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Glubux's Powerwall (2016)

(secondlifestorage.com)
386 points bentobean | 3 comments | 01 Apr 25 15:49 UTC | HN request time: 0.001s | source
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EGreg ◴[01 Apr 25 18:40 UTC] No.43550099[source]▶
Why not just dig a hole in the ground and make a gravity battery? Would be much more reusable without all the lithium garbage ... and also probably more efficient...

https://en.wikipedia.org/wiki/Gravity_battery

And the most efficient way would probably be to just have credits with the rest of the city grid. Sell electricity to them when you have a surplus (from solar) and then pay for electricity when you need it. These credits are a lot more efficient than storing the actual electricity in a battery hehe

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tecleandor ◴[01 Apr 25 19:34 UTC] No.43550561[source]▶
But how expensive would be to dig a, I don't know, 1000 by 6 feet hole in the ground? I have no idea of an equivalent gravity battery...
replies(1): >>43551545 #
1. thfuran ◴[01 Apr 25 21:30 UTC] No.43551545[source]▶
The average US household uses about 10,000 kwhr per year. That's roughly equivalent to the gravitational energy of dropping ten tons down a 200 mile hole.
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2. EGreg ◴[02 Apr 25 01:44 UTC] No.43552979[source]▶
The battery doesn’t have to hold the entire year’s energy — come on :-P
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3. mft_ ◴[02 Apr 25 10:37 UTC] No.43555355[source]▶
Indeed, but to store (let's say) half a day's energy, then (based on the previous calculation) it would presumably need ten tons dropping down a hole 0.274 miles, or 441 metres, deep?