My thoughts exactly. I charge drone batteries (with caution) and their "C" rating determines how fast you can charge them. It is a physical property of the cells. You need a beefier battery (higher "C") to charge at a higher speed, not a better charger. I need more details, as obviously drone batteries are clearly not EV batteries!
C rating still applies, charging at 1C is usually "fast" charging for most cells and that takes an hour, charging in 5 minutes is is 12C which is normally "bad", would need lots of active cooling.
50kw would take 2 hours on a 100kwh pack so it would only be 0.5C. To do it in 5 minutes would require 1.2 megawatts of charge rate.
The cable is one of several bottlenecks in the charging system. Existing DC fast chargers already circulate liquid coolant through the charging cable. That's one reason they are so short and heavy.
TBH, it kind of freaks me out to handle even just the 50 kW cables.
From the article:
"Ultimately, charge times will be dependent on the power output ratings of the power supply and charging cable, and the power input rating of the EV’s battery. To obtain a sub-five minute charge, all three components will need to be rated to 2,500 amperes."
Yeah, existing cables carry enough energy to boil a kettle in a few seconds, for comparison sake. 2500 amps at 480 volts pushes boiling a liter down to about half a second (so even a large kettle would boil in 2 seconds if you figured out how to just heat the water with the energy).
unlikely. electricity is easier to control safely than gas.
you don't need to start out full blast with electric cables. ramp up over a minute if necessary. we are also well versed in circuit breakers, and digital safety checks.
How many simultaneous safety system failures are needed for a problem to occur? Multiply the odds of that by the number of charging stations in service worldwide, which is a pretty big number.
Yes, it’s not recommended to do Tesla Supercharging regularly for this reason. Then there’s the matter of the actual charging infrastructure. It’s not like you can plug a ,as I’ve cable into your 100 amp circuit and it’s gonna work.
It is too bad electric vehicles still require strip mining, the equipment that does that all run on oil, as well as tires actually producing more pollution than what comes out of the pipe. I fear this is the next greenwashed "recycle and it will all be ok bs". And by that I mean most recycled material, excluding paper, only actually gets recycled in the sub 10% success rate.(you can view that on EPA's website) source: https://www.transportdive.com/news/tire-emissions-exhaust-st...
I didn't downvote but it doesn't seem like a stretch to imagine that industrial mining vehicles will go electric in the near future.
Tires are definitely an issue but producing gas involves a lot of trucks as well. Between all the work in oil pumping/refining/distribution there must be quite a bit of rubber burnt!
Edit - I think the tire issue definitely needs to be solved, but theres no reason it has to keep us using gas vehicles over electric
> I didn't downvote but it doesn't seem like a stretch to imagine that industrial mining vehicles will go electric in the near future.
Ah, I may have miscommunicated my concern, which is that the resources involved/required in the acquisition, sequestration, production, and recycling of batteries may ultimately be more damaging than conventional fuels [in the long run]. It is possible that I am wrong, however, it remains a personal point of concern.
this video compares co2 emissions of a tesla vs hybrid vs regular ice car. I think it is an interesting exploration of the topic although I think the presenter had a hard time getting correct data and his data on the EV is more conservative than Tesla's numbers.
I would definitely be interested in exploring this further. It seems probable to me that we won't have a better grasp on this for years yet as EVs are still pretty new and not widely adopted.
https://www.youtube.com/watch?v=MEqxaH47DTs
It's not remotely a stretch. The biggest mining machines in the world (open pit coal shovels in Europe) are already electric and have been for ages. In the rest of the mining industry most big manufacturers like CAT and Sandvik are releasing battery powered scoops, haul-trucks, etc. It's on its way but industrial adoption will surely follow consumer adoption. We do need better batteries, faster charging, and more experience before they can take over, but thankfully that consumer demand is paving the way (i.e. paying for the research).
The people who tend to make that argument are people who will eventually hand-wave away all efforts at electrifying society and transportation, minimize climate change and the efforts to stop it, and so on.
Yes, there are up-front environmental costs to electric cars, but I wager it's worth it.
Scenario: We could churn out 50,000,000 electric cars next year, with all the strip mining and oil-burning required. But somehow, we had nuclear/solar energy and a grid in the US capable of supporting the power draw. The outcome would be a much healthier country, on the whole.
The goal long term is to eliminate the use of fossil fuels. Transport is the most obvious "hard" problem - nuclear/solar/wind are clearly going to take over coal and gas. It would be beneficial to move transport over to electric now, to "centralize" the fossil fuel problem to power plants.
> The people who tend to make that argument are people who will eventually hand-wave away all efforts at electrifying society and transportation, minimize climate change and the efforts to stop it, and so on
This is not being fair or charitable. Some people are genuinely curious, like myself, but are treated as if some type of malice was intended just for asking.
Interesting to look up
Underground mining. Could try CIM. most underground mines have been using electrically powered machines for years. Some Decades. Air quality underground is big concern.
You asked for context. Experience is experience. I didn't say you were like that, and I answered the question assuming you in particular were asking in good faith.
(This one is doubly surprising, because gas cars have tires too. Even if tires were single-handedly melting glaciers, an EV would still be avoiding tailpipe emissions.)
EVs are not perfect, but they are better - considerably better - which is why there's so much misinformation about them. The oil industry has enormously effective PR.
Another thing to consider is how gasoline is transported around. Gas pipelines are possible but last mile delivery is inevitably a huge inefficient truck.
Moving electricity is a solved problem - power lines have no emissions.
“ Tires polluting more than exhaust is a myth. ” Did you even read the blog post you just linked? I did and it clearly said a non tailpipe emissions were 4/5ths of the emissions. Also debel.energy is literally an energy company that has incentive to combat anything that’d hurt their potential profit.
Not sure if commenting here will alert the parent as well, but I believe that myth stems from the fact that tires create more PM (Particulate Matter) than exhaust. Exhaust of course emits much more CO2. The article discusses them separately and even mentions regenerative braking could help reduce PM, which would mean EV's could reduce both types of pollution.
Hydrocarbons can come from wood and other biomass, too. Woodgas is not unheard of. Plants feed on the bulk of emissions, if you need the cycle completed for you.
the fact that people think tires matter in a comparison between EV and combustion engines is hilarious. 'these things both have tires, clearly EV is worse as a result.' facepalm
> under five minutes – about the same amount of time it takes to fill up a gas tank
'about' is doing some serious work there. Maybe it's on par with the entire time spent at the gas station, but I'd say "under two minutes" is a better estimate of the actual transfer.
The most popular truck in the US is the ford f150 which has a 26 gallon tank. The fill rate of gas stations is 10 gallons a minute in the USA (by law - they are capable of much faster fill rates). Even when only looking at trucks we are talking less than a 3 minute fill time for the vast majority of trucks.
An F150 is not what was being discussed, nor was 'the average american truck'. Generally in areas like this where the size is for the sake of utility and workload capacity, Super Duty (F250 and above) is the standard.
You are not towing livestock or machinery with an F150 typically, or with any practicality. Just in the vicinity where I live, looking out my door, F350 is a common choice, with King Ranch being the preferred trim line due to its towing capacity.
Gasoline has an energy content of ~120MJ/gallon (sources online seem to vary from 115 to 130) so that's an energy delivery rate of 1200MJ/min or 20MJ/s. 1W = 1J/s so that's 20MW or 20 million watts of power flowing through the filler hose that a gasoline vehicle is effectively being "recharged" at. No EV charging standard I know of even approaches 1MW.
EVs are optimized for oxygen free environments: Moon, Mars and so on. Gasoline trucks are optimized for Earth with 20℅ oxygen in the air.
Perhaps the solution for EV chargers is a special fuel that burns with oxygen and releases electricity. And it shouldn't have C in it, only H, N and O. I guess, its also allowed to use rare earth catalyzers.
Ammonia could be an interesting fuel for vehicles (easy to synthesise from electricity, quite energy dense). It's a bit toxic though (probably manageable) and the round trip efficiency of synthesized ammonia used in a fuel cell or internal combustion engine must be really low. It would only make sense if we had huge amounts of surplus energy.
Gasoline is burned at about 30-40% efficiency in cars while charging a battery is above 90%, probably over 95% (after the charger losses, that is whats going across the cable into car).
So with a gas pump your looking at more like 7-8MW equivalent. Even then EV's are more efficient at spending the energy with regenerative braking and no idle losses etc. which is why you 100+MPGe. So your probably closer to 3-4MW to get equivalent charge times as filling a normal car gas tank at like 2-3 minutes for similar range.
HPCVC charging spec is being worked on for 3 megawatts but its really targeted for charging large vehicles like Semi's but I would imagine that would trickle down to normal cars at some point if the issues of charging a battery that fast can be worked out.
Truly shows the massive amount of inefficiency of an ICE engine. My EV uses ~1MJ/mi (~3mi/kWh) while my ICE uses ~6MJ/mi (20mpg). The ICE 6x the energy cost to move a vehicle about the same mass, 4,400lbs (EV) to 4,200lbs (ICE)
The fill rate of regular gas stations in the US is up to 10 gallons a minute. They're not going around and slapping fines if your pump is only pumping at 9 gallons per minute. I'm pretty certain most pumps around me aren't going exactly 10 gallons per minute, I'm often waiting 2+ minutes for 16 gallons of gas, but not every time.
The electric charge up would take about twice as long as filling up with gasoline but in some cases that would be a good thing since you can leave an electric charging vehicle unattended while you go into the store or use the restroom. With gasoline you have to attend to the pumping operation the whole time. Neither is a huge use of one's time but being able to perform other tasks while refueling is a nice side benefit.
Do most people go buy things or use the bathroom when filling up? If I am in my local area (where 95% of my fill-ups happen), I never do either. If I am on a road trip, there is a small chance (10%?) that I do one or the other.
My main goal is to fill up and get going, but perhaps other people are different.
On road trips (driving for more than 2 hours), I almost always do. It's a good chance to have a break and stretch my legs.
When I fill up in my local area I do it at the supermarket (which all have a petrol station attached where I am), so it's more that the shopping has a petrol re-fuel attached. Another time (pre-covid) I would fill up is on the commute. But the office had some charging points there.
The main reason you don't see them as often in N/W-Europe and they are even explicitly forbidden by law in some though there are exceptions. In NL for example, in which case all methods to latch them are forbidden like putting a filler plug in the hole.
Two minutes is shorter than most pumps I've been to recently (and seems to be the theoretical max fill rate). Seems stations are using one actual pump for multiple dispensers. Meaning that it takes more like 5 minutes to actually fill my car from empty. Also, there's the "good enough" argument - 5 minutes gets you to the point where there's no perceivable difference.
5 minute charging would be a game changer. That means urban dwellers could use EVs the same as gas engine cars and that road trips look exactly the same as they do now (presumably gas stations would add EV stations with enough market penetration). This cable isn't the big issue in making that happen, but it's needed. Battery chemistry and power distribution become factors at that point, but we're on the way to solving those issues too
meanwhile i bought a 240v connector for my EV but never paid to have it hooked up because the 120v connector it came with it unexpectedly turned out to be fast enough for my use case.
I tend to get down to about 50% battery on my base model3 after a weekend of errands and it will charge back up to 80% overnight
I realize this new cable design would be more for on the road quick charging - but I think even that is pretty fast currently.
The Tesla truck, the only model that made sense of you do any back country/rural driving was the three engine 550mi (if I remember right) version. Even then, I would think a generator would need to be carried (and fuel).
Rural areas don’t have chargers for the most part. That said, I’ve seen some chargers along 395 in rural NV that surprised me.
Until range becomes less of a concern, I’m not getting rid of my Tacoma.
This is why I think the by hybrid market will still win for now. Tesla makes sense for people driving short distances but not really long distance trips.
The hybrid 2022 Tundra is expected to get 20-25/gal which is great for a truck that size. And it was on the radar before my Subaru was totaled - I’ll stick to my Tacoma (paid off).
I see no real solution to the CA no fossil fuel engines post 2030. Our infrastructure can’t handle it. The majority of the state is suburban to rural. I cringe when I see a friend’s posts driving from Seattle to Truckee in their Tesla. The added time for charging.
The start to my recent road trip - Truckee - Ashland; Ashland - port Townsend; the first leg cost the same as the second in fuel prices due to CA gas taxes; but the whole route would have taken 2-3x as long if we had to charge an EV.
GMaps gives me 12hr non-stop from Seattle to Truckee. Add 1hr total stops and it’s 13hr total (I’d stop much more frequently on a long trip like that, prob 15h total).
Using the Tesla planner you need ~5 stops at 20-30m each. Total time is 16 hours. Looks like it would only be slightly longer than gas for myself.
Stock Rivian performing well at Moab. Tesla are a marketing hype company and a major distraction IMO.
https://youtu.be/Yeth5v_5dPM
Regarding the 'could' article about potentially charging batteries faster: the plumbing analogy of a wider pipe/charging cable has to also take into consideration battery design and heat issues, a major BEV problem.
I think we are ~15 years away from safe and viable 100% BEV's before we break out of the affluent local transport virtue signaling markets.
Same for me. I have 240v mains in my garage, but I’ve never bother to get it wired up because the 120v receptacle has been good enough for my 20mi/day driving pattern. I’ll eventually get a dedicated 50amp circuit installed, but currently I can plug in every 2-3 nights and never think twice about range. Tesla Model Y. I’ve popped into a supercharger a couple times to “catch up” to go from 20% to 60% in ~20 minutes, if I’ve forgotten to plug in several nights in a row, very handy option to have as a back stop.
I don’t think the cable is the problem for the cars today. At a supercharger, I get throttled back from 150kw lrettt quickly, and it seems to settle in at 60kw.
If the cable really is the problem, why not just use a busbar with a couple hinges?
Highway range is the bugaboo that needs to be resolved though. Supercharging gets thermal throttling too quick.
If you have it, you do actually save electricity by using the higher-voltage connector. Just to toss some numbers out, ~85% charging efficiency at L1, ~95% using L2. FWIW.
This is where somebody pipes up and says unless it can drive 3,000 miles on one charge with 16 kids in the back whilst towing a 60 foot boat then it is useless for everybody.
They achieve this by "charging cable that can deliver a current 4.6 times that of the fastest available EV chargers".
However, that also means 4.6^2 = 21 times more losses in the transfer cable since losses are P = I × V = I² × R (where P are losses, I is current, V is voltage, and R is resistance of the cable).
Wouldn't be better to increase voltage? I guess that would require changes to cars?
The parent comment said that the losses would be 21 times higher. My thought was, surely the losses on a short, liquid cooled cable were pretty negligible to begin with..
Additionally, your demonstration is incorrect, with the same argument you can also write P = I×V = V²/R and conclude that you don't want to increase voltage.
The V in that equation is for voltage drop along the cable, though, not total system voltage relative to ground. And that voltage drop is proportional to total system current, but not total system voltage.
You're mixing up the supply voltage and the voltage drop in the wire. Increasing the supply voltage will decrease the voltage drop in the wire (assuming appropriate adjustments to the load). It's the same reason you're better off using an AC extension cord for your phone charger than using a long USB cable.
EV chargers and cars are already up to 800 volts, to charge a 100 kWh pack in 5 minutes you need 1.2 megawatts which is 1500 amps. Chargers and batteries might go up to 1000v but don’t think there are plans to go beyond that at this point.
It actually would be pretty brilliant to put a 4~20kV+ SiC buck converter at the end of a cable, drop down to target voltage at the end, given how vicious power losses in a cable are & how bloody efficient SiC buck converters are.
Still, getting enough output current is going to be hard. Even 750A (10 minute charge) is going to be rough. GeneSic makes some 3.3kV to247 mosfets that can do 200a, about $300 a pop on mouser. And even at better than the best efficiency that charger head would require really good active cooling, probably water cooled. Still i like the idea of staying ultra high voltage till the very end.
End of the cable isn't the best place, you will still need a connector capable to handle gazillion amps and also solid hunks of copper inside car to connect it to battery. Better to integrate it directly into battery packs.
Fully agreed. Just seems less likely. There's a chicken & egg/which comes first problem. I believe a lot of cars dont even have buck converters? That they rely on the charger to ramp/control voltage? Even if they do include converters, it'd be super expensive to go from a 1kV to a 4kV or 15kV buck converter.
Having ultra high voltage capable chargers that can power most cars seems like a necessary first start.
Maybe it's just me being paranoid, but gas/charging stations tend to be in "rugged" environment. If oil cable is slit for whatever reason, you have leaking oil. If power cable is split.. you're electrocuted and dead?
Nonetheless, I fully expect there to be at least a few deaths and injuries once EVs become more common. Probably not as likely via electrocution, but more likely via something catching fire. There are huge amounts of power being transferred; when (not if) something goes wrong, it tends to be quite catastrophic.
I drove off with a 30kW charger cable still attached and charging. Ironically during developement of functionality to prevent you from driving off with the cable attached.
The connector ripped out at the buss and ground faulted. Nothing spectacular happened.
This is huge. Hopefully they can move from the lab to the real world environment conditions in 1-2 years. Would love to start up an electric charging station using these super fast charging cables.
Why are we emulating a gas station pump at all for electric cars? Why not something you drive over and it self-guides itself to make contact with multiple contact-points beneath the car.
I think that's a fair question, but if we're going to power vehicles as they go down the road, doing it from above is a better solution.
But the most straightforward answer of why those ideas haven't caught on is because we have a whole lot of existing road infrastructure that we struggle to maintain now. The infrastructure required to charge battery vehicles is tiny in comparison, and on top of that, private industry will fund much of it.
Great idea, let's put pantographs on teslas. and while we're at it maybe we can reduce the maintenance requirements by putting them on sort of durable guideway, say made out of metal. and if we also use a metal wheel we can use the guideway for return current and only put up one wire...
You don’t have to put them on rails. We could have highway lanes that power vehicles for long distance travel, and then they rely on battery for local use. https://youtu.be/_3P_S7pL7Yg
This could have some big advantages to cramming larger batteries into vehicles and trying to charge them at higher rates. Cheaper, lighter and safer vehicles, and batteries that last longer.
I feel like a pantograph (https://en.wikipedia.org/wiki/Pantograph_(transport)) raised to connect to overhead lines in a charging lane with different speed limits would work fine. It’s certainly cheaper than something like building elevated rail networks.
Overhead power for trucks on trunk routes, with batteries for overtaking and for the 20 miles each end. Certainly in the UK almost all trucks spend their entire travel time in those areas.
That sounds very complicated. You have to design it for various ground clearances, it would be more expensive to install and maintain. You limit other uses for the ground space with whatever rails or guides that would be needed. Or, if it’s smart and uses vision or similar tech to align with the connectors, then more expense and maintenance.
On the car itself those contacts would need to be protected from road hazards. So more expense on that end to have a motorized cover the driver has to operate.
People know how to use plugs. They’re cheap and familiar. And if standards change, adapters are easier to build.
Because car manufacturers want to keep manufacturing cars. Some of the bigger manufactures don't even want to switch to EV's, they are being dragged screaming and kicking into the future.
Or maybe just swappable batteries? Dock, empty cell goes out through port A, new cell goes in through B, drive off?
I reckon the majority of the car weight is batteries, but this could lead to cheaper cars, perhaps with shorter range but able to “recharge” faster than a gas pump, and takes away the range anxiety of an aging battery you can’t easily replace.
Probably not factoring in some very obvious drawbacks here, of course.
Tesla tried this. The issue of battery condition is too difficult. No one wants to swap out their brand new pack and chance getting a heavily degraded pack back. Or swap out a heavily degraded pack to be offered a new pack but with a $10k surcharge for the improved battery condition.
In new electric cars the battery is a structural component so you can't really remove it to begin with.
I realise the moment has passed but structurally integrated batteries aside, this was a huge misconception of the likely reality of battery swap at scale. Starting gate, sure you get lemon packs. It's not like gasoline isn't plagued by low grade fuels and water contamination (it shuts down airports) -but then you get regulatory standards and people normalise to acceptably efficient removal of bad battery packs from the swap scheme. And since you don't own the pack, the problem amortises over the rental costs.
People broke the model with what-if games. It never got to critical mass. So it's basically VHS vs beta, for swappable vs integrated and swappable lost, on pretty specious grounds.
Integrated is good because strength and weight. Swappable was good on speed. Swappable is alive and well in e-scooters and probably works for trucks.
Battery swap did not advantage Tesla in the marketplace and possibly disadvantaged Tesla which had 2x range for most competitors. A viable battery swap economy ends range anxiety, at the density of swap shops. Tesla wouldn't have had a compelling story in swap.
From memory the battery pack in a Tesla weighs on the order of 300kg. It's quite a heavy thing to change even if the structural and battery conditions went away.
You're off by a factor of almost two. An 85KWh Tesla pack weighs in at 550 Kg. It's more than 7000 cells, so that's 350 Kg for the cells alone and then you still need to add all of the structure, interconnects, electronics and cooling.
Swapping in a multi-vendor world also implies standardization. It’s too early in this technology to standardize - that would stifle progress.
Swap stations would also be far more expensive to build and manage inventory for, and would carry higher liability for whatever automated mechanism moved the thousand pound pack packs around when it e.g. went out of alignment and crushed somebody’s car frame.
Yea, totally - I found this to be a lesser problem in cases like Tesla, where it's all proprietary anyway. You're correct that in a world of many standards, it becomes an issue
Maybe for freight trains too, since you can build the battery into a battery tender carriage, and railways have 150+ years experience at swapping carriages on and off trains.
Yes, it can be done. But as everyone here said, there are trade-offs. Most companies judged the tradeoffs to not be worth it at this point. This might change in the future.
I would say that they are right, because right now battery tech is advancing and standardisation would impose a cost to progress. NIO doing their thing is not standardisation.
But it does show that it can be done and that is important.
In the future we should definitely push to get to the point where EV battery swaps are routine.
I believe the reason Tesla gave up is because it requires a lot more infrastructure (expensive) than superchargers and is mechanically hard to implement (though they did show working solutions).
Also, it is a logistic pain since all battery exchange stations need a stock of batteries to charge, the size of which will depend on a lot of parameters.
Also this requires standardising the battery. Turning it into a "API". Tesla is a very fast company and introduces changes constantly to their process, unlike others whould wait for the launch of a new model. Standardising on battery model is incompatible with the Tasla mindset.
But a model like this is plausible. You would no longer care about the battery. You would no longer own the battery. If batteries were standardised, the infrastructure (not necessarily one company) would take care of the entire lifecycle of batteries (production, charging, maintenance, reuse, recycling). It could work but it is too early and technology is moving too fast.
Tesla was trying to swap rechargeable packs, right?
Another approach is to use non-rechargeable batteries. A few years ago a company demoed an EV using a non-rechargeable aluminum air battery with a range for something like 1000 miles.
Aluminum air batteries are not rechargeable but can be recycled. With this approach when you do a swap you'd be getting a new fully charged battery, and your old battery would be recycled to recover the aluminum.
The perfect solution would be to not own the battery packs, e.g. you buy the car without the battery and you swap the batteries that car manufacturer owns whenever you want to "recharge", for a fee.
Or it could have resulted in a commodification of battery condition that would have created markets that help eek out usefullness at the later stages of battery life.
A $10k surcharge to swap to a much newer battery also means you could have a $10k discount on buying an EV then slowly pay to swap to higher and higher battery grades.
Tesla batteries weigh over 1000 lbs. They're about a third of the total weight of the car, and they are embedded throughout the chassis.
What if we just swapped a part of it? The 85 kWh battery pack of the Model S, which weighs 1,200 lb, gets you about 400 miles. If you decided to make a part of it swappable, what size would be appropriate, and where would it fit? If we assumed there were a 50 pound battery you could just pop in and out (that would be pretty difficult to handle, but let's assume), that would only get you another 16 miles. Good for an emergency, yes, but not a replacement for a charging station, and that's a pretty big architectural shift, and requires battery stations everywhere, all for just another 16 miles.
> Why not something you drive over and it self-guides itself to make contact with multiple contact-points beneath the car
Real life. That's why.
How is your magical drive-over contact widget going to work after a few years of rain, mud, grit and other wear and tear and abuse ?
I would put my money on the "not very well" part of the board.
The benefit of the plug-in method is that the connector is stowed away from ground level, away from the elements, in a sheltered position.
Edit to add: Also I'm not an electrician, but there could be a little issue of arcing and other issues when it comes to high voltage / high amperage. Have you ever seen an electric train arcing in wet weather ? Imagine being stood right next to that !
There are EV busses made by ABB in collaboration with other local companies, e.g. TOSA in Geneva [1]. They charge on few stops on the route for some sub-minute (15-30s) periods and can operate the whole day without charging for longer stationary. The contact pads are hidden from weather, so the busses operate all year round for few years already.
It's not really something which could be deployed to general purpose personal vehicles, since they come in many shapes and sizes, but it's great to see such an idea executed for buses which seems like a great place for it.
True, but an electric train uses a very large amount of power, compared to charging up an EV in any configuration that's likely not going to be the major issue, besides that there is plenty of time in a charging situation to figure out the parameters of the vehicle, humidity, ideal voltage/amperage combination and so on.
Whereas for a train track/overhead wiring situation the voltage is simply always there, and there is no simple way to regulate the power delivered to what is actually required. In fact the opposite: the overhead system has to be able to deliver power to multiple locs on the same segment at once due to push/pull trains.
Yes. This is why this would be stupid with current battery technology. It would require astronomical cooling for the battery packs as well as all the charging infrastructure including the cable. I'm totally fine with ~10 kW for slow charging and 150 - 350 kW with fast charging. It's fast enough.
No, they could not. The cable is not the limiting factor AT ALL. The limiting factor is the speed at which you can insert energy into a battery. Everyone who has ever charged drone batteries knows this. Charge too fast, the batteries catch fire. 5C is doable, but 5 minutes would be 12C.
... in that other kinds of batteries are pushed less hard, yes. (since in drones longevity and safety aren't prioritized, the cells get tortured a lot more than would be acceptable in an automotive situation, and chemistry selected along those lines as well)
depends on a lot of things, including how the battery charging is laid out in the battery itself. if you have 100 cells and can charge them simultaneously vs 100 cells where you have to charge sequentially you're going to see huge differences in time.
every piece of the system impacts this including the cable. if the cable is a bottle neck you need to fix that before any optimizations downstream can be unlocked.
5C is a number indicating how much current you can out into the cell. In this case, 5 times the nominal capacity or 12 minutes. This is on a cell basis, so no matter how you do it, you cannot charge faster unless you have cells with a chemistry that can handle more. In that case you'd already have a 10C or 20C battery if the cooling and electronics could handle it.
My car already runs its thousands of cells mostly in parallel, because the manufacturer isn’t stupid.
I am usually battery-limited while charging instead of cable limited. I plugged into a 250kW charger on Friday and my car peaked at 132kW because even with a preconditioned and mostly-empty battery it can still only take so much.
EDIT: I overstated things a little. I’m not usually battery-limited: I’m usually limited by the fact that my garage can only provide like 10kW of power. A better cable isn’t doing much there without major(ly expensive) upgrades to the wiring in the walls.
If electrical service enters through the garage, the additional wiring is probably minimal (though Cu prices are very high!), however:
(Calculations for common US garages)
NEC calls for 240V/200A service for an average-sized residence. Wire downsizing is allowed to 83% of service rating, so 166A.
So if my math is reasonable, in an average US single-family residence, you have max 39.84kW safely available for charging, with no other demand in the house.
(missing factor: what is the efficiency of AC-DC conversion in these chargers?)
Even at best, this is still only 30% of your battery limits, but might be more than 10kW for many customers.
That is not correct. In order to fully charge a cell in 5 minutes, you need to charge that cell at 12C. That is just not possible with lithium batteries. 5C is pushing it. There is nothing to optimize, you would have to change the battery chemistry.
Everything else you mentioned is irrelevant, we are talking about all cells being charged at the same time which is really the only way that makes sense. There is no point in waiting to charge cells.
those are implementation details around the particular batteries. which is fine. nothing I said is absolving us of physical requirements. my point was entirely the system itself as a whole.
there are a number of ways to pluck the chicken. smaller more numerous cells -> same power, faster charging due to concurrency.
point was if your cable can't supply the power the entire point is irrelevant.
You don't seem to understand what "charging rate" means. There is nothing magical about subdividing lithium cells. No matter the size of the cell, you can't insert energy at a higher rate per unit of volume.
The limit is the battery chemistry or the chemistry related internal resistance of the battery, not the cable. Lowering the resistance of the cable helps keep the cable cooler, thinner and lowers losses but it is bullshit that lowering the resistance of the cable is going to make a 30 minute charge down to 5 minutes.
Of course, if the battery and charger currently takes 10 minutes, maybe.
Forget all that. If we tried to swich half the cars to electric overnight, the power grid would collapse into a permanent blackout. Has anyone estimated the cost and time of upgrading the power grid for electric cars? Is hydrogen delivery from power plants to electric charging stations a viable option to bridge the gap until the grid is upgraded?
I think the biggest issue in the UK is how to get cars parked on street to be charged overnight. In towns and cities (and elsewhere too) it is very common to park your car on the street, potentially a good distance away from your home. Where exactly to build the charging infrastructure for people parking like this.
I guess if you only need to charge at the same frequency as you would refuel you could have chargers in super market parking lots. Cars charge whilst you do your weekly shop. Or at work, if they have space.
I also heard about one idea to have chargers at every street light, as they already have an input from the grid in them.
Hopefully this is an issue that can be solved without having to re-wire huge portions of the urban areas.
> Where exactly to build the charging infrastructure for people parking like this.
On the sidewalks. There are a number of chargers like that in the city I live that are more or less subscription based.
> Cars charge whilst you do your weekly shop. Or at work, if they have space.
That's one excellent solution. You can take the money that won't be spent with healthcare (because air pollution) and channel it as incentives to build out that infrastructure.
> I also heard about one idea to have chargers at every street light, as they already have an input from the grid in them.
That's another interesting idea, if the power is available. With the move to efficient lighting, the need for power has been reduced and I assume the cable gauges have reflected that.
> Hopefully this is an issue that can be solved without having to re-wire huge portions of the urban areas.
If the cars can recharge for hours, the need to rewire for higher currents is smaller.
I guess street chargers work great if you park on the street and can leave your EV in the same spot even after it is charged, like a regular parking spot. Otherwise it's just a chore to charge and move your EV to a non-charging spot when it's finished (of which there would be fewer)?
I'm in a city in Norway. It is very common to park cars on the street: The city is expanding their curbside charging stations because of it, and spaces are reserved for electric cars. Most parking garages I've seen here have some charging stations and a number of workplaces do as well, though admittedly that infrastructure might be, in part, due to engine warmer things. Not all workplaces provide parking, but as mentioned, the spaces you pay for often have this as an option. A good number of gas stations and shopping centers have charging as well. I've only lived here 8 years and it has grown exponentially.
I'm pretty sure, however, that the government has taken some initiative to expand the infrastructure. After all, electric cars are pretty well subsidized and you get everyday driving perks (like being able to drive in the bus lane). When folks are buying new here, they are buying electric and they aren't worried about meeting their "all-electric" goals. And realistically, government involvement, organization, and action are going to be the things that make it more difficult in, say, the US or the UK (From what I can tell: I'm American and am not as intimate with UK politics)
No they wouldn’t. Steam turbines can take days to ramp up and connect to the grid. Several dams in my state barely reach full capacity and are not running 24/7. The co-op that supplies my power offers a flex plan that gives you free power from 11pm-6am. You’re supposed to schedule your car to charge during that time. If half the cars in my county did this nightly it would be easier to predict the nightly loads.
It probably will still provide some "payment" back, as long as some control is allowed for the grid operator.
At the moment they're happy with "charge any time between these hours", once everyone starts doing it it'll probably be "free if you leave your car plugged in and let us decide when and how much to charge".
Shifting demand has a price and they'll pay that to the users that help them achieve it in some form or other.
After all, if you don't charge it then, they'll need to provide the power later when it could cost them many multiples, it's just good business sense.
For a forum focused on meaningful and substantive discussion, the amount of incorrect information around EVs and the power grid is shocking.
GP's point is a good one although there is work happening to address that very problem. The point stands, though. EVs are a significant bump in both power and energy and will require significant investment in shoring up grid capacity. Sad this is downvoted.
>Steam turbines can take days to ramp up and connect to the grid
How is this relevant here? Also, the typical steam turbine takes hours to spin up and sync to the grid, not days. I am not aware of any steam turbines that require burning two day's worth of fuel just to connect to the grid.
>Several dams in my state barely reach full capacity and are not running 24/7.
Again, how is this relevant in a broader context? Lots of places have dams running dry just as equally many have dams overflowing.
>The co-op that supplies my power offers a flex plan that gives you free power from 11pm-6am.
Ok? This is not par for the course so i'm nor sure why you're mentioning it.
>You’re supposed to schedule your car to charge during that time.
And if you can't? What if offices suddenly have 50 EVs charging at the same time? Will this not lead to a capacity constraint? If you broaden the horizon, can this not lead to a localised collapse of the grid due to a demand surge?
>If half the cars in my county did this nightly it would be easier to predict the nightly loads.
It would also lead to a huge surge in power at the times when solar output is literally zero.
>What if offices suddenly have 50 EVs charging at the same time?
They do. No problems so far.
>Will this not lead to a capacity constraint?
No. Batteries and rooftop solar.
>If you broaden the horizon, can this not lead to a localised collapse of the grid due to a demand surge?
Not with batteries and rooftop solar, no. We good?
>It would also lead to a huge surge in power
It's not a "huge surge." Many other appliances are off at night. The grid has excess power at night. The larger problems are in the day, caused by things like massive use of AC, which problems will be ameliorated by installation of more rooftop solar. Win win.
>at the times when solar output is literally zero.
Batteries.
And, sometimes, when needed, you also, wait for it… use fossil fuels or other non-solar sources! We can cut fossil fuel use drastically and cut carbon emissions, but still use them when needed, and everything will be OK!
> We can cut fossil fuel use drastically and cut carbon emissions, but still use them when needed, and everything will be OK!
Not to detract from your core point as there are ways to solve this[1], but long term the necessary level of solution is 99.9% reduction over all sources of CO2, so no, it isn’t OK unless it’s no more than 8 hours per year[1].
[0] hydrogen, synthetic hydrocarbons, even burning wood instead of coal works in this situation, so long as the costs are lower than for fossil carbon
[1] on average, with a margin of error of way more than 100% depending on all the carbon sources that aren’t electrical
This is obviously going to be region-dependent, but I don't think upgrading the grid is avoidable, even if we kept using ICE cars. Energy usage _is_ going to continue increasing as population grows and HVAC requirements increase.
Also, I'd like to add some perspective with actual numbers: My whole house consumed 109.49 kWh yesterday, of which only about 12kWh was my car charging (I have a PHEV). That number wouldn't change significantly if I had an EV, as my driving habits would probably stay roughly the same.
So car charging accounts for ~10% of my electricity consumption these days. Yes, that's not insignificant, but it's also not 50-75%. It's probably less impact on the grid than adding a central heat pump to a house, and I don't see people spreading FUD about heat pumps.
For the grid itself, time-of-use is _the_ important factor, as the size of wires, equipment, etc. is what determines the peak load the grid can handle. If the actual demand exceeds that for even only one minute in the year, it means we need to upgrade the grid. Operators are very interested in flattening that peak, so will offer incentives to move electricity consumption to off-peak times. Here in Québec, the evening / night is peak time in winter, as we all have electric heating, and night-time is colder. If vehicle charging is a significant burden, they'll offer incentives to move that to daytime.
Two of the biggest crypto miners are in Texas, where (until very recently) power was essentially free at night. The winter storm this past February changed the economics a little bit, but for the most part, the Texas Power Grid creates more power than can be consumed at night. And supposedly if the power grid (ERCOT) has enough consumption, they will pay the miners to shut down.
> The co-op that supplies my power offers a flex plan that gives you free power from 11pm-6am. You’re supposed to schedule your car to charge during that time.
One thing I’ve realised recently, is that while this is an improvement compared to the status quo, at some point we’re likely to be running houses off car batteries in these hours and charging the cars off PV during the day. By the continuum hypothesis, at some point the net average power transfer into/out of cars/any given car is going to be zero, and I wonder what that will look like economically?
You won’t be doing that unless it’s a blackout.
The amount of extra cycles that would put on your battery wouldn’t be worth it. Considering the vast majority of the cost of a EV is your battery, the cost savings just don’t add up when you add the damage to your vehicles range and worth.
I’m not sure what average domestic nighttime electrical power use currently is, but 500 watts seems plausible, and cycling 6 kWh per day of an EV’s battery doesn’t seem like it will add much wear compared to normal use, unless you have better figures to estimate from?
Also, a major source of electrical demand is being systematically diminished: lighting. Energy-efficient lighting is more and more prevalent with each passing day.
Last year, my town's side streets were equipped with LED streetlights, which meant replacing 175W mercury-arc and 150W HPS fixtures with 40W LEDs that are noticeably brighter and produce a far more pleasant light.
If we were to try to switch all vehicles to EV “overnight”, we’d almost certainly also mandate PV on all car rooftops.
I have observed that discussion of this solution normally divides into these two groups:
(1) “That’s ridiculous, a car covered in with PV will only make enough electricity to go 10-30 miles per day!”
(2) “That’s a great idea, a car covered with PV will make enough electricity to go 10-30 miles power day, and most people only go 12-35 miles per day!”
When there is serious concern if the grid can cope, we should take all the mitigations we can get. Reducing aggregate charging demand by 90% is good even when every single driver still needs to use an external charger.
Just because you can't think of a solution does not mean others have not already thought of solutions. Rooftop solar for example. Doesn't work for all buildings, but we are talking about the aggregate effect on the grid, which it does work for in most locales. In other locales, there are other solutions. You mention hydrogen. Pretty corrosive and explosive stuff, but maybe.
Please stop downvoting the above comment. Sure, it is wrong thinking imho, but it is a doubt that a lot of people have, and it needs to be seen and addressed.
If we just downvote questions like this into oblivion, it kills the discussion and people continue on with their misconceptions, which never get addressed.
In my experience, many of the people who say things like this don't just have misconceptions, they have an axe to grind. In that case, preventing the spread of their misinformation may have more value than trying to 'educate' them.
It's not so much to educate those who have an ax to grind, and I tend to agree on where (many of) these people are coming from.
It's to allow everyone else to see under the open light how weak the ax is, and what a dull blade it has, and what poor metal it was forged out of, and how it was never a good ax to begin with.
Instead of just saying (not that you directly said this, but downvotes kind of say it): "let's not talk about that."
I think I agree with you, but I may have less faith in the ability of random people to get past the first argument and make it to the counterpoints. I'm probably being uncharitable; especially somewhere like HN.
OP here. The second sentence came out all wrong and the downvotes are deserved. What I was trying to ponder, was - given the summer blackouts (in certain areas) due to people running their ACs (more than on average) - how do we plan to cope with the advent of EVs.
So I did some googling[1] and apparently, until 2030 there's only 1 million EVs planned to hit the roads in the US, which is quite shocking given the dire trends of climate change and toxic pollution on this planet.
Another interesting fact is that the costs of extending the power grid will be passed on to all its consumers in the form of increased rates (as it should, because if you don't drive an EV, you should be "taxed" on the extra pollution your car creates).
Can confirm that this is a real concern In The Wild—even if it's not a good one—my (boomer, yes) uncle was just complaining to me a couple weeks ago that, "no-one's thought about how we're going to have enough electricity for all these electric cars".
> If we tried to swich half the cars to electric overnight
Let's not, then. The logistics of swapping 150 million cars in a single night would be a nightmare. Charging wouldn't be my first concern.
On a more realistic note, even if we outlawed the sale of ICE cars today and mandated that every single new car hitting the road was electric, the required growth of the grid would be feasible. It would take quite a few years to replace the entire fleet.
They don't lower the resistance - they just remove a lot of waste heat very quickly before the cable vaporizes.
When I was reading the article, I was wondering what that kind of current would do to the poor batteries in the car and how would they get rid of the extra heat.
super capacitors make more sense for the braking and acceleration. They aren't dense enough to really make any appreciable difference in charge time. They can be, however, dense enough to smooth out the power demands so you aren't trying to pull or push in too much power into the main battery during regular driving.
Funnily, that's exactly what the early Tesla Semis do. They have a charger aggregator which takes multiple supercharging stalls to charge one truck.
The issue is, of course, not one of delivering the power, but rather that the battery chemistries we have today can't accept that much power without being damaged.
What's the lower limit for a single rechargeable cell? That's the lower limit for the pack as well, if they can all be charged in parallel. I'm sure the thermal engineers would have fun dealing with that but it's possible in theory at least.
Many have mentioned why this isn't going to work from the perspective of practical charging of batteries. What must also be understood is that our electrical grid simply cannot handle massive numbers of electric vehicles hyper-charging, to coin a term.
I have said this many times: The problem is power. Many think about electrics in terms of energy. However, power is the problem. If a million cars need to charge in 5 minutes you will set transmission lines on fire and explode transformers (not really, just being dramatic). This is because the energy has to be delivered very quickly, which means we need the capacity to deliver power we simply do not currently have.
A full transition to electrics will likely require more than double the production capacity we have today. The models I've used to understand this say we need between 900 and 1400 GW over the current capacity of 1200 GW. And you can't do it with solar.
I don't know how to put it yet. There's an inequality developing with regards to electric vehicles. As their numbers increase they will use more and more of a resource that is truly scarce. We don't have enough power generation capacity. I haven't done the math on the threshold yet, but it is there. And so, everyone driving electric cars today and in the next, say, 5 to 10 years, is and will be abusing of a limited resource.
This, in a sense, isn't any different from using too much water. We have a limited supply. Some of us have removed most of our lawns and replaced them with either zero water alternatives or very low water plants and shrubs. Others have huge, lush, green lawns both in front and in the back of their homes that consume ridiculous amounts of water. It looks great, but they are doing it at the expense of others who respect the shared resource.
This aspect of electrics is going to become a political mess. It isn't there yet, but it will be at some point. My guess is that's the moment when politicians will come out of the woodwork and tax the shit out of electrics. It will be interesting to see what happens then.
Are there any studies on which kind of cars are kindest to power grid in the future? Should we incentivize 8 PHEV of 50 km range or 1 BEV of 400 km range?
Large charger banks don't pull directly from the grid. Utilities charge massive amounts for high current draws, for good reasons. They buffer using capacitors or batteries.
The vast majority of EVs charge at night when rates are low due to low demand. So while EVs will increase the energy demand on the grid, the peak power demand goes up less.
If all of transportation and industry switches away from fossil fuels towards electricity, it'll double energy requirements. But that transition will take decades. Even if all new cars are electric, turning over the entire fleet would take 20 years. Industry is even slower. Luckily wind solar and batteries are cheap, and decreasing in price 10-15% per year, so meeting that demand is going to be relatively easy.
Grids are expensive, which is why power generation is going to become increasingly localized.
> The vast majority of EVs charge at night when rates are low due to low demand.
Not true. If you actually model 300 million vehicles across all of our time zones and with different utilization modalities, you soon find out power demands become very much constant throughout the day.
That's not to say people cannot be incentivized to charge at certain times. However, you can't mandate that because everyone has different utilization patterns. If you have 15 million vehicles in California all charging between 6 PM and 6 AM you are going to have a serious power availability and deliver problem.
Solar? Well, that would require two things. First, sufficiently large batteries at home. Second, TWICE the generation and storage capacity anyone has at home today. I have a 13 kW array. If I wanted to use it to charge two electric vehicles I would have to at least double the size of the array and probably get something like 8 Powerwalls (haven't done the math, maybe more) to support the vehicles.
Why? Because solar systems are sized to supply what the home needs, not twice or three times current needs.
Nobody is going to double their installed solar capacity just for the heck of it. That said, if the utilities didn't steal excess generation capacity as they do (they pay you 1/10 what they charge you per kWh) there might be real incentives to install additional capacity because you could actually make money with your installation.
People average 30 miles a day and the EV is usually plugged in for over 12 hours. So the car only had to charge for an hour but can choose any of the 12 to do so. My car chooses to charge when its cheapest. That's an easy algorithm now, but if it gets more dynamic I'm confident my car will adapt.
And I'm not talking rooftop solar, I'm talking industrial solar, the type that is currently building at $10/MWh right now. Lots of that will get built because it'll be profitable to do so.
Modeled 2 to 5GW additional peak demand wost case increase from EV charging, compare with normal peak (in winter) 83 GW.
RTE is the high voltage grid operator in France (public monopoly).
I don't understand why people keep saying on forums that EV charging is a big issue for grids, it's clearly not and the grid operators themselves are saying it.
> I don't understand why people keep saying on forums that EV charging is a big issue for grids, it's clearly not and the grid operators themselves are saying it.
You have to do the math or you will never understand.
Alternatively, don't believe a word I said and go watch this:
I think he knows what he is talking about? And, interestingly enough, it confirms the results my model predicted years ago pretty much exactly.
Current generation capacity is 1200 GW. We need to more than double that if we are going to make a full transition to electric ground transport. Not only that, we need to revamp and retrofit our entire grid and distribution system all the way to each and every building. Yeah. He said it. I just happened to have done the math on this many years ago, you can find my comments on this on HN going back a while.
Too many people form strong opinions on myriad topics without ever bothering to spend a few days researching and quantifying the matter. I am not anti-electric vehicle or anti-renewables, I am just saying "We are not having the right discussion". Same applies to climate change, it's an absolute political circus. If we lie to ourselves we are never going to solve any real problems and everything becomes an emergency because so much time is wasted on absolute nonsense.
Do the math. Don't form opinions unless you truly understand a problem.
He says it's possible in the very video you pointed at, his exact words "... unless we have subsequent power generation at houses".
EV are the perfect demand shifting and averaging tool for the grid, which is why Elon Musk says what he says, you can reduce peak demand on the grid this way.
All that is in the report I cited, multi year study by lots of engineers on the case of the French grid.
Now of course the US electrical grid is not in real good shape compared to other developped countries, but full EV and end of fossil fuels is at least 3 decades away.
Australia went from zero to 25% of homes with solar in a decade, 2.4 times increase in the last five year according to
For yearly energy: USA vehicules drives about 3200000 millions miles per year, at 0.25 kWh/mile (TM3 LR) that's 800 billions kWh. Current electricity production in USA is 4000 billions kWh. Plus twenty percent is not that much.
Well, he sells solar panels and batteries. That's all I'll say.
It isn't that it is impossible with solar. The problem is that the massive scale of the necessary deployment in both panels and batteries will be far, very far, from "green". The scale of manufacturing and mining we would have to engage in would make any environmentalist vomit.
> USA vehicules drives about 3200000 millions miles per year, at 0.25 kWh/mile (TM3 LR) that's 800 billions kWh. Current electricity production in USA is 4000 billions kWh. Plus twenty percent is not that much.
This is wrong.
Why would Elon (and myself, starting many years ago) say we need to build an additional 900 to 1400 GW of generation capacity if all we need is 20% more?
One of the problems with simplified/generalized calculations is what I call the "physics cow problem". When you study physics we tend to simplify problems and eliminate variables (no friction, no air, no gravity, etc.) in order to be able to study the fundamentals. That's where, all of a sudden, a cow goes from being a highly complex organism to "assume a cow is a uniform sphere of milk one meter in diameter".
Well, you can't do that when you are talking about 300 million vehicles. You have to model time zones, work hours, miles driven, charging power/energy requirements, multimodal transportation (motorcycles, small cars, large cars, trucks, large trucks, massive trucks, forklifts, trains and whatever else you can imagine). You then have to create random-but-reasonable utilization profiles. Make enough of them to try to simulate the thousands of use-cases for vehicles. From the parent taking kids to school every day to the Uber driver, soccer mom, travelling sales person, warehouse operation, etc.
To this you have to add charging behaviors. People and companies are not going to charge their vehicles exactly the same way and at the same time. Some will want (or need) to fast-charge. Others will have the ability to slow charge during the day. And yet others will fast or slow charge at night. Some will have a routine, while others might appear to be more random due to utilization profile.
Anyhow, once you create enough variables and variability you can start to attach numbers and run simulations with various fleet characteristics over time and geography. Not easy, yet this is the only way to truly get a sense of proportion. You can't say "a cow is a uniform sphere of milk one meter in diameter" and get answers you can stake your reputation on.
As for the grid. Well, it needs a major upgrade. I can't speak for France or any other nation other than to say that I would not be surprised to learn that most countries have the same problem: The grid was designed to deliver power to cities, towns, homes, businesses and schools. Given that most cities of the world don't expand or change rapidly, it is likely that most power distribution systems were implemented with a little excess capacity, but not much. For example: No politician would have survived proposing that my neighborhood, which is about 25 years old, be built with twice the required power delivery capacity. Older parts of the world likely have it worse.
A transition to electrics will have to use electric energy to provide a portion of the energy now delivered through fossil fuels. That is a major step-change in energy delivery to homes and businesses. Maybe China is setup to handle this. I sincerely doubt most nations of the world are anywhere close to being able to manage it.
Ultimately, charge times will be dependent on the power output ratings of the power supply and charging cable, and the power input rating of the EV’s battery. To obtain a sub-five minute charge, all three components will need to be rated to 2,500 amperes.
Seems like they're missing that other tiny detail in the title.
Shouldn't be all that much. The total cars on road-trips, where this charging is used, is the same. Individual charges become bigger spikes but the total load of all those road-trips stays the same. For the cases where the total power is not available (e.g., multiple cars plugged in exactly at the same time) the charging station will just throttle the power like it already happens today in chargers that share a supply. What it does help with is a need for fewer chargers in total to support the same number of cars/charges.
Battery chemistry is also a challenge. Also it’s not just the charging cable but the electrical infrastructure behind that cable that also needs an upgrade. You can’t just pull 2k + amps across an endpoint of the grid without causing potential issues to others nearby, let alone the wiring required send that to the charging point where this cable is used. Interesting research, but this is a much bigger challenge than just the charging cable.
Also importantly, the more complex the cable is, the more expensive it will be to replace if someone comes along with some bolt sheers and clips the cable.
Our "current" (pun intended) cables can deliver 350kW of juice. That's already more than most car battery chemistries can accept for more than a few minutes before doing harm to the battery.
Not to mention the fact that even if you could deliver such high amounts of power, that'd translate into insane requirements on the grid, likely necessitating onsite storage to act as a buffer.
All in all, the recharge time problem is overblown. There isn't as much need for high speed charge infrastructure as you'd imagine. That's because most charging is happening at home at lower speeds. Your car almost certainly sits idle for more than 8 hours every day which is plenty of time to refill. Fast charging really only matters for long range excursions, which aren't terribly common.
Correct. Those streets are long distances from electrical lines (very often, power is buried next to the road). The "right" solution here is for cities to install charge points in the streets or to incentivize anyone with a parking lot to install charge points (or both).
I've not read the article yet but I would assume if the battery could take the load, then having charge points where the infrastructure can handle the load and deliver it would be ideal. Like you say as long as you recharge overnight, it should be good for most People
For folks who own a home with a garage, sure. Most people do not own a home with a garage. For the rest of us, fast charging is an absolute requirement — both for long term trips, yes, and just to keep juice in the car on a daily basis. It’s why I bought an ICE car last year: if you don’t own your own garage, there’s weak charging options available in most US cities.
I have to disagree with you. It's not overblown. If we were able to "top up" our electric vehicles in the same amount of time it takes our ICE vehicles, we've got a whole new ballgame in terms of adoption.
You have to take human nature into account.
"I'll just get gas in the morning"
Requiring careful planning and dedicated charging at home isn't going to lead to an electric car revolution.
While I admit it's not accessible to all, charging at home requires absolutely no planning. Park the car? plug it in.
Do that, and you'll end up with more than enough charge for daily tasks.
I drive an EV and the only time I worry about fast charging is on road trips. Which, for me that happens once every and a half hours while driving (approximately) and gives me a 30 minute break to wash the windshield, grab a snack, use a restroom.
All in all, not really a big deal.
That, to me, is why it's overblown. With cars getting even longer ranges, it becomes even less of an issue. The first EV with 500 miles of range will be a game changer.
And personally for me the UX of filling my gas tank (done in two or three minutes) vs. having to wait 15 to 60 minutes on one of my many tri-state weekend road trips is why I'm not excited yet to buy an EV.
So I'm gonna pay tons of more money for an EV yet not being offered the same level convenience. Thus eagerly awaiting the day where the same UX is offered.
It's being solved from both ends, on one side fast-charging is getting faster and on the other end the range is increasing. If the range is 600+ miles, you probably wouldn't mind a 30 minutes charging time because you want to stop to eat anyway.
On the other hand fast charging still has issues with capacity. If several cars want to fast-charge at the same time, there either aren't enough spots or when there are the charging rate is decreased because there isn't enough power available to fast-charge many cars. And this is with a minority of cars being electric, if everyone switches to EVs this problem becomes much bigger.
There is a lot of work to do on the grid and maybe some form of local storage of energy at larger highway charging stops.
The other problem is that range estimates do not take into account cold weather and no garage. I bought a hybrid and I probably should have bought an ICE that got in the 40mpg instead of the 55mpg hybrid since winter is very bad on batteries.
Part of it is an educational component. People think of EVs the same way they think of ICE. They essentially ask “how long does it take to fill up my tank” because that’s what they do with gas.
But what you would do for long road trips is fill up enough to complete the next leg of your trip. EVs charge faster the lower the battery charge is. There’s no reason why you should need to charge for 60 minutes during a road trip, unless you’re in an area where the charging network is still very underdeveloped (which is still too many places obviously).
I hear this all the time yet I think it's misguided. Trying to educate users that they're "holding it wrong" instead of satisfying expectations is a fundamental mistake.
For example, I make several trips each year to visit family out of state. This is in the Midwest US, where winters are no fun, and dramatically affect range for an EV. The route is roughly 400 miles, and takes about 5/12 hours. According to the route planner in my friends Model Y, I would need to make 3 stops and I'd arrive at the inlaws house with 25% charge. I'd have to charge overnight there (they won't ever have a fast charger), and that might get me to 35%, depending on the temperature. On the way home, since I'm not starting at 100% capacity, I would have to make 4 stops. This makes the trip outbound roughly 7 hours, and the trip home almost 8.
Now compare this to an ICE. We make one stop, for roughly 5 minutes to refill gas and use the bathroom. Both legs of the trip are about 6 hours tops.
“You’re holding it wrong” was a design flaw, the fact that batteries charge faster depending on the state of the battery pack is just physics.
Unless we get to a point where charging is faster by using a linear charge rate, what I said is always going to be true.
As per what your friends Tesla says, it’s obviously optimizing for the wrong thing, but that’s because it doesn’t have the correct information. It’s still going to be based on the owner’s judgement to actually make sure to operate their vehicle correctly.
Imagine a world where everyone drove EVs and we were suddenly switching to gas cars with manual transmissions (because automatics aren’t invented yet) learning to drive stick is not going to be a pleasant experience for more people. The fact of the matter is that there are going to be things to learn when adopting a new technology.
(Plenty of people are and were completely baffled by how to use a smartphone at first too)
Why do you think the route planner on the Tesla doesn't have the correct information? It knows the route, the expected electricity consumption, the location of superchargers, and the expected weather. It also has tons of information to predict how the car and battery would perform in that weather, and possibly on that exact route.
It doesn’t know you’re planning to leave the next day and go back.
You weren’t complaining about how it gets you there, you were complaining that it wouldn’t have enough charge to get you back. If it knew you needed to go back the next day after slow charging overnight, it would be able to optimize for that, but clearly it doesn’t.
Oh I'm most definitely complaining about how it gets me there. Having to take three stops on such a short trip, adding extra time to the trip is definitely something I wouldn't enjoy, no matter how great EV life is in the city. And since I make this trip 3-6 times per year, the frustration I would experience in this scenario makes it a non-starter.
Oh, and side note about smartphones; this is why the iPhone was so successful. You didn't need to be a geek familiar with odd Nokia or WinCE stuff to use it.
The iPhone was certainly way cleaner, but there are still just basic things to know about using one, that was my point.
Understanding that EVs charge faster with lower state of charge isn’t that complicated and is something people can easily understand and adapt their behavior to.
Exactly real life experience data vs. marketing/fan enthusiasts to Telsa stockholder speak which the majority im guessing are people who rarely drive ... just out of the city to visit family and friends here and there less then 100 to 200 miles away. EVs are perfect for those city dwellers those living close to cities and those who aren't roadtrippers.
Overall EVs are not prime time ready for non city folk who want to just get in there car and go without thought vs. map out a route for charging stations and wait 15 to 60 minutes to fill based on how far the next one is and other logistics. GOing to take awhile for the infrastructure to match gas cars/stations, as well as the technology (fast charging).
I wouldn’t recommend EVs yet to people outside of major cities (in the US anyways), but that’s also only a small fraction of people.
I’m also not a Tesla stock holder, nor am I a Tesla owner, nor do I have any interest in owning a Tesla. I’m just someone who owns an EV and is quite happy with it, and feel like it’s world explaining what it’s like from first hand experience myself.
Sure and sounds like you live close or live in a city. I'm 35 miles north of Baltimore right over the MD/PA line (closest to York PA) and work from home. I enjoy frequent road trips to New England and to the Mid-West so I would add those who are similar roadtrippers who just want to get out and go without thought nor have to wait 15 to possibly 60 minutes to charge the car EVs aren't ready for them either.
I do indeed live in/near a city, as do most people.
Obviously gas cars are better for road tripping, I never said otherwise. If you road trip every weekend then you’re going to be frustrated with an EV.
But I’ll reiterate that it is absolutely possible to road trip in an EV if you want or need to, and there is almost no reason why you should be sitting there charging it for 60 minutes assuming you are within range of other fast chargers further in your route.
If you spend most of your time driving around town and only road trip once every few months, the extra time you spend charging in the occasional road trip is generally not as big of a deal as people assume. Is it something that I personally like? Obviously it would be great if it were as fast as a gas car. But class cars have trade offs too. I haven’t had to make a separate trip to fuel my car since the last time I went on a road trip!
It seems to me like the ultimate solution is higher capacity. Imagine a car with a range not of 500 miles but 5,000. This is almost a round trip between New York and Los Angeles. I don't know how long a 10x advance in batteries would take. I guess they don't follow Moore's Law and we get that in the next few years, but maybe in the next few decades.
Then there is no need for network of charging stations. People just charge them overnight at home. They don't need fast charging. They just make sure they have enough for the day or, as a buffer, the next few days, which is a couple hundred miles. Most of the time the car's battery could be charged partially, like "only" a 1,000 miles of range. But before a vacation, you make sure you have it fully charged, or at least to a point where it covers your trip plus some buffer for the unexpected.
(EDIT: Sorry, you would have less need, not no need --- at least for something as pervasive as our network of gas stations. I was imagining even apartment parking lots having little outlets, but some apartments don't have parking lots and residents park in the street overnight.)
I don't have a garage, I live in a building of 7 apartments and no-one has a parking place.
To charge at home I'd need to pull a cable from my second floor window across the road, or sometimes around the corner if I don't find a parking spot in front of the building.
So until we put a ludicrous amount of curb-side charging columns, we need fast charging.
(I seldom use the car tho, long live public transport)
Good point. I was imagining outlets eventually in apartment parking lots. But for the many who don't even have a parking spot, and have to park on the street, we still need some public charging stations.
Apartments could install level 2 chargers in parking spaces or on the sides of buildings, but since they'd be an amenity there's usually not much ROI for them, especially in the current market as no well-kept apartment community is under 95% occupancy and has no issue filling vacancies.
If you have higher capacity batteries, you're carrying around extra weight you're not using.
The long range model 3 has a 480kg battery. Unless there's a massive revolutionary discovery in battery technology, for 10 times the range, you're going to need to carry (and accelerate) 10 times more mass every time you stop and go.
I am a massive BEV fanboy - but I don't see 5000 mile EVs happening anytime soon, if ever. The current energy densities are already ~200 Wh/kg. We can go max to 700Wh/kg. So at most we will have 1000 - 1500 miles of range.
These are pretty hard physical constraints that no amount of research will solve.
> EV charging stations and other types of electronics rely on liquid cooling systems to remove heat from within their wires.
Is this true? Are current car charging cables really liquid-cooled?
(The tech is interesting, but I'm extremely wary of university press releases and consider them less reliable than the worst yellow press publication).
Edit: Found a few examples, some very modern (<2 years) chargers may actually be using liquid cooling already. The new invention presented by Purdue (buried under more than two pages of drivel and self-praise) is that they're evaporating the cooling medium. This is already used e.g. in heat pipes, so the report does seem plausible.
The latest superchargers are ~250kw dc. Lets even say your battery is 120kwh and you're charging 20-100% to maximize kw. Afterall if you're low or high in batteries it wont charge at 250kw. Thusly lets say we're charging 100kwh. It's simple math to see you'd charge it in roughly 25 minutes. Which is typically what people are seeing with their teslas.
If you want to charge faster say 5 minutes. At 500kw it'd be down to probably 15 minutes or so. At 1,000kw or 1MW you'd charge in around 5 minutes. We havent talked about battery chemistry and what have you. That's what we need.
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[ 3.5 ms ] story [ 278 ms ] threadIn this case, the "power strip" is passing 50kw and needs active cooling.
50kw would take 2 hours on a 100kwh pack so it would only be 0.5C. To do it in 5 minutes would require 1.2 megawatts of charge rate.
TBH, it kind of freaks me out to handle even just the 50 kW cables.
From the article:
"Ultimately, charge times will be dependent on the power output ratings of the power supply and charging cable, and the power input rating of the EV’s battery. To obtain a sub-five minute charge, all three components will need to be rated to 2,500 amperes."
I wonder if anyone has been killed yet by a malfunctioning charging cable.
you don't need to start out full blast with electric cables. ramp up over a minute if necessary. we are also well versed in circuit breakers, and digital safety checks.
oh the cable isn't correctly connected? no power.
Tires are definitely an issue but producing gas involves a lot of trucks as well. Between all the work in oil pumping/refining/distribution there must be quite a bit of rubber burnt!
Edit - I think the tire issue definitely needs to be solved, but theres no reason it has to keep us using gas vehicles over electric
Ah, I may have miscommunicated my concern, which is that the resources involved/required in the acquisition, sequestration, production, and recycling of batteries may ultimately be more damaging than conventional fuels [in the long run]. It is possible that I am wrong, however, it remains a personal point of concern.
I would definitely be interested in exploring this further. It seems probable to me that we won't have a better grasp on this for years yet as EVs are still pretty new and not widely adopted. https://www.youtube.com/watch?v=MEqxaH47DTs
Yes, there are up-front environmental costs to electric cars, but I wager it's worth it.
Scenario: We could churn out 50,000,000 electric cars next year, with all the strip mining and oil-burning required. But somehow, we had nuclear/solar energy and a grid in the US capable of supporting the power draw. The outcome would be a much healthier country, on the whole.
The goal long term is to eliminate the use of fossil fuels. Transport is the most obvious "hard" problem - nuclear/solar/wind are clearly going to take over coal and gas. It would be beneficial to move transport over to electric now, to "centralize" the fossil fuel problem to power plants.
This is not being fair or charitable. Some people are genuinely curious, like myself, but are treated as if some type of malice was intended just for asking.
(And batteries can be recycled. Try recycling gasoline.)
Mining does not necessarily burn oil: https://web.mit.edu/12.000/www/m2016/finalwebsite/solutions/...
Tires polluting more than exhaust is a myth. It's honestly surprising anyone believes this one: https://www.dcbel.energy/2021/08/24/myth-busted-lifetime-ele...
(This one is doubly surprising, because gas cars have tires too. Even if tires were single-handedly melting glaciers, an EV would still be avoiding tailpipe emissions.)
EVs are not perfect, but they are better - considerably better - which is why there's so much misinformation about them. The oil industry has enormously effective PR.
Another thing to consider is how gasoline is transported around. Gas pipelines are possible but last mile delivery is inevitably a huge inefficient truck.
Moving electricity is a solved problem - power lines have no emissions.
Hydrocarbons can come from wood and other biomass, too. Woodgas is not unheard of. Plants feed on the bulk of emissions, if you need the cycle completed for you.
'about' is doing some serious work there. Maybe it's on par with the entire time spent at the gas station, but I'd say "under two minutes" is a better estimate of the actual transfer.
But I bet the equivalent of a big two-tank truck will need significantly more than 5 minutes.
https://www.edmunds.com/ford/f-150/2021/features-specs/
https://en.wikipedia.org/wiki/Gasoline_pump
You are not towing livestock or machinery with an F150 typically, or with any practicality. Just in the vicinity where I live, looking out my door, F350 is a common choice, with King Ranch being the preferred trim line due to its towing capacity.
Perhaps the solution for EV chargers is a special fuel that burns with oxygen and releases electricity. And it shouldn't have C in it, only H, N and O. I guess, its also allowed to use rare earth catalyzers.
So with a gas pump your looking at more like 7-8MW equivalent. Even then EV's are more efficient at spending the energy with regenerative braking and no idle losses etc. which is why you 100+MPGe. So your probably closer to 3-4MW to get equivalent charge times as filling a normal car gas tank at like 2-3 minutes for similar range.
HPCVC charging spec is being worked on for 3 megawatts but its really targeted for charging large vehicles like Semi's but I would imagine that would trickle down to normal cars at some point if the issues of charging a battery that fast can be worked out.
Surely there are “trucker pumps” in the US as well and 18-wheelers don’t have to fill at 10 gal?
IIRC in Europe standard flow is 40L/mn (about the same as the US’ 10 gal) but high-flow pumps can to up to 200 or so (50 gal / mn).
This might sound trivial but when you've spent 50 hours over the course of two weeks in the car with kids I assure you it is not.
My main goal is to fill up and get going, but perhaps other people are different.
When I fill up in my local area I do it at the supermarket (which all have a petrol station attached where I am), so it's more that the shopping has a petrol re-fuel attached. Another time (pre-covid) I would fill up is on the commute. But the office had some charging points there.
No you don't. ??? Why do you have to attend to it? Just use the trigger latch and let it fill.
I mean you can't really just walk away anyway, because there's usually other people who want to fill up, but that would apply equally to electric.
https://www.freeadvice.com/legal/what-are-the-laws-relating-...
The main reason you don't see them as often in N/W-Europe and they are even explicitly forbidden by law in some though there are exceptions. In NL for example, in which case all methods to latch them are forbidden like putting a filler plug in the hole.
5 minute charging would be a game changer. That means urban dwellers could use EVs the same as gas engine cars and that road trips look exactly the same as they do now (presumably gas stations would add EV stations with enough market penetration). This cable isn't the big issue in making that happen, but it's needed. Battery chemistry and power distribution become factors at that point, but we're on the way to solving those issues too
I tend to get down to about 50% battery on my base model3 after a weekend of errands and it will charge back up to 80% overnight
I realize this new cable design would be more for on the road quick charging - but I think even that is pretty fast currently.
Rural areas don’t have chargers for the most part. That said, I’ve seen some chargers along 395 in rural NV that surprised me.
Until range becomes less of a concern, I’m not getting rid of my Tacoma.
I see no real solution to the CA no fossil fuel engines post 2030. Our infrastructure can’t handle it. The majority of the state is suburban to rural. I cringe when I see a friend’s posts driving from Seattle to Truckee in their Tesla. The added time for charging.
The start to my recent road trip - Truckee - Ashland; Ashland - port Townsend; the first leg cost the same as the second in fuel prices due to CA gas taxes; but the whole route would have taken 2-3x as long if we had to charge an EV.
GMaps gives me 12hr non-stop from Seattle to Truckee. Add 1hr total stops and it’s 13hr total (I’d stop much more frequently on a long trip like that, prob 15h total).
Using the Tesla planner you need ~5 stops at 20-30m each. Total time is 16 hours. Looks like it would only be slightly longer than gas for myself.
Doesn't Toyota advocate for green hydrogen produced from renewables over battery EV?
Regarding the 'could' article about potentially charging batteries faster: the plumbing analogy of a wider pipe/charging cable has to also take into consideration battery design and heat issues, a major BEV problem.
I think we are ~15 years away from safe and viable 100% BEV's before we break out of the affluent local transport virtue signaling markets.
I don’t think the cable is the problem for the cars today. At a supercharger, I get throttled back from 150kw lrettt quickly, and it seems to settle in at 60kw.
If the cable really is the problem, why not just use a busbar with a couple hinges?
Highway range is the bugaboo that needs to be resolved though. Supercharging gets thermal throttling too quick.
https://www.chevybolt.org/threads/110v-vs-240v-which-is-more...
Okay that solves the cable problem but charging the battery at 12C? How does one solve that?
However, that also means 4.6^2 = 21 times more losses in the transfer cable since losses are P = I × V = I² × R (where P are losses, I is current, V is voltage, and R is resistance of the cable).
Wouldn't be better to increase voltage? I guess that would require changes to cars?
Additionally, your demonstration is incorrect, with the same argument you can also write P = I×V = V²/R and conclude that you don't want to increase voltage.
Still, getting enough output current is going to be hard. Even 750A (10 minute charge) is going to be rough. GeneSic makes some 3.3kV to247 mosfets that can do 200a, about $300 a pop on mouser. And even at better than the best efficiency that charger head would require really good active cooling, probably water cooled. Still i like the idea of staying ultra high voltage till the very end.
Having ultra high voltage capable chargers that can power most cars seems like a necessary first start.
also invented something which could be used to create more powerful electromagnets
-- than existing ones, given certain design constraints (space, cable width, number of turns, etc., etc.)
The connector ripped out at the buss and ground faulted. Nothing spectacular happened.
But the most straightforward answer of why those ideas haven't caught on is because we have a whole lot of existing road infrastructure that we struggle to maintain now. The infrastructure required to charge battery vehicles is tiny in comparison, and on top of that, private industry will fund much of it.
Maybe make these new Teslas high occupancy as well so dozens of people can go where they need to go at a time?
This could have some big advantages to cramming larger batteries into vehicles and trying to charge them at higher rates. Cheaper, lighter and safer vehicles, and batteries that last longer.
https://balkangreenenergynews.com/overhead-truck-power-line-...
On the car itself those contacts would need to be protected from road hazards. So more expense on that end to have a motorized cover the driver has to operate.
People know how to use plugs. They’re cheap and familiar. And if standards change, adapters are easier to build.
This is cool, though: https://youtu.be/octvXMaTG44
https://youtu.be/W3hVLG5iDec
I reckon the majority of the car weight is batteries, but this could lead to cheaper cars, perhaps with shorter range but able to “recharge” faster than a gas pump, and takes away the range anxiety of an aging battery you can’t easily replace.
Probably not factoring in some very obvious drawbacks here, of course.
People broke the model with what-if games. It never got to critical mass. So it's basically VHS vs beta, for swappable vs integrated and swappable lost, on pretty specious grounds.
Integrated is good because strength and weight. Swappable was good on speed. Swappable is alive and well in e-scooters and probably works for trucks.
Battery swap did not advantage Tesla in the marketplace and possibly disadvantaged Tesla which had 2x range for most competitors. A viable battery swap economy ends range anxiety, at the density of swap shops. Tesla wouldn't have had a compelling story in swap.
See https://thedriven.io/2021/11/16/nio-installs-first-battery-s..., https://electriccarsreport.com/2021/09/nio-launches-nio-es8-...
https://www.tesla.com/videos/battery-swap-event
No idea though how they thought they’d handle battery degradation.
Swap stations would also be far more expensive to build and manage inventory for, and would carry higher liability for whatever automated mechanism moved the thousand pound pack packs around when it e.g. went out of alignment and crushed somebody’s car frame.
Maybe for freight trains too, since you can build the battery into a battery tender carriage, and railways have 150+ years experience at swapping carriages on and off trains.
- the usage pattern does not justify the investment of electrification
- the company owning the trains is not in control of the railway and does not have any leverage over the railway owner.
- for some edge technical reason the line can not be electrified.
Forklifts, and possibly rubbish trucks which do frequent depot trips anyway as a function of their job
NIO and Gogoro are doing it.
4 million swaps for NIO: https://www.carscoops.com/2021/09/nio-customers-have-perform...
200 million for Gogoro: https://www.gogoro.com/news/400k-gogoro-network-subscribers/
I would say that they are right, because right now battery tech is advancing and standardisation would impose a cost to progress. NIO doing their thing is not standardisation. But it does show that it can be done and that is important.
In the future we should definitely push to get to the point where EV battery swaps are routine.
Also, it is a logistic pain since all battery exchange stations need a stock of batteries to charge, the size of which will depend on a lot of parameters.
Also this requires standardising the battery. Turning it into a "API". Tesla is a very fast company and introduces changes constantly to their process, unlike others whould wait for the launch of a new model. Standardising on battery model is incompatible with the Tasla mindset.
But a model like this is plausible. You would no longer care about the battery. You would no longer own the battery. If batteries were standardised, the infrastructure (not necessarily one company) would take care of the entire lifecycle of batteries (production, charging, maintenance, reuse, recycling). It could work but it is too early and technology is moving too fast.
Another approach is to use non-rechargeable batteries. A few years ago a company demoed an EV using a non-rechargeable aluminum air battery with a range for something like 1000 miles.
Aluminum air batteries are not rechargeable but can be recycled. With this approach when you do a swap you'd be getting a new fully charged battery, and your old battery would be recycled to recover the aluminum.
A $10k surcharge to swap to a much newer battery also means you could have a $10k discount on buying an EV then slowly pay to swap to higher and higher battery grades.
What if we just swapped a part of it? The 85 kWh battery pack of the Model S, which weighs 1,200 lb, gets you about 400 miles. If you decided to make a part of it swappable, what size would be appropriate, and where would it fit? If we assumed there were a 50 pound battery you could just pop in and out (that would be pretty difficult to handle, but let's assume), that would only get you another 16 miles. Good for an emergency, yes, but not a replacement for a charging station, and that's a pretty big architectural shift, and requires battery stations everywhere, all for just another 16 miles.
Real life. That's why.
How is your magical drive-over contact widget going to work after a few years of rain, mud, grit and other wear and tear and abuse ?
I would put my money on the "not very well" part of the board.
The benefit of the plug-in method is that the connector is stowed away from ground level, away from the elements, in a sheltered position.
Edit to add: Also I'm not an electrician, but there could be a little issue of arcing and other issues when it comes to high voltage / high amperage. Have you ever seen an electric train arcing in wet weather ? Imagine being stood right next to that !
1. https://youtu.be/fm3_N4Js3Nw
It's not really something which could be deployed to general purpose personal vehicles, since they come in many shapes and sizes, but it's great to see such an idea executed for buses which seems like a great place for it.
HV systems for close quarters use are made safe by technology.
The HV plug for your car could easily be wet as well, but it's made safe by having a signal wire and intelligence before it powers up or down.
For busses, Alstom have already got a ground based charging system, built upon their years of ground based power for trams.
https://www.alstom.com/our-solutions/infrastructure/srs-inno...
Whereas for a train track/overhead wiring situation the voltage is simply always there, and there is no simple way to regulate the power delivered to what is actually required. In fact the opposite: the overhead system has to be able to deliver power to multiple locs on the same segment at once due to push/pull trains.
> battery
> charged drone batteries
> the batteries catch fire
There's more than one "battery" type.
every piece of the system impacts this including the cable. if the cable is a bottle neck you need to fix that before any optimizations downstream can be unlocked.
I am usually battery-limited while charging instead of cable limited. I plugged into a 250kW charger on Friday and my car peaked at 132kW because even with a preconditioned and mostly-empty battery it can still only take so much.
EDIT: I overstated things a little. I’m not usually battery-limited: I’m usually limited by the fact that my garage can only provide like 10kW of power. A better cable isn’t doing much there without major(ly expensive) upgrades to the wiring in the walls.
(Calculations for common US garages)
NEC calls for 240V/200A service for an average-sized residence. Wire downsizing is allowed to 83% of service rating, so 166A.
So if my math is reasonable, in an average US single-family residence, you have max 39.84kW safely available for charging, with no other demand in the house.
(missing factor: what is the efficiency of AC-DC conversion in these chargers?)
Even at best, this is still only 30% of your battery limits, but might be more than 10kW for many customers.
Everything else you mentioned is irrelevant, we are talking about all cells being charged at the same time which is really the only way that makes sense. There is no point in waiting to charge cells.
there are a number of ways to pluck the chicken. smaller more numerous cells -> same power, faster charging due to concurrency.
point was if your cable can't supply the power the entire point is irrelevant.
Not really, because smaller cells -> less capacity -> lower current for same C rating.
One 1000 mAh battery charging at 5C means 5A charging current, while two 500 mAh batteries in parallel leads to 2 * 2.5A = 5A.
And AFAIK typically a larger battery scales better, that is, less dead space for connectors/housing etc so more mAh per volume.
my understanding was it was the chemistry of the cells that impacts the charging rate, not the physical size. happy to be wrong on that though.
scaling has mean dimensions. whats best for energy density may not necessarily be best for charging rates.
It's a good job nobody is suggesting that then.
>Has anyone estimated the cost and time of upgrading the power grid for electric cars?
I don't know about the US but in the UK we just need to take generation back to 2002 levels to cover the whole fleet moving to electric.
I guess if you only need to charge at the same frequency as you would refuel you could have chargers in super market parking lots. Cars charge whilst you do your weekly shop. Or at work, if they have space.
I also heard about one idea to have chargers at every street light, as they already have an input from the grid in them.
Hopefully this is an issue that can be solved without having to re-wire huge portions of the urban areas.
On the sidewalks. There are a number of chargers like that in the city I live that are more or less subscription based.
> Cars charge whilst you do your weekly shop. Or at work, if they have space.
That's one excellent solution. You can take the money that won't be spent with healthcare (because air pollution) and channel it as incentives to build out that infrastructure.
> I also heard about one idea to have chargers at every street light, as they already have an input from the grid in them.
That's another interesting idea, if the power is available. With the move to efficient lighting, the need for power has been reduced and I assume the cable gauges have reflected that.
> Hopefully this is an issue that can be solved without having to re-wire huge portions of the urban areas.
If the cars can recharge for hours, the need to rewire for higher currents is smaller.
This is already being done in London, and probably other areas.
https://www.ubitricity.com/charge-points/#lamppost
* https://www.youtube.com/watch?v=rKaEhBjt1ls
* https://www.youtube.com/watch?v=Frkw6aurVUY
Each area/street will probably have to examined individually to find the right solution for it.
Do it with wireless charging:
https://www.youtube.com/watch?v=aq7SP18sPKw
https://www.youtube.com/watch?v=9IoPA0rq0yw
I'm pretty sure, however, that the government has taken some initiative to expand the infrastructure. After all, electric cars are pretty well subsidized and you get everyday driving perks (like being able to drive in the bus lane). When folks are buying new here, they are buying electric and they aren't worried about meeting their "all-electric" goals. And realistically, government involvement, organization, and action are going to be the things that make it more difficult in, say, the US or the UK (From what I can tell: I'm American and am not as intimate with UK politics)
At the moment they're happy with "charge any time between these hours", once everyone starts doing it it'll probably be "free if you leave your car plugged in and let us decide when and how much to charge".
Shifting demand has a price and they'll pay that to the users that help them achieve it in some form or other.
After all, if you don't charge it then, they'll need to provide the power later when it could cost them many multiples, it's just good business sense.
GP's point is a good one although there is work happening to address that very problem. The point stands, though. EVs are a significant bump in both power and energy and will require significant investment in shoring up grid capacity. Sad this is downvoted.
>Steam turbines can take days to ramp up and connect to the grid
How is this relevant here? Also, the typical steam turbine takes hours to spin up and sync to the grid, not days. I am not aware of any steam turbines that require burning two day's worth of fuel just to connect to the grid.
>Several dams in my state barely reach full capacity and are not running 24/7.
Again, how is this relevant in a broader context? Lots of places have dams running dry just as equally many have dams overflowing.
>The co-op that supplies my power offers a flex plan that gives you free power from 11pm-6am.
Ok? This is not par for the course so i'm nor sure why you're mentioning it.
>You’re supposed to schedule your car to charge during that time.
And if you can't? What if offices suddenly have 50 EVs charging at the same time? Will this not lead to a capacity constraint? If you broaden the horizon, can this not lead to a localised collapse of the grid due to a demand surge?
>If half the cars in my county did this nightly it would be easier to predict the nightly loads.
It would also lead to a huge surge in power at the times when solar output is literally zero.
They do. No problems so far.
>Will this not lead to a capacity constraint?
No. Batteries and rooftop solar.
>If you broaden the horizon, can this not lead to a localised collapse of the grid due to a demand surge?
Not with batteries and rooftop solar, no. We good?
>It would also lead to a huge surge in power
It's not a "huge surge." Many other appliances are off at night. The grid has excess power at night. The larger problems are in the day, caused by things like massive use of AC, which problems will be ameliorated by installation of more rooftop solar. Win win.
>at the times when solar output is literally zero.
Batteries.
And, sometimes, when needed, you also, wait for it… use fossil fuels or other non-solar sources! We can cut fossil fuel use drastically and cut carbon emissions, but still use them when needed, and everything will be OK!
Not to detract from your core point as there are ways to solve this[1], but long term the necessary level of solution is 99.9% reduction over all sources of CO2, so no, it isn’t OK unless it’s no more than 8 hours per year[1].
[0] hydrogen, synthetic hydrocarbons, even burning wood instead of coal works in this situation, so long as the costs are lower than for fossil carbon
[1] on average, with a margin of error of way more than 100% depending on all the carbon sources that aren’t electrical
Also, I'd like to add some perspective with actual numbers: My whole house consumed 109.49 kWh yesterday, of which only about 12kWh was my car charging (I have a PHEV). That number wouldn't change significantly if I had an EV, as my driving habits would probably stay roughly the same.
So car charging accounts for ~10% of my electricity consumption these days. Yes, that's not insignificant, but it's also not 50-75%. It's probably less impact on the grid than adding a central heat pump to a house, and I don't see people spreading FUD about heat pumps.
For the grid itself, time-of-use is _the_ important factor, as the size of wires, equipment, etc. is what determines the peak load the grid can handle. If the actual demand exceeds that for even only one minute in the year, it means we need to upgrade the grid. Operators are very interested in flattening that peak, so will offer incentives to move electricity consumption to off-peak times. Here in Québec, the evening / night is peak time in winter, as we all have electric heating, and night-time is colder. If vehicle charging is a significant burden, they'll offer incentives to move that to daytime.
where are you? how are crypto miners not all over this?
Can you sign up for that plan and just mine Bitcoin during that time?
One thing I’ve realised recently, is that while this is an improvement compared to the status quo, at some point we’re likely to be running houses off car batteries in these hours and charging the cars off PV during the day. By the continuum hypothesis, at some point the net average power transfer into/out of cars/any given car is going to be zero, and I wonder what that will look like economically?
Last year, my town's side streets were equipped with LED streetlights, which meant replacing 175W mercury-arc and 150W HPS fixtures with 40W LEDs that are noticeably brighter and produce a far more pleasant light.
I have observed that discussion of this solution normally divides into these two groups:
(1) “That’s ridiculous, a car covered in with PV will only make enough electricity to go 10-30 miles per day!”
(2) “That’s a great idea, a car covered with PV will make enough electricity to go 10-30 miles power day, and most people only go 12-35 miles per day!”
When there is serious concern if the grid can cope, we should take all the mitigations we can get. Reducing aggregate charging demand by 90% is good even when every single driver still needs to use an external charger.
If we just downvote questions like this into oblivion, it kills the discussion and people continue on with their misconceptions, which never get addressed.
It's to allow everyone else to see under the open light how weak the ax is, and what a dull blade it has, and what poor metal it was forged out of, and how it was never a good ax to begin with.
Instead of just saying (not that you directly said this, but downvotes kind of say it): "let's not talk about that."
So I did some googling[1] and apparently, until 2030 there's only 1 million EVs planned to hit the roads in the US, which is quite shocking given the dire trends of climate change and toxic pollution on this planet.
Another interesting fact is that the costs of extending the power grid will be passed on to all its consumers in the form of increased rates (as it should, because if you don't drive an EV, you should be "taxed" on the extra pollution your car creates).
[1] https://www.bcg.com/publications/2019/costs-revving-up-the-g...
https://insideevs.com/news/340135/plug-in-electric-cars-sale...
Let's not, then. The logistics of swapping 150 million cars in a single night would be a nightmare. Charging wouldn't be my first concern.
On a more realistic note, even if we outlawed the sale of ICE cars today and mandated that every single new car hitting the road was electric, the required growth of the grid would be feasible. It would take quite a few years to replace the entire fleet.
When I was reading the article, I was wondering what that kind of current would do to the poor batteries in the car and how would they get rid of the extra heat.
https://en.wikipedia.org/wiki/Lithium-titanate_battery
Still not energy dense enough to replace Li-Ion but there are quite a few groups working on that problem.
That’s a great excuse to have railguns on every car.
The issue is, of course, not one of delivering the power, but rather that the battery chemistries we have today can't accept that much power without being damaged.
I have said this many times: The problem is power. Many think about electrics in terms of energy. However, power is the problem. If a million cars need to charge in 5 minutes you will set transmission lines on fire and explode transformers (not really, just being dramatic). This is because the energy has to be delivered very quickly, which means we need the capacity to deliver power we simply do not currently have.
A full transition to electrics will likely require more than double the production capacity we have today. The models I've used to understand this say we need between 900 and 1400 GW over the current capacity of 1200 GW. And you can't do it with solar.
I don't know how to put it yet. There's an inequality developing with regards to electric vehicles. As their numbers increase they will use more and more of a resource that is truly scarce. We don't have enough power generation capacity. I haven't done the math on the threshold yet, but it is there. And so, everyone driving electric cars today and in the next, say, 5 to 10 years, is and will be abusing of a limited resource.
This, in a sense, isn't any different from using too much water. We have a limited supply. Some of us have removed most of our lawns and replaced them with either zero water alternatives or very low water plants and shrubs. Others have huge, lush, green lawns both in front and in the back of their homes that consume ridiculous amounts of water. It looks great, but they are doing it at the expense of others who respect the shared resource.
This aspect of electrics is going to become a political mess. It isn't there yet, but it will be at some point. My guess is that's the moment when politicians will come out of the woodwork and tax the shit out of electrics. It will be interesting to see what happens then.
Nothing is simple.
The vast majority of EVs charge at night when rates are low due to low demand. So while EVs will increase the energy demand on the grid, the peak power demand goes up less.
If all of transportation and industry switches away from fossil fuels towards electricity, it'll double energy requirements. But that transition will take decades. Even if all new cars are electric, turning over the entire fleet would take 20 years. Industry is even slower. Luckily wind solar and batteries are cheap, and decreasing in price 10-15% per year, so meeting that demand is going to be relatively easy.
Grids are expensive, which is why power generation is going to become increasingly localized.
Not true. If you actually model 300 million vehicles across all of our time zones and with different utilization modalities, you soon find out power demands become very much constant throughout the day.
That's not to say people cannot be incentivized to charge at certain times. However, you can't mandate that because everyone has different utilization patterns. If you have 15 million vehicles in California all charging between 6 PM and 6 AM you are going to have a serious power availability and deliver problem.
Solar? Well, that would require two things. First, sufficiently large batteries at home. Second, TWICE the generation and storage capacity anyone has at home today. I have a 13 kW array. If I wanted to use it to charge two electric vehicles I would have to at least double the size of the array and probably get something like 8 Powerwalls (haven't done the math, maybe more) to support the vehicles.
Why? Because solar systems are sized to supply what the home needs, not twice or three times current needs.
Nobody is going to double their installed solar capacity just for the heck of it. That said, if the utilities didn't steal excess generation capacity as they do (they pay you 1/10 what they charge you per kWh) there might be real incentives to install additional capacity because you could actually make money with your installation.
Not a simple problem.
And I'm not talking rooftop solar, I'm talking industrial solar, the type that is currently building at $10/MWh right now. Lots of that will get built because it'll be profitable to do so.
https://www.rte-france.com/actualites/mobilite-electrique-lo...
Modeled 2 to 5GW additional peak demand wost case increase from EV charging, compare with normal peak (in winter) 83 GW.
RTE is the high voltage grid operator in France (public monopoly).
I don't understand why people keep saying on forums that EV charging is a big issue for grids, it's clearly not and the grid operators themselves are saying it.
You have to do the math or you will never understand.
Alternatively, don't believe a word I said and go watch this:
https://www.youtube.com/watch?v=ESIjxVudERY&t=3680s
I think he knows what he is talking about? And, interestingly enough, it confirms the results my model predicted years ago pretty much exactly.
Current generation capacity is 1200 GW. We need to more than double that if we are going to make a full transition to electric ground transport. Not only that, we need to revamp and retrofit our entire grid and distribution system all the way to each and every building. Yeah. He said it. I just happened to have done the math on this many years ago, you can find my comments on this on HN going back a while.
Too many people form strong opinions on myriad topics without ever bothering to spend a few days researching and quantifying the matter. I am not anti-electric vehicle or anti-renewables, I am just saying "We are not having the right discussion". Same applies to climate change, it's an absolute political circus. If we lie to ourselves we are never going to solve any real problems and everything becomes an emergency because so much time is wasted on absolute nonsense.
Do the math. Don't form opinions unless you truly understand a problem.
He says it's possible in the very video you pointed at, his exact words "... unless we have subsequent power generation at houses".
EV are the perfect demand shifting and averaging tool for the grid, which is why Elon Musk says what he says, you can reduce peak demand on the grid this way.
All that is in the report I cited, multi year study by lots of engineers on the case of the French grid.
Now of course the US electrical grid is not in real good shape compared to other developped countries, but full EV and end of fossil fuels is at least 3 decades away.
Australia went from zero to 25% of homes with solar in a decade, 2.4 times increase in the last five year according to
https://en.wikipedia.org/wiki/Solar_power_in_Australia
For yearly energy: USA vehicules drives about 3200000 millions miles per year, at 0.25 kWh/mile (TM3 LR) that's 800 billions kWh. Current electricity production in USA is 4000 billions kWh. Plus twenty percent is not that much.
It isn't that it is impossible with solar. The problem is that the massive scale of the necessary deployment in both panels and batteries will be far, very far, from "green". The scale of manufacturing and mining we would have to engage in would make any environmentalist vomit.
> USA vehicules drives about 3200000 millions miles per year, at 0.25 kWh/mile (TM3 LR) that's 800 billions kWh. Current electricity production in USA is 4000 billions kWh. Plus twenty percent is not that much.
This is wrong.
Why would Elon (and myself, starting many years ago) say we need to build an additional 900 to 1400 GW of generation capacity if all we need is 20% more?
One of the problems with simplified/generalized calculations is what I call the "physics cow problem". When you study physics we tend to simplify problems and eliminate variables (no friction, no air, no gravity, etc.) in order to be able to study the fundamentals. That's where, all of a sudden, a cow goes from being a highly complex organism to "assume a cow is a uniform sphere of milk one meter in diameter".
Well, you can't do that when you are talking about 300 million vehicles. You have to model time zones, work hours, miles driven, charging power/energy requirements, multimodal transportation (motorcycles, small cars, large cars, trucks, large trucks, massive trucks, forklifts, trains and whatever else you can imagine). You then have to create random-but-reasonable utilization profiles. Make enough of them to try to simulate the thousands of use-cases for vehicles. From the parent taking kids to school every day to the Uber driver, soccer mom, travelling sales person, warehouse operation, etc.
To this you have to add charging behaviors. People and companies are not going to charge their vehicles exactly the same way and at the same time. Some will want (or need) to fast-charge. Others will have the ability to slow charge during the day. And yet others will fast or slow charge at night. Some will have a routine, while others might appear to be more random due to utilization profile.
Anyhow, once you create enough variables and variability you can start to attach numbers and run simulations with various fleet characteristics over time and geography. Not easy, yet this is the only way to truly get a sense of proportion. You can't say "a cow is a uniform sphere of milk one meter in diameter" and get answers you can stake your reputation on.
As for the grid. Well, it needs a major upgrade. I can't speak for France or any other nation other than to say that I would not be surprised to learn that most countries have the same problem: The grid was designed to deliver power to cities, towns, homes, businesses and schools. Given that most cities of the world don't expand or change rapidly, it is likely that most power distribution systems were implemented with a little excess capacity, but not much. For example: No politician would have survived proposing that my neighborhood, which is about 25 years old, be built with twice the required power delivery capacity. Older parts of the world likely have it worse.
A transition to electrics will have to use electric energy to provide a portion of the energy now delivered through fossil fuels. That is a major step-change in energy delivery to homes and businesses. Maybe China is setup to handle this. I sincerely doubt most nations of the world are anywhere close to being able to manage it.
Seems like they're missing that other tiny detail in the title.
Also importantly, the more complex the cable is, the more expensive it will be to replace if someone comes along with some bolt sheers and clips the cable.
Our "current" (pun intended) cables can deliver 350kW of juice. That's already more than most car battery chemistries can accept for more than a few minutes before doing harm to the battery.
Not to mention the fact that even if you could deliver such high amounts of power, that'd translate into insane requirements on the grid, likely necessitating onsite storage to act as a buffer.
All in all, the recharge time problem is overblown. There isn't as much need for high speed charge infrastructure as you'd imagine. That's because most charging is happening at home at lower speeds. Your car almost certainly sits idle for more than 8 hours every day which is plenty of time to refill. Fast charging really only matters for long range excursions, which aren't terribly common.
And, of course, adding more level 2 charging at the curb.
You have to take human nature into account.
"I'll just get gas in the morning"
Requiring careful planning and dedicated charging at home isn't going to lead to an electric car revolution.
Do that, and you'll end up with more than enough charge for daily tasks.
I drive an EV and the only time I worry about fast charging is on road trips. Which, for me that happens once every and a half hours while driving (approximately) and gives me a 30 minute break to wash the windshield, grab a snack, use a restroom.
All in all, not really a big deal.
That, to me, is why it's overblown. With cars getting even longer ranges, it becomes even less of an issue. The first EV with 500 miles of range will be a game changer.
So I'm gonna pay tons of more money for an EV yet not being offered the same level convenience. Thus eagerly awaiting the day where the same UX is offered.
On the other hand fast charging still has issues with capacity. If several cars want to fast-charge at the same time, there either aren't enough spots or when there are the charging rate is decreased because there isn't enough power available to fast-charge many cars. And this is with a minority of cars being electric, if everyone switches to EVs this problem becomes much bigger.
There is a lot of work to do on the grid and maybe some form of local storage of energy at larger highway charging stops.
The other problem is that range estimates do not take into account cold weather and no garage. I bought a hybrid and I probably should have bought an ICE that got in the 40mpg instead of the 55mpg hybrid since winter is very bad on batteries.
But what you would do for long road trips is fill up enough to complete the next leg of your trip. EVs charge faster the lower the battery charge is. There’s no reason why you should need to charge for 60 minutes during a road trip, unless you’re in an area where the charging network is still very underdeveloped (which is still too many places obviously).
For example, I make several trips each year to visit family out of state. This is in the Midwest US, where winters are no fun, and dramatically affect range for an EV. The route is roughly 400 miles, and takes about 5/12 hours. According to the route planner in my friends Model Y, I would need to make 3 stops and I'd arrive at the inlaws house with 25% charge. I'd have to charge overnight there (they won't ever have a fast charger), and that might get me to 35%, depending on the temperature. On the way home, since I'm not starting at 100% capacity, I would have to make 4 stops. This makes the trip outbound roughly 7 hours, and the trip home almost 8.
Now compare this to an ICE. We make one stop, for roughly 5 minutes to refill gas and use the bathroom. Both legs of the trip are about 6 hours tops.
Unless we get to a point where charging is faster by using a linear charge rate, what I said is always going to be true.
As per what your friends Tesla says, it’s obviously optimizing for the wrong thing, but that’s because it doesn’t have the correct information. It’s still going to be based on the owner’s judgement to actually make sure to operate their vehicle correctly.
Imagine a world where everyone drove EVs and we were suddenly switching to gas cars with manual transmissions (because automatics aren’t invented yet) learning to drive stick is not going to be a pleasant experience for more people. The fact of the matter is that there are going to be things to learn when adopting a new technology.
(Plenty of people are and were completely baffled by how to use a smartphone at first too)
You weren’t complaining about how it gets you there, you were complaining that it wouldn’t have enough charge to get you back. If it knew you needed to go back the next day after slow charging overnight, it would be able to optimize for that, but clearly it doesn’t.
I understand that isn’t the case for everyone though.
Understanding that EVs charge faster with lower state of charge isn’t that complicated and is something people can easily understand and adapt their behavior to.
Overall EVs are not prime time ready for non city folk who want to just get in there car and go without thought vs. map out a route for charging stations and wait 15 to 60 minutes to fill based on how far the next one is and other logistics. GOing to take awhile for the infrastructure to match gas cars/stations, as well as the technology (fast charging).
I’m also not a Tesla stock holder, nor am I a Tesla owner, nor do I have any interest in owning a Tesla. I’m just someone who owns an EV and is quite happy with it, and feel like it’s world explaining what it’s like from first hand experience myself.
Obviously gas cars are better for road tripping, I never said otherwise. If you road trip every weekend then you’re going to be frustrated with an EV.
But I’ll reiterate that it is absolutely possible to road trip in an EV if you want or need to, and there is almost no reason why you should be sitting there charging it for 60 minutes assuming you are within range of other fast chargers further in your route.
If you spend most of your time driving around town and only road trip once every few months, the extra time you spend charging in the occasional road trip is generally not as big of a deal as people assume. Is it something that I personally like? Obviously it would be great if it were as fast as a gas car. But class cars have trade offs too. I haven’t had to make a separate trip to fuel my car since the last time I went on a road trip!
Then there is no need for network of charging stations. People just charge them overnight at home. They don't need fast charging. They just make sure they have enough for the day or, as a buffer, the next few days, which is a couple hundred miles. Most of the time the car's battery could be charged partially, like "only" a 1,000 miles of range. But before a vacation, you make sure you have it fully charged, or at least to a point where it covers your trip plus some buffer for the unexpected.
(EDIT: Sorry, you would have less need, not no need --- at least for something as pervasive as our network of gas stations. I was imagining even apartment parking lots having little outlets, but some apartments don't have parking lots and residents park in the street overnight.)
I don't have a garage, I live in a building of 7 apartments and no-one has a parking place.
To charge at home I'd need to pull a cable from my second floor window across the road, or sometimes around the corner if I don't find a parking spot in front of the building.
So until we put a ludicrous amount of curb-side charging columns, we need fast charging.
(I seldom use the car tho, long live public transport)
The long range model 3 has a 480kg battery. Unless there's a massive revolutionary discovery in battery technology, for 10 times the range, you're going to need to carry (and accelerate) 10 times more mass every time you stop and go.
These are pretty hard physical constraints that no amount of research will solve.
Is this true? Are current car charging cables really liquid-cooled?
(The tech is interesting, but I'm extremely wary of university press releases and consider them less reliable than the worst yellow press publication).
Edit: Found a few examples, some very modern (<2 years) chargers may actually be using liquid cooling already. The new invention presented by Purdue (buried under more than two pages of drivel and self-praise) is that they're evaporating the cooling medium. This is already used e.g. in heat pipes, so the report does seem plausible.
IIRC the version 3.0 supercharger cables are. Not sure about other DC fast chargers, but I wouldn't be surprised if the ones capable of 350kW are.
Slower DC chargers and L2 chargers aren't liquid cooled.
The latest superchargers are ~250kw dc. Lets even say your battery is 120kwh and you're charging 20-100% to maximize kw. Afterall if you're low or high in batteries it wont charge at 250kw. Thusly lets say we're charging 100kwh. It's simple math to see you'd charge it in roughly 25 minutes. Which is typically what people are seeing with their teslas.
If you want to charge faster say 5 minutes. At 500kw it'd be down to probably 15 minutes or so. At 1,000kw or 1MW you'd charge in around 5 minutes. We havent talked about battery chemistry and what have you. That's what we need.