Bottom line - not all the local solar production is measured at the grid level - much of it results in demand reduction which can't be directly attributed.

I think this will only increase - either due to local batteries, or more electricity driven heating systems ( heat pumps for example ).

And this isn't just homes - if you have a farm and have a big water reservoir which you fill by pumping water - and you had some solar panels - you'd just run the pumps when it was sunny - there is no particular need to run them at particular times ( same if you had a wind driven pump ).