Time-of-use electricity pricing
In theory it could save money if it allows companies to charge a different rate for every hour of the day. Don't put your washing machine on between 5 and 8, say.
That's what they did in Ontario, Canada a few years back when I was living there: you had the cheap tariff during the night, the peak rates during the day, and an intermediate pricing at a few other times. However, both the "peak" and the "intermediate" rates were substantially higher than the old time-average rate, while the "cheap" rate was only slightly below. They've also added a special, non-optional surcharge for having the smart meter installed, and upped the fixed costs.
At the same time this was happening, I've put in LED lighting throughout. I also religiously followed the "cheap" times for everything I could (dishwasher, washer, drier - and that's basically it; there is no real way to "defer" cooking, or watching the telly, or running the A/C or the furnace; sitting in the dark also gets a bit boring after a while). The net result was that our household's electricity consumption more or less halved over the next two years. During the same time, our electricity bill (again more or less) doubled. Then it dropped again for a while - but only because the government, eager to be re-elected, introduced an "electricity rebate" scheme - ie upped the taxes (which we notice only once a year, when it's time to pay up) to subside the electricity bill (which is an annoyance every month).
I suppose there must have been some people who ended up saving money with the smart-meter program in Ontario, but I have never met them.