Need help deciding which inverter for proposed system

[Daveyclimber]

I'm currently looking at a couple different inverters. I'm looking for split phase operation and have narrowed my current choices to either 2 SMA Sunny Island 6048 or 1 Growatt 12000T with 250V dual PV input. I am buying components for my near future build and have bought so far 12 Hanwha Q cells G6+ 350 watt panels and 6 EG4 100Ah batteries with TOP mounts. I'm interested in buying 6 more panels if possible. I'm in western Montana and we have little sunshine in the winter so I want to limit running my generator as much as possible.

I like the idea of the Sunny Islands but think it may be over complicating my install by having to have separate charge controllers and wiring up 2 inverters if I'm understanding correctly. It would be a bonus if I were not doing split phase. If one unit went down I'd still have some capability but since two unit are needed for split phase I would be sol anyway.

The Growatt seems very interesting as I could possibly use the integrated mppt and not have to buy additional controllers. Availability seems scarce as it appears to be a newer offering. Price is attractive.

Am I missing something? My 12 (possible 18) current panels are rated VOC 40.73 V , VMPP 34.07 V , ISC 10.79 A , IMPP 10.27 A. Lowest temp around -10F

Between building a home and trying to figure out my solar power system my brain is at full capacity. Thank you for your input and knowledge.

 

[Just John]

Really new, but might be worth looking into.

MPP LVX6048 Hybrid Inverter Split Phase 120/240VAC 48V | SanTan Solar

store.santansolar.com

 

[MichaelK]

Look at the Outback Radian, and The Schneider XW. Both very high quality split-phase 120/240V inverters.

 

[Just John]

Look at the Outback Radian, and The Schneider XW. Both very high quality split-phase 120/240V inverters.

I agree, very high quality. I am just impressed with the 500v solar charge controller and the grid powered charger at this price. Apparently it is having teething problems right now, but once worked out it's an impressive unit.

 

[Hedges]

I say Sunny Island. But instead of a charge controller, use AC coupled Sunny Boy.
This way you can program exactly the charge current your batteries want.
Separate charge controllers will either deliver too much current and damage the batteries, or if set to desired charge current the Sunny Islands will draw all that and more when powering a load.

SMA recommends 100 Ah lead-acid at 48V per Sunny Island as minimum (50 Ah if lithium.) But you can hook up just 100 Ah for two Sunny Island. Probably can't draw their 12kW continuous, 22kW surge with too small a battery.

Get way more PV panels. If you get a 7.7 kW Sunny Boy, 9 kW PV of one orientation is reasonable, but with multiple orientations could have 12 to 15kW.

Design your series/parallel connection of PV panels considering Isc, Voc, and local record cold temperature before buying panels and PV inverter. Make sure they fit together.

 

[Daveyclimber]

I pulled the trigger on the Growatt 12000T with 250v input. It is sized well for my intended panels and can actually add a few more strings but I'm short on room for them anyway. I really did initially want an 8048 Radian but it was priced out of my budget, same with Schneider for that matter with even less wattage available. I was also really looking hard at the SI but didn't care for the fact they were 120v inverters and you had to pair them for 240v and with current pricing would be in the Outback, Schneider price range. Maybe one day I will step up to the plate but I've already nearly reached my planned budget. So to date I have 6 EG4 100Ah batteries, 18 350 watt panels, diesel generator, mounts and racking and combiner boxes with SPD since I'm in a lightning breeding ground. Growatt 12000T and an additional charge controller for the outlying afternoon array. Of course I am goning to need a bunch of ancillary items and am building a 10x16 shed to store everything in.