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I've just started playing around with Home Assistant, initially as a way to display data from my Sofar ME3000SP system. I started out just using the really crappy Solarman app, but frankly I don't much like the idea of having the thing connected to China at all, plus the Solarman app is laggy and fairly unresponsive. The first fix was to connect a Raspberry Pi to the RS485/MODBUS connection on the inverter and run InfluxDB and Grafana on it, serving up a web page on the local network with info on the system. That worked OK, but wasn't very expandable or flexible, and although Grafana is pretty good my wife found the display hard to interpret - she wants something that says "it's OK to put the washing machine on now" in essence.

Next iteration was to install Home Assistant on another Raspberry Pi, this time indoors and with a HDD to store all the data. After a lot of faffing about I've got this sniffing data from the Solarman WiFi stick and logging and displaying it locally. This works OK, but only updates about every 30 seconds or so, so the gauges showing the live data are still a bit laggy.

Next iteration was to set up an ESP8266, connected to the inverter RS485 port, and acting as an MQTT client, sending data to Home Assistant. I've sort of got this working, and it updates faster than the Solarman WiFi stick (about every 5 seconds) but it's not quite 100%, as I need to sort out a template to convert the 2's complement data from the inverter. The bidirectional parameters, like battery charge and discharge, and grid power and current, are signed integers and I need to find a way to convert them to created sensor values using a template. Should be easy enough but I'm just not familiar with yaml or Jinja2, I'm very much an assembly language guy, happier with raw bit manipulation.

Next step is to make some user-friendly displays to stick on the wall to show the status of the house systems and also useful stuff like the weather. I've already integrated a solar output forecast into Home Assistant, that provides a useful prediction of solar generation for our system, at our location, taking account of the weather forecast, local horizon, etc, that just adds a dashed line plot to the HS energy display. I'd like to use that data to predict how much energy we're likely to be able to harvest each day and use that to determine when it makes sense to run the washing machine, charge the car, etc. This is the data from today, with the bar graph showing the actual solar production and the dashed line on that chart showing the prediction for today:

I use NodeRed for my displays though petty basic at the moment.

Not tried Node Red, might give it a go, though, as it looks a bit easier to get my (ageing) head around, perhaps. Home Assistant seems pretty straightforward as long as you want to do things that have already been done, but trying to get it to work with anything home brew is definitely not as easy, as the documentation covering the nuts and bolts of how Home Assistant works with regard to hardware is a bit thin. ESP Home is a bit better (from my perspective as someone that grew up writing assembly language for the 6800 series . . . ) as there seems to be more of of a hardware focus.

Interested in this as I’m looking to build something that combines all the various things I have into one place. Currently solar pv, Eddi, Iotawatt 14 channel monitor, Luxpower inverter and pylontech batteries. I was about to look at home assistant myself.

There’s a chap on YouTube, The EV Puzzle who does some interesting videos about his alternative energy stuff and he has everything combined through home assistant. I was going to message him and ask him to do a video about his home assistant setup

Currently I’m starting to play with EmonCMS but only in the early stages so far.

Getting basic stuff into a useful display with Home Assistant is reasonably easy, the hardest part I found was getting data from the battery inverter. That has everything needed available, as it has CTs on the grid supply at the meter and one on the PV supply, but getting access to all the data it logs internally needs some hardware. The Sofar ME3000SP has an RS485/MODBUS port, and all the internal registers in the inverter can be read from that (and some can be written as well to control the inverter). There's no off-the-shelf module to do this, unfortunately. Closest was the first setup I used, which was a Raspberry Pi with a USB to RS485 stick plugged in, with that wired to the inverter RS485 port.

Once you've got the data, either directly into whatever Home Assistant is running on, or via something else (I'm now using an ESP8266 connected to the inverter, that sends MQTT data to HA via WiFi), then you can fairly easily manipulate it. I have two display options at the moment, one that shows power and weather:
and the other that shows energy, as in the screenshot posted yesterday. Note the inverter temperature, this is with a thermostatically switched fan added to blow air over the heat sink. I have the inverter mounted in a small outbuilding, in the shade, but it generates a LOT of heat when it's charging and that quickly warms up the room it's in. It definitely needs good ventilation in this hot weather.

The power display is the most useful for everyday monitoring, as I've tried to make the green segments of the gauges show when we're generating enough to be able to turn loads on. Including a local weather forecast (this uses Met Office data from our nearest weather station) makes this more useful, as it allows a bit of prediction as to whether it's likely to be sunny later, or for the next few days. The Met Office will give out a free access API key on request, which makes this pretty easy to do. The forecast PV generation uses the PVGIS database (again free to access) combined with the local weather forecast. Not super accurate, but a useful guide.

I've started logging indoor temperature and also relative humidity inside our ventilation system extract duct (I want to make the boost function a bit better than just a fixed threshold hygrostat). The room temperature variation is interesting. This is the past 36 hours, note the way the whole house temperature rose by around half a degree when cooking lunch yesterday and how that heat then stayed in the house for many hours afterwards (we haven't yet had the heating on this autumn):

The extract duct humidity data is useful, it shows a very clear spike when the shower is running, the humidity in the duct increases by about 1% in 30 seconds, so it looks as if I can use rate of change of humidity to reliably trigger boost:
The spikes in humidity when cooking or just running a hot tap are also pretty clear from the plot. Interesting to see just how quickly the extract air gets more humid from relatively minor events in the house.

I did my university dissertation on the air humidity in properties and the effects of furniture. Didn't have the the tech available now- just a data logger!

The humidity in that plot is from inside the extract duct plenum chamber, the place where the ducts from the bathrooms, kitchen, utility room and WC all converge, so tends to be around 5% to 10% higher than the house humidity. At the moment the RH in the hall is 50%, the extract duct is showing 58%.

I have home assistant running now, in a VM on an old iMac. I've moved most of my shelly switches over from HomeKit, added a Zigbee network of power monitoring plugs, motion sensors for light automation and just put in 6 temperature sensors for various rooms. I have my Luxpower inverter connected to it so I can see what that's doing and also have my Iotawatt electricity monitor connected. Oh and the Myenergi Eddi is connected to. It's a very powerful setup, though by no means straightforward, I can see why so many people buy HomeKit and Alexa setups, most folks wouldn't put in the effort to get it working.

I'm about to set up the energy page this week to bring it all together. I'd like to get my SMA inverter connected but can't seem to log in to it, so that needs solving.

Not a bad idea to use a reasonably capable host machine.

I've just run into a slight issue with running HA on a Raspberry Pi, in that it struggles a bit to compile for ESPHome devices. Sometimes it works OK, sometimes it doesn't, seems to be dependent on the available free memory. Not the end of the world, as there other ways of getting ESPHome on to devices, but a nuisance, as it makes updating ESPHome devices harder than it needs to be. Doing it OTA via HA is very simple, as long as it works. Yesterday I had the Raspberry Pi crash and lock up whilst trying to compile a pretty simple ESPHome bit of code.

Might be because I'm using a fairly old Raspberry Pi Model 3B. Don't have a lot of choice, as buying a new Raspberry Pi seems to be near impossible now, looks like all their production is going to industrial customers and there seem to be very few units available for retail.