Yeah so depending on the weather the batt usually fully charged by midday then it heats the hot water up then starts feeding back into the grid, so the yellow is excess and going back into the grid, the green is what I use my self (not including charging battery) but the total height is what the panels have generated that day, Not had a day yet where the battery was not fully charged, need some gloomy days to test how well it charges in those conditions hehe
We can quite easily run off the battery the whole evening / over night and usually left with 40% in the morning, if we have a late meal or roast it can use quite a chunk of the battery and its almost dead in the morning. Iv pretty much avoided the grid so far apart from a couple mistakes, Over summer I think it will be super efficient and save us a good chunk of change. No idea about winter yet but will learn as that comes around. I'm sure it will still cover out background usage but will hit the grid a bit for high energy devices.
Iv signed up with octopus energy export tariff now just waiting for it to be setup, at the moment all the excess is getting given away for free!