Which ends up being about 500 seconds of being online per day, or the equivalent of using your home’s Wifi to watch one 8-minute youtube video.
For all its faults, the SmartMeter uses the same frequency, and about the same power level, as normal home WiFi signals (2.4GHz). The transmitter is tiny, since all it has to do is reach to the next SmartMeter.
I’m much more concerned with the apparent fire risk these things have (no UL listing), and the intrusive view of your power usage that it affords anyone who cares to look.