This video debunks the much-hyped Energy Vault

Originally published at: This video debunks the much-hyped Energy Vault | Boing Boing


There’s probably some engineering principle out there that dictates an inverse relationship between how whiz-bang-sci-fi-looking the concept renderings are and how practical the design will be to build and operate.


I’m a fan of this guy’s videos but conventional hydroelectric technology just doesn’t work everywhere, especially in places with flat terrain. Building an artificial hill or digging an enormous pit to allow hydro storage in a place like Florida would be completely impractical. Even a deep, large-volume pit to allow for a more stable gantry would be pretty challenging, though maybe a variation of that is worth considering. I’m thinking of the miles-deep slanted mineshafts that already exist in many locations. The ore cars are pulled up and down the shafts with cables. Make those ore cars heavy enough and you might be able to make use of that potential energy.
(Hey, it turns out that people are already seriously looking at this. Mine shafts set to become energy storage hubs thanks to British invention)

Stability problems could be solved easily enough through design revisions but to me Adam’s strongest argument against the tower concept is that concrete is very energy intensive to produce, so building the thing would have a huge initial carbon footprint that it would take a long time to make up for.


Why not simply pump water into a reservoir and use conventional hydroelectric technology?

As I understand it, the places where that is practical is pretty limited. But, where it is practical it would work well.


What about a heavier weight over a shallower pit? Build a steel-reinforced concrete shell and fill it with dirt or whatever to save material?

Or a series of water towers to pump water into instead of a single reservoir?


My mechanical engineering friend had always planned on building a self-sufficient house, using known techniques of passive house heating and cooling management. But beyond any solar power installation for electricity, he also intended to have two ‘ponds’, one higher than the other. The lower pond would have a pump system powered by windmill that moved water to the upper pond whenever the wind blows (as it does in Western Kansas), and the upper pond would have an enclosed water route to empty into the lower pond on demand … said route lined with micro-turbines for energy production.
Unfortunately, he died in 2012, way too young, so I’ll never see the results of his dreams. But I believed in his concept then, and I believe in it now. Hydro is well-known, established, and a system as described could be developed and implemented using existing tech and produce a known/calculable value of output.

ETA: yes, this is a single house concept, not an Industrial solution. And yes, it also requires land sufficient to hold two water sources. But it doesn’t take much of a delta in height between water source 1 and water source 2 to produce a flow sufficient to generate electricity. IIRC / YMMV


It seems like a conveyor belt would also be more efficient than the big lever arms of a crane. Moving lots of small material seems inherently more efficient than a large bulk all at once, especially as a way to store energy that is continuous like solar or wind.

The problem with big mass / short drop is that the mechanical gearing to lower that mass a short distance over a long time is going to eat up a lot of your energy in friction.


OK, I got it. We use the excess energy to wind up a giant fan blade. And when the wind stops blowing, we let that fan blade go, which will power the wind turbines!


In order to have the same energy storage with less vertical travel the winches, wire ropes, etc would need to be upsized proportionally and you’d probably end up with equipment that’s more challenging to build and maintain with more significant consequences for single-point failures. Lowering and raising a 12,000 ton weight down a 5000’ slanted mineshaft (as is being experimented with in the UK) is easier to engineer than lowering a 300,000 ton weight (or, alternately, 25 separate 12,000 ton weights) down a 200’ deep pit.

The other nice thing about making use of mine shaft technology is that we’ve already got lots of experience with it and wouldn’t need to invent a lot of new stuff.


A similar scheme.


We can also use the extra power for search lights aimed at the solar panel fields.

I feel like we are close to perpetualality.


Similarly, this could help put the fun back in funicular.


Gravity is the weakest of the four forces. Using gravity to store energy is almost always going to be an awful way to go about it.

That being said, pumped hydro is pretty good for storage, but it won’t work most places. You need a lot of vertical relief and a lot of water.


Concrete is just a versatile construction element and “easy” to work with. To build a “standard” size block where weight is actually a good thing you could use waste products from metal production. You’d need a shell, possibly fabricated, and then fill it full of scrap slag. You’d still need a binder, but something like compressed earth block might work great if the shell protected it from the elements.

Also…this thing is going to have a massive foot print load. Depending on soil type you might end up with another Millennium Tower.

The best part of this video is the dripping sarcasm. Why not go for broke and just build a giant superconducting storage ring. The worst case scenario is a coolant failure and how you handle several hundred to a terawatt of power.

Why don’t they just make it an enormous guillotine?

Proper preparation etc.


Has it ever left?


Typical engineers who live in their simulated SolidWorks or ProEngineer world. Everything fits perfectly and works smoothly until they actually build the thing and come up against real-world tolerances.


I was actually thinking of filling old shipping containers with rocks or whatever. You can often buy them fairly cheap and plenty of equipment already exists for lifting and moving those things so one could piggyback on existing technology. But there’s a limit to how high you could stack those things, or any shell-based design where the filler had less compressive strength than concrete.

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Those standing around saying something is impossible should get out of the way of those doing it. I don’t give a rats ass if this YouTuber think it’s a dumb idea. It’s between the inventor, his investors, and the market to decide. Unless there’s government subsides, the rest of us should just butt out.


And then there’s the EF5 tornadoes…