The sun is (slowly) out so I have been using my “solar charging” flow again for a few days now.
It is working very good now.
My return energy is below 200W.
I wont get any better because the resolution of controlling the Amina is (1Ampere x220V=) 220Watt resolution)
In the middle the readout of my energy meter. You can see the peak loads (my quooker) does not affect the charging.
You can also see it nicely stays around zero.
The top is rhe mean value (1min) of that same readout. I use that as input for my flow
At the bottom is the current usage of the Amina, that is nicely following the mean (with a resolution of 1A)
The setup is also robust for sudden changes. Below you see the response of sudden high usage (my induction cooking switching on for a boiled egg during lunch 
)
Thanks for sharing these insights.