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Can “second life” EV batteries work as grid-scale energy storage?

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Re: Can “second life” EV batteries work as grid-scale energy storage?

#101

Post by plqbfbv »

dukeofdoom wrote: post #25

Seems like the market is going the hybrid route. It's kind of easy to see why, best of both worlds. Some BYD hybrids have crazy ranges like 1500 km on a tank of gas. The more practical car is winning. They put in a much small battery in these for fast charge, and the daily commute range. And you have gas, for longer trips. Maybe smaller batteries would be better for grid-scale storage too. If they're lighter and easi…

> best of both worlds

And the worst too: https://evclinic.eu/2025/09/27/if-you-drive-a-hybrid-may-god...

I don't have first-hand experience, but these guys have an EV repair shop for a while and do also hybrids, their articles always offer lots of insight.

Short run down:

- micro/mild hybrids are useless: batteries too small, engines too small to be the sole source of power, so contribution to emission reduction is very small, batteries tend to fail early because they're very small

- full hybrids have bigger batteries and engines large enough to run pure EV, but you still rely on ICE engine for everything, so there's no ability to charge at home or save on gas

- plug-in hybrids are full hybrids, but you can charge them externally; according to many studies the estimated emissions are much higher than declared, because people simply don't charge them at home and run on ICE the whole time

In all these types of hybrids the batteries are smaller than pure EVs, so they cycle faster and degrade faster. You're carrying two drivetrains all the time with added weight, one of which has plenty of maintenance items. So they're not drop-in replacements.

From what I've seen from EVClinic above, many manufacturers use custom pouch cells, not cylindrical modules like the more advanced pure EVs, so you can't repair an individual failed cell. That means full pack replacement. For many manufacturers you can't order replacement parts of the electric drivetrain, and if you do, they cost a huge chunk of the car.

So all in all if everything's well, you're good. If something goes wrong, be prepared to spend the same as you would spend for a battery replacement of a pure EV, or even more.

Re: Can “second life” EV batteries work as grid-scale energy storage?

#102

Post by apendleton »

pfdietz wrote: post #84
apendleton wrote: post #72

Earlier quoted context omitted.

> It would require a technological breakthrough that we have not yet imagined. Maybe, but not necessarily. The necessary breakthrough might have been high-temperature superconducting magnets, in which case not only has it been imagined, but it has already occurred, and we're just waiting for the engineering atop that breakthrough to progress enough to demonstrate a working prototype (the magnets have been demonstrate…

High temperature superconducting magnets are not a panacea for the problems with DT fusion. Those issues follow from limits on power/area at the first wall, and the needed thickness of the first wall; these ensure DT reactors will have low volumetric power density, regardless of the confinement scheme used. With HTSC magnets, a tokamak much smaller than ITER could be built, but ITER is so horrifically bad that one ca…

Oh for sure, I'm not claiming that CFS (or Tokamak Energy or Type One or whoever else) will for sure succeed, or if they do, that they've already solved all the problems that will need solving to do so. My only assertion/prediction is that I think if they end up succeeding, when future historians look back and write the history of this energy revolution or whatnot, HTSC magnets will turn out to have been the key breakthrough that made it possible.

Re: Can “second life” EV batteries work as grid-scale energy storage?

#103

Post by apendleton »

epistasis wrote: post #94
pfdietz wrote: post #84

Earlier quoted context omitted.

High temperature superconducting magnets are not a panacea for the problems with DT fusion. Those issues follow from limits on power/area at the first wall, and the needed thickness of the first wall; these ensure DT reactors will have low volumetric power density, regardless of the confinement scheme used. With HTSC magnets, a tokamak much smaller than ITER could be built, but ITER is so horrifically bad that one ca…

And these are not new issues, they've been known for more than 40 years, but never addressed. From the 1983 Led > But even though radiation damage rates and heat transfer requirements are much more severe in a fusion reactor, the power density is only one-tenth as large. This is a strong indication that fusion would be substantially more expensive than fission because, to put it simply, greater effort would be requir…

In terms of cost of materials to build a reactor, sure, that seems right. But most of the cost of fission is dealing with its regulatory burden, and fusion seems on track to largely avoid the worst of that. It seems conceivable that it ends up being cheaper for entirely political/bureaucratic reasons.

Re: Can “second life” EV batteries work as grid-scale energy storage?

#104

Post by Rebelgecko »

duskwuff wrote: post #48
Rebelgecko wrote: post #17

Earlier quoted context omitted.

I've been intrigued by used solar panels for sale, seems like you can get an amazing price for ones that are only lightly degraded. Is there a downside, or do you just mean that it isn't popular currently?

How much of a difference does it actually make in terms of the all-inclusive price of installation (e.g. panels, inverters, mounting hardware, and labor)? (Asking because I genuinely don't know, not because I have a specific answer in mind.)

Labor is by far the top cost. But I'm intrigued by the economics of a small setups paired with like a <5kwh battery. And for something like that where you literally just throw 4-6 panels out, you can just brute force by buying more panels instead of optimizing angles. Basically a slightly beefier version of a European balcony setup

Re: Can “second life” EV batteries work as grid-scale energy storage?

#105

Post by seanmcdirmid »

jbm wrote: post #90
ACCount37 wrote: post #8

Earlier quoted context omitted.

A lot of the early EV battery life projections were based on Nissan Leaf Gen 1. Which had a horrendous battery pack that combined poor choice of chemistry, aggressive usage and a complete lack of active cooling. When EVs with good battery pack engineering started hitting the streets, they outperformed those early projections by a lot. And by now, it's getting clear that battery pack isn't as much of a concern - with…

I am a bit more concerned about batteries now as opposed to an year ago. We had this article from Elektrek [1] about battery issues in South Korea. When I asked my local electric maintenance shop [2, sorry for the FB link], they said they have started seeing the same issue in Model 3s and Ys in Canada as well. (They also said that it is too early to tell how common it would become) This may bode well for recycling si…

Tesla made powerwalls a product for a reason. They were supposed to come from outdated Tesla cars, but that never materialized. If it is materializing now, they already know what they are going to do.

Re: Can “second life” EV batteries work as grid-scale energy storage?

#106

Post by guelo »

ACCount37 wrote: post #8
bryanlarsen wrote: post #2

This is less useful than most people expected. Redwood has been struggling because the expected battery turnover is not occurring. EV batteries are lasting a long time, so they stay in the car are and not being recycled or reused in any quantity yet. If EV batteries last 20+ years in EV's, it'll be > 2040 before there are significant numbers of EV batteries available to recycle or reuse. https://www.geotab.com/blog/e…

A lot of the early EV battery life projections were based on Nissan Leaf Gen 1. Which had a horrendous battery pack that combined poor choice of chemistry, aggressive usage and a complete lack of active cooling. When EVs with good battery pack engineering started hitting the streets, they outperformed those early projections by a lot. And by now, it's getting clear that battery pack isn't as much of a concern - with…

That's amazing good news for the environment, thank you I hadn't heard this.

Re: Can “second life” EV batteries work as grid-scale energy storage?

#107

Post by pfdietz »

maxerickson wrote: post #100
pfdietz wrote: post #49

Earlier quoted context omitted.

The low cost of the modules themselves has led to the suggestion of cost optimized DC-coupled PV systems being used to directly drive resistive heaters. The cost per unit of thermal energy in a cost optimized system moderate scale system (> residential, Low cost modules allow one to do away with things like optimally tilted modules and single axis tracking. The modules can also be tightly packed, reducing mounting an…

What's the proposed system design? For example, in January, I get about 9 hours of sunlight and have an average daily high of 25 F. I'm gonna need to store heat somehow or another.

The place I saw this most clearly described was in Standard Thermal's concept, which will store the heat in huge piles of dirt heated to 600 C. The thermal time constant of such piles can be many years.

https://www.orcasciences.com/articles/standard-thermal-copy

https://austinvernon.substack.com/p/building-ultra-cheap-ene...

https://news.ycombinator.com/item?id=45012942

Re: Can “second life” EV batteries work as grid-scale energy storage?

#108

Post by pfdietz »

apendleton wrote: post #103
epistasis wrote: post #94

Earlier quoted context omitted.

And these are not new issues, they've been known for more than 40 years, but never addressed. From the 1983 Led > But even though radiation damage rates and heat transfer requirements are much more severe in a fusion reactor, the power density is only one-tenth as large. This is a strong indication that fusion would be substantially more expensive than fission because, to put it simply, greater effort would be requir…

In terms of cost of materials to build a reactor, sure, that seems right. But most of the cost of fission is dealing with its regulatory burden, and fusion seems on track to largely avoid the worst of that. It seems conceivable that it ends up being cheaper for entirely political/bureaucratic reasons.

Relaxed regulatory burden doesn't seem to be making fission competitive in China; renewables are greatly overwhelming it now, particularly solar.

We might ask why regulations are so putatively damaging to nuclear, when they aren't to civil aviation. One possibility is that aircraft are simply easier to retrofit when design flaws are found. If there's a problem with welding in a nuclear plant (for example) it's extremely difficult to repair. Witness the fiasco of Flamanville 3 in France, the EPR plant that went many times over budget.

What would this imply for fusion? Nothing good. A fusion reactor is very complex, and any design flaw in the hot part will be extremely difficult to fix, as no hands on access will be allowed after the thing has started operation, due to induced radioactivity. This includes design or manufacturing flaws that cause mere operations problems, like leaks in cooling channels, not just flaws that might present public safety risks (if any could exist.) The operator will view a smaller problem that renders their plant unusable nearly as bad as a larger problem that also threatens the public.

I was struck by a recent analysis of deterioration of the tritium breeding blanket that just went ahead and assumed there were no initial cracks in the welded structure more than a certain very small size. Guaranteeing quality of all the welds in a very large complex fusion reactor, an order of magnitude or more larger than a fission reactor of the same power output, sounds like a recipe for extreme cost.

Re: Can “second life” EV batteries work as grid-scale energy storage?

#109

Post by nandomrumber »

trhway wrote: post #32
p0w3n3d wrote: post #18

Earlier quoted context omitted.

Tesla batteries fail after 8 years at least from models up to 2014

Prius Plugin 2015 (last year of that model) - full charge/discharge at least 3-4 times a week, currently still a bit more than 80% of capacity (granted the battery seems somewhat overbuilt, yet it is normally does 10-15C which is much tougher mode than in a pure EV where 2-3C is usually enough and only high-end Teslas and the likes would do 5-6C). There has been large continuous improvement in lithium batteries over…

What does any of this mean?

What is c in this context?

Re: Can “second life” EV batteries work as grid-scale energy storage?

#110

Post by hinkley »

marcosdumay wrote: post #97
hinkley wrote: post #76

Earlier quoted context omitted.

It used to be 30. So fifty more years?

Yep, it was 30 years at the 60s. If it keeps halving every 85 years, we'll get it approximately never :)

Zeno's Fusion Paradox
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