Shame to hear about that re. insulation, some of the council houses weren't built with much insulation I know!
The kit I'm looking into doesn't include battery storage. But it could do, think it was and extra grand-ish plus VAT. It would make sense if you were out mostly around the middle of the day.
As we are around a lot in the day, our daytime usage is pretty high and a lot of excess can be dumped into hot water. I felt that battery tech is still developing pretty rapidly so thought I'd reconsider that option as and when the inverter died.
You can use battery and grid tie inverter to fill in on your consuption at night, but if you use hot water you should either fit a conventional boiler or fit a hot water tank before your boiler (not all combis allow this), at 55 deg your combi wouldn't be working at all. You can now also have state changing chemicals which do away with the water tank.
My early fits system (55p thanks lads) was £11.5 grand, paid for itself in 7 years, but I'm considering fitting one on the daughters house non fit, with water heating and battery system, short payback as well but everything is scaled down.
A modified fits stystem where the goverment (us I know) gave a discount on energy costs for fitting solar should be the clever way to most houses having solar, over 20 years it would grow and grow.