I didn’t want to use the Shelly either. I ended up interfacing with my smart meter directly over the builtin data port, so for all three phases I get the exact same power values as the ones my electricity provider uses for billing.
Much easier and probably safer setup. I’ve got the single phase version and it works great. Firmware can be modified easily if you want to bypass the Emporia cloud and app and tie it directly to HA.
In the end it was quite easy to set up the PZEMs, the first “difficulty” was to descide which ESP-board to use, and from there how to wire it, the second is that the PZEMs have an internal addressing that needs to be updated for two of them if they are to be connected to one sinlge ESP-board, how to is described over on the esphome.io webpage
I recently installed one of them. Disassembling and flashing with OpenBK is quite easy, however the BL0942 onboard is connected via SPI but OpenBK currently only supports BL0492 over UART. Therefore I had to modify the circuit with some extra wires, it now works, but if you have no experience with such mods its probably easier to just go with the Tuya Integration.
Could you please give some feedback on iammeter.
Is it able to deal with those noisy (modern) loads - how far off is it from what the main utility meter is showing?
Well, at the beginning i entered all data: price per kWh (low/high) and fixed costs and when i checked my electricity bills for a few months end prices were pretty close, so it seems that it’s measurement is pretty accurate. Honestly, i didn’t check kWh numbers (silly me…), but i guess i just forgot to check since end price is pretty much the same, and in that case kWh numbers are, too.
So far iammeter works like a charm, no dropouts, glitches… it’s pricey, yes, but i think that shelly is pretty much similar priced. If nothing else these devices are great way to check out how devices are connected over all 3 phases and if any of phase is overloaded (and re-wiring is needed).
Thanks for the update, this is great news.
I have one more question:
Are you on net metering / can this device handle that?
net metering short explanation:
say that for one hour:
L1 - consumes 1kW from the grid
L2 - consumes 1kW from the grid
L3 - sends 3kW to the grid (solar production)
In net metering the meter will show:
usage: 0
export: 1kWh
Shelly 3em can’t do this - in this case it will show:
usage 2kWh
export: 3kWh
I’m not on net metering, since i don’t produce any electricity,i just monitor my consumption. But, yes, as far as i know iammeter does support net metering: https://www.iammeter.com/docs/net-energy-meter
IMHO the information you described from Shelly is more complete than the “net metering” and you can still do the calculations with a very simple template sensor.