[wlesieutre]

Not an expert, but from what I read the expectation is for sodium ion batteries to get substantially cheaper than lithium, mainly due to material cost.

Lithium makes up 0.002% of the Earth's crust, meanwhile sodium is 2.36%, and there's quite a lot of it in the ocean.

https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth...

The main downside is power density, which for grid storage is not as big a deal as it is for vehicles. But it will still be some years of research on sodium batteries for the cost advantage and manufacturing scale to materialize.

[xbmcuser]

AT grid scale, sodium quickly closes the gap on lithium. The safety overhead, active cooling, and physical spacing needed to control lithium’s thermal runaway risk eat away most of its energy density advantage. Plus, CATL is hitting cost parity between full sodium BESS and LFP BESS systems.

[lebuffon]

The other big reason is the longevity. LFP life span gives you about 2000-5000 cycles depending on where your application can't tolerate the capacity reduction. Sodium Ion can go to 10,000 cycles (27 years) with a 70% capacity reduction at that life.

This makes financing a large grid scale storage plant look way better to the bean counters because the investment continues to work and make money, after the 5 year amortization, typical of a corporate investment. This will be the kicker IMHO.

[tromp]

> Sodium Ion can go to 10,000 cycles (27 years) with a 70% capacity reduction at that life.

The article claims much better:

> the company’s GS1.1 [Sodium Ion] system will store energy for 20 years, over roughly 20,000 cycles, and still retain 80 percent of its capacity. For LFP, a basic durability benchmark pegs them at 70 percent capacity after 8,000 cycles.

[lebuffon]

Excellent. I stand corrected. I was using published Chinese numbers.

[s1artibartfast]

Does it really look more favorable? My understanding was that such far future returns had minimal Net Present Value

[tim333]

I saw an interview with I think the CATL ceo and he was saying it's quite a headache ensuring the batteries last that long. Grid storage companies want 25 or 30 year guarantees. It sounds like sodium may have the advantage there.

[hansvm]

Net Present Value isn't quite the right thing to look at. Inflation-adjusted energy prices have been rising over time, so the thing these batteries are projected to deliver (fixed impact on that electricity grid) increases in value over time even after the NPV discount. The more important component is the "risk-adjusted" NPV, which may or may not make tech like this effectively worthless.

[s1artibartfast]

why dont you think revenue from energy prices isnt baked into the NPV? The time discout is applied, on top of whatever the revenue model is.

[someothherguyy]

SIBs have TR risks as well, no?

https://www.sciencedirect.com/science/article/abs/pii/S24058...

[Aboutplants]

I’d love a shed sized battery sitting on the corner of my property if it could give me 5-7 days of power.

[scarecrowbob]

I'm writing this from my off grid shack.

I have 15kwh of lifepo, and even if it weren't hooked to 4kw of solar I could still run my fridge, charge my phone, and run the fan in my fireplace for 4-6 days... longer if I dump the fridge.

It's 6U of deep 19" rack space.

So 2 x that isn't an entire shed-sized battery.

Though I'd happily have a shed-sized battery... I suspect that delivering and covering something that size would cost more than the batteries I already have, though.

[defrost]

> It's 6U of deep 19" rack space.

If the GP commenter is typing in from the UK .. that's a not uncommon garden tool shed size.

By contrast modern Australian farm sheds have clouds forming within them and host birds that seasonally migrate from one side to the other.

[rbanffy]

You’ll be fine as long as you don’t go near the corners. The spiders are… vicious…

[UltraSane]

They make hyper-insulated refrigerators for use on ships with limited electricity that use either vacuum insulated panels or aerogel insulation.

[scarecrowbob]

Fortunately for me, I could just bop down to the bog box store and buy a more appropriate fridge from vevor; horses for courses.

I've never had to turn off my fridge, though it does have interesting-to-me usage patterns; it's weird what you can learn once everything you use has a watt-meter. I can look at the weekly graph and recall when I turned on a hammond organ or cooked in my instapot.

[trainsarebetter]

Check out https://github.com/dalathegreat/Battery-Emulator

Re use old ev batteries unmodified for battery storage

[bickfordb]

For something like a battery backup that last decades that doesn't need maintenance, maybe you could bury it out of the way (like under a deck or lawn?), maybe even under the frost line.

[pixl97]

Underground is a big problem with it comes to water permeation and flooding.

The other potential problem with a lot of energy systems that use things that have hydrogen in them is running power over the systems for long periods of time can start to leak hydrogen. You'll always want to ensure you have ventilation to ensure whatever is outgassing can escape the system. You'll end up with explosions, hydrogen embrittlement, or interesting corrosion in ways you didn't think were possible.

[someothherguyy]

might need to be in some special containment at that size, depending on the technology -- some sodium ion battery implementations are very toxic / highly reactive / flammable.

[rsyring]

That would you pay for that shed size battery?

[SturgeonsLaw]

Depending on just how much more cost effective sodium battery tech gets, that might not be a questionable proposition

[CyanLite2]

You can get a 16kWh LFP battery for $2-3k USD.

[AussieWog93]

I mean, I pay around $2,000 (AUD) per annum for electricity from the grid.

If this battery plus some solar panels could get us free power for the next 20+ years, that's easily worth $15-$20k or so.

[scarecrowbob]

I am about 2 years in to my off-grid solar setup. The cost for the easement was looking to be about $25k, plus about 30k for the wire, transformer, et.

I live in middle of nowhere so I just built out a system myself. I am about 8k into it. It's not the biggest system (6kw inverter, 4kw panels, 15kwh storage) but it's fine for one old man living a 2kM in the high desert.

[lostlogin]

Just to clarify - you were looking at 50k+ for an on grid setup and solar + battery has cost you 8k so far?

[scarecrowbob]

Yes.

I live in a very rural spot with a difficult-to-deal-with Electric Association, with a Ute reservation on one side and unpowered parcels on other sides; I don't think that the easement is a typical issue.

And to be clear, I didn't count my labor in designing or implementing the system. I suspect that would have been somewhere in the neighborhood of another $10K if I had to get a hands-off, turn-key version of this same system.

And at some point I will likely double much of the capacity, at which point I will be able to run a mig welder at night if I want...

[zx8080]

It's called diesel fuel.

[cucumber3732842]

>The main downside is power density, which for grid storage is not as big a deal

It matters less but it's still a big deal though. You need to inject the power near where you need it otherwise you have to upgrade everything between you and them, roughly speaking. So you can't put your battery in BFE where land is cheap.

Cost increases from that plus environmental and site development regs (which are always more in denser areas) screw you too. So between the upgrades and the overhead there might not be a valley of profitability because all the sites you could toss a battery on and the sites where someone who has a more $$ use case than you will outbid you on the raw land.

So the end result is you wind up having to shoehorn a bunch of little developments into small crappy parcels but then the fixed costs of development come back to bite you so density matters there because the more jiggling electrons you can pack in the more revenue you can have to offset your fixed costs.

That said, anything that lets you tell the NFPA, the environmentalists and the local screeching Karens to take their setbacks and shove them hugely improves density, especially on small sites, so the reduction in cooling needs and runaway protection that sodium gets you might make it denser once the tech is fully vetted. Every foot you can shave off the effective footprint of a battery (after accounting for fire setbacks, service space, etc) hugely increases the number of sites that are developable.

[rbanffy]

> You need to inject the power near where you need it otherwise you have to upgrade everything between you and them

Or you install them near your solar/wind farm (or where the power connects to shore, if it’s offshore). If it’s a shore install, you might run a desalination side business when you have surplus energy.

[reacharavindh]

A dystopian possibly impractical dream.. imagine a pyramid like structure in every neighborhood, made from blocks of such cheap sodium ion batteries, the outside of the pyramid is covered in soil and greens, the top which could even be a windmill. The green space is for walking around, kids playing, a few bike trails, whatever fun. The whole neighborhood is power buffered through this pyramid. The national power grid only needs to supply these pyramids.. with renewable energy. The houses, parking lots etc have solar panels that feed into the pyramid.

[rbanffy]

If you make them with Lithium batteries every neighbourhood can have their own volcano.

I’ll show myself out.