[stevehull]

PV guys - got a couple questions. I am just itching to get my self install 15 kW system up, but am doing my homework, carefully.

Will go with Enphase - for a lot of reasons not relevant here. That said, I can put in poly panels (250 watt) with M215s for a 15 kW system for a LOT less than a mono system. The poly system (lower wattage panels) requires more panels for 15 kW, so additional racking, wiring and inverter costs are in there. Even with fewer panels/racking/wiring, the mono system (M250 and 300 watt mono panels) is ~ 15% more for an equivalent size kW system. All else is the same (wiring to box, etc). The prices were checked on a variety of sites (Renvu, Wholesalesolar, etc). I have plenty of roof room for the additional poly panels, so space is not the issue.

I know about the Enphase C250 that has 72 cell compatibility, but that is three phase.

1'st question. Just go with cheapest 15 kW system, in this case poly?

Second issue. 300+ watt 72 cell panels are becoming the norm (vs 60 cell). I have heard that Enphase has a higher wattage, higher cell microinverter in the works ("M300"?). The M250 simply can't take the higher voltages that the 72 cell 300+ watt panels put out.

Question 2 Even though I can't stand it, is it worth it to wait until this newer inverter model is released? This will push down prices for M250 and certainly M215s.

I know that the system MUST be in service and utility accepted by Dec 31, 2016 to get Federal tax credit.

Waiting sucks . . . but better to plan carefully (measure twice, cut once) . . . .

Thanks in advance,


Steve