[ninkendo]

> "just to boil water" has got to be the biggest understatement that I've heard in a while.

It’s also a good illustration of how much we depend on extreme energy densities for everyday use cases. Coming up with a good storage solution for renewable fuels is going to be a defining challenge for our generation.

[smt88]

This is my favorite method so far:

https://qz.com/1355672/stacking-concrete-blocks-is-a-surpris...

Works well, portable, space efficient (could house it in the center of a skyscraper), and easy to disguise as something aesthetically pleasing

[maxerickson]

A much larger battery (129 megawatt-hours) can fit into a similar footprint:

https://hornsdalepowerreserve.com.au/

(it takes ~1 hectare, which maybe the tower of blocks won't have quite that footprint, it'll be at least that imposing)

[smt88]

But aren't the drawbacks of a Lithium ion battery going to outweigh the benefits of saving the space?

[maxerickson]

In a literal sense, apparently not. There's a real actual 100 megawatt-hour lithium-ion grid battery and (concrete?) pie in the sky ideas for using dry mass for gravity storage.

[smt88]

I wouldn't say it's "pie in the sky" when the technology already exists and has been demonstrated. It's a really simple system.

In a sense, you're right that any technology currently in use is better than a technology that isn't, but if every discussion ended there, we'd have no new technology.

My question was assuming someone is choosing between lithium ion and gravity storage. My understanding is that lithium mining is pretty awful for humans and the environment, the batteries can explode easily, and their lifespan is limited.

Besides being a weird shape, what are the drawbacks of storing energy in concrete blocks?

[jwatt]

I guess abandoned mines with both above and below ground storage areas might also be useful. The deeper the better.

[agumonkey]

True, but it's also a very non critical example. Lastly, I'm trying to make a solar concentrated kettle. TCO Free kWatts

[maxerickson]

Methane/propane/butanol all work fine, they just cost more than petroleum derived gasoline.

Hydrogen is also probably feasible, just hard to store.