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Gravity batteries try to beat chemical ones with winches, weights, mine shafts

sciencemag.org

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Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#61

Post by Xylakant »

eraserj wrote: post #52
tshaddox wrote: post #36

Earlier quoted context omitted.

Isn’t tidal energy just harnessing some of the existing gravitational potential energy of the Moon-Earth system, which is roughly similar to any system that harnesses energy from a massive object falling due to gravity?

But again, slowing tidal currents must be drawing energy from somewhere until there is none left.

It basically draws energy from the moon orbiting earth. It could theoretically alter that orbit, but given that the moon/earth system has a lot of mass, the timescale for that to happen is extraordinarily large.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#62

Post by andijcr »

flal_ wrote: post #55
inasio wrote: post #45

Gravity and electromagnetic forces are somewhat similar, they both have infinite range, decay as 1/r, one key difference is that the electromagnetic force is 10^36 stronger than gravity [0]. Just for that reason I'm always immediately skeptical of projects of this type. [0] https://en.wikipedia.org/wiki/Fundamental_interaction

Yet, gravity is strong enough to initiate nuclear fusion at the core of stars, or create black holes... That 10^36 argument is non sensical to me.

it is strong enough at the scale of a star, on earth my foot electromagnetic repulsion against the floor is enough to counteract all of the planet pull

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#63

Post by timonoko »

If you pump one cubic meter of air 100 meter deep, the energy stored equals a tonweight at 100 meter up. That is 9.81 kJ aka 2.7 Wh. This is inifinitely scalable and suits flat places like Australia.

One and only minor problem is how we prevent the 2.7 GWh energy storage, which is 1E9 m^3 aka one cubic kilometer inflatable container, not rupturing or raising up.

But otherwise ingenious nicht wahr?

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#64

Post by [deleted] »

ObscureScience wrote: post #50
xyzzyz wrote: post #6

Earlier quoted context omitted.

Yeah, if you do the math, it turns out that you need impractically large weights lifted to unreasonable height. Like, suppose you’re lifting 100 ton weight 100 meters high. That’s a rather large and heavyweight system. How much energy you can store this way? Less than $5 worth of electricity, as it turn out. This is basically the same as pumped water storage, but instead of immense amount of water you can pump betwee…

Too me, pumping water seems like a pretty good solutiuon. If you are located on the coast, and can move let's say a million tons something like 100-200m up, that's not trivial and doesn't seem that impractical.

[deleted]

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#65

Post by rcxdude »

jb775 wrote: post #39
nl wrote: post #30

Earlier quoted context omitted.

> It's crazy how little we understand about gravity if you think about it. We understand most things about it > It's a perpetual energy source right in front of us, No it's not. It's a good way to store energy but in no way is a source. > and can barely offer a basic explanation as to what powers it It's not something that has power. It's a consequence of entropy. > It even impacts time itself You sound surprised by…

IMO you grossly overestimate the amount humans know about things. Science is basically a stream of updated realizations that the previous "known" things were actually wrong.

and you vastly underestimate it

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#66

Post by bigsparky »

jb775 wrote: post #47
exporectomy wrote: post #40

Earlier quoted context omitted.

You shouldn't repeat unsubstantiated rumors like that. Can you even name these disappeared scientists or know anything at all that could be used to verify those stories?

If you dare to venture, need to follow deep rabbit holes. Look into: work of Harold Aspden (and his coworkers & previous research partners), plancks equation origins and drop offs, dewey larson physics, piesel electric effect origin and drop offs, the adams motor, ellen brown, what maxwells equation actually determines and where it selectively isn't being used

I think you are getting unwarranted downvotes. If you are someone with a dislike of information you can just ignore it... downvotes unnecessary.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#67

Post by bluescrn »

PurpleFoxy wrote: post #60
Gauge_Irrahphe wrote: post #56

The technology isn't incredibly immature. On the contrary, it's understood to the tiniest detail. If it doesn't work, it won't work.

Isn’t pumped hydro a realistic solution? There should be a massive amount of energy in moving all that water up a mountain.

Pumped storage hydro makes far more sense. Which is why it's already in use.

Maybe the efficiency can be improved upon with a small-scale 'gravity battery', but water has massive advantages when it comes to scaling it up, as well as being able to combine it with traditional hydro, where nature moves much of the water for you.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#68

Post by pedrocr »

rakoo wrote: post #48

As usual everyone is fixated on price when the real hurdle will be scale. If we're going to replace our existing fossil fuel plants we need at least as much capacity. A quick grep in the article tells me these guys have a plan for a 4MW plant that involves a 1km shaft. That's the same order of magnitude as a single wind turbine, which is already one of the worst ratio of power output per quantity of resource and land…

That's the wrong comparison. We don't need to replace generation capacity with the same capacity of batteries. Batteries don't generate any electricity after all. We need batteries to smooth out differences between demand and generation. The total amount we'll need is very much still up in the air. Better interconnects, good use of existing hydro, overbuilding renewables, shaping demand, are all other ways to balance loads and guarantee enough power at all times, all of which reduce the need for batteries.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#69

Post by PeterisP »

o_p wrote: post #20
choeger wrote: post #13

Stopped reading at a total cost of more than $300 per MWh for batteries. Quick back-of-the-napkin calculation: Car batteries come in at less than $100/KWh. They're good for at least 1000 cycles at 80% capacity. That gives us at least 0.8MWh for a 100$ investment. It's very, very unlikely that initial construction of the site and operational costs more than triple that price.

This doesnt account the short duration of batteries, I have to replace them every time they go past their lifetime, so in the long term their cost is much higher

The heavy machinery with moving parts lifting thousands and thousands of tons is also going to need maintenance and wear&tear replacements. The problem with scale is that all these proposed gravity batteries need much, much more machinery than an equivalent pumped capacity pumped hydro or chemical battery plant.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#70

Post by labawi »

inasio wrote: post #45

Gravity and electromagnetic forces are somewhat similar, they both have infinite range, decay as 1/r, one key difference is that the electromagnetic force is 10^36 stronger than gravity [0]. Just for that reason I'm always immediately skeptical of projects of this type. [0] https://en.wikipedia.org/wiki/Fundamental_interaction

On Earth, gravity has a bonus of a free massive side plate. As a battery, it might work better on Jupiter and unusable in free space, but it still stores orders of magnitude more energy than we use, in abundant cheap materials. I liked the trains-on-hills project - seems easy enough to build in large quantities and stores reasonable amounts of energy.

With electromagnetic, we are barely capable of scraping a bit of energy from the surface without the device self-destructing. Even in superconductors, only a fraction of electrons whizzes around and even high-energy plasma is a mixture of both charges.

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