> If you’re in the Netherland you can get something like a “slimme lezer”, plug it into the p1 port of your energy meter and it will pop up in Home Assistant with the right sensors.

If only the meters had ny power nearby or offered a 5V USB port on it so you could plug in your reader and forget it. But no. Now I'd have to keep a small Li-ion battery living in -20C since the meters are typically outside and there is never any power nearby since they are in a closed cabinet. Only the people who have indoor power meters (I know zero cases of that with detached houses, I think the power companies require the meter to be outside in a cabinet they can access without access to the house.