72-cell versus 60-cell for residential?

[Fafrd]

I'm planning a 3kW system and 72-cell panels lay out much more efficiently on my roof than 60-cell panels.

I'm interested to know whether there are any reasons to avoid 72-cell panels for residential solar systems.

I'm in the Bay Area so snow is a non-issue.

[Amy@altE]

Hey! I just released a video on that last week! Go to YouTube and search "Solar Panels for Beginners: 60 cell vs 72 cell solar panels ".

The big question for you would be what inverter are you planning on using? Enphase doesn't support 72 cell for residential. If using a centralized string inverter, string sizes may be restricted when using 72 cell because you may be limited to 11 72 cell panels in series instead of 13 60 cell. SolarEdge should be fine with either.

[Fafrd]

Thanks for the response.

Yeah, I know about the Microinverter issue - I had posted a new thread in the 'Equipment' forum about the different Microinverters I am considering for feedback, but got no response, so thought I'd try here.

I'm looking at a 3kW system using Dual 500W Microinverters from APS or NPT or single 250W Microniverters from NPT or Darfon.

So I know about the Microinverter issue as well as the greater unwieldyness of the panels but am trying to understand whether there are any other significant reasons to avoid 72-cell panels for residential.

72-cells fit in portrait and I can get my 3kW with 9 335W panels, while 60-cell need to be mounted in landscape and I need 11 275W panels for 3kW, so racking costs are double for 60-cell and I need 11 Microinverters instead of 9 (or 5 duals).

It's a no-brainier for my system unless there are strong reasons to avoid the less-beaten path (hence the thread .

[Amy@altE]

SolarEdge with 72 cell is your answer.

[Fafrd]

If I go with the 6kW Solaredge for future upgrade ability, the Solaredge+Optimizer solution costs about 20% more than the Microinverter option, but you raise a good point that when factoring service and support into the equation, that savings may be a false economy.

The other reason I was leaning towards Microinverters is that I felt more comfortable managing a Microinverter-based DIY install, but I'm now discovering that DIY install may not be as straightforward as I had hoped due to the complexity of the permitting process and the fact that finding outfits that will help with permitting only appears to be difficult/impossible (at least here in the Bay Area).

[bcroe]

I'm planning a 3kW system and 72-cell panels lay out much more efficiently on my roof than 60-cell panels.
I'm interested to know whether there are any reasons to avoid 72-cell panels for residential solar systems.
I'm in the Bay Area so snow is a non-issue.

I'm using both in the same string inverter system. A string of 10 @ 72 cell panels in series produce the same voltage as 12 @ 60
cell panels. Just so the panels in any string have similar Imp. The 72s are much harder to handle, but fitting the location and
some economics can be important. Bruce Roe

[Fafrd]

Appreciate the heads-up. The 72s fit in portrait and 60s need to be installed in landscape, meaning roughly double the racking cost as well as 20% more Microinverters.

When you say 'much harder to handle' could you be more specific? I've been assuming that 2 adults can pretty easily handle a 72-cell panel (while 60-cell panels might just barely be manageable by one adult) - is there anything more to it than that?

[bcroe]

When you say 'much harder to handle' could you be more specific? I've been assuming that 2 adults can pretty easily handle a 72-cell panel (while 60-cell panels might just barely be manageable by one adult) - is there anything more to it than that?

As I recall my 60 cell weigh about 36 lb but my older 72s weigh about 60 lb, beside just being bigger and catching more wind. On the ground I
made a rig so one person could tip a 72 into place; not needed on a 60 cell. Bruce Roe

[Fafrd]

The SunEdison 335W panels I am looking at weigh 47 lbs, so a bit heavier than your 60s, but not too bad (progress of technology with time, I suppose). Your rig looks great and I may need to rig up something to easily get the panels up to the roof, but 2 workers should be able to position the panels on the rack, right?

[foo1bar]

When you say 'much harder to handle' could you be more specific? I've been assuming that 2 adults can pretty easily handle a 72-cell panel (while 60-cell panels might just barely be manageable by one adult) - is there anything more to it than that?

I think it'll be more difficult to get a 72 cell to the roof.
I brought my 60-cell panels up by leaning over the edge and grabbing it from someone down below who was holding it up. I don't think that'd work with 72's.
OTOH, if I had brought them up by telescoping forklift, it would have been easy either way.

[Fafrd]

I saw some guy that rigged up a 'lift' using a ladder, two skateboards, and some woodworking skills, so I may do something similar. If the main issue is getting the 72-cell panels up to the roof, I think that is sonething I can manage. If there are other significant issues beyond that, I'd prefer to avoid a surprise...

It's a single story less than 10 feet to the eave with easy access from the side, so getting panels to the roof seems manageable with enough manpower (and the sub-50lb weight)...

[foo1bar]

I saw some guy that rigged up a 'lift' using a ladder, two skateboards, and some woodworking skills, so I may do something similar.

Another option is to borrow some scaffolding - then you can set it up so you only have to go up a few feet at a time.

[inetdog]

Another option is to borrow some scaffolding - then you can set it up so you only have to go up a few feet at a time.

Or do as the Romans did at Masada and build an enormous earth ramp?