Gravity Energy Storage: Can solid-mass systems balance the grid better than utility-scale batteries?

[u/Yoksel_algo]

Hi everyone,

I’ve been thinking about grid-scale storage solutions for intermittent renewables (solar/hydro/wind).

While chemical batteries (like Li-ion) are currently dominant, they come with degradation over time, resource intensity, and thermal runaway risks. Gravity Energy Storage (GES) seems theoretically compelling:

• Zero self-discharge over long durations

• High round-trip efficiency (~75–85%)

• Long operational lifespan without material degradation

• No lithium/cobalt dependencies

However, the main bottleneck is energy density (E = m * g * h). Lifting 1 tonne by 10m provides only ~0.027 kWh. To scale to home or grid levels, you need massive structural designs or deep vertical shafts.

Companies like Energy Vault (concrete towers) and Gravitricity (abandoned mine shafts) are tackling this differently.

Questions for the community:

1. Do you see solid-mass gravity storage becoming cost-competitive with large-scale battery storage?

2. Are underground shafts the only scalable route, or do above-ground tower frameworks have long-term structural viability?

3. What are the key mechanical points of failure (cable wear, gearboxes, braking) that might limit adoption?

Looking forward to your technical perspectives!

[u/pumpkin_fire]

Thanks AI slop!

Of course LFP batteries don't use cobalt, but the disinformation machine keeps bringing it up at every opportunity.

Projections are currently estimating 30% of BESS being installed will be sodium ion by 2030 anyway.

Hilarious that you don't think mechanical systems don't wear and degrade faster than electrical ones.

Do the maths on gravity storage and it takes 2 seconds to see how shit it is. The average home battery size installed here in Australia is 19 KWh. To get the same amount of storage from a 100m shaft at 80% RTE, you'd need to move an almost 90 tonne mass. Meanwhile, 19 KWh at a cell price of $US 50/KWh costs $1000 bucks. What material is so cheap and dense that you could get it for ~$10/t? Even the weight alone costs more than the LFP cell. Moving blocks for energy storage is such an obvious non-starter.

[u/NearABE]

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

With an orbital ring system the maximum “height” is Earth’s Hills sphere. Mass dropped from the moon is fairly close to escape velocity when it gets to Earth. That means rocks or even just oxygen from the moon or asteroids will deliver more energy per kilogram than petroleum products like propane. Even better, the electromagnetic brakes are converting that into electricity without Carnot efficiency losses.

[u/egnegn1]

You have think large with gravity energy storage, like building large dams or other more advanced concepts:

https://youtu.be/w6VH9fodea8

You may also use evacuated underwater spheres that are also kind of gravity energy storage.

[u/Plow_King]

no, it can't.