Sanity Checking + Advice on SolarEdge

[sensij]

Congrats, those are good prices. Renvu has really good prices on Ironridge. Did you decide on the panels. How about Canadian 300 Mono. They should match the size of your current panels. I thought they are about 56c /W. Are you adding to your current setup ?

Buying CS6K-280M's from Tandem, just over $150 / ea + tax, free delivery. The system linked in my signature is my old house, now rented, this is for a new install where I'm living now. If you can find 300's for that price, and need the extra power, I think that is a fine choice. For me, the 280's are already more than I need, just putting excess capacity in because I'll be up there anyway.

[J.P.M.]

Hi JPM,
I will take it all. I agree with everything. I have done the interior efficiencies where possible i.e. Hybrid water heater, high efficiency AC/HP 18.5 SEER, upgrading my pool-pump etc. Its a big house and I have an EV. Looking to get another for wife soon. So I will very much use what I produce. Per my goals, 11.7kW (utility limit) with net-metering should account for 95 to 100% of my annual consumption. FYI, I do not have natural gas at home. This PV systems will represent essentially ALL of my household's energy/fuel demands. (except inter city travel).

That said, I am limited to South facing roof space. Limited to about 31 72c panels or 40 60c panels. I want to be able to produce as much as possible without crossing the 11,764W DC limit that my utility has. Beyond that I have to get $1M insurance because I am considered a Generation Plant. So essentially, I am optimizing against cost of equipment and maximum AC power I can generate within the 11.7KW DC ceiling.

Now If I am looking at about 60c/W for 300W 60 cell panels which mean I will be able to fit all panels facing south.
However, I can also get 325W 72 cell panels at 45c / W. But that will mean of the 4 strings, 1 will get pushed to West and produce only 85%.

==> Marc - I hope you don't mind me starting this tangent on your thread! Btw I called superior today and expecting a call back. Lets see.

As you see fit, just question everything everyone says, maybe and even particularly me. None of us is as smart as all of us.

One other issue: You may be able to fit a lot of panels of any size in/on a particular area, but for several reasons, some of them practical, you may not be able, or want to fill every available sq. ft. or m of roof w/panels.

Good luck.

[aleenoor]

so you can fit 168 more cells on the south roof by using 60cell modules. I would go with 295w canadian or pretty much anything over 280 watt 60 cell south facing.
at 295 X 40 = 11.8kw which is just over your limit or 290 X 40 - 11.6kw just under.
Have you looked into how much the liability insurance will cost above what is already on your homeowners policy? Mine already had it.


BTW: 325W 72 cell modules are just under 17% efficient which is equivalent to a 275W 60cell module.

Yep, i am at the same match but the 325W 72c are 20c a watt cheaper ... comes out to $2400 .. That's the only reason I was considering 72 cell. Not to mention if i do go with SE then 4 or 5 less optimizes to buy and less racking too.

[ButchDeal]

Yep, i am at the same match but the 325W 72c are 20c a watt cheaper ... comes out to $2400 .. That's the only reason I was considering 72 cell. Not to mention if i do go with SE then 4 or 5 less optimizes to buy and less racking too.

optimizers for 72 cell modules cost more than optimizers for 60 cell modules.
because of the efficiency difference, you would be a little better off with more efficient 60 cell modules. 300W 60 cells that you mentioned are pretty costly. look for 290w or even 280W modules. the 290w ones are really last years. We have already switched our base discount model to the 295 Canadian.

[aleenoor]

Yep, i am at the same match but the 325W 72c are 20c a watt cheaper ... comes out to $2400 .. That's the only reason I was considering 72 cell. Not to mention if i do go with SE then 4 or 5 less optimizes to buy and less racking too.

Here is a quick diagram of what i am looking at.

[sensij]

Here is a quick diagram of what i am looking at.

Maybe I'm not looking at the picture correctly, but don't you need a ridge setback on the eastern array?

Edit: I see Magius's system is right up to the ridge too, so maybe your AHJ is ok with it. If so, the 72 cell layout looks cleaner to me, but 60 cell gets you more power. I'm not a big fan of the landscape+portrait combination, but understand that it saves you from installing on a 3rd face, so it might be a reasonable compromise to make.

[aleenoor]

Maybe I'm not looking at the picture correctly, but don't you need a ridge setback on the eastern array?

Edit: I see Magius's system is right up to the ridge too, so maybe your AHJ is ok with it. If so, the 72 cell layout looks cleaner to me, but 60 cell gets you more power. I'm not a big fan of the landscape+portrait combination, but understand that it saves you from installing on a 3rd face, so it might be a reasonable compromise to make.

These are not to scale , but the panel corners should be about 5 inches from the ridges.

[Magius]

For whatever it might or might not be worth, the graphic I posted earlier is to scale. I sent my installer a .PDF of my house plans and he used some kind of software to turn it into a 3D model. He then came out with a drone to take photos of the roof and map out all the vents, pipes and other obstructions you see in the model. It was an impressive service compared to the hand-drawings I've seen from several other installers, not that it amounts to much more than a pretty picture. On the plus side, when it came to installation everything went exactly where it was supposed to, no need for updates on the roof as is often the case with less rigorous drawings and plans.

Also, I'd never heard of the ridge setback, but looking it up now I see that some areas (California) require 3 feet?! That would be a ton of wasted space on both sides of a ridge, and my roof is almost all ridge . I'm glad we don't have to deal with that requirement here.

[aleenoor]

For whatever it might or might not be worth, the graphic I posted earlier is to scale. I sent my installer a .PDF of my house plans and he used some kind of software to turn it into a 3D model. He then came out with a drone to take photos of the roof and map out all the vents, pipes and other obstructions you see in the model. It was an impressive service compared to the hand-drawings I've seen from several other installers, not that it amounts to much more than a pretty picture. On the plus side, when it came to installation everything went exactly where it was supposed to, no need for updates on the roof as is often the case with less rigorous drawings and plans.

Also, I'd never heard of the ridge setback, but looking it up now I see that some areas (California) require 3 feet?! That would be a ton of wasted space on both sides of a ridge, and my roof is almost all ridge . I'm glad we don't have to deal with that requirement here.

Yeah, that sure is a good service. I am still waiting to hear back. However, to make up for it, I have taken a few trip to my roof to take detailed measurements and have accounted for all the vents, pipes shading , etc. Only questions is how close can I go to a ridge and still be compliant. Specially with us being in hurricane territory.

Marc, Would you happen to have some pictures of your actual installed panels . Trying to gauge, what was the minimum distance left from ridges and eaves etc. Also, what kind of racking did they use ?

[J.P.M.]

These are not to scale , but the panel corners should be about 5 inches from the ridges.

So how much ridge clearance is required by either your AHJ or other (fire) jurisdiction. CA requires 3 ft. Other states/jurisdictions following national codes may/may not require the same. Did you check ? Also, code requirement or not, it's common sense and good practice to avoid covering roof penetrations. Some jurisdictions require vents to have clearance all around (CA is 6").

Looking before leaping is always a good idea. What you don't know or what you assume can hurt you.

[Magius]

The best image I have is the one I used as the "site image" on my monitoring portal. The web page doesn't really show it well, it's barely more than a thumbnail in the lower right. That said if you download the SE app and visit my portal that way the site image is displayed much larger across the top of the screen.

I can email you the original high-res version of that image later this evening when I get home, and if you're interested my installer also put together a ~60s video of drone footage from different angles that you might be able to pause to get a better look. I forget how large the video is, it might be too much to email, but I could drop it on a Dropbox or Google Drive or something for you?

[aleenoor]

The best image I have is the one I used as the "site image" on my monitoring portal. The web page doesn't really show it well, it's barely more than a thumbnail in the lower right. That said if you download the SE app and visit my portal that way the site image is displayed much larger across the top of the screen.

I can email you the original high-res version of that image later this evening when I get home, and if you're interested my installer also put together a ~60s video of drone footage from different angles that you might be able to pause to get a better look. I forget how large the video is, it might be too much to email, but I could drop it on a Dropbox or Google Drive or something for you?

That would be great. Google Drive will work. btw just missed a call from Richard Smith from Superior. Will call him back soon.

[aleenoor]

So how much ridge clearance is required by either your AHJ or other (fire) jurisdiction. CA requires 3 ft. Other states/jurisdictions following national codes may/may not require the same. Did you check ? Also, code requirement or not, it's common sense and good practice to avoid covering roof penetrations. Some jurisdictions require vents to have clearance all around (CA is 6").

Looking before leaping is always a good idea. What you don't know or what you assume can hurt you.

I agree. Once I have an installer finalized, I will bank on his experience to finalize the layout etc.

[aleenoor]

Hi All, I have a question for all the pros here. Would you prefer one of the following panels over the other.

Canadian Solar CS6K-295MS (Black Frame White Back) $0.54 /W

https://www.civicsolar.com/product/canadian-solar-cs6k-300ms-300w-mono-quintech-blkwht-solar-panel-5bb

Hanwha Q-Cell Q.PEAK G4.1 ( will get either 300W or 295W) $0.58/W

https://www.civicsolar.com/product/hanwha-qcells-qpeak-g31-300w-blkwht-solar-panel

Also, really struggling to decide between KACO (2x5KW ) or SolarEdge (SE11.4kw+P300 ) The KACO setup will be about $2200 ($1500 after tax incentive) cheaper for me (I do not need rapid shutdown). Some info about my system is:

11.8kw (40x295W). All South (180) facing at 26.6 degree or 6:12 pitch. Mix of Portrait and Landscape. Minimal Shading but up to 3 or 4 panels will get shading very early in the morning and late afternoon due to some trees and a step b/w the 2 arrays.

Thanks a lot for your insights.

[sensij]

I'm not sure what there is to say at this point. The design with the Kaco is straightforward, two inverters gives you 4 mppt's, so you can make strings of 10 panels and land nicely in the voltage range the inverter wants to see. I'm not sure how monitoring works on those, but they have an ethernet port, so presumably there is something available. If you go with SolarEdge, maybe you lose a little bit less production to shade, but $1500 seems like a lot of ground to make up if you don't have any shade during the middle portion of the day. You get individual panel monitoring, which might be worth something to you, but you also get the risk of failure of an optimizer, which could be a headache if it happens in the middle of your array and you need to clear a path through good panels to get to it. Kaco's US division is relatively new, which is probably a point in favor of SolarEdge today given SE's current market share, but SolarEdge hasn't been around all that long either.

The Canadian Solar panels are slightly smaller than the Hanwha panels. It was enough of a difference to affect my installation, so I went with Canadian Solar. I'm not sure that you'll really see any difference between them in performance.