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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?

#151

Post by bruce511 »

apendleton wrote: post #72
epistasis wrote: post #27

Earlier quoted context omitted.

There's currently no technological path for fusion to be cheaper than fission. It would require a technological breakthrough that we have not yet imagined. And already, solar plus storage is cheaper than new nuclear. And solar and storage are getting cheaper at a tremendous rate. It's hard to imagine a scenario where fusion could ever catch up to solar and storage technology. It may be useful in places with poor sola…

> 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…

One can discuss base load and season shifting all day long. But ultimately fusion will fail for two simple reasons; time and money.

If we started building a fusion commercial scale plant today (ie started by planning, permits, environmental assessments, public consultation, inevitable lawsuits, never mind actual construction and provisioning) it'd come online in what? 10 years? 15 years? 20 years?

Want to deploy more batteries? It can be online in months. And needs no more construction than a warehouse.

Financially fusion requires hundreds of billions, committed now, with revenue (not returns) projected at 10 years away (which will slide.) Whereas solar + storage (lots and lots of storage) requires anything from thousands to billions depending on how much you want to spend. We can start tomorrow, it'll be online in less than 2 years (probably a lot less) and since running costs are basically 0, immediate revenue means immediate returns.

Of course I'm not even allowing for fusion being "10 years" from "ready". It's been 10 years from ready for 50 years. By the time it is ready, much less the time before it comes online, it'll be redundant. And no one will be putting up the cash to build one.

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

#152

Post by kragen »

kragen wrote: post #130
maxerickson wrote: post #100

Earlier quoted context omitted.

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.

I haven't seen pfdietz's proposed system design, but a so-called "sand battery," consisting of a box of sand with a heating element running through it, should work fine. You can PWM the heating element with a power MOSFET to keep it from overheating; you can measure its temperature with its own resistance, but also want additional thermocouple probes for the sand and to measure the surface of the box. A fan can blow…

A thing I forgot to calculate: with 75m of wire dissipating 533 watts per meter, how thick should the wire be? Suppose we divide it into three 25m circuits so that we still have most of our heat if a wire burns out, and suppose we're using 48Vdc. So E²/R = 13.3kW, R = E²/13.3kW = 0.173Ω, and each of those elements is carrying an astonishing 277 amps. So we want 7 milliohms per meter. It turns out that that's about 12-gauge copper wire, nominally 5 milliohms per meter. 2 millimeters across. A higher-resistivity metal like iron or nichrome would have to be even thicker.

Better idea: put 9 2.7-meter wires in parallel on each of the three circuits, so each wire can have 9×0.173Ω = 1.56 Ω = 0.58Ω/m. That's 32-gauge copper magnet wire, 0.2mm diameter, 0.54Ω/m; or its thicker equivalent in other metals. Iron's resistivity is 5.7 times copper's, so you need a 5.7 times thicker wire: 0.5mm, 24-gauge. Nichrome is 11 times the resistivity of iron, so you'd need 1.6-mm-diameter nichrome.

I don't know, I think the copper would probably melt faster than the sand could conduct the heat away from it, and the nichrome would definitely be fine, but too expensive. But you can extrapolate from this how to solve the problem: by shortening the distance along the heating wires to low-resistance busbars (possibly made of rebar or leftover angle iron) and thus increasing the number of parallel paths, you allow the use of higher-resistance-per-unit-length and thus cheaper and more workable heating elements; the limit of this lightweighting is that the wires' surface area in contact with the sand must cool them enough to prevent melting. By this method you can use a small amount of a conductor of any resistivity at all, limited mainly by the temperature.

All these metals are fine at 700°, or for that matter 1000°. Copper will have less of a tendency to oxidize than iron, which would require a reducing atmosphere, and nichrome will oxidize but remain protected by its oxidation. (A reducing atmosphere will destroy nichrome.) But, at a lower temperature still, like 600°, you could use 10μm thick household aluminum foil, which is much easier to work with than any kind of 20μm wire, but has a similar ratio of surface area to volume. It has 54% more resistivity than copper, so a 10μm × 1mm strip is 2.7 ohms per meter. Our previous objective of 0.58Ω/m is a 4.6mm-wide-strip, which transfers heat to the sand along its 9.2mm perimeter, like a 10-gauge wire. 75m × 4.6mm is the size of about 5 or 6 pages of A4 paper cut into strips.

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

#153

Post by taneq »

numpad0 wrote: post #88
formerly_proven wrote: post #58

Earlier quoted context omitted.

EVs no, but I think some Toyota hybrids (which are of course not even PHEVs) still use NiMH. Toyota tends to be very tight-lipped about their batteries and their sizes (or rather, lack thereof).

Tends to be tight lipped??? It is in the catalog[1]! It is more that American consumers aren't tech obsessed than Toyota being reluctant to share. Even just looking at online media reports[2][3] clearly sourced from some exact same press event, it is obvious that US English equivalents are much lighter in content than Japanese versions. They're putting the information out, no one's reading it. It's just been the type…

Interestingly they don't tell you anything (unless I missed it) about the battery for the non-plugin hybrids, eg. the Corolla Cross: https://www.toyota.com/corollacross/features/mpg_other_price...

I was looking up this year's Corolla a while ago and likewise there was minimal info that I could see about the battery capacity, which I think I figured out was about 3kWh.

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

#154

Post by throwaway270925 »

JohnLocke4 wrote: post #19
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…

In 2040 fusion energy advancements will have gotten far enough to be the next technological step and make this redundant anyway

With solar, fusion energy is already here! There is just a bit of wireless transmission involved after generation.

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

#155

Post by cyberax »

pfdietz wrote: post #146
cyberax wrote: post #140

Earlier quoted context omitted.

Regulation is not a problem, and even the construction costs are not terrible. We can take the Rooppur NPP as a base, it produces reliable energy at 6-7 cents per kWh. The reason for cost overruns is simply because NPPs are one-off products, the Western countries don't have a pipeline for NPP production. For comparison, utility-scale solar with 16 hours of storage is 21 cents: https://www.utilitydive.com/news/higher-…

If I understand correctly, the cost/year of an engineer in India is maybe 1/3rd that in the US, and for general labor the disparity is even larger. So it shouldn't be too surprising NPP construction in India is cheaper than in the US. India doesn't have a large NPP pipeline, they just have cheaper labor.

(Bangladesh, not India)

Yes, but solar power panels are also mostly produced in China, where engineers still get less than 1/3 of the US/Europe salary.

European power plants will be more expensive, but even with the LCOE of 12 (twice that of Rooppur) it's still going to be way cheaper than storage for areas that get cold weather (Midwest, Germany, most of China).

Anything south of California? Yeah, just get solar+wind, no need to bother with nuclear.

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

#156

Post by beAbU »

cogman10 wrote: post #23
whatever1 wrote: post #10

Earlier quoted context omitted.

We are only 5-6 years into the car ev market. Tesla model 3 started being sold in 2018 in meaningful numbers

Still have mine. Battery capacity is around 80% of the new capacity. I'm not planning on switching anytime soon as it's got plenty of range still. I'll probably swap the pack out when it hits 70% in the next 2 or 3 years.

Your 2018 tesla has a battery SOH of 80%?

How many km's on the clock, and how often do you fast charge if you dont mind me asking?

To me that SOH stat sounds really bad!

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

#157

Post by adwn »

overfeed wrote: post #149
Lucian6 wrote: post #66

[dead]

> Having worked extensively with battery systems, I think the grid storage potential of second-life EV batteries is more complex than it appears. Complex, by t very much doable. Toyota implemented such a system with enough packs to power a Mazda factory [1] > However, you need to factor in significant integration costs (~$50-75/kWh) to build compatible BMS systems and thermal management. Shouldn't this be a once-off…

> Shouldn't this be a once-off cost per battery-pack version?

A BMS isn't just software. It requires a µC, voltage and temperature sensors for cell monitoring, and power electronics for cell balancing. However, those are all comparatively cheap, especially at scale, and the quoted cost of 50–75 US$/kWh looks ridiculously overpriced to me.

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

#158

Post by jbm »

MetaWhirledPeas wrote: post #132
jbm wrote: post #90

Earlier quoted context omitted.

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…

I would be more concerned if the source were anyone but Electrek~. Their vendetta against Tesla has forfeited all their credibility on Tesla news. "many of these vehicles are now out of warranty, as they sometimes exceed the maximum mileage" They have good numbers for the number of affected vehicles, but the best they can do for out-of-warranty stats is "many" and "sometimes". Convenient. ~To be fair this applies to…

I can respect that. For what it is worth, I validated with a well-trusted local shop that works on EVs (and works with Tesla) that said the issue is starting to pop up. Moreover, it's the government of Korea that is making this claim as well.

(I also find it difficult to separate noise from signal about Tesla. However, I don't consider them innocent victims; besides the elephant in the room, they literally eliminated their PR department)

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

#159

Post by CursedSilicon »

MetaWhirledPeas wrote: post #132
jbm wrote: post #90

Earlier quoted context omitted.

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…

I would be more concerned if the source were anyone but Electrek~. Their vendetta against Tesla has forfeited all their credibility on Tesla news. "many of these vehicles are now out of warranty, as they sometimes exceed the maximum mileage" They have good numbers for the number of affected vehicles, but the best they can do for out-of-warranty stats is "many" and "sometimes". Convenient. ~To be fair this applies to…

>Dunking on Tesla is its own industry these days, it seems.

Are you suggesting Tesla is criticized without good reason?

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

#160

Post by jbm »

wcfields wrote: post #37
cogman10 wrote: post #20

Earlier quoted context omitted.

I'll defend the leaf a little. LiPo batteries were quiet expensive when it was initially released. NiMH was really the only option in town. And with a lower energy density battery that's also heavier, adding a cooling system would have also added a bunch of weight to the already heavy car with a barely usable range of 100 miles. Gen 2, however, had no excuses. They had every opportunity to add active cooling and they…

On the used market you'll find absolutely cooked (literally) Leafs whose first life was in Arizona and barely have enough range to back out of the driveway.

Is there any value in fixing the battery on these? IE: Do the other components last long enough to be worth the cost?

It seems like procuring the battery is not as expensive as the Tesla battery (I see someone who did it themselves for $6k on Youtube with the battery from a wrecked leaf). In comparison, the cost I see for my Model 3 is about ~$18k CAD.

Getting a car up and running for $8k might be worth it if it is otherwise dependable, but I've only heard unfortunate stories about the first gen Leaf.

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