I'm struggling a bit with finalizing my PV layout to add ~4kW to my existing system consisting of (33) 250W LG panels and Enphase M215 microinverters that were installed in 2014. For the purposes of layout I am looking at 455W SolarEver panels, although a few other versions are better with some specific layouts.
My roof is kind of a clerestory style with a 2:12 pitch facing south and a 1:24 pitch facing north, but broken into a few different stepped sections that are highest in the west and lowest in the east. It had a modified-bitumen rolled roof originally that was leaking, so we went with a silicone coating over the whole roof in 2021 that was not installed especially well; some sections have serious bubbling issues, although they don't leak. I will eventually need to re-roof the worst sections, but it should last at least another 5-7 years. The house is close to the ocean and gets a lot of salt build-up and corrosion.
My original plan was to take the ~10% generation penalty with using the largest north-pitched roof section, but that happens to be the worst area of the roof for bubbling and the most likely to need a full re-roof. I can add about 12 455W panels to the section.
As I was confirmiming some dimensions though I realized that the level of corrosion on the M215's is really bad, and some of the panels aren't any better. The inverters and panels are under warranty though, so changing them out is about $100 in labor each time as they fail. A second option would be to replace an array of (8) 250W panels with (14) 455W panels. This section of roof is in pretty good condition, and close to where I would put the new AIO inverter. It is a little more complicated dealing with utility approval and permitting, but not the end of the world.
I have a third option, which is to rip out the other (25) panels and microinverters, relocate a couple of plumbing vents, decommission my solar hot water system and install (26) 455W panels with new supports and everything... but that is too much work to do until I am replacing that section of roof.
So, anybody have thoughts to get me out of my analysis-paralysis? Also, any good ideas for roof types for low slope and a lot of salt in the air that accommodates PV painlessly?
My roof is kind of a clerestory style with a 2:12 pitch facing south and a 1:24 pitch facing north, but broken into a few different stepped sections that are highest in the west and lowest in the east. It had a modified-bitumen rolled roof originally that was leaking, so we went with a silicone coating over the whole roof in 2021 that was not installed especially well; some sections have serious bubbling issues, although they don't leak. I will eventually need to re-roof the worst sections, but it should last at least another 5-7 years. The house is close to the ocean and gets a lot of salt build-up and corrosion.
My original plan was to take the ~10% generation penalty with using the largest north-pitched roof section, but that happens to be the worst area of the roof for bubbling and the most likely to need a full re-roof. I can add about 12 455W panels to the section.
As I was confirmiming some dimensions though I realized that the level of corrosion on the M215's is really bad, and some of the panels aren't any better. The inverters and panels are under warranty though, so changing them out is about $100 in labor each time as they fail. A second option would be to replace an array of (8) 250W panels with (14) 455W panels. This section of roof is in pretty good condition, and close to where I would put the new AIO inverter. It is a little more complicated dealing with utility approval and permitting, but not the end of the world.
I have a third option, which is to rip out the other (25) panels and microinverters, relocate a couple of plumbing vents, decommission my solar hot water system and install (26) 455W panels with new supports and everything... but that is too much work to do until I am replacing that section of roof.
So, anybody have thoughts to get me out of my analysis-paralysis? Also, any good ideas for roof types for low slope and a lot of salt in the air that accommodates PV painlessly?
