The nice thing about gravity batteries is that they can form a closed loop with water supply, too, pumping reclaimed water back up into reservoirs when there's excess power. I'd expect compressed air to have much higher energy density, but it would be interesting to see if anyone has the numbers.
Cranes would work, but I think you’re ignoring the massive difference in mass between what the biggest cranes in the world can lift and even the smallest reservoir.
https://qz.com/1355672/stacking-concrete-blocks-is-a-surpris...
I believe there's a beta test facility under construction now.
https://en.wikipedia.org/wiki/Energy_return_on_investment#ES...
according to the wiki, pumped hydroelectric storage has a ratio of 704 where as compressed air energy storage has a ratio of 792.
(Compressed air: limited by container tensile strength; gravity batteries: limited by strength of cables)
I suspect even the constants involved are the same (given the materials are almost uniformly under nominal load), although I don't have time to investigate right now (a good curiosity research topic!).
Just because it's dangerous in a way you're not used to doesn't mean it's more dangerous.
When talking about battery failure how quickly the energy is released is important.
>A "grid scale" compressed air tank going pop is going to do a lot more damage in the immediate vicinity but won't do anything 50mi away. You can't say the same thing about a dam burst.
If your comparing it to an entire dam, then your looking at underground storage of compressed gas in caverns. For that I agree both are dangerous in different ways.
But the context I was talking about was compressed air tanks which are more comparable to chemical batteries and gravity storage. Catastrophic failure of compressed air tanks is generally going to be more destructive than many other similar alternatives.
>Just because it's dangerous in a way you're not used to doesn't mean it's more dangerous.
A large lithium battery is much less likely to level several buildings than an air tank storing a similar amount of energy. I'm not saying that the dangers of compressed air can't be engineered around, but by almost any reasonable, objective metric you could come up with, compressed air is more dangerous.
TBF I'm pretty comfortable with a proper steel tank.
But, nowadays I'd be afraid to use any of the fiber wrapped ones. I remember in the middle of the 2000s when a lot of new companies jumped into the Fiber-wrapped tank market... and shortly thereafter there were a notable number of recalls in/around the bonding between the fiber and metal layers of the tanks.
And, mind you, this was all in the paintball industry, which was a field where many did not have an understanding of the dangers of a piece of fiberglass with 800-5000PSI pushing it somewhere.
Happened more than once:
phone rings
Boss working at field nearby: "Hey, someone might be coming across the street to try to fill a tank that we refused to fill because it was (damaged/out of hydro)"
Me: "Yeah, I turned them away 5 minutes ago."
Customer walks in
Customer: "Hey the field said they were out of air but otherwise they would fill this."