Hacker News Reader

Comment by WalterBright | Hacker News Reader

One thing puzzles me. LI batteries are appropriate for cars because of their high energy density. But for grid applications, density is not much of an issue. They can have large, heavy batteries. So why not use a cheaper/joule battery technology for grid applications?

View on HN

That might happen long term but short term the lack of production capacity is the problem. And right now a lot of companies are investing in vastly expanding production capacity for lithium ion batteries. We've simply never needed batteries at this scale before EVs started happening.

Tesla seems early in the grid storage market. Probably some companies are trying to come up with cheaper ways to do that. So, long term, I think cost will go down by quite a bit. Ten years from now, there will probably be a few companies cranking out cheap batteries for grid and domestic use that are optimized for $/kwh instead of kg/kwh.

> We've simply never needed batteries at this scale before EVs started happening.

Is that really true?

There a a LOT of lead acid batteries out there, considering there's been at least one sold alongside nearly every internal combustion engine larger than a handheld tool.

I can think of a few reasons (as a layperson). They're heavily investing in li-ion battery production, really optimizing for that one in particular.

But I think they can also produce the battery packs in huge amounts and sell them in multiple products - Powerwall, Powerpack and now this one.

And I suspect these ones are more easily manageable.

Because both demand and supply aren't there yet. Grid storage isn't needed yet and when it is lithium ion is cheaper because its cross subsidized.

This leaves the grid battery manufacturers with no market so they don't expand production.

This talk by Dr Sadoway is pretty amazing regarding his team's design for utility-scale liquid metal batteries: https://www.youtube.com/watch?v=NiRrvxjrJ1U It's an hour long, but it's well worth the time investment.

This is not merely a theoretical technology. A company has been created around this technology: http://www.ambri.com

(I am not connected to any of this, but I am quite excited by it.)

In addition to what others have commented on: You can think of it as a way to boot-strap the market. That's easier with existing established technology. Once they're delivering massive quantities of grid storage batteries, it might be relatively easy to justify doing a big investment in a different chemistry and hopefully you can just swap it in for the old one (with some changes to charging electronics probably)

No one is building those batteries at scale yet. Battery chemistry -> efficient production line -> market is a VERY long game (decades).

Power curves are one reason lead isn't more used (they spike a fair bit). The other one to look at is how the tech itself scales, almost all batteries all catch fire easily due to the chemical processes. That becomes a bigger problem the more you pack them in and there has been more research in getting Lithium cells to not catch fire than lead acid lately.

Apart from economies of scale on lithium batteries - Perhaps the extra weight makes construction more complicated even though the heavier batteries are cheaper. Like, unless they're being built on site, you've still got to get them there, etc.

Economy of scale which should help bring costs down. It's easier to take them to Mars.

Reply on news.ycombinator.com