[Schroedingersat]

A day's worth puts it in the power limited regime where $100/kWh 4C batteries are already close to viable, and can use the 50x higher power per $ and higher efficiency for minute by minute arbitrage to offset costs. Do you have sources for real projects that can beat $60/kWh capacity and $600/kW power (what you'd be competing with by the time construction finished)? Moreover it also needs to beat hydrogen or methane storage (electricity->chemical-electricity) which (sans capex for tanks because I can't find good numbers, but I think it adds about 20%) is about $100/MWh out and $1000/kW using current technology including energy and projected to fall to somewhere around $40 and $500 in realistic timescales.

To make it impossible to mine more fossil fuels even for a mixture of slave-driving sociopaths unrestrained by law and theocrats actively seeking apocalypse we need to be able to use a MWh at night in mid winter that was produced at 2pm in summer for less than around $40 and then do it another billion times without hitting some resource limit. Hydrogen with storage is shockingly close, and if synthetic ammonia/methane or metal hydride get over the line, noone will look at fossil fuels again.

You seem to be telling me that pumped hydro is already there, but I can't find a decent source agreeing with you (or any numbers dealing with this use case for that matter).

[ncmncm]

What I am saying about pumped hydro is that it is deeply mature technology, with no surprises in store. All the equipment is essentially unchanged for decades, except for control-system electronics. All that is new is reservoirs not fed by watersheds.

There are actually dozens of shallow reservoirs behind earthen dams way high up in California's Sierra Nevada mountain range, many almost a century old, constructed with bulldozers that used pulleys instead of hydraulics, hauled up there on fantastically bad cart-track roads. The reservoirs feed penstocks down to Pelton wheels thousands of feet below. For storage, they just attached pumps to the penstocks to push water back up.

[Schroedingersat]

> What I am saying about pumped hydro is that it is deeply mature technology, with no surprises in store. All the equipment is essentially unchanged for decades, except for control-system electronics. All that is new is reservoirs not fed by watersheds.

And I can attach a washing machine motor to my water tank. If it produces basically nothing and costs double the alternative, it's not relevant to the discussion.

> There are actually dozens of shallow reservoirs behind earthen dams way high up in California's Sierra Nevada mountain range, many almost a century old, constructed with bulldozers that used pulleys instead of hydraulics, hauled up there on fantastically bad cart-track roads. The reservoirs feed penstocks down to Pelton wheels thousands of feet below. For storage, they just attached pumps to the penstocks to push water back up.

So there are no new projects which not destroying an ecosystem that are on cost parity with batteries then?

Also as an aside, how pathetic is capitalism as an organizational system that we can't achieve the types of things that were done with horses and carts and pulley bulldozers in the past?