It's not about reducing them, it's time-shifting them. The big electric consumers are A/C, heating, refrigeration, hot water heating, and car battery charging. All of those are very amenable to time shifting, and this shifting can be automated.
That's an interesting idea. The current residential home appliance setup is totally not amenable to it - I don't even know where my refrigerator & hot water heating on-switches are, I rarely touch the A/C & heating, and I'm certainly not going to remember the rates at a give time of day as a consumer (I likely wouldn't even be home or awake when they're lowest). But if rates actually varied throughout the day, I could imagine smart-thermostats and smart-switches being a very lucrative new market. Manufacture a piece of silicon & copper and it saves you a hundred dollars a month in electricity; I like the idea.
I'm on a time-of-use tariff, and I use the timer on my washing machine to have it finish just before the end of the very cheap overnight rate. That alone has made a pretty big difference.
You bet. There'd quickly be add-ons to adapt existing systems to do this, and powerful incentives for the manufacturers of those systems to bring out new designs to take full advantage.
My electric bill is hundreds of dollars a month. Cutting it in half would be very motivating to me to buy new systems.
I would only categorize car battery charging as very amenable to time shifting, and the various kinds of heating and cooling as slightly to moderately amenable.
With refrigeration especially, you want to keep it in a very narrow temperature band. You could design a fridge that keeps an ice reservoir worth several hours, but without that you have very little ability to time shift.
With minor engineering changes, you can timeshift quite a bit.
Consider hot water heaters. When power goes out, mine will keep water hot enough for a shower for 2 days. Two days. That means the design can be changed to heat water up to, say, 200 degrees, and then mix it with cold water to bring it down to 100 or so when demanded, and one should never need to run the heater more than a couple hours a day when power is cheap.
Storing hot and cold water can also timeshift heating/cooling your house with a simple and inexpensive system (little more than a controller and a water tank). Much, much cheaper than battery storage.
Mix-down hot water heaters have been a thing since I've been alive (read: any commercial building) - it's not new or strange tech, just find a competent plumber and be willing to pay triple. Or DIY if you're that sort of guy - it's not exceedingly difficult.
If I were building a home today I'd "fake" this by simply using a standard tank water heater overspec'ed for my usage, heat that only with solar power on a intermittent basis, and put a tankless water-heater in-line for when/if the temp from the boiler gets too low. I've seen this implemented in more than a handful of higher end new construction myself and it seems like the least hacky/most supportable-by-mortals means of accomplishing it in the typical home.
