>I don't know if aluminum can operate with such fluctuating power In case you're curious, this came up a few years ago in a discussion and at least at the time

>I don't know if aluminum can operate with such fluctuating power In case you're curious, this came up a few years ago in a discussion and at least at the time I checked a typical Hall-Héroult electrolysis smelter could last without power for something like 4 hours or so, maybe 5, and some countries did in fact use them as part of their electrical grid control. But they can't have power interrupted indefinitely because the pots are permanently damaged and require replacement or extremely expensive repair if the liquid metal completely solidifies in them. The molten state represents a significant thermal mass hence the hours of lag time, but it can't just be remelted from total cool down either. I do wonder if an economical design could be made that specifically tried to enhance this aspect as a core design feature, some sort of vacuum insulation or the like perhaps to reduce passive thermal loss and bring outage time more towards 12 hours? But even at 4 apparently it can be good enough for moderation of some intermittent demand (which in turn means extremely cheap electricity). Using something like this as "energy storage" that is also directly economically productive seems worth pursuing though. Another possibility would be to investigate direct carbon extraction from the air, either for storage or to turn into fully synthetic net-neutral hydrocarbons. If the electricity is essentially free anyway, even enormously consuming processes like that could make sense.