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Originally posted by MGE
(power times time) need an HOURS unit. Bruce Roe
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That does not make sense, maybe you mean 594KWHours? All your energy numbers
(power times time) need an HOURS unit. Bruce Roe
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That is probably a good suggestion, but as readers may have gathered my philosophy is it is easier to ask for forgiveness. I think the city would want to see the usual engineering for the racking that was presumably done on the original install. In my installs, SCE & PG&E only saw a single line diagram with very little detail about orientation. SDG&E may be different and your experience with them is probably more valuable.Last edited by Ampster; 09-03-2023, 05:02 PM.9 kW solar, 42kWh LFP storage. EV owner since 2012Comment
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Yes Im going to call SDG&E on next week and get confirmation on my proposed changes and will request an approval in writing, if they are willing.
Looking at my original application for installing my Photovoltaic Generating Facility all they asked for was.
Inverter Manufacturer Enphase Energy
Inverter Model # M215-60-2LL-S2x-NA
Inverter CEC Rating (per unit) 215.0
Quantity of Inverters 34
Weighted Efficiency 0.96
Single or 3 Phase Single
PV Panel Manufacturer Suniva
PV Panel Model # OPT-260-60-4-1B0
PV Panel CEC Rating 232.8
PV Panel Nameplate Rating 260.0
Quantity of PV Panels 34
Total Capacity (kW) 7.915
Inverter # from above 1
If I remember correctly they also wanted a one-line-diagram of the proposed install, but no specifics on mounting.
Nothing was referenced as far as placement, orientation, racking etc.
See what they say.Last edited by MGE; 09-03-2023, 05:25 PM.Comment
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Thank you.
My permit/application looks quite similar with additional stuff on my CSI incentive claim form (both from 2013 BTW).
I'm being a PITA for the sole reason of having been involved in about 150 or so installs in my HOA since ~ 2007.
I'm the guy in my HOA that gets to review, recommend and sheppard all the PV installs in my HOA, officially for conformance to the CC & R's, unofficially to maybe help prevent or at least minimize the likelihood of my neighbors screwing themselves or getting too badly screwed by vendors (but with very limited success on both counts).
No way I've seen it alI, but I've seen a lot.
One common characteristic for my neighbors with PV systems (the ~ 150): The owners want to believe that whatever makes life easy for them is fact, and usually for things like array changes and size bumps the installer reinforces that opinion and tells the owners what they want to hear and to simply skunk it through.
To be honest about it, my experience is that they (the owners) usually get away with it but the potential consequences are IMO, pretty big, especially (for example) if a fire can be traced to a (faulty) non inspected PV system. Seems like most of my neighbors don't think globally about such things and seem more interested in "getting even" with SDG & E and eliminating most of their electric bill.
In one particular case of an attempted skunk-through, an inspector spotted a 2 array install location being changed to 1 array of the same size (inspectors are roaming around here all the time - N. County San Diego) and got porky about filing an amended permit because the wiring was being changed around and the inspector claimed that involved some considerations with respect to NEC particulars and circuit breaker sizes and some other things I can't remember the particulars about. He could have red-tagged it and stopped work but the whole thing worked out because (according to the inspector - who in always right) NEC requirements were still met and also because the 2 MPPT's weren't changing size or panels and anyway the inspector was in a hurry.
Still NOMB and opinion only but my guess is that you'll be told that a 1 kW increase in system size will be OK w/SDG & E and not jeopardize the system's NEM 1.0 status.
I'm not sure what the city might say, but better to get it resolved than get surprised.
Take what you want of the above. Scrap the rest.Last edited by J.P.M.; 09-04-2023, 12:49 PM.Comment
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I don't know if it's good or not, but it does seem to me to have the advantage of propinquity.
I too appreciate that fortune favors the bold and I generally practice that approach, but I've also found out by example and experience that it can easily slaughter those unprepared along with their brash foolishness who then leave a mess that might have been avoided with a bit more due diligence and professionalism.
A pinch of foresight vs. a pound of cure or look before you leap type of thing. Take the shot, just be prepared. Sort of like a lawyer in court who always knows the answers before asking the questions.
Seems better to me to play heads' up ball, do the due diligence up front and avoid the mea culpas afterwards, but I was lucky in having good mentors many long years ago coming up as a P.E.
Just my $0.02.Last edited by J.P.M.; 09-04-2023, 11:30 AM.Comment
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Bad news to report.
I inadvertently used some incorrect wattage values in my postings.
I used the default value of “ fixed open mount” instead of the “roof mount” in my calculations.
I just went back through my comments and changed the values to the correct ones.
I apoligize to anybody who responded to my thread as their comments are now probably inaccurate as well due to my bogus info.
So….
In a nutshell.
Sorry.
My zip is 92117.
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I just did a quick PVWatts run on your arrays.
In verifying your modeled output for no more than my own use and curiosity, I used all your supplied system info and then forced the combined model output to match the most recent 8 (eight) years of your array's average output by modifying the system loss parameter until the model's output matched your reported output +/- a few kWhr/yr. (The first year's production or so is usually about 3-5 % higher due to panel burn-in ).
FWIW, the system loss parameter needed to be a bit greater than 20 %.
Most roof mounted arrays around San Diego match up pretty well with the model by using a 10% system loss parameter.
Assuming your supplied data is good, with the 10 % loss parameter, your arrays model out at ~ 14,550 kWh/yr. vs. the ~12,500 kWh/yr. you're averaging now, with that difference being about the equivalent of what 4 X 260 STC W panels in a south facing 22 deg. slope would generate in a fouled condition.
My guess is that you're in an area where the panels fouls rather quickly and, like most, yours don't get cleaned except by rain, and, unless you've got a lot of shade, that fouling is most of the reason for the 20% system loss parameter. For a lot of arrays around here, especially near the coast and/or in areas near the freeways or in tightly packed housing or such as in the developing areas along the 56 near the 805 merge with the construction dust, the marine layer and dust combine to form a fouling layer whose runoff is not as easily moved or much affected by gravity, especially on the lower sloped panels such as 2 of your 3 arrays.
All that written/said to ask a question: How often do you clean the arrays ?
And a comment: With the above thoughts in mind, and unless you've got a lot of shade, if your panels are not currently cleaned by hosing on a regular basis, you might restore something like the amount of production you'd gain by adding 4X260 W panels to the south facing array for the cost of a 20 minute trip to the roof with a hose about 1X/month or so and avoid all/most of the hassles we've been discussing about permitting and such.
At least it might be worth a trip to the roof on a regular basis as an experiment. what have you got to lose ?Comment
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I used to regularly clean my panels maybe every other month at first and then unfortunately tapered off since then.
My first year was my best at 13.268Mw hrs.
So I realize that I am leaving $ on the table to some extent.
So I want to add my additional panels to recapture my projected “Max” output potential.
Will I actually change the arrays that are facing W, probably not, but I will figure those losses into my projections on the new string.
Probably will be adding technically more than 1k in new production to help recoup my less than producing existing panels.
We’ll see what the Utility Co. says this week.
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Good news is I spoke to a rep by the name of James in the solar planning dept. at SDGE.
I asked him if it was ok to change the azimuth and tilt angles of my two arrays ( same string ) to the S at 22* using and not changing the wiring, racking type etc. and he said no problem as it sounded like I had been leaving some production on the table for 10 + years.
So it looks like I will be gaining that amount as well in theory as well as the addition to of the 1k.
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Well, that is good news.
Congratulations!
Between the reorientation of half your system to the more favorable orientation and the addition of ~1 STC kW of panels you'll probably be picking up about 3,000 - 3,500 kWh/yr. of production even if you don't hose the array.
Hose the system down 1X/month if it doesn't rain, especially in the summer and add a few % to the annual production on top of that.
As long as you've done the due diligence this far, I'd respectfully suggest you consider checking with the city for any permitting issues that they might have. The POCO and the permitting authority both need to be covered.Comment
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How much to add is dependent on the capacity of your inverter and whether you want to replace it. In California any system upgrades are on hold at the PUC has allowed the three utility monopolies to change the metering program in an effort to kill private solar ownership by their customers.
The utility in Hawaii with the Oahu Rule was successful in killing solar in that state and driving 90% of the solar installers out of business. Our PUC is a captive agency and it does not help that our governor Gavin Newsom, is corrupt and duplicitous.Comment
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Inverter size is a non issue as I used micros.Comment
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It is not true that system upgrades are on hold in California at the CPUC. Each of the three Investor Owned Utilities processes system upgrades for their customers and there is no restriction or hold on those upgrades. I agree the current rules under NEM 3.0 are not as favorable as NEM 2.0
it should also be noted that there are at least a dozen Municipal Utilities like SMUD and LADWP and others that are not regulated by the CPUC.Last edited by Ampster; 09-24-2023, 12:22 AM.9 kW solar, 42kWh LFP storage. EV owner since 2012Comment
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