[SmooL]

> My gut feeling is that transmission lines would still be cheaper

Transmission lines are great for moving electricity, but only if there's demand for that electricity _right now_. Otherwise, you have to store it - which is a problem, because battery tech right now isn't great (or rather, it's not good enough for grid-scale requirements) . This iron powder could be thought of as a "battery". It might be harder to move than compared to a transmission line, but it's _stored_ energy and can be redeemed at a later time.

[cogman10]

> or rather, it’s not good enough for grid-scale requirements

I disagree with this point. LFP batteries are cheap, high density, and have huge cycle life. The big drawback of LFPs is manufacturing is just starting to ramp up on them. That is, they aren’t available.

LFPs just came out of patent protection last year and you are already starting to see them everywhere. The biggest problem with LFPs today is demand is outstripping supply.

[ac29]

Assuming LFP means Lithium Iron Phosphate (LiFePO4)?

Not sure how to reconcile "they aren't available" with "starting to see them everywhere".

They're great batteries (especially compared to lead acid) and at least in small quantities, they have been widely available for years.

[Turskarama]

I can't see Lithium batteries of ANY kind ultimately being used for grid scale storage, beyond the initial pilot batteries we have going up now.

Current worldwide lithium production is at 3% of what it needs to be to electrify every car, which is a use case that has strict weight requirements. Ramping up lithium production by a factor of 30 is a big deal, and that's before we use any of it for grid storage!

Grid batteries are static so weight is not a concern, using the chemistry whose main advantage is weight for this purpose is a waste of resources. Heavy battery chemistries have largely been ignored because traditionally batteries have always been for mobile purposes, so we can expect an even better learning curve from low energy density but cheap battery technologies such as iron-air.

[coryrc]

If we're using renewables, we need seasonal shifting, so cycle life doesn't matter at one cycle per year.

You could build nuclear to supply your winter power, but then you're overbuilt for summer and don't need any renewable. Or you could store heat directly in the ground like that Alberta pilot project, heat collectors on the roofs all summer drive the heat underground, pump it back out all winter.

Or our current plan, pretend to be "green" by spending money on solar while increasing coal usage and no feasible plan to replace space heating.

[concordDance]

Got any numbers here?

[rootusrootus]

> not good enough for grid-scale requirements

Is that still true? Aren't there a number of very successful grid battery installations now? And given the steady decline in battery costs, it ought to just get better and better.

[dgacmu]

Batteries are amazing for short term supply / grid stabilization. They can supply massive current on very short notice. But the cost per kilowatt hour is still painfully high if we're talking about more than a handful of hours. Fortunately, it's still headed downward.

[xyzzyz]

There are successful grid battery installations, but as far as I know, there are no grid-scale battery installations. Existing installations have really small capacity, and are only used for things like demand smoothing. The only energy storage solution deployed at scale is pumped hydro storage.

[hankman86]

But isn’t that the point of transmission lines - match supply and demand? Given a large enough region, there is going to be a place where renewable electricity can be produced. Case in point being offshore wind turbines where there are almost always strong winds to spin these. Moving this electricity to where it is consumed is a huge issue though. Existing power grids were created with centralised power stations in mind, which are usually located close to where the electricity will be needed.

[SmooL]

Yes, but transmission lines can only go so far, and you still lack the ability to arbitrage over time instead of just spatially. E.g. from a solar power POV, it's night everywhere in a given region at the same time.

[DennisP]

In the US we're especially bad at building new long-distance transmission. Some projects have languished for decades.

There are probably other places where it's difficult to get that large-enough region, for geographic or geopolitical reasons.

[bradknowles]

You can use those transmission lines to move the energy to a facility where it would then be stored.

In fact, you have to use some sort of transmission lines to get energy to those locations, otherwise you have no way to get energy to or from them. Even if they have local power generation, you still have to use transmission lines to get that power out.