Do you realize that the curtailing of water heaters would only need be done maybe 12 days a year (summer peak or winter peak)? No one at the electric utility wants to coerce you into taking a cold shower. It is a matter of not wasting resources. Electricity is very hard to store. It should be done on a voluntary basis by providing users with savings incentives.
Finally, you got my point. Voluntarily, without fear of reprisal/shut off. If I volunteer, great. If not, unless I fail to pay my bill, screw them. They should not have the ability to shut off my power for anything less than lack of payment on my part. We have energy problems in this country because of NIMBYs, watermelons, and government interference. Not because of lack of resources.