Yikes! It would have been obvious to the site assessor, and certainly the install crew, that the bottome row was going to be shaded most of the year.
In hindsight, you might have tried to eliminate or move those penetrations during the re-roof. If any could have been shifted up toward the peak, ever inch helps. They were constrained by those.
Had i looked at this, I would have placed aas many panels as possible on the top row, and had the array start one foot from the left gable end, not 3 feet. Then one more panel may have fit on the top row before the top vent stack. Then I would have continued after the vent stack with the top row until the 3-foot clearance path. Then I would have turned the bottom row to landscape, started at the 1-foot line oon left, and included as many panels as needed to cover your usage.
I think they could still fix it, by removing the panels, sliding the top 3 rows of rails left a bit, removing the bottom row of rails, and moving that row up to accomodate the landscape bottom row, and extending the rail runs right to get your 19 panels back on, or even add one or two additional if they have some spares. Of course, it is a lot of work, and they may not be willing to do that. They would have to also flash/seal the old bottom row of where the mounts used to be. They may not have to slide the rails left, if they can get all the panels back on with the 3-foot clearance on left remaining.
Right now, you have 19 panels, with 10 on top row, likely not shaded at all other than by the tree in early morn, and with 9 on bottom row, likely shaded most of the year, other than maybe 2-3 months around summer solstice. There are 3 bypass diodes in a solar panel, and with the half-cut panels you have they are located in the center, splitting the panel basically into 6 independent sectors. During the part of the year when the shade reaches more than 50% of the bottom panel, those panels are not producing much at all, since all 6 sectors have some shade. During the part of the year when shade starts covering the bottom edge and until it comes halfway up the panel, then 3 sectors are not producing and you get about 50% of the panel production. I would be interested to see the enphase monitoring of this. I would expect to see a part of the year where only the top row panels are producing (10/19 = 53%), like Dec and Jan?, and a part of the year when the top row and half the bottom row ((10+4.5)/19 = 76%) are producing, and maybe a small part of the year when all panels are producing (100%), like May - July.
Of course, some times in the morning or evening, because of the azimuth angle the neighbor house would not really be shading the panels so the above does not apply during those times, and also there may be some times where scattered light is enough to keep some current flowing in the panel even though it is not getting direct sunlight.
Did you look at the enlighten monitoring portal to see differences between the two rows of panels? You can run per module daily or monthly energy production reports to look at differences, and you can also play back the Power production output to see the differences between the rows, and look at how the array was shaded and correlate the impact.
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Ken Nadsady
AviSun Renewable Energy
Hudson OH
Knadsady@avisun.net------------------------------
Original Message:
Sent: 01-21-2022 12:31 PM
From: Eric Otto
Subject: Is it common for production to be less than estimated?
Ken -- here are two photos.
Photo of front of house from street:
Here's a clip from the permit drawings:
From the drawing, the ridge setback is 18", but because of some of the roof obstruction seen in the photos, the actual ridge setback is more than 18". As you can see in the photos, it is a shingle roof, which I had installed 1 year before the solar was installed. It is a 6.08 kW solar PV system, with 19 Hanwha Q Peak Duo BLK 320w solar panels, Enphase IQ 7 microinverters, and IronRidge XR100 solar racking system.
------------------------------
Eric Otto
ericlotto@gmail.com
Original Message:
Sent: 01-21-2022 11:17 AM
From: Ken Nadsady
Subject: Is it common for production to be less than estimated?
Can you describe or show a photo of how the actual installed array was located? Was it installed just like the model shows? The roof clearances they have shown look like they used 3 feet from ridge and 3 feet from both gable ends. Most jurisdictions allow 18 inches from ridge and only require the 3 foot path on one of the gable ends. Maybe they still can rearrange them, although if this is composition shingle roof, they would need to make sure any old mounting locations were properly flashed/weatherproofed. If metal roof, they could rearrange pretty easily.
Is this an enphase or SolarEdge system? If so, it probably would be relatively easy for them to add a few more panels to get your generation closer to what they estimated. Also, what model solar panel was used? Half-cut cell (120) designs are more tolerant to shading across the short edge than standard 60-cell panels.
------------------------------
Ken Nadsady
AviSun Renewable Energy
Hudson OH
Knadsady@avisun.net
Original Message:
Sent: 01-20-2022 03:06 PM
From: Eric Otto
Subject: Is it common for production to be less than estimated?
Thanks, John, for the reply.
I had a bit more back and forth with the installer -- see below.
01/19 me to installer:
"XXX,
Thanks for the response. I dropped the other XXX staff that I included in my original email -- please feel free to add them back if you feel it's appropriate.
My concern is that the numbers in your original proposal, including but not limited to annual production, estimated annual savings, cashflow, and ROI, were all based on your analysis that did not include the shading by my neighbor's house, which appears to be significant. My decision to accept the proposal was based on the numbers in your original proposal, which it turns out are not even close to accurate. It is hard to believe that the shading by my neighbor's house was not considered, as the house and its proximity is easily seen in aerial imagery. A quick look at Google Maps Street View clearly gives a sense of the heights of the houses, and an indication that shading would be an issue. XXX staff (XXX?) performed a technical visit to my property, and inspected my roof -- it would be impossible to not see and understand the height, proximity, and shading of my neighbor's house.
Also, back in 2018, when I was first considering solar, I was working with XXX (XXX). XXX prepared a Bright Harvest report, which is attached for your review. From the shadows in the images, this report appears to consider shading by my neighbor's house. XXX did indicate that there would be shade constraints. When I reached out to you in 2020, I provided the report -- see email dated 07/27/20. I assumed that XXX would again consider shading by my neighbor's house.
I feel that not considering the shading by my neighbor's house is a significant error. How can you make me whole?"
01/20 installer to me:
"Hi Eric
Thank you for reaching out. Agreed that my entire team does not need to be on this email, but I am adding back my boss and one of the owners of XXX, XXX.
I am very sorry for the inconvenience, and I appreciate your concerns. While I agree that this does change the dynamics of your financial return, XXX does not provide any sort of guarantees on the production estimates, and in our purchase agreement, there are no mentions of any expected production amounts. We made reasonable, good faith estimates for the production of the system, and when taking into account production values, we do not model the entirety of the surrounding areas. We limit the extent of our shading reports to the clients' immediate vicinity, in this case, the property boundaries. You also signed up through our bulk-purchasing program and saved well over $.70/w off of our normal system cost. While the Solarize Chicagoland Program has many benefits, it also means that the reviews and analyses that were performed were streamlined to expedite the installation timeline. As you mentioned, you had received multiple quotes from other companies, and also received a Bright Harvest report from XXX, so you were aware that your home was not an ideal candidate for solar. No company would be able to achieve a higher production than what we installed on your home.
While I understand that this is not an ideal situation, I am not sure exactly what you are expecting XXX to do.
Let us know your thoughts and any questions.
Thank you,
XXX"
Not sure what to do at this point. Suggestions?
------------------------------
Eric Otto
ericlotto@gmail.com
Original Message:
Sent: 01-20-2022 02:42 PM
From: John Lynch
Subject: Is it common for production to be less than estimated?
Hi Eric,
I agree with Dara. Your installer should have taken into account the neighboring topography when doing the production estimate. Did you get more than one estimate before selecting the installer? If so, were others more accurate?
In our own case, the installer produced a zoomed out satellite view and 3D model with LIDAR overlay. Ours is a 7kW system comprising 22 x 320W LG panels with Enphase IQ7+ microinverters. We live in the Northeast. Our installer's annual estimate was 8,039 kWh. In our first full year we generated 8,696 kWh followed by 8,545 kWh the following year. The estimates have turned out to be quite accurate.
I think your installer should do something for you such as adding panels to try to get your production closer to his estimate.
Good luck,
John Lynch
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John Lynch
jlynchcc@gmail.com
Original Message:
Sent: 01-17-2022 05:32 AM
From: Eric Otto
Subject: Is it common for production to be less than estimated?
Dana: Thanks for your helpful responses.
It would be great to hear from others, including those tagged in Carly's response. I'm still thinking about how to respond to my installer.
------------------------------
Eric Otto
ericlotto@gmail.com
Original Message:
Sent: 01-14-2022 12:10 PM
From: Dara Bortman
Subject: Is it common for production to be less than estimated?
Wow. Yes. If you have neighbors that are close to you (and it looks like you do), then of course their assessments should include all obstructions including other buildings, all trees that cast shade on your home (whether on your property or not), chimneys, etc. It maybe makes sense that their preliminary assessment was off (maybe ) but once you expressed interest and actually signed a contract and they came on-sight and saw your property they should have double-checked and adjusted their preliminary estimate and given you an updated, actual one to show you what you could really expect. His response is laughably nonchalant. I would ask how he intends to make you whole since yours (and his in his proposal I would guess) ROI and cashflow analysis for whether to purchase the system was based on his wildly optimistic production estimates. They could/should offer to add a few more panels onto your system to get you closer to what they estimated. I will say that estimates are estimates. And being 5% or even maybe 10% off in any given year can be expected due to fluctuations in weather, etc. But in this case it's completely disingenuous to say that they ignored a property that's so close to your home. It looks like you live in a city-like area, not the suburbs or a rural area where neighbors are more spread out. That being the case, ignoring trees and buildings just because they're not on your property is irresponsible. What if there was a highrise building to the south of you? Would they have ignored that in their initial assessment? Personally - I feel they owe you some money back or some additional panels for free. Let's see what the rest of the crowd thinks. :-)
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Dara Bortman
Exact Solar
Yardley PA
dara@exactsolar.com
Original Message:
Sent: 01-14-2022 10:57 AM
From: Eric Otto
Subject: Is it common for production to be less than estimated?
Thanks for the responses. I reached out to the company that designed, permitted, and installed my system. Here's what I wrote:
"Good morning, XXX.
My solar panels were installed in October 2020. On a monthly basis, I have been comparing the actual production (kWh) to the estimated production (kWh) provided by Windfree -- see attachments. To date, the highest actual production was 89% of the estimated production (March 2021); the lowest actual production was 32% of the estimated production (January 2021); and the average monthly actual production for 2021 was 69% of the estimated production. Is this normal? Not normal? Is something wrong with my system? Were the estimates provided by Windfree not good? Thanks in advance!"
Here is their response:
"Hi Eric
Thanks for reaching out – when I originally reviewed your home and provided the estimate, I did review your home and its existing obstructions, along with the trees in the surrounding area, something like shown below:
However, what we did not consider was your neighbor that lives to your south, as shown below with lidar activated:
Typically, we only model the customers property and not neighboring buildings, so that is why we missed that obstruction when we modeled the shading report. I am very sorry for missing that. After reviewing what you sent, and reviewing your property in greater depth, it is understandable that your system is going to produce quite a bit less in the winter months. The system is definitely working properly, just within the constraints of your home's solar access.
Let me know if you have any questions or concerns,
Thank you,
XXX"
So, how should I respond? It's clear that they didn't consider my neighbor's house -- seems like a huge error or omission.
--
Eric
Original Message:
Sent: 1/11/2022 1:02:00 PM
From: Dara Bortman
Subject: RE: Is it common for production to be less than estimated?
Hi Eric -
The estimates your installer gave you are estimates based on averages but they should be relatively close...or at least some months should be. There are always going to excessively snowy months with lower than average production during a snowy winter, or cloudier than normal months, but also sunnier than normal months so it should generally even out. Did your system come with a production guarantee? If not, that's okay...it should have come with a warranty and that gives you the right to check in with your installer and ask why your numbers are so much lower than they estimated. Did they give you estimated production numbers by month or just a single annual estimated production number that you then divided by 12 to get a monthly number? At a minimum, you should be able to ask your installer for a PV Watts output report that shows you how many kwhs your system should generate every specific month of the year (Jan - Dec) based on the size of your system, their shade measurements, your equipment installed, etc. Also ask them how the actual production of your system compares to other customers' systems of theirs (did everyone have a very bad January in 2021 in your area compared to prior years, for example?) Of course, you can't directly compare production of your system with someone else's (unless they have the exact same sized system with panels that face in the exact same directions, using the same equipment, with the exact same shade, etc), but they should be able to tell you if their production estimates are generally better than what you've seen and if so, what might be causing your issues. As a relatively new customer, they should be interested in making you happy, ensuring your system is functioning properly and making you "whole" if they misled you or miscalculated for some reason. I would start by asking a bunch of questions - mistakes can happen. But then be forceful about mitigation if the issues continue and you're not getting what they promised. You might be able to make a complaint to the PUC in your state about it if it's egregious...depends on where you are. But I would go into the conversation initially assuming that your installer will partner with you in identifying if there are issues and fixing them. I hope that helps!
------------------------------
Dara Bortman
Yardley PA
dara@exactsolar.com
Original Message:
Sent: 01-10-2022 10:11 AM
From: Eric Otto
Subject: Is it common for production to be less than estimated?
My solar panels were installed in October 2020. On a monthly basis, I have been comparing the actual production (kWh) to the estimated production (kWh) provided by my installer. To date, the highest actual production was 89% of the estimated production (March 2021); the lowest actual production was 32% of the estimated production (January 2021); and the average monthly actual production for 2021 was 69% of the estimated production. Is this normal? Not normal? Is something wrong with my system? Were the estimates provided by my installer not good? Thanks in advance!
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