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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?

#21

Post by benzible »

dylan604 wrote: post #9

Without being a battery chemistry expert, why do these battery packs become not useful for an EV yet could still be useful for energy storage. They keep saying that 80% of life becomes unusable for EV, but that's still a lot of life. Is it that grid energy is more of a constant drain while the EV is lots of hard pulls (for lack of better wording)? In an EV, the battery cannot provide the higher volts being requested…

It's not just about capacity (80% is still a lot), it's that degraded batteries lose their ability to deliver high current under load—so acceleration suffers and voltage sags under hard pulls. For grid storage, you're doing slow, steady charge/discharge cycles over hours, so the same battery that can't handle aggressive driving anymore works perfectly fine. Plus, grid storage has virtually unlimited space and no range anxiety, so if you need 25% more packs to hit your capacity target, you just stack them in a warehouse where real estate is cheap.

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

#22

Post by [deleted] »

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

[deleted]

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

#23

Post by cogman10 »

whatever1 wrote: post #10
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…

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.

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

#25

Post by dukeofdoom »

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 easier to handle.

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

#26

Post by miahi »

benzible wrote: post #21
dylan604 wrote: post #9

Without being a battery chemistry expert, why do these battery packs become not useful for an EV yet could still be useful for energy storage. They keep saying that 80% of life becomes unusable for EV, but that's still a lot of life. Is it that grid energy is more of a constant drain while the EV is lots of hard pulls (for lack of better wording)? In an EV, the battery cannot provide the higher volts being requested…

It's not just about capacity (80% is still a lot), it's that degraded batteries lose their ability to deliver high current under load—so acceleration suffers and voltage sags under hard pulls. For grid storage, you're doing slow, steady charge/discharge cycles over hours, so the same battery that can't handle aggressive driving anymore works perfectly fine. Plus, grid storage has virtually unlimited space and no rang…

Also, batteries will degrade faster over time when they start to degrade, because they need more frequent charging. Their internal resistance increase and that promotes heat buildup during fast charging/discharging, another thing that promotes degradation. Slow charge/discharge cycles also help with heat management.

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

#27

Post by epistasis »

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

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 solar resources, like fission is now, but that's a very very long time from now.

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

#28

Post by pinkgolem »

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…

i have heard that hybrid's have a maintanance problem?

is not a concern, double the technologie in the same space?

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

#30

Post by stetrain »

p0w3n3d wrote: post #18
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…

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

The number of Teslas sold up to 2014 is less than 1% of all Teslas sold.

Tesla has an 8-year battery and drivetrain warranty but they don't necessarily fail after that date.

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