[RE-wrenches] Advice needed on upsizing a battery & grid interactive inverter stack

[Mick Abraham]

Yo, Mechanics~

A client is considering a "biggest ever for me" battery based power system.
They will probably scale down their ambitions once the cost realities settle
in but for now they've asked me to look for battery based inverter systems
which can scale bigger than a triple stack of Xantrex XW6048 inverters. Your
advice would be welcomed.

* The system must be split phase 120/240, not 3 phase.

* Outback seems "out" because the inverter group should handle backup
battery recharge using grid or generator AC...and we also want to sell
excess PV power to the grid.

* No cobbled together AC coupled systems would be considered without a
convincing way to feather the end of charge on the battery when the grid is
down...float & all. I don't want to go back to the days of clunky, coarse
battery "end of charge" care.

* Sunny Island/Sunny Boy is in contention but I'm not keen on having to
stack in pairs to maintain the 120/240 three wire architecture. A single
Sunny Island failure would take down two of the yellow boxes. What is the
limit on stack-ability for Sunny Island?

* A battery sales rep suggested Satcon brand but I think that's bogus
advice. Satcon is pure grid intertie only, right?

***********************************************

So...there is your challenge de la semaine (challenge of the week). Who
builds an inverter system with Xantrex XW-like features only bigger...much
bigger? OR: who could supply the "Mother of Sunny Island/Sunny Boy"
system? Replies would be welcomed on the  List or off.

The Wrench List is the Bomb!

Mick Abraham, Proprietor
www.abrahamsolar.com

Voice: 970-731-4675
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