KNX

[mental jasper]

Then you could buy an input device that supports S0 or just an energy meter that supports knx. I'd go for the latter.

Eg. https://lingg-janke.de/knx-smart-metering-produkte/elektro-energiezaehler/

Or a binary input https://www.mdt.de/Binaereingaenge.html

[vapid estuary]

but the i-luxus has a binary input possibility. but it is not supporting SO impulses