See my post #20.
They power it off - grid-by-grid, if memory serves - during peak loading. No specific monitoring is involved, beyond "uh-oh, were approaching the red line, shut down smart meters, starting with grid X-432 and rolling over every 15 minutes from there". Approximately.
Now, could smart metering be used for purposes more nefarious? I'm certain it could. But in my particular case - some years ago - it was unobtrusive and saved me a lot of money at a time when I really needed it.
That makes sense.
What worries me is that my air conditioning will shut down when you need it the most — peak hours.
The problem with central air is that it takes a while to cool the rooms down. What might be gained by shutting it down during peak hours might mean that it runs longer into the evening to try to recover. The savings may be nil but I guess it allows the power company to balance the load.
Is there a kill switch on the thermostat?