I just pulled the trigger on an ESY Sunhome system; HM6-30 to augment my existing 6.6kW solar with 5kW Sungrow inverter that I plan to leave as-is for warranty purposes. Therefore an AC coupled system.
So here I am starting a thread to begin conversation about integration of the ESY Sunhome system into Home Assistant…
So first, let it be known, there is an existing integration that has been worked on over here - It’s practically got everything you would need to integrate, and uses MQTT based approach to retrieve inverter parameters.
However, there’s two big shortcomings;
- Reliance on that public (no auth) MQTT server
- The MQTT values omit cumulative production/consumption values, therefore relying on integral Riemann Sum calculations to produce kWh values from instantaneous kW values. There are updated too infrequently which will result in measurement inaccuracies over time. And when the network goes out or Home Assistant is not running the values cannot be counted.
I reached out to ESY earlier last week before signing my contract to see if they were open to sharing any RS485/modbus specification with me, however was met with overall reluctance on that front:
Hi Nick,
Thank you very much for reaching out to us.
Unfortunately, we currently do not provide the access to Modbus/RS485 data interface on residential products. We have already discussed this issue with our app development team, but due to limited development resources, this functionality may not be available in this year. Instead, we recommend you to use our mobile application, ‘ESYsunhome’, which allows you to view, configure, and manage your battery-inverter system fully online. I have attached the user guide to this email for your reference.
Please feel free to reach out to us if you have any further questions.
Which is a bit of a shame. I will try going back and forth with them a little to see what wiggle room we might have, but ultimately the best outcome here would be to achieve a truly local integration (even if that is just Modbus over TCP/IP).
There’s some cross-discussion happening over on Whirlpool and I’ve been discussing with a few folks over in the ESY Sunhome Battery Users Australia facebook group.
This brand has a lot going for it, and I really want it to succeed and achieve a critical mass of adoption - It is very reasonably priced hardware in a stackable form factor. The only piece that seems to be letting it down right now (especially compared to upper-tier products like Sigenergy is the software and integration)