[floatrock]

It's also very capital-intensive. Ideally you would want a useful energy-intensive process with low capital costs so coming online during these peaks but staying idle for the other 80% of the day has minimal impacts.

I wonder if hydrogen generation would be more along the lines of what you're thinking. Hydrogen is an energy store not an energy source -- it takes more energy to produce hydrogen than you get out. But that just means it's a type of battery. It seems conceptually simple to produce... if a plant can be made simple enough (low enough capital costs that the idle time matters less), I wonder if hydrogen generation/burning has been studied as grid-level storage to do this kind of time-of-day energy arbitrage.

(With the amount of interest in grid-level storage and by the law of markets-are-efficient, presumably someone has run the numbers...)