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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?

#261

Post by pfdietz »

bluGill wrote: post #210
alvah wrote: post #134

Earlier quoted context omitted.

Is it worth using heat pumps in this setup (in addition to resistive elements)? I understand they can't reach the absolute temperature of resistive heating, but from an efficiency POV for the first few tens of degrees they are much more efficient.

Depends - the problem with heat pumps is when you need them the most they don't work. If it never gets below -10c (exact temperature needs more study, could be as low as -25) where you live they are fine - but that implies you live in an area where you don't get many cold days and so the expense isn't worth it (it also implies you live where it gets hot in sumner so you want ac anyway and the marginal additional cost…

I think unless you're in an area dominated by cooling needs, an optimally sized heat pump system will not cover 100% of heating needs. It would make sense to make it smaller and use a backup resistive heater for rare very cold events.

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

#262

Post by pfdietz »

kragen wrote: post #260
pfdietz wrote: post #259

Earlier quoted context omitted.

600 C is about what a coal fired power plant would use. And 600 C is around the maximum that you want if you're using cheap steel for the pipes. Much beyond that and creep becomes a problem. So I don't think 1000 C is their target.

Hmm! Interesting! I would have thought that 600° would be close to the minimum for producing supercritical steam, so any energy stored up to 600° would be "overhead" that couldn't be effectively recovered—only the heating above that. And I assumed they would have to use cheap ceramic for the pipes, because oxidation is usually a problem for cheap steel even below 600°.

The critical temperature of water is 374 C.

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

#263

Post by satellite2 »

torginus wrote: post #85
archi42 wrote: post #68

Earlier quoted context omitted.

Residential batteries are not that expensive anymore, at least not all of them. That's a misconception I also held until a few years ago ;-) My first 14.3 kWh pack cost about 2800$ DDP from China, delivered 03/2023. For that one I did calculate how long it took for amortization, which I projected at about 5 years. The second, identical pack was delivered 08/2024 and cost 2000$ DDP. Since we got an EV that's drawing a…

My new batteries were about 250EUR/kWh - my 10KWh unit cost 2500 EUR - scaling it up to a decent used 5 year old EV price - you can have one for 15k with 60+ kWh batteries, so I'd say it's at a very similar price.

Do you mind citing providers/product names?

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

#264

Post by trainsarebetter »

ACCount37 wrote: post #45
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…

Leaf Gen 1 didn't have NiMH. It had a lithium-based battery chemistry, but some bastard offshoot of it. One that really didn't fare well under high current draw, or deep discharge, or high temperatures, or being looked at wrong.

1st gen was LMO

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

#265

Post by trainsarebetter »

bluGill wrote: post #207
jbm wrote: post #160

Earlier quoted context omitted.

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 o…

Is it worth spending money on a car that old? You are putting more than the car is worth into fixing it and you won't get that back if you sell. You also have no idea when/if something else will go. thew worst case is the day after you fix it someone hits you and the repairs will be $30,000 - what it cost new and there are still a lot of worn out parts: insurance will give you $4000 and tell you to eat the loss.

30000? What? Leaf packs are swap able between years… here in bc 2k and you have a newer pack in

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

#266

Post by kragen »

pfdietz wrote: post #262
kragen wrote: post #260

Earlier quoted context omitted.

Hmm! Interesting! I would have thought that 600° would be close to the minimum for producing supercritical steam, so any energy stored up to 600° would be "overhead" that couldn't be effectively recovered—only the heating above that. And I assumed they would have to use cheap ceramic for the pipes, because oxidation is usually a problem for cheap steel even below 600°.

The critical temperature of water is 374 C.

You're right; I wonder why they operate supercritical steam turbines at 600° instead? https://direns.minesparis.psl.eu/Sites/Thopt/en/co/cycles-su... https://www.mdpi.com/2673-7264/5/1/1 https://www.modernpowersystems.com/analysis/is-700-c-steam-t...

Oh, apparently because of "dramatic improvements in power plant performance":

> Starting with the traditional 2400 psi / 1000 F (165 bar / 538 C) single-reheat cycle, dramatic improvements in power plant performance can be achieved by raising inlet steam conditions to levels up to 4500 psi/310 bar and temperatures to levels in excess of 1112 F/600 C. It has become industry practice to refer to such steam conditions, and in fact any supercritical conditions where the throttle and/or reheat steam temperatures exceed 1050 F/566 C, as “ultrasupercritical”.

https://www.gevernova.com/content/dam/gepower-new/global/en_...

Anyway, those are the plants that Standard Thermal wants to sell their product/service to. And once the hot dirt falls below 600°, it can no longer heat the water to 600°. So I think they have to be aiming far above that temperature, which is also why heating element reliability is a challenge and why the clays in the soil are firing (a phenomenon which only happens at 600° for the lowest-firing terra-cotta clays, more typically requiring 1000°–1400°).

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

#267

Post by cyberax »

pfdietz wrote: post #257
cyberax wrote: post #246

Earlier quoted context omitted.

> As we pointed out, PV is still trouncing nuclear in China. So if the difference is smaller there, it's still in favor of solar. Sure. Solar is easy to scale when you don't care about reliability, nobody is arguing with that. But it's another issue entirely when you need a stable grid. I'm not aware of any countries (even tropical ones) that managed anything close to 100% renewables with solar. E.g. Hawaii has to pa…

And nuclear is scalable if you force other sources off the grid in favor of nuclear (and force customers to not use renewables "behind the meter"). In a fair grid, solar and wind get built out, and the residual demand has no baseload component. Unless nuclear is given the right to force other sources off the grid it becomes inappropriate. In Texas now there is no chance of new nuclear construction. ERCOT is a competi…

> And nuclear is scalable if you force other sources off the grid in favor of nuclear (and force customers to not use renewables "behind the meter").

Not really? Nuclear is not any different from coal. And plenty of countries have coal generation in the mix. France also is majority-nuclear.

And so far, nuclear is the second known technology (after hydro) that actually demonstrated close to 100% fossil-free grid.

So far, there is nothing similar for solar. Even though it's supposed to be oh-so-cheap.

> In Texas now there is no chance of new nuclear construction. ERCOT is a competitive market and new nuclear simply doesn't make sense.

Well, yeah. Because they can just allow the grid to die during the next Arctic air blast.

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

#268

Post by bluGill »

pfdietz wrote: post #261
bluGill wrote: post #210

Earlier quoted context omitted.

Depends - the problem with heat pumps is when you need them the most they don't work. If it never gets below -10c (exact temperature needs more study, could be as low as -25) where you live they are fine - but that implies you live in an area where you don't get many cold days and so the expense isn't worth it (it also implies you live where it gets hot in sumner so you want ac anyway and the marginal additional cost…

I think unless you're in an area dominated by cooling needs, an optimally sized heat pump system will not cover 100% of heating needs. It would make sense to make it smaller and use a backup resistive heater for rare very cold events.

cooling is more important but not by much. however the real problem is temperature delta: 100f-70f is 30 degrees, 70f-10f is 60 degrees. If you size a system for cooling it can't make up.

of course things arenot actually linear on temperature but as a rough estimate it gets the point across.

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

#269

Post by bluGill »

trainsarebetter wrote: post #265
bluGill wrote: post #207

Earlier quoted context omitted.

Is it worth spending money on a car that old? You are putting more than the car is worth into fixing it and you won't get that back if you sell. You also have no idea when/if something else will go. thew worst case is the day after you fix it someone hits you and the repairs will be $30,000 - what it cost new and there are still a lot of worn out parts: insurance will give you $4000 and tell you to eat the loss.

30000? What? Leaf packs are swap able between years… here in bc 2k and you have a newer pack in

30k is the real cost to repair some accident damage to a leaf - think bent frame. this could happen anytime. Nobody would pay that price to the whole car ends up in a junk yard.

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

#270

Post by cyberax »

ben_w wrote: post #249
cyberax wrote: post #247

Earlier quoted context omitted.

> Half the country is a mid-latitude desert. What makes you think the whole country has "weeks" with zero solar? The "whole country" is irrelevant. You can't transmit arbitrary amounts of power across the large geographic areas, most of energy has to be generated in a reasonably close proximity. > And it does have to be the whole country in this case, because one thing a centrally planned economy can do well is joini…

> The "whole country" is irrelevant. You can't transmit arbitrary amounts of power across the large geographic areas, most of energy has to be generated in a reasonably close proximity. Only technically correct because you said "arbitrary": it's well within China's manufacturing capabilities to make a grid that can transmit 3 TW over 40,000 km, with a conductor cross section so thick it only has 1 Ω resistance. As in…

> Only technically correct because you said "arbitrary": it's well within China's manufacturing capabilities to make a grid that can transmit 3 TW over 40,000 km, with a conductor cross section so thick it only has 1 Ω resistance.

And it'll turn out to cost more than building a nuke in each backyard.

> I have, in fact, done the maths on this.

No.

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