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AndrewDucker

An AA battery contains approximately the same as 1 ton raised 1m. (About 3Wh)

A Tesla Powerwall contains about 13.5kwH (about 4,000 times as much)

So you can either raise 100 tons 10m above your house, or you can have 1/13 of a Tesla Powerwall.

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There is a company that claims they can store energy by lifting and lowering heavy blocks with a crane

https://www.energyvault.com/products/g-vault-gravity-energy-...

I like the picture, but the the size of the construction is enormous, especially if you're considering a tank for some kind of pumped hydro. Hydroelectric power is practical because a dam in a strategic location can back up much more than 1000x of its volume in water. If you had to build all those walls forget about it.

That is obviously a scam. Not a chance in hell.

I am giving that one a 0% chance of long term success.

Edit: no seriously. Do some back of the napkin maths. The amount of energy stored is too small. Way too small. And then the infrastructure to haul hige blocks of concrete around.

It's the same scam selling ideas that sound good to people who don't understand what a "joule" as Pavegen and the other systems that generate energy from footfall or passing cars. Mechanical energy is pretty "low grade" as energy goes.

It 100% works, but it's a system that has very specific applications and doesn't scale up well. And the best systems use a magical property of some fairly heavy materials called "being liquid" to simplify the logistics of getting millions of tonnes of weight to the lifting mechanism.

One of them is moving almost seven thousand 25-tonne concrete blocks around. I can't see how it would ever compete with something like compressed air.

It just seems so awfully wasteful.

If someone can find some real costs I would be more than happy.

7000 * 25t / 2.5t/m^3 = 70,000m^3 of water. So about 1% of the water storage of Dinorwig, which runs dry in about 6 hours of use.

Now, I know reservoirs are ecologically pretty iffy, expensive and obviously geographically sensitive, so you can't slap them around everywhere. But all these mechanical schemes have big "look what they need to mimic a fraction of our power" vibes!

I could imagine that steel-on-steel block movements could actually be quite efficient and effective in limited scenarios, but logistically it just seems like a lot of squeeze for not a lot of juice considering how much power is required to be stored for utility-scale projects. I would like to say that that they're just delusional people truly hoping it'll work, but I think there's a core of hard-nosed scammers who smell money for a shiny PPT and a plausible-to-non-engineers Wile E. Coyote/Troll Physics contraption with big numbers in the brochure: 7000 blocks! 25 tonnes per block! Megajoules! Efficiencies! Scale! Repurposed coal mining infrastructure! They even have AI in the spiel now: https://www.energyvault.com/solutions/software

Or maybe it'll work and I'll look stupid in 30 years when there are huge fields of hundreds of kilometre-deep boreholes with 100 kilotonne masses moving up and down in them. But somehow it seems quite unlikely on a practical level considering the cost of boring gigantic holes that you'd have to do to make it scale. Onsies-twosie installations in a few mines here and there may work for lucky outlying towns, but they aren't civilisational scale solutions.

Oh, but only at about 145 meters. Dinorvig has a fall of over 300m.

And this is why gravity is considered a weak force.

Sit down. Now stand up. Congratulations, you just beat the gravity force generated by a whole f*cking planet.

Now try to escape it.

What limits me is the lack of solid matter to push against, not lack of strength in my muscles.

Gpt says that would require about 275 million steps on a magic rigid weightless stairway. Roughly 4.1 million calories. So at Phelps level energy expenditures you are still talking over a year of climbing every day.

Well, 100kg raised 10000m is only about 2350 food calories, from a purely physics perspective.

You'd need to go to about 47km for the end of the stairs to reach escape velocity I think? Past geo. Was using 20% efficiency. Still something off there.

GPT not so good at elementary physics evidently.

Assuming you don't have to carry your food... 4.1 million calories would be around 0.5 tons of olive oil.

ok, but what do you say?

You are not hiking much in the mountains, are you? 1000m of elevation gain per day are no problem for a slightly out of shape sit-all-day programmer. Not sure how high up you want me to go, but given a high enough mountain (and a thick jacket and supplemental oxygen) and most people here can do that in a few weeks or months.

That doesn't really escape the gravity well, does it?

It would if there was a mountain that kept going up, and you had oxygen to breathe.

Now if it were a magnet..

And the strong force holding two protons together in an atom is on the order of 10 pounds.

I wondered when anybody would bring nuclear fission into this discussion.

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