Not quite true. Unused electrical power isn't dumped as there is no real way to dump it. It simply isn't generated. The power of gas or steam turbines is regulated to match the electrical demand on the grid. Minor fluctuations are covered by storing or removing kinetic energy in the turbines and generators for the short time it takes to adjust throttles to loads.
The real problem is that a generating system on line but with little load has a lot of recirculating power that is used to run the generating system (pumps mostly). The energy cost to run a generator with little load is where the waste comes in. Therefore a 1hr cutback in power demand is a wasted gesture.
I know that, but was trying for a simple explanation.
Thanks for expanding on my point as it remains the same. Turning off lights may save on your bill but the energy not used (as the power generating plant adjust to lower loads) will be used when everyone turns their lights back on an hour later.
“has a lot of recirculating power”
You got an A till that!