All right, now assume making a 120m deep hole is cheaper than building a 120m tower. BTW, how many 120m deep holes have you seen in your life? You seem to be expert at them.
I have seen a few 120m towers. They call them skyscrappers.
Anyway, all this for 20Kwh. I can get a Nissan Leaf with a 40/60Kwh battery for way less than a skyscrapper. Most likely for way less than what it costs to make a 120m deep hole.
Long story short: cranes and concrete don't make a practical battery, but they make for many articles and publications.
Before you say "but lithium is hard to find, and concrete isn't": you can also make lead batteries, and ni/cd batteries, and liquid air batteries too. I don't expect the Earth to run out of air in the next decades.
Sorry, I guess I'm coming across wrongly somehow? I think 120m towers are crap as an energy storage solution. Maybe they could shove them inside skyscrapers that are being built, but that seems like a reach, especially given the size of the blocks needed for things to be practical. Leveraging existing mine shafts for it seems relatively sane. The work is done, it's unused, might as well get some ongoing value out of it, vs building a whole sodding great tower.
Static concrete being able to store power like a battery, like the article is talking about, is ideal if it works (possibly with caveats depending on how quickly it degrades). It's a ubiquitous material, used all over the place. It'd be getting value out of something that is going to be used anyway.
Gravity batteries are practical if you don't have to construct most of the infrastructure. Examples would include a bunch of mountains already there to construct a dam and have hydro pump storage, or an unusually nice and straight mine shaft that was already paid by the mine.
Anything heavy can be used as a gravity battery. Water in hydro pump for example. Or lead, or concrete. Lead is not that cheap, concrete is not that effective. For water we usually have already constructed a dam, it's just a case of adding another pipe and a pump.
But I guarantee you that if we were to construct a dam, pipe and pump just for energy storage - instead of taking an already existing dam we built for another reason, it would also not be as good as a bunch of batteries in pretty much all relevant factors.
I have seen a few 120m towers. They call them skyscrappers.
Anyway, all this for 20Kwh. I can get a Nissan Leaf with a 40/60Kwh battery for way less than a skyscrapper. Most likely for way less than what it costs to make a 120m deep hole.
Long story short: cranes and concrete don't make a practical battery, but they make for many articles and publications.
Before you say "but lithium is hard to find, and concrete isn't": you can also make lead batteries, and ni/cd batteries, and liquid air batteries too. I don't expect the Earth to run out of air in the next decades.