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Energy Vault – Gravitational Batteries

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Re: Energy Vault – Gravitational Batteries

#11

Post by kumarvvr »

1 Ton of mass, at 100 m height, holds 0.2778 kWh of energy.

100 tons (3 bricks as per their design) - 27.778 kWH

100 x 100 Tons (300 bricks ) - 27.78 MWH.

However, as per their design, not all bricks store the same amount of energy.

The lower section of bricks would not be economical.

Every Ton of Concrete, on average produces 0.9 Tons of CO2 during its manufacturing process.

1 MWH of electricity generation, on average, produces 0.417 Tons of CO2.

1 Ton of weight, lifted to 100 m and put down, if say, takes 3 minutes (Average estimate, someone correct me on this), then working without break for 7 years, it will break-even for the amount of CO2 it has saved vs. amount of CO2 it has produced.

After that, it offsets CO2 produced.

However, this is only true for those blocks that are lifted to 100 m.

Those at lower levels, will have progressively more years to break-even.

A better design would be to build the platform to store the bricks from say, 50 m or so onwards, or use natural geographic features to increase height, like on cliffs, etc.

Re: Energy Vault – Gravitational Batteries

#12

Post by kumarvvr »

I really wish humanity comes up with a good way to store large quantities of electricity (not counting Hydro Batteries).

Compressed air in mines is a good alternative, with heat of compression also stored.

I am actually looking for ways to make this small scale. As in, creating a storage system for domestic use.

In developing countries, average energy usage per house hold, would be not more than 10 kWh per day.

Compressed air is slightly dangerous, so are flywheel systems, not to mention complexity of operation.

Chemical conversion of captured carbon to liquid fuels seems to be a viable solution.

Re: Energy Vault – Gravitational Batteries

#13

Post by desman »

kumarvvr wrote: post #11

1 Ton of mass, at 100 m height, holds 0.2778 kWh of energy. 100 tons (3 bricks as per their design) - 27.778 kWH 100 x 100 Tons (300 bricks ) - 27.78 MWH. However, as per their design, not all bricks store the same amount of energy. The lower section of bricks would not be economical. Every Ton of Concrete, on average produces 0.9 Tons of CO2 during its manufacturing process. 1 MWH of electricity generation, on avera…

...and using water instead of concrete. And then you get pumped storage https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit... which is reasonably widely used and doesn't attract as much investors' attention as this "innovation"

Re: Energy Vault – Gravitational Batteries

#16

Post by simonebrunozzi »

imtringued wrote: post #2

Building cranes is most the boring part of this project. It's far more interesting to know how they are going to make the 35 ton weights. I don't know anything about the construction industry but some googling showed that 1 m^3 of concrete weighs 2.4 tons. You will need 15 m^3 weights. 1 m^3 costs $200 so each weight costs $3000. 35000kg×9.81m/s^2×100m is 34335000 Joules or 9.5kWH. $3000 / 9.5kWH is $315 per kWH. I'm…

I would use depleted uranium for that. Many countries have to store thousands of tons of it, and governments will pay you for storing it. Instead of making it sit idle, you might as well use one of its finest qualities (density).

Re: Energy Vault – Gravitational Batteries

#17

Post by vidarh »

choeger wrote: post #5
imtringued wrote: post #2

Building cranes is most the boring part of this project. It's far more interesting to know how they are going to make the 35 ton weights. I don't know anything about the construction industry but some googling showed that 1 m^3 of concrete weighs 2.4 tons. You will need 15 m^3 weights. 1 m^3 costs $200 so each weight costs $3000. 35000kg×9.81m/s^2×100m is 34335000 Joules or 9.5kWH. $3000 / 9.5kWH is $315 per kWH. I'm…

> This is not rocket science. it is literally rock science ;) Seriously, in Germany, concrete costs arount 100 EUR per cubic meter. So we would end up with around 150 EUR per kwh capacity. But they would not have to use concrete for the task. They could as well use 23 m^3 gravel (which goes down to 10EUR) and some steel scaffolding. Or even just plain water (35m^3).

They're using "composite" bricks that include waste material (I can't find any obvious references to exactly what kind of mix of materials), so my guess would be the material cost will be rather low.

Re: Energy Vault – Gravitational Batteries

#18

Post by kumarvvr »

desman wrote: post #13
kumarvvr wrote: post #11

1 Ton of mass, at 100 m height, holds 0.2778 kWh of energy. 100 tons (3 bricks as per their design) - 27.778 kWH 100 x 100 Tons (300 bricks ) - 27.78 MWH. However, as per their design, not all bricks store the same amount of energy. The lower section of bricks would not be economical. Every Ton of Concrete, on average produces 0.9 Tons of CO2 during its manufacturing process. 1 MWH of electricity generation, on avera…

...and using water instead of concrete. And then you get pumped storage https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit... which is reasonably widely used and doesn't attract as much investors' attention as this "innovation"

To be fair, Pumped Storage is really dependent on Geography. It has downstream affects on environment due to having reservoirs where none have been and all.

It's powerful, cheap and long lasting, but not easily available.

One can't eat the cake and have it too.

Re: Energy Vault – Gravitational Batteries

#19

Post by jedimastert »

kumarvvr wrote: post #12

I really wish humanity comes up with a good way to store large quantities of electricity (not counting Hydro Batteries). Compressed air in mines is a good alternative, with heat of compression also stored. I am actually looking for ways to make this small scale. As in, creating a storage system for domestic use. In developing countries, average energy usage per house hold, would be not more than 10 kWh per day. Compr…

> I am actually looking for ways to make this small scale. As in, creating a storage system for domestic use.

Mildly interesting thought: grandfather clocks have been using this form of battery for a very long time

Re: Energy Vault – Gravitational Batteries

#20

Post by desman »

kumarvvr wrote: post #18
desman wrote: post #13

Earlier quoted context omitted.

...and using water instead of concrete. And then you get pumped storage https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit... which is reasonably widely used and doesn't attract as much investors' attention as this "innovation"

To be fair, Pumped Storage is really dependent on Geography. It has downstream affects on environment due to having reservoirs where none have been and all. It's powerful, cheap and long lasting, but not easily available. One can't eat the cake and have it too.

Well, this thing also depends on geography. There aren't many places where such a construct would be easy to build: seismic situation, static stability for these enormous weights, winds (it's actually quite funny to see cranes side by side with wind turbines in their commercial)
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