[TheGeminon]

I think this is likely more of an energy storage project, rather than an energy production one (which seems to be the stance the article takes).

At grid-level, battery tech is challenging, requiring technologies like pumped storage that require particular environments (e.g. damming a river) and can't really be transported.

If this works out you could use excess solar during the day to deoxidize the rust produced, and then run the iron reactor overnight, or on cloudy, windless days.

[dmix]

How does that battery/production distinction work? How is it a battery if it is consuming/burning a fuel? More as a stable fallback or something?

[balaga01]

Well, if you can burn it to produce energy + spent fuel

and then put back energy in the spent fuel to make new fuel again

then you have really a battery. That's how li-ion batteries work. The issue is the efficiency: how much of the energy you used to recharge the "battery" (iron) is going to be available when you discharge (burn) it

[dmix]

Thanks that makes sense

[wongarsu]

Non-rechargeable batteries are also consuming a fuel. The products just stay in the same enclosed container. Same with rechargable batteries, just that there the process is easily reversible.

It is a bit of a fuzzy distinction. Batteries are typically simple chemical reactions that cause electrons to move around. But viewed from the outside a hydrogen fuel cell behaves the same; so why not call this one a battery too (especially since the process is reversible).

[samus]

A useful distinction seems to be that batteries are solid state and don't use high process heat, else something would be seriously wrong. Of course, the underlying reactions are probably very similar if you look at them with a chemist's eye.