter.jpg

[SunEagle]

Well maybe not a different inverter but the Contractor should have explained that with some panels facing East and the rest facing West you could not generate the total wattage of all the panels at the same time. You may get 10kw production around Noon but you will never get the full 13kw or 14kw at any part of the day.

Now if all 40 panels were facing in the same direction (say South) you could generate much closer to the total panel wattage and would then need a bigger inverter or 2 inverters.

You really don't have a bad system unless your contract stated you would get the full 13kw of panels production at the same time and you need that much. Otherwise you are getting production much longer throughout the day based on your East/West panel orientation.

[ButchDeal]

do you have 208V in your home? if so that inverter would peak at 10kW.

As SunEagle said though with two azimuths, you are not likely to get to that peak too much.
do you have some graphs you can share or a public solaredge site?

[tidalforce]

I'm not sure if I have 208 or 240 (How would I find out? I have a newer home built in the US-Colorado)

Thanks. I guess I'm less concerned about peak output vs making sure I generate the expected amount over the course of the year. They estimated my system would generate 17596 kWh/yr. I was hoping that since they installed higher wattage panels that I would end up producing more than what they originally quoted me. Here is the link to my data so far. Thanks for taking a look and providing guidance.

-JC

https://monitoringpublic.solaredge.com/solaredge-web/p/site/public?name=JC#/dashboard

[ButchDeal]

You have 240v. You can tell by clicking in the inverter and info.
It also does not look like you are clipping anyplace in the few days of operation.
it also looks like they installed 42 pv modules and they are listed as 360w so yeas the system size is larger at 15.12kW

module 1.3.6 seems to be producing about half the power of the ones around it. Is it shadowed? Dirty?

[tidalforce]

They are replacing the optimizer on that module next week. So given that my system is larger at 15 kW, can I expect to generate more than the estimated 17596 kWh/yr? And since I am not clipping anywhere my inverter is fine for the system I have?

Thanks,
JC

[ButchDeal]

They are replacing the optimizer on that module next week. So given that my system is larger at 15 kW, can I expect to generate more than the estimated 17596 kWh/yr? And since I am not clipping anywhere my inverter is fine for the system I have?

Thanks,
JC

What makes you suspect the optimizer over the pv module?

[tidalforce]

Replacing the optimizer was the contractor/solaredge's call. I just informed them that module was acting up.

[J.P.M.]

I'm not sure if I have 208 or 240 (How would I find out? I have a newer home built in the US-Colorado)

Thanks. I guess I'm less concerned about peak output vs making sure I generate the expected amount over the course of the year. They estimated my system would generate 17596 kWh/yr. I was hoping that since they installed higher wattage panels that I would end up producing more than what they originally quoted me. Here is the link to my data so far. Thanks for taking a look and providing guidance.

-JC

https://monitoringpublic.solaredge.c...=JC#/dashboard

If the larger wattage panels are the same physical size and in the same orientations, to a 1st approx., the larger STC wattage panel will produce additional output that's about in the same ratio as each panel's STC eff.
Then, if the inverter can handle all the additional output, that ratio will be a 1st approx. of the additional output of the larger STC wattage paneled system over the smaller STC wattage panels.

Run PVWatts treating each orientation as a separate array. Add the results for an approx. of annual production. Do that for both panel options for a comparison.

Use 10 % system losses and the hourly output option. Add each hour's output for each array. Sort that spreadsheet column max. to min. for a SWAG of how close you are to maxing out the inverter as well as a SWAG of how many hours over a year that inverter max. might be exceeded.

With inputs that reasonably reflect system realities, the PVWatts model usually produces output that's ~ +/- 10% or so for any year. Any 30 day model totals are probably +/- 30 % or a bit less of what actually happens.

If your interested, run the same total array size w/a 180 deg. ax, 40 deg. tilt for a SWAG comparison of what the orientations you have might produce over a year vs. what an optimum orientation would produce over the same period. Chances are, your current E-W orientations will produce less annual output than a single all south 40 deg. tilt array of the same STC wattage, with max. total output for any hour for the current array(s) being less between maybe 1000 hrs. and 1400 hrs. solar time, with probably a flatter, broader top or maybe a bit of a bimodal distribution when averaged by hour over a year. So, the E-W array will clip an inverter less than an array oriented for max. annual output. That may save a few bucks on the inverter downsize, but annual system output will be less, meaning more panels or wattage will be needed for the same annual output, making it harder to get the same cost effectiveness as an optimally oriented array would achieve under the same climatic and site operating conditions.

[tidalforce]

Thanks JPM. I was able to comprehend the first part of your post, but the single array spreadsheet was a bit over my head. One question I do have left is if I have a 15.12kW system (because they installed more panels and higher wattage) why does my system still show as 13kW on the solaredge site? Was that 13kW entered by the contractor?

[J.P.M.]

Thanks JPM. I was able to comprehend the first part of your post, but the single array spreadsheet was a bit over my head. One question I do have left is if I have a 15.12kW system (because they installed more panels and higher wattage) why does my system still show as 13kW on the solaredge site? Was that 13kW entered by the contractor?

You're most welcome.

If you did the arrays you have w/PVWatts, the single array is similar input but half the work and with different tilt and azimuth. What's over your head ?

Not ducking the question, but I don't have an answer to SolarEdge reporting size question as I'm mostly ignorant of the particulars of how SolarEdge or your installer configures their equipment.

What did the installer say when you asked them ?

[macaddict]

Twhy does my system still show as 13kW on the solaredge site? Was that 13kW entered by the contractor?

Yes, the contractor puts this number in the admin page of the monitoring site.