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DuncanCunningham
Forum Supporter
Posts: 485
Joined: Thu Mar 26, 2015 10:02 am
Delivery Date: 15 Apr 2015
Location: Bountiful, UT

Re: Our solar production

Fri Dec 08, 2017 8:45 am

I'm too lazy to get those kind of stats.. I'll just take mine from the APSystems webpage I can login to. October could of been better as a Micro-Inverter had issues and it took weeks to get a RMA figured out. Most of that wasn't down to APsystems. Once the process was followed they matched the support promised. I was down two 325Watt panels for over a month.

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Statler: Wake up you old fool. You slept through the show.
Waldorf: Who's a fool? You watched it.

2015 Leaf S (leased until May 2018, Bought out in Jan 2017)
2012 Leaf SL (purchased May 2015)

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davewill
Posts: 4824
Joined: Thu Mar 17, 2011 6:04 pm
Location: San Diego, CA, US

Re: Our solar production

Mon Dec 11, 2017 2:52 pm

Well, I hadn't checked on my production for a while, so I did. Low and behold, the much of the last year is showing a significant decline, especially Nov, and Dec isn't looking any better despite unseasonably warm and sunny weather in SoCal this fall. Just as telling the peak numbers are lower, too.


Code: Select all

         2017        2016
Jan     787.68     846.75
Feb     827.43   1,260.48
Mar   1,420.07   1,364.66
Apr   1,569.70   1,421.10
May   1,343.54   1,234.13
Jun   1,473.96   1,486.90
Jul   1,516.38   1,620.35
Aug   1,340.45   1,476.57
Sep   1,156.03   1,234.49
Oct   1,129.70   1,111.95
Nov     787.77     992.07
Dec     324.97     749.82


Plus the system has been showing a steady year by year decline, then a steeper one this year (we aren't going to make enough between now and the end of the year to make this look tons better.

Code: Select all

Energy Table
2012    6,132.38   
2013   15,442.73
2014   15,280.89
2015   14,966.99
2016   14,799.27
2017   13,675.74


I'm on a lease, so I called Sunpower. They agreed there is something up and will be sending out a technician. Should all be on their dime.
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RegGuheert
Posts: 5671
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

Re: Our solar production

Mon Dec 11, 2017 5:19 pm

davewill wrote:Plus the system has been showing a steady year by year decline, then a steeper one this year (we aren't going to make enough between now and the end of the year to make this look tons better.

Code: Select all

Energy Table
2012    6,132.38   
2013   15,442.73
2014   15,280.89
2015   14,966.99
2016   14,799.27
2017   13,675.74


I'm on a lease, so I called Sunpower. They agreed there is something up and will be sending out a technician. Should all be on their dime.
Wow! You've lost about 9% of your production in four years. (I used 14.1 MWh for this year.) That's better than a Nissan LEAF battery, but not a whole lot better.

I wonder if Tony Williams would share his annual numbers to give a trend for comparison.
RegGuheert
2011 Leaf SL Demo vehicle
10K miles: Apr 14, 2013, 20K miles (55.7Ah): Aug 7, 2014, 30K miles (52.0Ah): Dec 30, 2015, 40K miles (49.8Ah): Feb 8, 2017, 50K miles (47.2Ah): Dec 7, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

NeilBlanchard
Posts: 614
Joined: Sat Oct 11, 2014 5:02 pm
Delivery Date: 14 Oct 2014
Leaf Number: 306278

Re: Our solar production

Tue Dec 12, 2017 11:02 am

davewill wrote:Well, I hadn't checked on my production for a while, so I did. Low and behold, the much of the last year is showing a significant decline, especially Nov, and Dec isn't looking any better despite unseasonably warm and sunny weather in SoCal this fall. Just as telling the peak numbers are lower, too.


Code: Select all

         2017        2016
Jan     787.68     846.75
Feb     827.43   1,260.48
Mar   1,420.07   1,364.66
Apr   1,569.70   1,421.10
May   1,343.54   1,234.13
Jun   1,473.96   1,486.90
Jul   1,516.38   1,620.35
Aug   1,340.45   1,476.57
Sep   1,156.03   1,234.49
Oct   1,129.70   1,111.95
Nov     787.77     992.07
Dec     324.97     749.82


Plus the system has been showing a steady year by year decline, then a steeper one this year (we aren't going to make enough between now and the end of the year to make this look tons better.

Code: Select all

Energy Table
2012    6,132.38   
2013   15,442.73
2014   15,280.89
2015   14,966.99
2016   14,799.27
2017   13,675.74


I'm on a lease, so I called Sunpower. They agreed there is something up and will be sending out a technician. Should all be on their dime.


Are trees growing taller, and shading your system more over time?

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dgpcolorado
Posts: 2979
Joined: Sat Aug 20, 2011 1:56 pm
Delivery Date: 15 Dec 2011
Location: The Western Slope, Colorado

Re: Our solar production

Tue Dec 12, 2017 1:08 pm

One thing that I do see very clearly from day-to-day is that I get better production in colder temperatures, other things being equal. Is it possible that generally warmer weather this year, and in recent years, is causing a drop in production?

I was told when I got my panels that production would drop over the first two years and then decline only gradually for the next twenty or so. I get a lot more "weather" here than there is in San Diego, so my production fluctuates somewhat; any significant production drop seems lost in the weather noise:

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              Old panels       New panels
2009             1165 kWh
2010             1132
2011             1203
2012             1227
2013             1179             2148
2014             1145             2072
2015             1125             2034
2016             1150             2077
2017             1109             1988 (as of Dec 11)


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Solar panels on 6 January of this year. Mostly sunny, unseasonably warm, and dry so far this fall.
Blue 2012 SV Dec 2011 to Feb 2016
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GRA
Posts: 7738
Joined: Mon Sep 19, 2011 1:49 pm
Location: East side of San Francisco Bay

Re: Our solar production

Tue Dec 12, 2017 6:40 pm

dgpcolorado wrote:One thing that I do see very clearly from day-to-day is that I get better production in colder temperatures, other things being equal. Is it possible that generally warmer weather this year, and in recent years, is causing a drop in production?

Production will always be better in colder temps, as the voltage will sag with higher temps (modules typically run 20-25C higher than ambient), so it's possible. Cleaning or lack of same is also an issue, but another factor could be gradual scratching of the glass surfaces of the modules due to blowing sand etc. With the exception of cleaning it's not worth worrying about, assuming you've made no changes since you installed it, as there's not much you can do about it. Anyway, here's a decent primer on the factors involved: https://www.civicsolar.com/support/installer/articles/how-solar-panel-temperature-affects-efficiency

As your array is stand-alone rather than roof mounted, restricted air circulation shouldn't be a problem for you.
Last edited by GRA on Wed Dec 13, 2017 6:24 pm, edited 1 time in total.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

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User avatar
RegGuheert
Posts: 5671
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

Re: Our solar production

Wed Dec 13, 2017 6:42 am

dgpcolorado wrote:Is it possible that generally warmer weather this year, and in recent years, is causing a drop in production?
Nope, with a temperature coefficient of power of -0.3%/K, the average temperature of San Diego, CA, would have had to have risen by over 54 degrees Fahrenheit to account for a 9.1% drop in production. In fact, there was no real change in temperatures between 2013 and 2017:

Image
RegGuheert
2011 Leaf SL Demo vehicle
10K miles: Apr 14, 2013, 20K miles (55.7Ah): Aug 7, 2014, 30K miles (52.0Ah): Dec 30, 2015, 40K miles (49.8Ah): Feb 8, 2017, 50K miles (47.2Ah): Dec 7, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

User avatar
davewill
Posts: 4824
Joined: Thu Mar 17, 2011 6:04 pm
Location: San Diego, CA, US

Re: Our solar production

Thu Dec 14, 2017 11:31 am

NeilBlanchard wrote:Are trees growing taller, and shading your system more over time?

Nope, clear air over and around of my house. As far at temperature, not enough difference to explain things. Mainly I was noting that we've had not a drop of rain and no cloudy days this fall.

Before I thought it was dirt and I'd have to clean them at some point, but the last year's drop seems a little big for that.
2014 Rav4 EV, Blizzard Pearl White
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