When oxygen from the air passes over small pieces of iron inside the battery, the iron rusts and produces electricity. To recharge the battery, an electric current removes the oxygen from the rust, turning it back into iron
Every week we can read about some new & exotic chemical processes that can (maybe, hopefully 😇) be used for batteries… but “the iron and the rust”, that is old.
So: Why haven’t we heard of any iron-rust-batteries before?
Form’s iron-air batteries are heavier and less efficient than their counterparts; they can only return about 50% to 70% of the energy used to charge them
Oh. Damn.
So, that’s why, I guess. 50% sounds terrible.
almost three times as cheap
Oops? Now we are in business again? Maybe, hopefully 😇
I really find it interesting.
It’s also clever politics. Minnesota has the largest iron mining operations in the entire United States, so choosing iron as your core battery technology is a smart (albeit cynical) way to drum to some local support with the promise of bringing new demand back to the taconite mines.
Whether that will be strong enough to overcome the extreme negative sentiments around datacenter projects? Who knows…
I hope tf not.
Hear hear.
Well, if you want to argue against it, you could use the above-mentioned 50% as your argument.
These 50% can be spelled out as “inefficiency”.
These 50% mean that the whole thing needs to build twice as many wind turbines and twice as many solar fields in the first place. They need to generate twice the energy only for satisfying the inefficiency of their battery.
(No, it is not exactly true. They generate the better part of the wind and solar energy for feeding the data center, and only a fraction of the generated energy goes into the battery)


