Energy Vault – Gravitational Batteries

Re:Energy Vault – Gravitational Batteries by ulnarkressty on Monday January 11, 2021 @06:32AM (#25727571)

Water towers could also be economical and straightforward to produce / maintain as power storage sites for a small community.

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Re:Energy Vault – Gravitational Batteries by lovemenot on Monday January 11, 2021 @07:27AM (#25727996)

A large water tank of 500m3 on a high tower at 50M above an underground storage tank yields approx 70 kWh at best.

Not much, but a bit better than nothing. Especially if the tower and upper tank can be dual-purposed. Of course in that case you'd lose some energy capacity to maintain water pressure head.

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Re:Energy Vault – Gravitational Batteries by zupa-hu on Monday January 11, 2021 @08:28AM (#25728574)

> A large water tank of 500m3 on a high tower at 50M above an underground storage tank yields approx 70 kWh at best.

Correct, so if you want 70 MWh you need 1000x more water. 500.000m3 is merely a 80x80x80m cube.

Or to put it in different perspective, to lift it by 50m you need 2x this volume (another container 50m higher), which is 1.000.000m3, or 1M m3. The volume of the Pyramid of Gyza [1] is 2.5M m3. So that wouldn't even be the biggest building on Earth.

[1] - https://en.wikipedia.org/wiki/Great_Pyramid_of_Giza

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