Now why couldn’t we build something like this right into a wind turbine? They’re already pretty high up. Just have it lift one giant concrete block up and down.
> Now, how much energy can it store? This is given by potential energy formula E=mgh, thus E=100kg⋅9.8m/s2⋅10m=9.8kJ≈2.7Wh.
> For comparison, a single AA-sized battery stores about 2Wh of energy.
https://physics.stackexchange.com/questions/305563/why-dont-...
Wind turbine height: 99 meters. 100 kilogram lead weight == about a large person. So, a normal turbine maybe can hold about 100 people's worth of additional weight (elephant or two) * 10 (height multiplier) = ~1,000 AA batteries worth of stored power.
At first it seems a bit silly that the bottom layers aren't lifted off the ground much at all, but if a tower is N meters high, the average height of each block is N/2, so that's only a factor of 2 loss. (For example, if each block were 1m tall, a stack of 100 of them would be 100m tall, and the average block would be 49.5m off the ground.)
And of course also because concrete is a combination of cheap, strong, and heavy. All of these serve as multipliers for energy storage practicality.
One simple demonstration is to look at how a small magnet can combat the gravity of the entire planet when it holds an metal object in place above the ground.
Relative to combustibles such as hydrocarbons, ammonia, or hydrogen, not so much.
(It's possible to synthesize carbon-neutral hydrocarbons, though with high round-trip losses, and not yet proved at scale.)
More weight means more tower, with means using an existing tower doesn't save you much money.