HA Natural Gas Alarm - Possible via ESPHome?

Hello all,

To give a bit of background we have an neighbor that had a natural gas pipe running insides the wall that was leaking. As all houses in the neighborhood were built around the same time by the same constructor we are a bit concerned something similar could happen. We therefore thought could be a good idea to look for a natural gas alarm.
I’m looking for a device the cloud be integrated with HA, ideally battery powered.
Any suggestions? I could not find any…

The only natural gas detectors I could find that could be integrated with HA seem to be zigbee devices supported by zigbee2mqqt.
I would be happy to go this route but these devices are all 120v powered. And here I realized that I could not find any battery powered natural gas alarms/detectors of any type. Maybe the type of sensor is too power hungry?
The issue is that to my knowledge natural gas detectors are to be installed closed to the ceiling and we do not have any power outlet close to the ceiling…
Wanting to avoid to have to call an electrician to install a power outlet close to the ceiling the only other option would be an extension cord and this is not an ideal solution.

I came to the conclusion that if this detector needs to be wired then it would be best if it was PoE. This is because I do have an unused Ethernet port in the kitchen behind the fridge and I could easily run another Ethernet cable to the attic to place a second detector close to the gas boiler.
Now I have found PoE natural gas detectors do exist, however these are all industrial equipment: very nice but very expensive, definitely an over kill for this application and most probably not straight forward to be integrated in HA (if even possible at all).

So here is where the idea to go through ESPHome came along…
I came across the Dahua DHI-HY-GA40A that is a 12v powered natural gas alarm (with high volume buzzer) that also has NO relay output.
The idea would be to use a ESP32 PoE board like the Olimex ESP32-POE running ESPHome. Connect the NO relay of the Dahua to a digital input of the ESP32 and integrate this way the sensor in HA. The Dahua would be powered by the Olimex via a step-up (boost) regulator (5v to 12v). As per the documentation the Olimex can deliver 4W of power and the consumption of the Dahua should be ~0.8W.
What do you think could this work? Any other ideas for a battery or PoE powered natural gas alarm integrated in HA?

My understanding is these sensors use a heating element of some type, and so requires a stronger power source than batteries can supply for a functional solution. I install the Shelly natural gas sensors a couple years ago. No problems and they run and you can run their self tests from Home Assistant. Doing a ‘real’ test where you bring the gas level up to a point that triggers the sensor is a bit more a challenging test. Good hunting!