If your elec. co. offers any kind of deal like this, go for it.
Certainly nothing wrong with a good reminder, but interruptible
service has been around for many years. Hope you have not been paying
the full rate all this time. Many people probably don't bother because
of the need for the extra metering, but it's very cost effective as
you state.
This is a recent offering. THey only thing they installed was a
device near the water heater high on the adjacent wall. He installed
it in ten minutes.