Not sure where you are in the world, but I'm using OpenEnergyMonitor

Personally, I'm using their Raspberry Pi version (EmonPI) to monitor my total house energy - grid in, solar in and solar export and pull the data directly into HA.

But there's other options available too, like the 6-channel monitoring, so you could potentially monitor separate circuits and / or high energy systems like heatpumps, etc. They have options for 3-phase too...

In my case, power in AND power out to the grid both flashed the LED on the supply meter (mentioned elsewhere here), so I had to go with CT sensors which I put inside the consumer unit... had a little trouble with calibration due to the electrical noise in there, but +/- a few W is nothing when I have to heat my home with electricity at 4kW+