Earlier quoted context omitted.
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 st…
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…
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.