I doubt it. Looking at bitcoin mining hardware, from what I can tell is that ASIC rigs cost about $2-5 per Watt of energy consumed, let's say $4/Watt. Since one might guess that the economic lifetime of ASIC hardware is approximately, say, 3 years (and that's being pretty gracious), then the capital cost of your bitcoin mining rig is about 15 cents per kWh IF YOU OPERATE IT CONSTANTLY.

...but if you only operate it the 25 percent of the time that electricity is free or negative or something, then the capital cost per Watt is like 60 cents per kWh.

Residential electricity is about 11 cents per Watt. Industrial electricity is about 7 cents per Watt, and cheaper in places like the Northwest US with lots of hydro power.

So it doesn't really make sense to buy ASIC hardware and idle it most of the time. You're better off paying even residential electricity rates and operating 100% of the time. If you have access to wholesale/industrial electricity rates, then it makes even less sense to idle your mining hardware most the time.

It MAY make sense to idle the hardware if prices spike, but if you're not operating your hardware the vast majority of the time, then you're not operating cost-optimally.

This point is generally true and applies to other proposed demand-response energy-sinks like hydrogen production: if your capital-cost-per-watt of demand is not very low, then it doesn't make sense to idle production. Capital cost of electrolysis should be the primary focus of any large-scale effort to leverage renewably produced hydrogen, or there's no way to compete IMHO.