[quote=no_such_reality][quote=AN]NSR, do you mean inverter instead of converter?[/quote]

Yes, the transformer inverter, although I think transformerless inverters are now available.

There’s a boatload of sizes, but a few sizes at any technology level, if you’re following what I’m saying.

So we have a SunnyBoy Inverter.

This is the SunnyBoy – 5000 (5kW)
http://www.wholesalesolar.com/products.folder/inverter-folder/SB5000US.html

This is the SunnyBoy – 8000 (8kW)
http://www.wholesalesolar.com/products.folder/inverter-folder/SB8000US.html

The cost looks like wholesale is about $600. Not including install (the same), or those add-ins (the same).

So if you’re looking at $25K for a total system, adding $600 for a larger inverter and a few more panels won’t bump you that much. Probably an additional $2-$3K for 2-3kW more panels.[/quote]
I agree with you. But not all of us have the luxury of having the correct facing roof with big enough space to fit all the panels you need. For me, the maximum number of panels I can fit on my roof is 15. If I go with regular inverter, then the max number of panels I can put on my roof is 12 (multiple of 4), so, we decided to go with an Enphase micro-inverter (1 inverter per panel). It’s a little more expensive, but it allow me to get the max number of panels on my roof.