Is this the best panel layout for my roof?

[iwood]

The picture is hopefully somewhat self-explanatory. 12 Silfab 500watt panels. Trying to achieve minimal shading. Two strings going into an EG4 6000XP. I did some math and figured out shadow lengths at the winter and summer solstices to identify the best racking options. I also used the iron ridge tool to determine panel spacing. I created the strings based on likelihood of shading in the later afternoon in winter. String A should never see any shade. String B may see shading in winter in the early morning and late afternoon.

The sources of shade are:

• The AC unit is annoyingly right in the middle of things and will likely shade panel 6 from 2:30PM onward in winter.
• Late afternoon shade from trees to the south may get panels 10-12 even after I give them a shave this winter (which my neighbor very kindly agreed).
• I have a vent in front of panel 12 to shorten or bend after I talk to my general contractor.

It's ballast mount. I settled on a 20° pitch hoping the angle is enough to reduce dust and bird crap and not be too terrible in winter. This is in SoCal.

Does this seem like a sensible plan? Should I be considering something else? What have I overlooked? Can I get any more panels up there that won't get shaded?

I haven't settled on the panels yet but figured higher wattage will maximize space and the Silfabs look like a good (albeit a little pricey) product.

• Power at Mpp: 500 Watts.
• Isc: 13.48 Amps.
• Voc: 45.78 Volts.
• Imp: 12.89 Amps.
• Vmp: 38.80 Volts.
• Efficiency: 21.0%
• Cell: 132 Half cells mono PERC.
• Maximum system voltage: 1500 Volts.

 

[chrisski]

I don't think you'll get much better. I can't speak to setbacks for fireman etc. If shading is a issue, that's when I'd consider mini inverters on each panel, but for batteries, this makes AC Coupling which has its own issues.

I did some math and figured out shadow lengths at the winter and summer solstices to identify the best racking options.

Did you include how much the trees grow? I use 1' to 2' per year.

 

[iwood]

I don't think you'll get much better. I can't speak to setbacks for fireman etc. If shading is a issue, that's when I'd consider mini inverters on each panel, but for batteries, this makes AC Coupling which has its own issues.

Did you include how much the trees grow? I use 1' to 2' per year.

I think i have the setbacks right. The top of the image is cropped a bit. I am trying to avoid micro inverters by optimizing placement instead. I accept if I want to add more panels, they will be shaded at different points and will need micro inverters. I can probably get another 6 on the tile and in the less ideal areas next to the panels in this design.

As for tree growth, yes, I've made a deal with the neighbor that when he gets the trees trimmed (they grow into my driveway) I will pay a little bit extra to have them chop a few feet off the top. They're already almost 40' tall so no one is going to notice if they have a flat top.

 

[再生可能 エネルギー]

The picture is hopefully somewhat self-explanatory. 12 Silfab 500watt panels. Trying to achieve minimal shading. Two strings going into an EG4 6000XP. I did some math and figured out shadow lengths at the winter and summer solstices to identify the best racking options. I also used the iron ridge tool to determine panel spacing. I created the strings based on likelihood of shading in the later afternoon in winter. String A should never see any shade. String B may see shading in winter in the early morning and late afternoon.

Do you have a flat roof in the area where you are installing the PV?

Looking at the shade of the wall on the left, it seems that the 4 North PV are already inclined toward the south.​

And the 3 South PV then seems to be inclined in the opposite direction toward the north, bu I might be wong?​

What kind of ballast mount are you using to hold the panels? How much weight are you adding to the ballasts?

Do you plan to install any Rapid Shutdown systems and optimisers or PV monitoring devices?