To add to my initial thoughts on gravity storage, the formula for potential energy in a gravity battery is basically mass x height x 9.8 m/s^2 . The sheer amount of weight and distance necessary to store a reasonably useful amount of energy makes for very large scale engineering projects.
The typical cell phone battery holds about 4000 mAh in a 3.7V battery, which translates to about 14.8 Wh, or 53.3 kJ. In order to get the equivalent storage in a gravity systems with a 1000 kg (1 tonne) weight, you’d need to raise it about 5.4 meters, with 100% efficiency.
A Tesla battery capacity is 75 kWh for some of the long range models, which translates to 270 MJ. To store that amount of energy you’d need to raise a 1-tonne weight about 27.6 km, about 3 times the altitude of Mt Everest and more than double the typical cruising altitude of commercial passenger jets.
So the most practical real-world projects they’re pursuing tend to use weights of around 20-25 tonnes in abandoned mine shafts as deep as 3km, and can recover the energy at something like 80% efficiency. Each weight can therefore store something like 735 MJ or 204 kWh (aka 3 Tesla batteries). But obviously these types of projects are very expensive and complex, and require enormous scale to be cost effective.
Gridscale batteries also have the benefit of being a very good place to reuse tired automobile batteries that otherwise would just be dumped. If we can get batteries that last 10-15 years in an automobile then another 10-15 in a grid scale deployment that’s far better than just lasting 15-20 years in an automobile. It also sucks that batteries completely die and have to be disposed of somehow because that’s not sustainable at all, but maybe there will be advancements in the future that make that less of a problem
I’m not sure about technological advancements, but there might be economic developments where the price of lithium rises to be high enough that recycling the materials in old batteries becomes a no-brainer and pays for itself. Some are working on scaling lithium battery recycling, and there are serious engineering challenges involved, but the long term trends on lithium prices makes R&D in recycling a pretty attractive investment.
To add to my initial thoughts on gravity storage, the formula for potential energy in a gravity battery is basically mass x height x 9.8 m/s^2 . The sheer amount of weight and distance necessary to store a reasonably useful amount of energy makes for very large scale engineering projects.
The typical cell phone battery holds about 4000 mAh in a 3.7V battery, which translates to about 14.8 Wh, or 53.3 kJ. In order to get the equivalent storage in a gravity systems with a 1000 kg (1 tonne) weight, you’d need to raise it about 5.4 meters, with 100% efficiency.
A Tesla battery capacity is 75 kWh for some of the long range models, which translates to 270 MJ. To store that amount of energy you’d need to raise a 1-tonne weight about 27.6 km, about 3 times the altitude of Mt Everest and more than double the typical cruising altitude of commercial passenger jets.
So the most practical real-world projects they’re pursuing tend to use weights of around 20-25 tonnes in abandoned mine shafts as deep as 3km, and can recover the energy at something like 80% efficiency. Each weight can therefore store something like 735 MJ or 204 kWh (aka 3 Tesla batteries). But obviously these types of projects are very expensive and complex, and require enormous scale to be cost effective.
Gridscale batteries also have the benefit of being a very good place to reuse tired automobile batteries that otherwise would just be dumped. If we can get batteries that last 10-15 years in an automobile then another 10-15 in a grid scale deployment that’s far better than just lasting 15-20 years in an automobile. It also sucks that batteries completely die and have to be disposed of somehow because that’s not sustainable at all, but maybe there will be advancements in the future that make that less of a problem
I’m not sure about technological advancements, but there might be economic developments where the price of lithium rises to be high enough that recycling the materials in old batteries becomes a no-brainer and pays for itself. Some are working on scaling lithium battery recycling, and there are serious engineering challenges involved, but the long term trends on lithium prices makes R&D in recycling a pretty attractive investment.