Used Electric Car Batteries Could Be Crucial To A Clean Energy Future

[mspohr]

Interesting article in ThinkProgress about reuse of EV batteries. They point out that EV batteries removed from service have up to 80% of their capacity and that these have many years of life left for stationary storage.
They say that LG Chem is selling batteries for the Volt and Bolt for $145/kwh. Companies are buying used batteries for $100/kwh.
BMW and GM have pilot projects for used batteries combined with solar and wind and also used in cooperation with electric utilities for demand smoothing.
"Ultimately Tesla and GM and the other major EV companies are going to sell hundreds of thousands of vehicles over the next few years with battery packs that cost as little as $145/kWh. That means a staggering amount of low-cost used batteries will be available by the middle of the next decade.
When the trickle of second-life batteries turns into a flood, the business of electricity storage and demand response — both of which enable far deeper penetration of renewable power — will never be the same."

http://thinkprogress.org/climate/2016/05/09/3775606/used-second-life-electric-car-batteries/

 

[tander]

So the batteries get used in the cars, then they get refurbished and used for home storage, what happens after that? Do they go back to the gigafactory and get melted down for new ones?

 

[FlatSix911]

A great idea for the stationary reuse in the lifecycle of the battery.
This article shows very little battery capacity loss over time/miles.
According to the graph, capacity drop for Model S 85 kWh should be just below 10% on average after 100,000 miles.

Tesla Model S Battery Life Study Charted By Plug In America

 

[mspohr]

So the batteries get used in the cars, then they get refurbished and used for home storage, what happens after that? Do they go back to the gigafactory and get melted down for new ones?

I believe that the plan is for the Gigafactory to recycle batteries. It does seem like it will be many years before that is necessary. It could be 8-10 years in the car and another 10 years of stationary use.

 

[tander]

I believe that the plan is for the Gigafactory to recycle batteries. It does seem like it will be many years before that is necessary. It could be 8-10 years in the car and another 10 years of stationary use.

Interesting, it would be cool if they ended up doing some kind of truly full circle recycling. I don't want to see mountains of batteries in India or somewhere someday.

 

[mspohr]

Interesting, it would be cool if they ended up doing some kind of truly full circle recycling. I don't want to see mountains of batteries in India or somewhere someday.

Lithium batteries are relatively nontoxic and easy to recycle. Metal case, carbon, and a small amount of lithium which is not toxic like cadmium and some other battery components.

 

[scaesare]

Tesla has been aiming for recycling for some time:

Tesla's Closed Loop Battery Recycling Program

I expect that it's the gigafactory that will eventually allow this to be implemented.

 

[CHG-ON]

Li batteries are apparently just about 100% recyclable. Just think, a product that powers a car for 8-10 years, a home for 20-30 years (I have read), and is then recycled for another go around. It would be great. But I wonder if, that many years down the road, we will be looking at batteries as we do oil. Being an obsolete energy source.

 

[Uncle Paul]

It has been mentioned that some time down the road (8-10 years) Tesla owners will not need to buy new battery packs, but just replace the lowest performing individual cells in their packs.

Kind of like a tune-up for an ICE vehicle to bring their performance back up to original specs in a very economical manner.

This battery powered transportation just keeps getting better and better.

 

[JRP3]

It has been mentioned that some time down the road (8-10 years) Tesla owners will not need to buy new battery packs, but just replace the lowest performing individual cells in their packs.

That is unlikely to be the case. The cells should age at a similar rate so it's unlikely that some cells are significantly different than others, plus, it's not practical to remove individual cells and replace them. You could replace modules, but again unlikely one module would be significantly different than others. You'd also be introducing new cells into an old pack creating an unbalanced pack.

Interestingly JB Strauble just gave a talk where he said used EV batteries for stationary storage is unlikely because in 15 years or so when used packs become available the newer battery technology will be so much better and cheaper it's not worth re-purposing old packs. Jump to the 24 minute mark:

 

[mspohr]

Interesting point about battery recycling: "All of the materials which were used to make the new battery are still there when the battery is at the end of its useful life." Lots of research on recycling batteries.

 

[MitchJi]

Interesting article in ThinkProgress about reuse of EV batteries. They point out that EV batteries removed from service have up to 80% of their capacity and that these have many years of life left for stationary storage.
They say that LG Chem is selling batteries for the Volt and Bolt for $145/kwh.

Why Used Electric Car Batteries Could Be Crucial To A Clean Energy Future

LG Chem is charging GM about $225 per kWh.
And JB and Tesla disagree on the topic of reusing car batteries for grid storage:

Things Tesla examined and likely won't come about that we thought might:
1) Vehicle to grid - seems unlikely from their perspective
2) Re-use of vehicle batteries in stationary storage - also seems unlikely

Just because Tesla believes it doesn't mean it's correct.

 

[JRP3]

Just because Tesla believes it doesn't mean it's correct.

No, but they've probably spent more time looking at it than anyone else. Seems to me that used batteries for grid storage would only make sense if EV cell chemistry reached deep cycling numbers closer to daily cycling grid storage. There is a reason Tesla went with NMC for grid storage instead of NCA. If some future EV cell chemistry doesn't trade off cycle life for energy density then it might work. Same would be true of vehicle to grid, though I think EV's are currently capable of that to some degree, as long as it's very shallow cycling just for FR and peak leveling.

 

[MitchJi]

No, but they've probably spent more time looking at it than anyone else. Seems to me that used batteries for grid storage would only make sense if EV cell chemistry reached deep cycling numbers closer to daily cycling grid storage. There is a reason Tesla went with NMC for grid storage instead of NCA. If some future EV cell chemistry doesn't trade off cycle life for energy density then it might work. Same would be true of vehicle to grid, though I think EV's are currently capable of that to some degree, as long as it's very shallow cycling just for FR and peak leveling.

I believe that he's correct as far as using used batteries for grid storage.

But I disagree with his reasoning, and yours, on V-to-G.

 

[JRP3]

Well he and I differ somewhat on V to G as I said for shallow cycling, which I do think could provide useful support. Any significant cycling of the pack on a daily basis would negatively affect it's life. You're trading EV miles for grid "miles", and EV miles are more valuable.

The other part of his concern is the regulatory and technical requirements of hooking the vehicle to the grid which would add cost and complexity.

 

[miimura]

There will be used automotive batteries that have not used up their cycle life. There are a lot of cars that are written off because the cost to make it a fully working car exceeded its value. Those batteries can be put to good use for low volume applications. The problem is that the supply consistency and available quantity is not something that you can build a business on. Therefore, especially for Tesla Energy and others with ideas to scale up their products, used batteries make no sense. I that context I agree with JB. However, I personally have no problem repurposing an automotive lithium ion battery pack (or two) for my own personal home battery storage system. I think that when HVDC off-grid inverters are readily available there would also be a modest market for interface kits to use automotive battery packs intact. With 48VDC nominal battery packs the norm in off-grid systems, you have to break down automotive packs to use the cells.