16kw system only produces maximum of 11 -12kw (phoenix, AZ)

[h2ofun]

Definitely not as much production as all pointing south, but still a lot of production around the summer solstice assuming the roof pitch on the North plane is not too bad.

We have 4 kW of our 12 kW on North facing surfaces roof and they kick in strongly from late April through August. And also start producing earlier because the south side has some shading until 8:30.

I had a choice, some north facing panels or none of them. Yep, they kick butt in the summer, so way better than nothing, and a 26% tax write off.

 

[Laketime]

Sorry when I wrote that I was distracted at work.
I thought I only had like 3 panels facing north and I kinda screenshotted in a hurry without looking.
Looks like I have 17 facing north and 29 facing south with 2 facing east.

I feel like someone should have discussed this with me prior to me getting my system, I probably would have gotten a smaller system with less panels on the north side since those aren't nearly as useful...

You will still produce from those panels but much less than if they were south facing. It's a very large purchase for a home so I hate to say it but some research needs to be done. You have to remember that Tesla is still a for profit company who wants to sell you as much as you will buy.

 

[Bigriver]

@Squeezit, you already have a lot of people who have chimed in on your situation and I think you have much of your answer to your situation. But there are a few things I would add that I didn’t see mentioned:
- For any given month, there is a lot of variation from year to year in solar production. Don’t be hasty to jump to conclusions based on a few months. For example, I’ve had stellar September production and dismal September production.
- Peak production rate (kW) occurs for me in the spring. This is when the air is clearer, the temps cooler while the angle at which it hits my roof is optimized. That is when I can sometimes catch instantaneous production rates that exceed what I see any other time of the year. But during the summer, I get peak energy produced (kWh) primarily due to the length of the days. By August, tho, days are already shortening.
- The clarity of the air can vary a lot from day to day. I am on the east coast but I have had some periods affected by the Western forest fires. It’s not a visible smoke, but an upper level haze that does affect the UV rays.

 

[sorka]

Hey thanks a ton for the responses guys. I was sure something was wrong with my system because when it was 120 outside, I was definitely getting higher numbers.

Anyways, the front of my inverters say this:
Inverter 1
Max power - point current (Imp) 11.48 A
Max Power - Point Voltage (Vmp) 380 v
Max system voltage (voc) 480 v
Short-circuit current (isc) 15 A

Inverter 2
Max power - point current (Imp) 20.14 A
Max Power - Point Voltage (Vmp) 400 v
Max system voltage (voc) 480 v
Short-circuit current (isc) 30 A

Inverter 1 is SE10000H-US
Inverter 2 is SE3800H-US

Sorry for being so late on adding this info

Please post screen shots of your weekly panel production from the app or website. Are all the panels facing the same direction? Can you post panel layout, angle, and which inverters each panel is hooked up to?
Also, when's the last time your panels were cleaned?

 

[sorka]

Sorry when I wrote that I was distracted at work.
I thought I only had like 3 panels facing north and I kinda screenshotted in a hurry without looking.
Looks like I have 17 facing north and 29 facing south with 2 facing east.

I feel like someone should have discussed this with me prior to me getting my system, I probably would have gotten a smaller system with less panels on the north side since those aren't nearly as useful...

Your system is working fine. If you haven't cleaned your panels in a month, do that and you'll get a 5% boost.

 

[dareed1]

I used New Mexico State's spreadsheet to pull the expected peak power from your array. If my entries were correct ( I guessed that your roof has a 25 degree tilt) then in late May/early June, the system efficiency was about 90% which I think is very reasonable given the likely panel temperatures. For September 21, if the efficiency stayed the same, and if the optical density of the atmosphere was typical (unlikely given the fires in CA) you might expect to see 12.4kW at peak.
I think the system is performing normally.

The calculated drop in peak power is almost entirely due to the north facing panels. The south facing panels actually calculate to produce 1% more peak power than last June, because typically the optical depth of the atmosphere is less in September, although that probably doesn't apply this year.

 

[Squeezit]

Your system is working fine. If you haven't cleaned your panels in a month, do that and you'll get a 5% boost.

My house is waaay too tall, and way too steep. I can't get up there to clean my panels sadly! Maybe if I buy a really tall extending ladder, though I wouldn't be able to get any except the closest panels.

 

[ptdusn]

My house is waaay too tall, and way too steep. I can't get up there to clean my panels sadly! Maybe if I buy a really tall extending ladder, though I wouldn't be able to get any except the closest panels.

I live in Gilbert and found at the Home Depot, Windex Outdoor glass cleaner, which attaches to your hose and can spray up to your panels. There is a short YouTube video on how to use from a fellow solar owner.