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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

#11

Post by ecpottinger »

xyzzyz wrote: post #6
goldenkey wrote: post #2

And these systems are way larger, more dangerous (wind) and not as efficient as magnetic bearing flywheels. https://en.wikipedia.org/wiki/Flywheel_energy_storage

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…

Great, now calculate how much a flywheel system that stores that much energy will cost vs cheap concrete blocks. Magnetic bearings and large vacuum chambers do not come cheap.

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

#13

Post by choeger »

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.

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

#15

Post by alexchamberlain »

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.

Their marketing has the LCOS of those 2 solutions the other way around - $171 for Gravity, $367 for Litium Ion batteries.

See https://gravitricity.com/technology/

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

#17

Post by _rpd »

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.

Here’s what the article says about cost:

> For a 25-year project, he estimates that Gravitricity would cost $171 for each megawatt-hour. Jessika Trancik, an energy storage researcher at the Massachusetts Institute of Technology, says that number is aspirational and still needs to be supported with field data. But Schmidt’s calculation of the lifetime cost per megawatt-hour for lithium-ion batteries, $367, is more than twice as much. Flow batteries, a promising grid-scale technology that stores charge in large tanks of liquid electrolyte, come in at $274 per megawatt-hour

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

#18

Post by jb775 »

It's crazy how little we understand about gravity if you think about it. It's a perpetual energy source right in front of us, but we never really think about it, and can barely offer a basic explanation as to what powers it. It even impacts time itself[1] for christ sake. I think better understanding gravity is the solution to all human energy needs. (interesting to note I have heard stories of disappeared scientists who made advancements in gravity research years back)

[1] http://thescienceexplorer.com/universe/how-gravity-changes-t...

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

#20

Post by o_p »

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
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