9.1 kWh SunPower SPR-A415-G-AC System - Issues with Install?

Hello Bato367 and welcome to Solar Panel Talk

Sorry to hear about your system not performing as you thought. Sometimes an installation takes shortcuts or does not provide all the information that a homeowner desires. With you being up in Colorado I would expect snow but I would have hoped like you to have a system that shed it through the way it is mounted. I agree that the tilt should have been more then 4 degrees but unless you have in writing or if you forced the installer to put the panels on your shed you may be out of luck on how they perform during the winter.

Also just a point of knowledge. They installed a 9.1kw system not a 9,1kWh system. Also it does seem that 7,100 kWh is no where near enough power generated by a 9.1kw system for 6 months of production. That comes to less that 1000 kWh per month. So please make sure you have the correct values or if you do then I would think that 7100 value since June should get the installer to think that something is wrong.

Yes, my mistake: it is a 9.1 kW system. And the 7,100 kWh has been produced over 8.5 months now. I don't believe it is in writing that they would install it at a specified angle but having it specifically stated in the Sun Power manual (10 degree minimum) I believe that has some weight to it. Yes, here in the high desert we don't get a lot of snow by any means but the fact that one snow knocks out production for 6 weeks is a bummer. While I look at other panels nearby and they we're melted weeks before mine. They keep telling me production is "looking good". I don't believe it is and believe it could be so much better.

I have never worked in solar but if I did, I would never install a system at 4 degrees. Dirt, snow, un-optimized production etc.

Thank you for your help. It's good to have these opinions on what a system should and shouldn't be capable of.

I do realize if say the system was at 20 degree tilt, then it may or may not be worth adding 10-15 degrees of tilt.

But, 4 degrees to 30-36 degrees seems like an enormous difference (and potentially large boost).

Tilting the panels to the correct angle makes sense unless the racking can cause the panels to catch the wind and be torn off.

Down here in Florida we have to meet Hurricane conditions which makes an installation more tricky and costly.

That makes sense. I did consider that, and 45 mph gusts here are about as windy as it gets.

Have you plugged in your system specs into the pvwatts solar calculator to see if system is producing anywhere close to expected performance? https://pvwatts.nrel.gov/pvwatts.php

You're welcome in advance. Just remember you asked the questions.

1.) Given that you lost about 5 weeks or so of production, 7,100 kWh of production since June doesn't seem all that far off the mark.

Here's why I think so: Not having your zip, I used Meeker CO for a PVWatts run at 4 deg. tilt and 180 deg. az. w/10 % system loss parameter and the model gave me about 12,800 kWh/yr. for a 9.1 kW system.

2.) When you write of wiring not being correct, are you referring to system wiring or monitor wiring ?

3.) Just like a well insulated horizontal roof (or a roof over an uninsulated space), most horizontal solar arrays in snow country don't shed snow well, if at all.

4.) FWIW, with the same PVWatts inputs except for a 40 degree (the local array location latitude) array tilt, the model produces about 14,500 kWh/yr of production. What's your annual usage ?

I'd stay on the vendor. The squeaky wheel gets the grease.
I don't think it's unreasonable to expect the system to monitor correctly as long as what you wanted in monitoring was made clear to the vendor up front. Vendors are not clairvoyant.
You will get what you put in writing on the contract.

To me, your situation looks like the common one that happens when some self education is missing.
The vendor could have been more upfront and advised that mostly horizontal panels can easily have production shortfalls in snow country and suggested alternatives such as tilting the panels ( as is often seen in areas with regular snow events).
That said, IMO, you could have been more proactive in educating yourself about what you were getting into.
So much for what degrees and experiences in the sciences are worth when critical thinking skills are not used.

FWIW and not unlike closing the barn door after the horse has left, and making an assumption that with a pole barn comes some land, I'd have made the system a ground mount with a minimum of 4-5 ft. of minimum ground clearance, tilted it at latitude + maybe 10 degrees or so with about a 190 - 200 degree azimuth, and got something else other than Sunpsower equipment - it's quality stuff but overpriced with no more reliability and annual output per installed STC kW than other quality stuff.

Caveat Emptor.

Take what you want of the above. Scrap the rest.

I have not. Thank you for that tip!

I have not heard of any consumer installer taking into account snow for the
installation. Your setup is about the worst in that regard. Solar production in
some areas is way down in Dec-Jan due to clouds, and one approach is to
just oversize enough to compensate. But in Sticky Snow Tolerant PV Mounting
I show some examples of ways to minimize snow impact.

About the only foolproof way is to use tracking motors to turn the panels away
from incoming snow. But tilting them straight up for the season greatly reduces
accumulation. No motors here, but the panels can have the tilt changed. After
many storms, I go out and remove a minimal amount of snow, sometimes just
tapping on a group of panels is enough to cause all the snow to fall off. But
the key things are being able to reach the panels from the ground, having a
steep elevation in winter, and having a lot of vertical space around EACH
panel for snow to fall through, without piling up high enough to obstruct sun.
Bruce Roe

array20R2.JPG

81507

Monitor wiring. It doesn't account for my garage/barn which houses a refrigerator, deep freeze and the homes AC unit. They've acknowledged, just haven't indicated how/when they will fix it.

We weren't here for a full year prior to solar but based on the 6 months prior to solar install (dec-may) our average usage was 1,059 kWh/month.

I assumed since they do solar for a living they would have had the initiative to install with some degree of tilt. I was not aware they would throw panels on a nearly flat roof and call her good. In retrospect I should have made them clarify I suppose. When you pay for an oil change and the car require 6 quarts but they put 4 in, it still works. Is it correct? Absolutely not. That is not the fault of the consumer. That is the installer.

We paid for a 9.1 kW system, get much less because of an install that doesn't even meet the manufacturers minimum tilt, the monitor wiring isn't correct, and I should've done more self-education and exercised more critical thinking skills.

Got it.

1) Wiring: Did Sunpower provide a schematic for you? This should show your entire electrical layout. Since you are in Colorado, my guess is that you have a meter breaker panel with breakers for your house, garage and solar. I'm also guessing they installed a PVS6 that uses one set of consumption CT's. They probably got lazy and just installed the CT's on your house breaker. I saw an installation manual to install multiple CT's for the PVS5, but not the PVS6.

2) Lower than potential production: By chance, did you do your install through a state sponsored energy trust? In Oregon, we have the Energy Trust of Oregon and contractors on their qualified list must design the install to at least 85% of potential production in order to qualify for Energy Trust rebates. This forces installers to do a site survey and run a simulation tool to quote you a % potential production number. Just a thought.

I have not seen a schematic no. Maybe the installer has it, but I haven't seen one. The installer mentioned that yes, they do need to run a wire from the house main panel to the subpanel in the garage/barn in order to fix it correctly. They just aren't seeing it as an issue, and they don't seem to have any interest/urgency to complete it.

It was installed through a private local solar company. They never mentioned a trust and I don't recall ever seeing that in the contract no.

This is my first solar experience, so I didn't know if this how the industry operates, and this is a common experience/install or if this is an install where they took shortcuts to make up their margins?

Because for the system it is, it was a good deal as I shopped other SunPower dealers, and this local dealer is well-regarded with what I have seen. Though, there are only about 2 main solar companies in the whole valley and a smaller 3rd one. So not a lot of competition.

The install itself was really good and clean. They did great work. They just tell me "It will make it up this summer" and "SunPower's don't require the high tilt angle others do because they're so efficient". I just don't buy it.

So, in the app when it says I have produced 72% of my consumption to date, in reality it is about 62% when I account for the missing consumption in the garage/barn. Forgot to mention also: no, they never performed a site survey. Maybe it was done on the desktop but no they never really measured any angles of nearby trees (which only shade in deep winter part of the morning) and no they never measured the roof pitch or suggested anything.

Thank you for your insight.

Right, I do not buy it either. Bruce Roe

Hey, are you in Mesa County Colorado? If yes, your county building department has a handout for photovoltaic installations. They require drawings, etc. You might be able to get documents from the county in addition from your installer.

Thanks!