This Southern California solar farm is using retired EV batteries for storing the power and then send to the grid when needed. This way the retired batteries can extend their usefulness for several…::A Southern California company is showing how repurposing EV batteries for stationary storage can extend their usefulness for several years.
That’s actually an ingenious idea I hadn’t thought about. How much cheaper are these batteries once they’ve been retired? Would this be a viable option for someone running solar at home, and wanting to store the power for later use, or is a home battery still the better option?
Yea, with a car you can’t really use them once the range gets low enough
With this, a bunch of batteries can work together for much longer. You also don’t need to worry about weight since they’re in one place
A Tesla Model 3, for example, has a battery capacity of 50 to 82 kWh. Let’s assume the lowest capacity of 50 kWh. A car battery is basically unusable long before it has lost around half its capacity. So 25 kWh. American households on average consume 10.6 MWh annually or about 29 kWh per day.
So an old Tesla battery still provides enough electricity to power an American household for nearly an entire day.
Really puts into perspective what a monumental waste of energy individual traffic, also with electric cars, is as well.
I thought I read that this was a plan Tesla had to repurpose the car batteries into power walls for home consumers. Not sure that ever ended up happening but great to see the retired car batteries given a second life
It’s the same cells inside both batteries. The difference is that the used EV car battery will store less power per volume since it’s worn out. It is a wonderful idea. A solar farm doesn’t care as much about volume and weight as a car does. For a home it would be fine as long as you’re trying to squeeze every inch cube of your property.
A 50 KWh or more battery pack will be overkill for most homes. But those will likely be available for cheap soon so it might still be a good option. Putting a pack that weighs several hundred kilos in your basement might be difficult, though.
I don’t know that a basement would be a good location regardless. If that thing sparks up, it’ll take out half the building before the fire department shows up.
Depends on the chemistry. I’d want NMC batteries outside and LFPs can be anywhere.
I use mine as a box spring in my bedroom
I’m assuming that doing full charge/discharge cycles on them daily will put more wear on them than every day driving would?
But if your buying them at scrap value and the. Still selling them as scrap after a few more years I guess it works out.
The way lithium batteries work, they wear out less if you only discharge and charge them slightly. So a battery that is charged to 60%, discharged to 40%, and repeated like that will keep most of its capacity even after years of prolonged use. On the other hand, charging a battery quickly, until it is full, or discharging it until it is nearly empty will reduce its capacity over time.
A Tesla Model 3 has a battery capacity of at least 50 kWh. Even if it has lost half of its capacity, the 20% capacity difference between 60% and 40% charge, or more realistically, the 50% difference between 75% and 25%, still represents 12.5 kWh of capacity. Suppose you had an array of 1,000 such batteries. That would represent 12.5 MWh of storage capacity, enough to power ten thousand homes (at 1.2 kW each) for an hour. Certainly nothing to sneeze at.
I’ve seen some interesting use cases for EVs themselves as a form of energy storage. Not necessarily to discharge as a voltage regulation mechanism, but as a predictive load for evening daily swing.
Being packed away in a static location has much lower energy density requirements than driving around with the battery on-board. Getting the most out of them and then reprocessing the materials seems better than just reprocessing right away once they’re no longer useful for EVs.
Exactly, it goes from being about the capacity:weight ratio to capacity:cost and as a bonus also postpones having to use powernto recycle them (and hopefully it’ll be cheaper/more efficient to do so then).
In practice they’re used more as a sort of capacitor to provide voltage regulation on the grid, basically what gas is doing for reliability. Not sure how often that wouldn’t involve a full discharge, but I know most gas in this context is running way below its capability.
So like… do electric car owners just need to buy new batteries? That’s the most expensive part!
Sometimes, but not often. These are mostly 1st gen EV batteries, so they’re pretty old. It’s mentioned in the article that once capacity diminishes to the point of effecting range the old battery is replaced. Old units can be refurbished. These units could also be situations where the car surrounding the battery failed (accident, hail damage, etc) and they decided to scrap it and reclaim the battery.
The article mentions that they mostly use batteries from the Nissan Leaf and Honda Clarity. I’m not sure about the latter, but the Nissan Leaf does not have any kind of battery management system. That keeps the battery warm in winter and cool in summer, and helps it last a lot longer. Nearly every major EV on the market does this, but the Leaf is the big exception. It’s also the one car where you’ll see severe range degradation on an older model.
What an atrociously dangerous planned design.
- Poor design: Thermal runaway is a serious problem that this setup has a very high chance of occurring. When it occurs, not if, it will spread fast from one container to the next and it will not be able to be put out that is the current fire fighting procedure for the state.
- It is very dangerous because these old batteries produce a very toxic and dangerous compounds when in thermal runaway. Again firefighting procedures cover hazmat requirements and it’s well documented the dangerous compounds that are present especially in these older batteries.
Net result. It will create another unstoppable fire that will dump poisons into ground water and the air recklessly endangering anyone down wind.
Solutions not problems:
- Isolate each container in an empty dam that is able to be filled with super chilled salt water the moment a runaway begins.
- Design fire suppression and shutdown to protect residents and the grid. Keep personal onsite to monitor with the authority to immediately react to fire incidents.
This is a way to get off gas as it’s used for reliability and voltage regulation. There’s a few locations running pilots with different energy storage techs like this. One of the main problems with integrating renewables is they aren’t dispatchable generation so you’re basically throwing unknowns in to the system. This is mediated through programs like demand response and load following with gas, but the goal of decommissioning gas and fossils entirely while still providing reliability is hampered because of this gap in capability. Renewables paired with storage would accommodate more less flexible renewables and SMRs, and allow for more electrification of the economy with less climate impact. More electric arc furnaces!
Good idea but good luck to the people who will try to take the fire out
Edit: I’m not saying that it’s bad, of course renewable, solar, electric is good. But knowing how horrible electric vehicle fires are to put out, I don’t see a fire of piled up batteries being an easy challenge for firefighters
Any energy storage device has risks. In this case the risk is higher, but so is the overall energy storage capability. If you store them off to the side in their own little building, there’s no real risk beyond loss of investment and environmental impacts.
Not to mention, firefighters now have tools to fight these types of fires.
Also since it’s in one place, you can build in detection and fire suppression measures.
Could be as simple as having the tools nearby (fire hydrant style), or as complex as automating the checks and suppression (cut off power, isolate the problem cells, spray em)
If these batteries are stable (ie only needs maintenance rarely) , is there a reason not to keep them in a closed, CO2 filled enclosure?
Lithium batteries can produce oxygen when at high temperature. I’m not sure if they would produce enough to be able to start burning in such conditions, but I wouldn’t rule it out (maybe someone better versed in chemistry knows). And once they start burning, the fire heats them up more, so they produce more oxygen, whch further fuels the fire.
I wouldn’t be as worried about oxygen, but more worried about properly sealing the container off as a water leak could cause the lithium in the battery’s to produce hydrogen.
But the odds off either happening are very slim.
Edit: the water has to come in contact with the lithium.
That would be cool, maybe cost to keep the CO2 levels maintained and leak proof? I’d be curious to learn more about CO2 filled enclosures. I think some rare books are kept in them?
Another alternative could be to flood the room with CO2 when an issue is detected. But I guess that’s just fire suppression again
Batteries and by extension EVs have a much lower risk of catching fire than ICE cars. Stop repeating fossil fuel industry gaslighting.
Lower risk yes, but also harder to put out yes, and also the comparison here isn’t about cars at all.
It still shouldn’t be an issue as long as you place the storage somewhere where the fire can be contained easily, then worst case the whole storage burns down but there wouldn’t be significant collateral damage.
Yeah, a huge tank of oil or natural gas or pile of coal is a total cake walk to extinguish! /s
For real.
