Interesting point about the economics of Energy Vault. I had not actually done the math before. $80 seems low for current prices but it's about the right order

Interesting point about the economics of Energy Vault. I had not actually done the math before. $80 seems low for current prices but it's about the right order of magnitude. OTOH there is at least one project being built to store 100 MWh, and they have a bunch of investors for millions of dollars. That's a bunch of smart people who surely did at least 5 minutes of math to validate the idea, which makes me wonder what they saw that's missing from this analysis. It's possible it's all just a big scam, but strikes me as unlikely. Also, doesn't thermal storage have the same problem with long-term storage of energy not producing a lot of revenue? Perhaps the capital investment is lower, but the yearly income would be order-of-magnitude the same. I was pretty much agreeing with you about thermal being the cheap option, but thanks for the breakout. Do you know of any examples of 10 GWh thermal storage? Just curious, I haven't really poked into that area too much.