Solar Panels Query

[River Song]

OK - I've got a little more information but not a lot.

The Solar Panels are to be installed 2nd week September

Solar Panels on roof go to inverter in loft. No idea of size or spec.
There is also by the inverter some kind of AC/DC switch / Isolator.

From there is is fed to the mains/grid.

In the event that Grid fails then I have nothing. Ideally, after the installers have left, :-)
I would like to take a spur of some kind and charge some batteries and then run some 12v circuits
for fridge etc etc etc

I must admit its nice to have someone else pay for this lot. I don't mind paying for the extras.

The guy says the idea is to run as much electricity as possible during the day when its free
but how do you know that you are using too much and therefore paying for the extra?

it's all far too technical for a blonde ;-)