Thunderf00t
6 HN mentions · mentioned in 5 months, 2019–2022
23:53 · 749K views · Aug 5, 2019
A Thunderf00t video debunking Energy Vault, a gravity-based energy storage scheme that stacks concrete blocks with cranes. He argues it is impractical and compares it to pseudoscience.
Used as a critical reference to argue gravity energy storage is impractical, not as a general recommendation.
6 comments from Hacker News
[LINK] this video [LINK] Softbank invested. What else do you need to know? By contrast, this is not stupid: [LINK] They might still not execute well, but the idea is sound. What is different? They use a single weight, up to thousands of tons. It is suspended in a disused mineshaft, up to a kilometer deep, protected from weather. The one weight just goes up and down, i.e. it has just two moving parts, the weight and the winch. Winches are extra-mature technology. They are talking about sealing the shaft and compressing hydrogen into it. And, maybe storing heat there, besides. Both ideas are also simple, but they don't have to work for the product to be viable; if they do work, they add value. My impression is they added those so their solution could seem more "innovative": the weight in the shaft, by itself, is a sure thing , so probably missed out on some long-shot seed subsidies. Funding in the energy sector is not well aligned. They will probably need to figure ways to get their cost lower. Batteries are approaching $200/MWh, with people expecting that to hit $100. Certain chemistries ("Form") are quoting $20, but are probably over-optimistic. 50 years operation with no degradation could beat a nominally cheaper system that needs the expensive part replaced regularly.
This idea is nuts, just watch this video if you don't understand why. Does no one do fundamentals at school anymore, water is around the same density as concrete (~2.4 times smaller) except you can just use a simple pump. The reason they use concrete in these designs is because if they used water people would say it's stupid. That's literally the reason. It's the same for mineshafts. These concepts are introduced to confuse you. "But pumped hydro requires some very specific geography—two big reservoirs of water" So does concrete. Expect you are building the geography and it'll be around the same size if it stores around the same energy.
This is a joke Here's an example video to explain if you can't see why - this video [edit] I know it's a waste trying to talk to the death cult, but surely you can see 12,000 tonnes is just 23 * 23 * 23 meters cube of water. You could pump this up a hill, with a simple pump and a simple pipe into a hole No need for $$$ af mining engineers to work in a mine continuously. In a complex engineering task where pieces are moving everywhere. Fumes can kill. Noisy. You get you have to move the 500 tonne concretes block when it gets to the bottom (and top).... all this machinery needs people.
I’m not sure this idea is all that they’re marketing it as. Here’s a video discussing the drawbacks [0], the guy doing the video can be kind of abrasive at times but worth watching/skimming as a counterpoint. [0]: this video
Wasn’t Energy Vault debunked as being too impractical? Here: this video These guys “solve” the wind and control problem by digging a 300m deep pipe for the weights.