We can't use much of it yet because we haven't the renewable generating capacity to charge it from. (Charging it from fossil fuels would be beyond stupid.) Several varieties are getting cheaper very fast, and new, cheaper ones are being invented, so when the time comes it will cost a lot less. Likewise, carbon capture: building that out now would be stupid if it diverted money that could be spent building renewables that displace carbon emission.
It is also why building nukes is stupid: they displace way less carbon emissions, per dollar, than renewables, and first spend a decade displacing none at all. For the price of the coal burned waiting for the nuke to come on line, you could build that much solar, never mind what you are wasting on building the nuke, and it would start displacing carbon emissions almost immediately.
Batteries and pumped hydro are very far from the only practical storage media. But the assertion you read that pumped hydro does not scale is deliberately deceptive.
I would read Tom Murphy's posts from a different light. His message has consistently been 'unbounded exponentials aren't real, why are you pretending they are?'.
In that light 'pumped hydro can't scale' means 'stop trying to use this for Petawatt hours of energy storage you idiot, you'll destroy everything'.
Some of his more recent posts have been worryingly easy to coopt by the 'maek moar fossil fuels and nuclear' crowd, which his previous posts indicate he should be even more strongly opposed to.
The general message of degrowth and steady state economy is positive even if 'pumped hydro can't scale indefinitely' sounds a bit like 'pumped hydro can't decarbonize the current scale of the economy', and he gets the scale required to maintain status quo consumption a bit wrong.
I do wish he'd make this distinction clearer though.
We can't use much of it yet because we haven't the renewable generating capacity to charge it from. (Charging it from fossil fuels would be beyond stupid.) Several varieties are getting cheaper very fast, and new, cheaper ones are being invented, so when the time comes it will cost a lot less. Likewise, carbon capture: building that out now would be stupid if it diverted money that could be spent building renewables that displace carbon emission.
It is also why building nukes is stupid: they displace way less carbon emissions, per dollar, than renewables, and first spend a decade displacing none at all. For the price of the coal burned waiting for the nuke to come on line, you could build that much solar, never mind what you are wasting on building the nuke, and it would start displacing carbon emissions almost immediately.
Batteries and pumped hydro are very far from the only practical storage media. But the assertion you read that pumped hydro does not scale is deliberately deceptive.