Alan,
I think that you may have the wrong end of the stick here.
I think that what is being proposed is a Battery Bank feeding a Permanently installed Inverter, which would provide the same 230V supply as the PoCo Mains.
Provided that the capacity is there in the Battery bank and in the Inverter(s), I really can't see why this couldn't work.
I've worked with LOTS of 12 and 24V installations in my time and to have a bit in reserve is always good.
With the rising price of fuel in general, I would sort of think that getting away from Petroleum-based generation would be a good option.
The thing is, the place would be wired for 240V as per normal and fused the same but it would be fed from an Inverter.
And before anyone starts to rubbish Inverters as to thier size, you can get them in sizes, up to 150kVA, fully Sine-Wave Compensated, which means you can run a Microwave oven on them properly.
