Energy Monitoring for heat pump - hardware choices

Hardware
1

Want to add energy monitoring to our heat pump - the onboard consumed energy monitoring is rubbish when the heat pump is in idle. I’m geeky enough to want the truth :grinning:

Simple solution Shelly EM with a 50A clamp https://shellystore.co.uk/product/shelly-em-50a/ It works with HA and pretty easy to install but read of issues with strange readings at low power consumptions?

Someone told me about this:

Also easy to install as it uses a clamp so don’t have to mess with existing heat pump wiring and it’s a proper certified meter so no dodgy readings…
… but it’s RS485 Modbus so need something else to get it into HA

Seen this HF Wireless Networking Modbus TPC Elfin-EW11 RJ45 RS485 to WIFI Serial Server | eBay

or this: RS485 to WiFi/Ethernet Module (Modbus/MQTT Gateway) | The Pi Hut

either of which (plus a suitable powersupply) should let HA read the meter - assuming I can handle the configuration.

What do you think? Any and all comments or ideas much appreciated. Thanks

2

I would go for solution which has MQTT support for easy integration into HA. I used a custom ESP solution myself to connect the RS485 of my Gree heat pump to HA, like described here: Modbus Controller — ESPHome

3

Thanks. I’d rather go with off the shelf solutions.
Priorities are accuracy and reliability - stuff I make wouldn’t qualify!

4

I’m putting together a little system to measure COP of my ATW heatpump (MrCool / Gree / etc outdoor unit, to a diy water coil indoors). An ESP8266 w/ lcd screen board, DS18b20 temp sensors for water deltaT, hall effect turbine flow meter for water flow rate, and Emporia Vue energy monitor that I’ll reflash to ESPHome. The arduino code on the little ESP8266 will listen to the Vue mqtt for electricity use, measure temperature and flow, calc and display data and COP on the tiny screen and send over MQTT for database and plotting elsewhere.