Home Energy Monitoring

It took me a while. It all started quite some time ago when I came across this vide on DIY Whole Home Power Monitoring with ESPHome & Home Assistant. Things have changed (mostly improved) but the basics still apply. The video is a great start to Home Assistant and ESPHome learning curve. When I started I knew almost nothing about this stuff.

Knowing this would be a difficult project (well maybe not THAT difficult, but such when you can make many mistakes on the way and even do not recognize them until very late), I took quite systematic approach. 

Started with Home Assistant Yellow. It is a great option for a Home Assistant box, as it has Zigbee / Thread radio bulti in and can be powered via PoE. Also has plenty of storage. Setting up Home Assistant is a breeze, as there is a dedicated image available to be installed via the Raspberry Pi imager.

The next step was ordering the CircuitSetup boards (the main board and 3 add-on boards for 24 channels in total). I also ordered (via AliExpress) the current transformers - 6 bigger ones and 18 micro.

When all arrived and I started testing the basics (on a desk setup with a light bulb as the reference power consumption device), there were several surprises. In particular, I was super surprised with the seamless integration of the ESPHome environment into the HomeAssistant environment. Basically once you flash the ESP32 board initially over USB cable, the next edits/updates can be compiled remotely and flashed over the air from within the Home Assistant session. The integration is really, really good.

As all went like a breeze, I was hoping for smooth and quick finish. Then I noticed the measured results were not entirely accurate. What was worse the bias/offset residual values were changing with every reboot, so offsetting them manually was impossible. It took me a while to convince the software authors that there was a problem. Ultimately it ended well (but took a couple of weeks), and now every one can enjoy way more accurate readings.  

Then came a very busy Autumn and I knew I needed at least a full day (or two) to put everything together. So here comes the quiet period between Christmas and the New Year :) The installation included ripping out the remains of an old (and unused) energy meter, cleaning up the electrical panel and installing the meter together with a bunch of current transformers to measure individual circuits.

Home Assistant has very nice energy monitoring dashboard, capable of tracking solar panel generation, gas usage etc. In my case it is all way simpler - I only consume electrical power from the grid, but have always been wondering what is the contribution of certain devices / subsystems into the total. The setup is not yet complete (I still have 9 out of 24 channels unused), but it looks promising. There was some "coding" involved. The way ESP Home works with YAML files is quite novel. There are tons of things happening in the background, while the "coding" part is really declarative (but can be quite complex). Amdreas Spiess has a good introduction to this concept in one of his recent videos.