wyliesdiesels
Well-known member
yes it should be grounded. are theyre any pre drilled holes in it for a green screw?
Main Service Panel + DIY Solar?
- Thread starter sfanale
- Start date
There does appear to be a hole on one side, possibly intended for a grounding point. I didn't see any labeling or a bus bar included, but my guess was I had to ground this box. I just picked up a little ground lug at HD before lunch, so hopefully by the end of today, I will have all the wiring wrapped up.
wyliesdiesels
Well-known member
typically ground bars are purchased separately
As Wylie mentioned, mine is grounded.
The inverter is on the left. The wires comes out the back of the inverter (emt) into a LB to turn 90 degrees and then into the side of the disconnect box. Looks to be a continuous piece of wire, grounded to the conduit and then disconnect box and then the main panel/breaker. Dont forget the PV breaker usually needs to be at the opposite end of the main breaker in the main panel
The inverter is on the left. The wires comes out the back of the inverter (emt) into a LB to turn 90 degrees and then into the side of the disconnect box. Looks to be a continuous piece of wire, grounded to the conduit and then disconnect box and then the main panel/breaker. Dont forget the PV breaker usually needs to be at the opposite end of the main breaker in the main panel
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Thanks for the additional photos! Helpful.
I wrapped most of the wiring today. Specifically got the “irreversible crimp” on the roof jbox ground path:
I don’t get the concept of why THAT ground needs to be permanent, but other parts can be screwed into terminals?? But alas... I’ve been made to understand it’s a requirement to pass. Ground bushing too for the FMC.
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I wrapped most of the wiring today. Specifically got the “irreversible crimp” on the roof jbox ground path:
I don’t get the concept of why THAT ground needs to be permanent, but other parts can be screwed into terminals?? But alas... I’ve been made to understand it’s a requirement to pass. Ground bushing too for the FMC.
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Re: SoCal Sawdust + DIY Solar?
Yesterday, my dad and I got all the panels mounted and wires up:
Cut and capped the railing on both sides as well so it’s all nice and flush:
I also labeled up my panels:
My inspection is in about an hour, so fingers crossed I pass in one shot!
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Yesterday, my dad and I got all the panels mounted and wires up:
Cut and capped the railing on both sides as well so it’s all nice and flush:
I also labeled up my panels:
My inspection is in about an hour, so fingers crossed I pass in one shot!
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Re: SoCal Sawdust + DIY Solar?
inspection passed, no problem:
Monday SDGE should flip me over to TOU net metering and I can power up the system. Thanks everyone for the assistance and advice.
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inspection passed, no problem:
Monday SDGE should flip me over to TOU net metering and I can power up the system. Thanks everyone for the assistance and advice.
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Yes, they are mounted under panels into the rails. If there was a problem with a micro, you’d have to remove that one panel. Could be annoying if it happened.
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When I had my panels installed in 2016, the micro-inverters at the time couldn't handle the output of the panels and 'clipping' could incur during peak production. I opted to go with 'optimizers' instead along with a string inverter. I take it things have changed?
https://www.solarpowerworldonline.c...r-installation-value-using-inverter-clipping/
https://www.solarpowerworldonline.c...r-installation-value-using-inverter-clipping/
I don't know how much clipping really applies to the QS-1 inverters in my situation. My system is pretty modest, only 15x 320W panels. Each QS-1 is rated for 1200w total, and connects 4 modules. That puts me right about 1:1 AC/DC ratio under optimal conditions. If anything, I am under-leveraging the inverters and leaving money on the table. Clipping would be more of a consideration for systems where you are pushing the limits of the inverters--more efficient residential systems or commercial systems where they purposely oversize the modules to the inverters to maximize payback.
That's interesting - I never heard of a quad micro-inverter before.
If, it's the 'APsystems QS1' your talking about, it looks like they can handle a panel up to 375w before clipping starts to occur.
I also see that they won't let you create an account to monitor the system if you're not a professional installer. Is that going to be a problem?
If, it's the 'APsystems QS1' your talking about, it looks like they can handle a panel up to 375w before clipping starts to occur.
I also see that they won't let you create an account to monitor the system if you're not a professional installer. Is that going to be a problem?
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That’s the correct ones. AP systems QS-1, four to one inverter which makes the install SUPER SIMPLE. I ran two of them per trunk line to my jbox, but I think you can link up to 3 in a single trunk line. Makes scaling the systems really easy.
The wholesale company who sold me the hardware is setting up my monitoring account. I should have the account all done Monday along with SDGE.
Might not be the perfect setup for every application, but it’s a really nice option for a smaller scale setup like mine where I don’t need a 12.5kw string inverter. And nicer than doing 15 unique inverters. I still get panel level monitoring too.
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The wholesale company who sold me the hardware is setting up my monitoring account. I should have the account all done Monday along with SDGE.
Might not be the perfect setup for every application, but it’s a really nice option for a smaller scale setup like mine where I don’t need a 12.5kw string inverter. And nicer than doing 15 unique inverters. I still get panel level monitoring too.
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Got my first full day of monitoring recorded:
The peak power reported is just shy of 4400w. The lab optimal rating would be 4800w for my system. I am at 11.5 degree angle and facing due west so... pretty good efficiency! Actually better than my pvwatts estimate.
And... looking at the SDGE metering report, it looks like The system is producing throughout the majority of the peak pricing hours, which was a goal for me. Not only that, but over producing compared to my use in the last hours of the peak. I think my west facing array helps a bit with that:
Obviously this is peak summer production so have to wait a full year to see all the seasons of production before I get too excited.
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The peak power reported is just shy of 4400w. The lab optimal rating would be 4800w for my system. I am at 11.5 degree angle and facing due west so... pretty good efficiency! Actually better than my pvwatts estimate.
And... looking at the SDGE metering report, it looks like The system is producing throughout the majority of the peak pricing hours, which was a goal for me. Not only that, but over producing compared to my use in the last hours of the peak. I think my west facing array helps a bit with that:
Obviously this is peak summer production so have to wait a full year to see all the seasons of production before I get too excited.
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Last edited:
Congrats
My house is skewed slightly to the North West. So we had a choice of putting 21 panels on either the East or West Roof. (South roof full with 18 panels) I went with the West roof for that very reason - production in the later afternoon/early evening is worth more
PVWatts was way off for me. After a full year of production, to get the PVWatts numbers to match my actual production numbers I had to drop the System Losses down to 2%
You should register your system at:
https://pvoutput.org/
It's funny that your system peaked straight across between 1 PM - 3PM, I usually get a fairly smooth curve unless it's cloudy.
This is from today
My house is skewed slightly to the North West. So we had a choice of putting 21 panels on either the East or West Roof. (South roof full with 18 panels) I went with the West roof for that very reason - production in the later afternoon/early evening is worth more
PVWatts was way off for me. After a full year of production, to get the PVWatts numbers to match my actual production numbers I had to drop the System Losses down to 2%
You should register your system at:
https://pvoutput.org/
It's funny that your system peaked straight across between 1 PM - 3PM, I usually get a fairly smooth curve unless it's cloudy.
This is from today
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wyliesdiesels
Well-known member
Got my first full day of monitoring recorded:
The peak power reported is just shy of 4400w. The lab optimal rating would be 4800w for my system. I am at 11.5 degree angle and facing due west so... pretty good efficiency! Actually better than my pvwatts estimate.
And... looking at the SDGE metering report, it looks like The system is producing throughout the majority of the peak pricing hours, which was a goal for me. Not only that, but over producing compared to my use in the last hours of the peak. I think my west facing array helps a bit with that:
Obviously this is peak summer production so have to wait a full year to see all the seasons of production before I get too excited.
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so what is your ROI?
Congrats
My house is skewed slightly to the North West. So we had a choice of putting 21 panels on either the East or West Roof. (South roof full with 18 panels) I went with the West roof for that very reason - production in the later afternoon/early evening is worth more
PVWatts was way off for me. After a full year of production, to get the PVWatts numbers to match my actual production numbers I had to drop the System Losses down to 2%
You should register your system at:
https://pvoutput.org/
It's funny that your system peaked straight across between 1 PM - 3PM, I usually get a fairly smooth curve unless it's cloudy.
This is from today
Yea today was cloudy so the morning wasn’t as productive. I was also looking at that flat spot and trying to interpret the data. I don’t think its clipping because the inverters should still have another 100w total and only one or two panels barely broke 300w. I am guessing that’s approaching the real world panel output for this particular configuration. So the panels just don’t fully supply the inverters at that point maybe? I need more data points to really understand.
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Well... the range based on pvwatts high and lower estimates was 6.5years to 7.5years. If we assume every month will outperform PVwatts, then... 6ish? Ask me again in a year hahaha!
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WisJim
Well-known member
I have 205 watt panels with Enphase m215 microinverters and they clip occasionally, especially on cold sunny March days. I'm impressed with getting over the rated output from these panels often. Everything is functioning properly after o er seven years for the array with microinverters. Some of my other panels are approaching 40 years of service.
Hard to say, but 'clipping' was my first thought also. Are you able to look at the output of each individual panel as the day progresses? My Solar Edge inverter has a 'playback' feature and charts the data every 15 minutes. It is useful to see if the panels are performing properly. For example, I have one panel next to the water heater roof vent that gets some shade from it in the afternoon. In this pic, you can see the lower right panel is underperforming because of it.
In another month, our system will have been installed for 4 years, and so far it has produced 80.54 MWh. 20,000 kWh a year is worth about $5k using $.25 per kWh so 2 more years the system will have paid for itself. I thought San Diego electrical rates were even more expensive?
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It would be my first guess also, just need to see more data over time to know. I do have single panel monitoring as well, here is the highest output on that same day:
The best panel is 305w which is over the inverter 300w rating so it’s reasonable to think it’s clipping. Really only one or two panels which beat 300w and for only a few minutes, not extensively for hours. Could be that one or two of the inverters maxed out, but others didn’t which is why it’s flat without ever reaching the theoretical max 4500w output.
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The best panel is 305w which is over the inverter 300w rating so it’s reasonable to think it’s clipping. Really only one or two panels which beat 300w and for only a few minutes, not extensively for hours. Could be that one or two of the inverters maxed out, but others didn’t which is why it’s flat without ever reaching the theoretical max 4500w output.
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Are you aware there are two different way to 'rate' solar panels?
STC - Factory Standard Test Conditions is considered the 'Name Plate' rating
PTC - PV USA Test Conditions. Real World testing, factors in temp of the panels, etc
My LG panels have a nameplate rating of 330 watts. Real World/PTC rating is 306 watts.
There is a downloadable excel file where you can look up PTC ratings from the California Energy Commission
https://www.energy.ca.gov/media/2368
STC - Factory Standard Test Conditions is considered the 'Name Plate' rating
PTC - PV USA Test Conditions. Real World testing, factors in temp of the panels, etc
My LG panels have a nameplate rating of 330 watts. Real World/PTC rating is 306 watts.
There is a downloadable excel file where you can look up PTC ratings from the California Energy Commission
https://www.energy.ca.gov/media/2368
OH THEY ARE (https://www.sdge.com/whenmatters#plans), but only at certain times and seasons. Time of use rates in the summer vary from $0.20 to $0.52 per kWh. The winter rates are much more reasonable, max $0.27 I think. Generating as much solar power during that on peak, 4pm-9pm, time slot was a high priority. My system did a pretty good job between 4pm-7:30pm with excess generation, so hopefully when we do run the AC those few hot weeks in San Diego, I still wont see a bill.
Otherwise, the repurchase rate for excess generation after the annual true up period is a joke. I think its $0.04 per kWh. Basically nothing.
Yes I was aware. Hanwha actually provides their own "normal operating conditions" number as well. The panels are nameplate rated 320w, PTC says 297w, and Hanwha nominal was ~230w.
This is why I say its possible its clipping, but generally speaking the panels are pretty balanced to the inverters to get me that near 1:1 DC:AC ratio. I think given the inverters are certainly not 100% efficient, its likely why there is a flat spot. After a few weeks of data I'll have a better feel for it.
Yes exactly! On top of the 100% certain annual rate increases, the federal incentives are shrinking annually. This year it’s 26% and keeps dropping each year.
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alfredeneuman
Well-known member
Glad to hear you're happy with it!