If we're dealing with rural areas reliable internet isn't always a given. The UK had an interesting solution for this for older electricity meters which encodes data in the BBC Radio 4 LW (198 kHz AM) radio station. Most of the country is covered by a single transmitter because of how efficiently LF waves propagate and it doesn't require an internet connection to work. Sadly I think the rise of smart meters will probably be the death knell for Radio 4 LW too.

I think it's easy to forget how flakey the internet can be outside of major cities in some places. Having lived in places that are fairly off the beaten track I wouldn't want my electricity bill to depend on always having a reliable WiFi connection for example.