By the time there is enough, storage will be massively cheaper. In the meantime, charging storage from gas or coal and then drawing it down is the same as burning gas or coal for immediate use, just with losses.
I could see Norway or Switzerland being major players in pumped hydro storage, given their geography.
Awhile back I did a bunch of math to try to figure out how much stored gravitational energy is in Lake Mead, and if I didn't make any major mistakes it came out to be about as much energy as the U.S. uses (as electrical energy) in 24 hours. The idea of moving that amount of water around on short time scales is hard to fathom.
Lake Mead stores (well, stored) radically less energy than mountaintop reservoirs with thousands of feet of "head" can hold behind cheap earthen dikes. Look up "penstock".
Stored energy (in a fixed gravitational field) is the product of height and mass. Hoover dam has a "hydraulic height" of 576 feet according to a government website, though the average height of any given drop of water is less than that because the lake is deep (or it was, anyways).
The thing about lake Mead is that the volume of water is absolutely huge. I don't think there are any mountaintop reservoirs anywhere close to it because though the altitude difference could be a lot more, it's hard to store large amounts of water on a mountaintop.
If we estimate that the average height of water in Lake Mead is 400 feet and it holds 26 million acre feet, then a pumped hydro storage system with 4,000 feet of altitude difference would need to hold 2.6 million acre feet to be equivalent. I'm pretty sure there's nothing like that in the U.S. The Bath County Pumped Storage Station in Virginia has an upper reservoir of about 35.6 thousand acre feet and a vertical distance of 380 meters (1,246 feet).
Sweden has lots of high mountains that may have shallow reservoirs built cheaply on top of. Reservoirs with earthen dikes are radically cheaper than the sort of dams needed for traditional hydro power, and may be placed almost anywhere, because they do not need or destroy a watershed. Lots of small ones, placed close to users, are better than one big one like Lake Mead.
1. https://www.visualcapitalist.com/breaking-down-the-cost-of-a...
2. https://www.cnbc.com/2022/05/18/ev-battery-costs-set-to-spik...
As you already knew.
> Batteries will probably be cheaper,
The above commenter clearly thinks that batteries are going to provide cheap storage.
If you have some alternative plan for storage at the scale of tens of terawatt hours, please do tell.
It's great for countries that have it, but you're not going to be storing much hydroelectricity outside of mountainous regions.