Current mass produced batteries, which tend to hover around 260-300 Wh/kg. Higher density (but still under 500) are available, but in far smaller quantities for a very high cost.
The exciting part of this announcement is that if anyone can scale manufacturing, it is them.
What battery pack that I can buy right now is 300Wh/kg? Sincerely curious because that's 50Wh/kg above what people are using in some very expensive UAVs.
Even if we get this high energy density, I'm skeptical about its utility/impact. Right now we are barely able to mine enough lithium for our current batteries, which are used for phones and a few (percent-wise) EVs. As far as I know, and please correct me, we need to increase production by at least 8x for 5-10 rare earth elements in order for everyone to use EVs. Where are these extra rare minerals going to come from?
Yes, it would seem preferable to reuse the same energy storage over and over again, as opposed to digging it out of the ground at huge expense, shipping it across the world, and then spreading it out into the environment as a cloud of toxic particles after one use.
You're forgetting to take into account that an electric drivetrain (power electronics and electric motor) is several times more efficient than a gasoline drivetrain (ICE motor and gearbox). It also weighs less.
You do have to lug the battery around even when depleted but electric motors are ~3 times more efficient than combustion engines, so if you got to energy density parity you would still have a much lighter car, all the time.
>This is a little under 2x the density of [the best] current batteries.
[brackets mine]
But the best batteries contain unacceptably high levels of cobalt. Practical EV batteries are made with nickel or iron, maybe vanadium someday, and have lower density than pure LiCoO2.
>CATL is already producing a ton of batteries, lending them some credibility.
A couple of years ago CATL claimed that they had figured out how to make durable sodium-ion batteries with a ferricyanide cathode, to be released in 2023. The press cheered about the end of lithium dependence.
Yesterday, not long before this announcement, it was revealed that CATL's "sodium-ion" battery contains lithium:
"CATL and BYD's sodium-ion batteries to be put into mass production will both be a mix of sodium-ion and lithium-ion batteries, according to local media."
While I agree that the blurb you quote strongly implies that the sodium-ion batteries contain lithium, I don't think the article itself really says that.
> CATL and BYD's sodium-ion batteries will both be carried in mass-produced vehicles within the year, and they [the vehicle battery packs] will both be a mix of sodium-ion and lithium-ion batteries, according to a report by local media 36kr today.
By my reading of that, and the rest of the article, it's saying that the vehicle battery will be assembled from of a mix of sodium-ion and lithium-ion battery cells, not that the sodium-ion cells contain lithium.
> With its pioneering AB battery system integration technology, CATL has achieved a mix of sodium ion and lithium ion, allowing them to complement each other and thus increase the energy density of the battery system, Huang said at the time.
Basically, a "battery system" using only sodium-ion cells does not yet have enough energy density to support their range targets, so they are using a mix of cell types to improve the energy density and increase the vehicle range.
Yes, I'm always skeptical whenever battery breakthroughs are announced because it's easy to make a breakthrough in the lab, but almost impossible to transition it into mass production.
This has a lot of potential coming from CATL. However, there is no mention of price. I'm betting this is going to be very expensive.
This is why I generally skip over any "breakthrough" science/tech stories on HN.
News articles on breakthrough discoveries are mostly bullshit and even when they aren't, most of the time they don't affect my life in the slightest because the tech is impractical or expensive.
It may be interesting to read about science discoveries, but I don't want to take the time to sort out the bullshit from what's real just to find out that the breakthrough is irrelevant to me and society at large.
There's also kind of a grey zone in there of "no, I can't buy it, but if I was a major car manufacturer I could." I wish we had access to all the good stuff as retail customers, but that's just not how it is.
(This is especially frustrating on the EV conversion front, since the best parts are usually unobtainable except from salvage vehicles. The products specifically made for EV conversion are usually rather underwhelming compared to what the OEMs can get.)
Cool! What didn’t occur to me until I learnt it was that you get a multiplicative benefit with energy density when weight is a major factor (air transport, especially) because you need to spend less energy accelerating mass used by the battery itself.
Same with jet fuel on a plane. They calculate the amount to fuel carefully to be efficient but safe. Too much and the plane is heavier and uses more fuel. Too little and you might run out if put into a holding then diverted.
Obviously jet fuel is what it is it wont get more dense but a more efficient engine means less fuel needed means even more efficiency and so on.
The Qantas 16h 45m flight from Dallas to Sydney aims for Brisbane, and then turns to Sydney as the plane approaches Australia. (10th longest commercial route in the world).
This allows the plane to land at Brisbane and refuel if the calculations are done wrong. Couldn't find stats on how many times it's had to land in BNE.
Pre-COVID, it was apparently common to try and off-load passengers to single stopover flights to reduce fuel needs (I was one of those passengers, and the crew confirmed it was a regular occurance).
It was something I had never considered but it is wild to think about. I believe it was Vaclav Smil that highlighted it to me. On its longest trip an A380(I think?) takes off weighing 400 tons and lands weighing 200 tons. That kind of thing is just cool to ponder.
For a battery of arbitrary weight you need to spend the same amount of energy accelerating its mass, irrespective of how much energy that battery contains.
Right, I believe GP's point is that for a given capacity, you now need fewer kilograms of batteries to store it, meaning the percentage of overall capacity used to accelerate the mass of the battery itself goes down.
The article mentions aircraft multiple times. Once a range is achieved through available energy, reducing weight is a goal. The energy is more useful the less weight you need to move as then you can shave off a bit more weight as less energy was needed.
Your car may not need this as much, an aircraft does.
Yes that’s correct. Probably a better way of articulating what I meant to say is that unlike adding more battery mass which gives you diminishing returns as that additional weight must be carried too, improvements in energy density give you gains closer to 1:1. Though in retrospect this isn’t a very interesting or insightful statement, hah.
I just realized how much energy efficiency is being squeezed out of a Tesla. It's incredible.
A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg, which is 13.2 km/l or 15.3 km/kg. Diesel has a mind-boggling 12700 Wh/kg energy density[1], which translates to an efficiency of ~827 Wh/km for the Chevy.
By contrast, the Tesla Model S, has a ~540 kg battery[2]. At 272 Wh/kg (from the posted article), that's ~147 kWh of energy storage, and the Tesla can do a rated 650km on a single charge[3]. So that's an efficiency of ~225 Wh/km, which is ~27% of the energy required to run a normal car!
It just wouldn't have been possible to run cars on batteries without this efficiency bump.
The big reason for this is thermodynamics. A conventional internal combustion engine car has to convert chemical energy to kinetic energy - the absolute best theoretical efficiency of this might be 70%, but in practice it's more like 30%. Electric cars have to pay the same thermodynamic penalty, but they pay it at the power station (In practice, thanks to renewables, not all the electricity used to charge a car will come from hydrocarbons - but let's assume it does for ease of comparison sakes). It's much easier to build highly efficient hydrocarbon power stations - typical efficiencies range from 40-60%.
So when you look at the headline "efficiency" of an electric car, you need to take that thermodynamic penalty into account first.
A modern series hybrid like a Toyota Prius is effectively an electric vehicle and a gas generator (which means it has the same efficiency gains due to regenerative braking). That gets 52 mpg, which is about 493 Wh/km. If you generated the 225 Wh the Tesla needs in even the most efficient combined cycle gas turbine powerplant you'd need 375 Wh. Less - but not nearly as drastic as it first seems.
Renewables change the picture though - once you have significant renewable generation the carbon intensity of electricity starts dropping, which means that remote powerplant vs local powerplant argument falls apart. That is when the real power of electric vehicles kicks in - they can take their energy from anywhere.
It is a sign of the success of the oil industry that this analysis always takes the cost of electricity generation back to the source, but assumes that fuel stations pump from a perfect source of naturally refined/distilled hydrocarbons.
It is surprisingly difficult to get numbers on how much oil is used to extract, refine and transport oil.
> the absolute best theoretical efficiency of this might be 70%
While ICE are heat engines with a theoretical limit of 70%, they’re more specialised subsets described by the Otto (gas) and Diesel (… diesel) cycles, which have a much lower theoretical maximum.
Generation can be from clean sources and is already happening in some jurisdictions.
Even if a clean source is not available, the pollution can best be controlled at the source. In this period of history, hundreds of millions of people make billions of polluting trips every day in their communities.
Although owning any car is the poorest choice of all for the environment, there are two ecological benefits to driving a BEV or a PHEV.
* better efficiency than ICE
* zero emissions in the case of BEV, zero emissions *for most trips* in the case of PHEV
The Prius' efficiency comes from much much more than regenerative braking. Part is a focus on good aero and low weight, like many electric cars. But most is from leveraging the electric motors to allow the engine to run at max thermal efficiency (probably a touch above your 30% figure) at nearly all times.
ICEs are most efficient under medium-low RPMs and high load. The electric motors can sustain low speed cruising, letting the engine shut off entirely if it wouldn't be well utilized, and also fill in for high torque demand to keep engine power output lower.
> A modern series hybrid like a Toyota Prius is effectively an electric vehicle and a gas generator (which means it has the same efficiency gains due to regenerative braking). That gets 52 mpg, which is about 493 Wh/km.
Wait, does a new prius or something like a hyundai ioniq (also 52-53 mpg) not have the internal combustion engine mechanically coupled to the transmission and drive wheels anymore?
Though that makes me think that hybrids have a real future. Or hydrogen fuel cells.
Anything that doesn't require charging directly from the grid all the time, because although parts of the USA and Norway are ready for that, it's very tricky to get right globally.
Maybe hybrids like the Prius get to be so efficient that such cars will have a truly negligible impact on global warming.
One of the big sources of electricity generation here is hydroelectric, so I've been joking with my kids for a while that we have a water powered car. The first time I brought it up sparked a fun conversation as they wanted to understand how water makes electricity, and then started rabbit-holing on how magnets are involved in everything.
> Renewables change the picture though - once you have significant renewable generation the carbon intensity of electricity starts dropping, which means that remote powerplant vs local powerplant argument falls apart. That is when the real power of electric vehicles kicks in - they can take their energy from anywhere.
How close/far would you say we are as a society on "having significant renewable generation"?
> A conventional internal combustion engine car has to convert chemical energy to kinetic energy - the absolute best theoretical efficiency of this might be 70%
You mean thermal energy?
Both cars are converting chemical energy to kinetic. The theoretical maximum for this is 100%. But one uses a thermal intermediate step, that reduces that maximum.
BMW claim that a diesel 3 series will get 61mpg. Volkswagen reckon a Golf 2.0 TDI will do 68mpg. Electric is still significantly better, but you didn't need pick a terrible diesel car as an example.
My diesel 3 series (2.9 litre, late 90s design) would get 8.83 L/100 km (32 mpg UK, 26 mpg US) driving round town, stopping at traffic lights and averaging <20 mph and never getting past 3rd gear. This didn't require much care, just a question of not trying to accelerate too hard at low RPMs or doing a 0-60 run from every stop.
Engine technology will presumably have moved on in the past 25 years, and efficiency will have improved, but you'll still get crappy fuel economy for stopping and starting all the time.
Volkswagen has already been caught cheating (on its emissions) —- not sure I would trust their claims without an independent third party checking on that.
The Cruze is way better than that anyway, you'd need to be in an excruciating traffic jam to get that low mileage.
Well, my 12 years old (gas) Honda Fit does +40MPG being very "pedal happy" and near 50 driving normally, and my dad's 20 years old (diesel) Citroen Xsara Picasso does around 60MPG
I had a BMW series 3. 61mpg is 3.8l/100km and that's… dreamland. You can probably achieve that in ideal conditions, driving 50km/h on a highway.
Very few people check the facts, and the only reliable way to know yourself is to take notes at the pump: gas pumped vs km travelled. I did check for a while and the numbers were quite different :-)
On a related note, for the VW ID.4, the manufacturer states 17kWh/100km which is actually achievable (much to my surprise) in city driving when it isn't cold. My real numbers are closer to 21kWh/100km. This goes up really quickly if you exceed 130km/h.
Relative efficiencies also explain why city/highway efficiency is inverted between EV & ICE.
Gasoline is rather energy dense, but the ICE is rather wasteful.
There is a certain base load of energy being generated by an ICE engine, regardless of if you are moving or how slow you go. This is why carmakers experimented with things like rapid stop/start engines, regen batteries&motors, etc.
ICE becomes more efficient as you reach highway speeds, which is why highway mpg is better than city mpg.
Batteries by contrast are not very energy dense, while EV motors are extremely efficient.
The only energy being consumed is that which is needed to move the car, plus fight rolling & wind resistance, and power AC/heat. Wind resistance increases with the square of speed.
EVs as a result are most efficient at low speed, and at highway speeds become noticeably less efficient as you go from 55->65->75mph. This is also why running AC/heat has a noticeable impact on range in EVs.
Meh, the only reason EVs are more efficient in the city is because of regen braking.
An ICE car traveling at a constant 30mph is going to get much better fuel economy than an ICE car traveling at a constant 75mph. The difference is that <=30mph roads usually have a lot of stop-and-go.
Maximum heating power in my 2015 Tesla Model S 70D is 6 kW. Travelling for 100 km at 100 km/h costs about 25 kWh. I drive in shirtsleeves and barefoot in the Norwegian mountains at -20⁰C and the heater doesn't seem to be running hard. So unless you are traveling in severe arctic conditions the heater really isn't more than a few percent of the load.
Teslabjørn has a video where he turned his Model X into a sauna getting 40⁰C inside while it was -10⁰C outside.
The 272 Wh/kg is at cell level not pack level which the Tesla weight refers to. In my X has about 92 kWh usable energy when new and it uses around 225 Wh/km at 120 km/h and 170 at 90.
The 3 and Y is even more efficient, mostly due to size. But it has a smaller battery, I can get about 69 kWh out of my AWD 3 after losses and it hovers around 170-180 Wh/km at 120 km/h and 130-140 at 90.
How the hell a Chevy Cruze gets 31mpg with a diesel??? A VW Passat TDI will easily get 60+ imperial MPG, I've had it get close to 70 on long runs(that's 50 and 58 American MPG respectively).
Are American diesels this inefficient?? Looking at pictures online the Chevy cruze doesn't seem like a bigger/heavier car than a Passat, so what gives??
Here in the Netherlands, we'd translate 31mpg to "1 per 11". One can drive 11km on 1L of fuel. 1 per 11 is a joke. It's associated with heavy petrol cars from the 80s and 90s, before anybody even attempted efficiency.
Even my 15 year old diesel car had an efficiency of 1/22. Adjust you driving style and I'd get 1/25. Range: 1000km, with an ordinary sized tank.
It seems Americans haven't even started with efficiency, quite likely because there was no pressure to do so due to low fuel prices. Not in their homes, not in their cars, not anywhere.
Meanwhile, fairly common cycling parameters lead to well under 10 Wh/km at comfortable cruising speeds, and with things like velomobiles you kinda start around 5 Wh/km, and 3 Wh/km is possible without significantly compromising the practicality of the vehicle.
But it’s still a useful comparison to contemplate, especially when considering the nascent category Lightweight Electric Vehicles, which in its most interesting form isn’t far off “ebike minus pedals”. Cars are still pretty power-inefficient as a general concept.
Not only that. The more important conclusion is that actually ICE cars are stupendously inefficient.
All that extra energy ICE cars carry isn't actually being put to use very well. They don't have more powerful engines. They don't have more torque. They don't have more acceleration. And even their range isn't that much better. You can of course get models that take something like 100+ liters of petrol. But the per liter performance only gets worse if you do that (heavier cars are less efficient).
The reality is that yes, fuel is very energy dense but sadly most of that isn't transformed into motion when you use it. You are instead making lots of noise (vibrations) and heat. Both are actually bad for your car. So, you use most of the energy to wear out your car faster. The more powerful the car, the less efficient they are. And the faster they break down.
For diesel, this is really really bad. Most gasoline cars will run more economic than this, let alone diesel.
If your diesel runs less then 17 to 18 km/l something is wrong.
(my opinion is based on how things are in .nl, other parts of the world can and will be different of course)
This is definitely not an apples-to-apples comparison. With an EV the ball is already at the top of the hill and merely needs to be rolled down, with an ICE car, the ball has to be pushed up the hill first. The power plant does all of the heavy lifting for the EV.
Not a mark against EVs of course - it kind of just makes sense. I'm sure future generations will laugh that every vehicle used to have its own on-board power generation facility. It's too bad the dumb power-plant-under-hood way is still so much cheaper than the EV approach of course.
Maybe I missed something, but seems very weird to compare kg of diesel fuel to kg of battery. The posted article's figure of 272Wh/kg is for battery capacity, not energy yield from source fuel.
225 Wh/km is even high for most routes and cars. Unless you drive fast on motorways or in cold climate, it's often easy to get to 150 Wh/km (15 kwh/100km as often displayed).
31mpg is not very efficient. Lots of current diesel engines in Europe are certified at 50+MPG. There's even a Car and Driver test where, with very efficient (and boring) driving you can get 70+MPG out of a Diesel Cruze...
@25% Viable for mining.................... 22,000,000,000 Kilograms [2], [3]
Tesla S battery weight.................... 540 Kilograms per car [4]
Lithium weight per Tesla S battery........ 63 Kilograms per battery [4]
Max Tesla S (global) production possible.. 349,206,349 units (See Edit below)
Number of automobiles running in the USA.. 102,000,000 units [1]
Number of automobiles running in the World 1,500,000,000 units [5]
So, even if we theoretically assume that the earth's entire known Li reserves are used for EV usage, we cannot replace more than 25% of the currently running cars in the world.
So, we have a bigger problem ahead of us (over the next decade) that will act as an opposing force against EV penetration and replacement of the IC engine.
Solutions possibly lie in exploring other battery chemistries while improving the efficiency of Li extraction.
Edit: As some of the comments below point out, the Li content in a Tesla Model S battery is approx. 63 Kg. That makes the Max Tesla S (production) possible to 349 million units. So, in theory, one could replace all IC engines in automobiles plying in the USA. That then leaves the rest of the world. So, the problem still remains.
You didn't cite sources for the critical pieces of that (the first three numbers). You also assumed that the battery is 100% lithium, which is obviously wrong. A random Googling says closer to 62kg. And now I'm tired of bothering to fact check you.
I'm also going to say that all the car companies, battery companies, and governments in the world probably took six seconds to do basic math before investing trillions of dollars in it.
> I have a fundamental question though. Will EVs (Li battery based) achieve the holy grail of IC engine replacement?
Even if they couldn't, why would you limit your analysis to Li-based batteries? It's basic economics that when a resource becomes rarer, it becomes more costly and alternatives spring up. EVs with Sodium batteries are already on the market in China. This whole Lithium fear mongering is such a red herring.
> Owing to continuing exploration, identified lithium resources have increased substantially...
Emphasis added from your [3].
Ever think maybe your 88,000,000,000 Kilograms number isn't actually all the lithium on the planet, and maybe there's more undiscovered under the ground? Or do you think all the lithium on the planet was discovered in 2023, and now there won't be any more reserves found?
Strange how this maximum amount of lithium reserves keeps magically growing year over year over year over year. I wonder how it magically appears.
There are many cars from 00-05 and with emission levels that are relatively low; if one is to make a somewhat absurd suggestion to prove a point, I'd suggest many smaller petrol and dieselbcars would be cleaner than an EV _if_ the EV was charged with 100% coal power.
Luckily, most people don't charge their teslas with coal power.
It would be slightly worse in colder climates. I wish car manufactures would allow for easy installation for range extenders in the front trunk. I'd be a great source of heat for the heat pump. Range anxiety would be gone. No carbon tax since it would be an aftermarket solution.
It seems Mazda MX-30 r-ev is the only thing you can buy.
> which is ~27% of the energy required to run a normal car!
This is because you're not comparing the same things: going from thermal energy to mechanical energy has a much lower efficiency than going from electricity to mechanical energy. But that electricity has to come from somewhere, and most of the losses happen at the electricity generation place instead of in the car.
> It just wouldn't have been possible to run cars on batteries without this efficiency bump.
Electric motor have always been far more efficient than ICE ones, even in the 19th. In fact, the difference was even bigger, because combustion engine sucked hard back then, whereas electric engine didn't make as much progress as combustion engine ones (that doesn't mean that they didn't make progress, they did, but there's far less of a difference between an electric engine of 1920 and the one in a Tesla, than between an ICE engine then and now).
Sorry, but this is BS. Modern electric engines in Tesla Model 3 use high-speed power transistors to precisely modulate the magnetic field. Back in 1920 all you could do was a collector plate with brushes.
The difference is like the difference between carburetor engines and direct fuel injection.
During the introduction to a speech by J. B. Straubel, the presenter said his mentor’s motivations were that 1% of the energy in the gas tank was moving the passenger, 12% the car, and the rest was lost.
We should measure efficiency based on that number.
Something you left out here is that the full capacity of the battery can’t be used. Tesla uses more of the battery than other manufacturers, which gives them a higher range per rated watt hour.
On top of that, they have more efficient components. When you compare a model S to a lightweight Carbon Fiber BMW i3, with a much smaller pack, you’ll see that the modelS still squeezes out a higher mpgE rating.
For a normal, new car, anything above 6l/100km for that size of a car (and usually around 5) is something's wrong with the car. That's more than twice the efficiency of described one from 1976.
The problem is that at that point liquid hydrogen already spent 70% of the energy stored in it (80% efficiency of electrolysis * 40% liquefying efficiency) .
Its almost like electric cars are cleaner, more efficient and better for the environment. Telsa's are god tier level of engineering under the hood. (Maybe not so much fit and finish). The only reason the gov't isn't buying these for everyone is because Tesla disrupted deeply entrenched companies and people don't like Elon.
model Y consistently do 150Wh/km which is just nuts...
one thing with petrol chemical too is it's not carrying all the energy with it, the oxygen came from atmosphere while EV is carrying the entire energy required to run with itself..
Gasoline internal combustion engines run at about 30% efficiency. Diesel does somewhat better at about 40% for car size engines, and about 50% for the really big ones. Electric motors easily exceed 90% efficiency. The EV wins even without regenerative breaking, even accounting for the losses in the batteries.
Regen braking is 60-70% efficient, and it also limits your ability to free roll (let go of the gas and let the car use its inertia) for example going downhill or on level highways. Polestar for example recommends to lower the OPD sensitivity on highways to increase efficiency.
There are theoretical maximum efficiencies for thermodynamic cycles in combustion engines. I believe the limit in the diesel cycle is around 40%. Petrol engines are lower still.
At a continuous 80km/h on a level road in the summer I can get down to 160Wh/km even in my 2015 S 70D. I have a friend with a Kia Eniro and he gets similar numbers to you most of the time.
DC is better then AC and both depends on how much the battery is already charged, temperature of the battery, the infrastructure (charging cables for example).
The range is somewhere from low 80's for low amperage AC charging on cold weather using a low quality granny charger cable to high 90's for a warm battery on a dedicated high power DC charger.
This of course doesn't include losses in transmission from the power station and in electricity production.
31mpg is pretty low, even for us gallons. The most sold l car in the UK is (shockingly) the nissan qashqai. They get about 48mpg in imperial gallons which is about 40mpg for the US.
So, how about we apologize in public to the engineers who said no to radar, cause boy oh boy would that one have eaten battery, which would need additional batteries, which would have torrn into the car rocket equation ?
500 Wh/kg means Sulphur cathode, which also explains the solid electrolyte. Roughly speaking, it'll be 3x as energy dense but only a 1/2 as volumetrically efficient (so, a given capacity battery will weigh 1/3 less but take up twice as much space).
There are other approaches to Li-S (and Al-S and Mn-S) which will be less expensive. Grats to CATL for bringing this to market, but the race for sure isn't over yet.
Honestly it doesn't seem like that big a drawback. EVs for instance have reclaimed lots of space from under the hood, the gas tank, the exhaust system and more.
A lot of other comments are saying 2x as dense (that current norms are around 250Wh/kg for mass produced and widely available product)… can you square that with your 3x claim? Am I missing something?
> During the presentation, CATL said its working with partners on the development of electric passenger aircraft practicing aviation-level standards and testing in accordance with aviation-grade safety and quality requirements.
Get ready for passenger drones[0], delivery drones[1] and just drones in general, because this is what this breakthrough means really.
- cost?
- what new chemicals are involved and what is the environmental impact?
- how many cycles can the new battery take?
- volume? (density is always shown as weight/mass, it's not the only thing that matters)?
- how does it behave under environmental changes (temp / pressure / etc ...)
Yes, there are tradeoffs with all of these. We can easily get one or some good looking stats, but to get good results with all of these parameters is the real challenge.
The claims about new battery chemistry are rarely farfetched or inaccurate, but we as a society (and especially the reporters) don't do a good job of interpreting the claims, focusing on one promising sounding parameter and neglecting all others.
The manufacturers are also not helping by omitting this sort of critically important information that you have highlighted (lying by omission).
Let's consider Cessna-172S ([4]). Its characteristics:
- 130 kW engine, Lycoming_O-360 that weighs 117 kg. For comparison, an electric motor of this range would weigh 11-13 kg (at 10-12 kW/kg, [2]). That saves 100+ kg weight immediately and we can put 50+ kWh batteries instead.
- It carries up to 200 liters of kerosene ([3]), which weighs 164 kg. We can place 82 kWh of batteries instead.
- The engine consumes around 30 liters/hour ([1]), which gives us ~6.7 hours of flight time or the equivalent of 6.7*130=871 kWh for an electric-power plane.
- The fuel tank weighs about ~14 kg (source: an LLM, sorry) and gives us another 7 kWh.
So, we can put 50+82+7=139 kWh. By using modern materials, we can probably increase it to ~180 kWh, which will give us about 1.5 hours of flight time / 300 km range. This is much less than 6.7 hours, but quite practical for recreation and short flights. And it would be much cheaper to run too.
That said, still not practical for medium and long flights.
The point not considered is the Cessna 172 is an extraordinarily draggy airframe - it didn't need to be clean and laminar because fuel was (relatively) cheap.
Electric aircraft of the future will have half the drag or less. High aspect ratios, flush fairings, streamlined cockpits etc.
> quite practical for recreation and short flights
Perfectly agree with everything, but 1.5hr may be very short if you need to have 30 minutes of reserve at landing. On the saving side, you don’t have to have an alternator to transform ICE energy into energy for the dashboard instruments. On the downside, you now need to heat the cabin manually, rather than reusing the ICE heat.
The power requirement at cruising speed would quite a lot less than max power would it not? If cruse consumed 60% of max you'd be using closer to 80kW which would give you over 2 hours flight time.
324 nmi range for the regular variant. Around 65 nmi for the electric version.
This is with older batteries, probably with very bad pack-level energy density. The battery pack can even be swapped. Great to avoid having to wait for charging, but probably terrible for weight.
If you design the aircraft for electric flight from the ground up (see Maxwell X-57 for how you could do that), with a structural battery pack, and with 300-500wh/kg batteries, I'm willing to bet a 2-5 times increase in range is viable.
A lot of people won't fully fuel up their 172 so they can bring more weight, either baggage or passengers. I don't think anyone would fly 6.5 hours in one either, but 2+ is normal for non-training flights.
Well, they were already possible and being sold. But with relatively short but usable ranges. Those now more than double with this battery. Which makes those planes usable in a lot more scenarios.
Consider the Eviation Alice, one of the 9 passenger prototype electrical planes that is currently undergoing test flights (i.e. it definitely works). The advertised range is 250nm. Not amazing. But far enough for a lot of regional flights.
What would happen if you double the battery capacity without increasing the weight? You more than double that range. This is counter intuitive until you realize that you are not going to need more energy for taking off, or reserves. All that extra energy goes into extending cruise range. So you get more than 250nm extra. Basically, it's probably getting closer to 600nm. That's still not amazing but there are a lot of flights every day that are much shorter than that. All of those are now doable with electrical planes. At a fraction of the fuel cost.
Most flights are short haul. And they are, well, short. Which means, all of those are in scope for electrical planes. Small planes work well for these too. You don't have to cram hundreds of people in a plane if you eliminate fuel cost as a major cost factor. That's the only reason we do that. It's not like it's pleasant or comfortable. 20 ten passenger planes can do the work of one passenger jet. But it can do it more flexible and cover more destinations too.
Electrical planes are not about doing exactly the same things that we do with traditional planes but about doing a lot more than that. Basically, less noise, less pollution, less cost, means that a whole lot of flights that would be considered decadent and obscene right now become perfectly feasible and reasonable. A ten minute hop across town. Why not? Live 70 miles from your office? Not a problem, you commute there in under 15 minutes. For the price of a few cups of coffee.
> Most flights are short haul. And they are, well, short. Which means, all of those are in scope for electrical planes.
Exactly. In the EU, Eurocontrol (European Organisation for the Safety of Air Navigation) says 30.6% of flights in 2020 were 0-500km, roughly within the range of the Eviation Alice currently. A further 43.6% of flights in the EU are between 500 and 1500km.
Source [1]
> You don't have to cram hundreds of people in a plane if you eliminate fuel cost as a major cost factor. That's the only reason we do that.
Not only. Gate capacity and runway capacity is an issue too. But that might also be easier to resolve with smaller electric planes. E.g. there's Liliums approach of vertical takeoff from little more than a helipad-sized platform, but even non VTOL planes capable of taking off from short runways would be helpful.
ICE engines only manage to turn ~15% of the stored energy in gasoline into actual work. A bit of googling suggests that jet engines are about 35% efficient. Stored electricity is much more efficiently turned into mechanical work... Electric engines have 75-90% efficiency. So, you get a lot more work or unit of stored energy.
That factor 6 already seems to include the efficiency of the engine. Pure chemical energy density of kerosene is 12000 W/kg, 24x the new battery's energy densitiy.
Yes. 12kWh/kg chemical energy for kerosene, a little more for avgas. But with a 25% efficiency you are only getting 3kWh out of a kg of fuel. Electric motors tend to have higher efficiency -- maybe up to 75% so you might nearly get 500Wh from a kg of battery.
Yep. Also... kerosene gets spent. Pilots can also dump fuel in emergency when it's too heavy to land. Battery powered planes can't dump electricity, so I'd imagine some trade offs that have to be made.
That is a very good and often overlooked point. So in average on a flight one has to calculate maybe with 60% weight of kerosene, while the battery keeps 100% of its weight during the entire flight.
Electric planes could recharge using solar or wind. As efficiency increases with these technologies, it would mean planes wouldn't require carrying the same watt-for-watt energy as fuel.
I feel that synthetic kerosene via electrolysis is a far more viable path to sustainable aviation than battery-electric engines. The energy-inefficiency doesn’t really matter as long as you can keep the total cost of the flight within consumer reach.
Carbon neutral synthetic fuels might make sense for airliners, because they're already pretty efficient, reliable and incomprehensibly powerful and there's tons of other stuff in them that'd require maintenance even if you took out the engines.
They don't make sense for general aviation planes that are usually a fifty year-old engine design that requires expensive overhauls and guzzles expensive fuel wrapped in a bit of aluminum.
The best application I've seen for the currently available electric airplanes are flight schools. One plane I looked into has a flight time of 1.5hrs, which is plenty for training. When I last priced out instructor time, 30% of the cost was the fuel. This means that flight schools could cut prices by up to 25% or so. That being said, the plane I looked into was $250k, while a student level ICE plane could be had for $20-50k.
I don’t think Musk has given a writeup of his reasons for thinking 400wh/kg is the magic number, but a lot of research has been done that says similar numbers. This paper https://www.sciencedirect.com/science/article/pii/S2666691X2... is a good review; it cites researchers saying 800wh/kg for an electric Airbus A320, NASA saying 400Wh/kg for general aviation and 750Wh/kg for regional aviation, and other researchers saying 600Wh/kg for commercial regional aircraft and 820Wh/kg for commercial narrow-body aircraft.
That paper also sketches out the argument for electric flight at close to current battery densities rather than close to kerosene energy densities. It goes:
Jet fuel gets roughly 28% final efficiency while electric gets roughly 90%, so divide jet fuel by 3 to get 4,000 effective Wh/kg.
That is getting close to current energy densities of batteries. You only need to find one more ~2x improvement that electric flight can obtain over jet fuel to bring it into the range of 500Wh/kg, which CATL is saying they have in production right now.
(Presumably Musk’s magic 400Wh/kg number involved another 2.5x improvement, though I don’t know where specifically he thought it would come from. The internet seems to think he said you can go higher because you don’t need oxidizer from the air to burn jet fuel, but that doesn’t sound right since you still need to push on the air with your fans and you’ll run out of that at high altitude before you run out of oxygen, so it must be coming from somewhere else. Regardless, the point is that jet fuel imposes design constraints that trap you in a local maximum of aircraft efficiency, and electric engines allow you to explore a wider space which may have much much higher maximums.)
I assume it's a limit motivated more by how far you can go rather than the cost of fueling/charging. Like, above a certain weight/energy store ratio, it's either too heavy to fly or would just have an incredibly limited range.
Soaring is currently making the switch, not only as sustainers, but also for starting. There are models from major manufacturers, like the Schleicher AS 33/34 me [1] or Antares [2].
The point isn't necessarily to equal or beat kerosene in terms of weight and range, but rather to be good enough that electric aircraft are usable for many or most use cases.
Planes tend to be very expensive to operate, due to maintenance and fuel costs. Some people would be happy to trade range for dramatically lower operating costs.
Nope, the variable is cost per passenger. Large jets only exist because fuel is really expensive. The cost per passenger gets astronomical with smaller planes. That's why only rich people can afford that. Big planes are more economical. Because of the fuel.
This is simply not true with electrical planes. A mega watt hour of power is about 60-100$. And much cheaper than that with renewables. Not at retail prices of course. But if you consume power by the mwh, you'd be investing in your own generation (solar + storage) pretty soon. A mwh is about what you need to move a small electrical plane a few hundred miles. The kerosene cost for a similar journey in a small jet is going to be hundreds of dollars, even for a small jet. The smallest jets burn 50-100 gallons of fuel per hour (in cruise). Depending where you get your fuel, that ranges from 3-5$ per gallon. That's why small jets are only for rich people. Even a very short flight sets you back hundreds of dollars. A simple propeller plane is cheaper. But we're still talking 5-10 gallons per hour. That's why people talk about 100$ hamburgers. Because that's what it costs to take your tiny plane out to grab a burger somewhere.
Big big jets are a bit more economical with fuel than small ones. But they only makes sense if you can distribute fuel cost among many passengers.
With electrical, you can use lots of smaller planes cost effectively rather than having to put lots of people in a few bigger ones. For the same reason, you don't need big airports either. Or worry about pollution. And even the noise of small electrical planes is not as much of a problem. And with autonomous flight, we won't even need pilots long term. Small electrical planes are good enough and much nicer for passengers, more flexible to operate, etc.
Not at this density. This is the minimum requirement for medium length large airplanes. Small aircraft are already viable with mass produced batteries.
As they scale production of these, hopefully they can get 20% additional improvements at the cell/pack level, reaching potential to replace the most common flights.
Video[0] isn't a direct answer, but I found it helpful for understanding the trade offs that come when considering using electric power for a plane vs regular fuel. They show the math in an easy to follow diagram.
tl;dr for their small kit aircraft the weight of batteries they would need to match the stored energy of equivalent fuel (even with a battery at 500wh/kg) would be 5-10x heavier, and also not get lighter during the flight. They said for long range it doesn't make sense, but that there are lots of companies iterating in the short range electric space.
Seems like marketing hype to me. An 8-hour transatlantic flight requires something like 600MWhr of energy. That's about 75MW, which is in small nuclear reactor territory.
Replacing transatlantic flights is out of the question (for batteries for now). But there exists shorter routes, and according to this list [1] on Wikipedia, the busiest route in the world is 449km long. That's probably also not doable now, but maybe in some years?
For the first years it will probably only be a few wierd, short routes in rich countries like Norway with 110% financial support from the state. But when they can safely fly 5-600km there is a actually quite a number of routes with a lot of passengers out there.
The US very nearly built a 60MW nuclear reactor for use in airplanes after their scaled down design at 2.5MW was successfully built, ran, and tested. This was done in the 1950s and, incidentally, required inventing molten salt reactors. https://en.m.wikipedia.org/wiki/Aircraft_Reactor_Experiment
(They actually planned to go all the way to 350MW, which could theoretically run a transatlantic passenger jet with 2,000 passengers, assuming it’s even possible to build such an airframe.)
It’s interesting that battery stories generate so much opprobrium when battery performance has increased so dramatically over the last couple of decades.
Their main energy density boost is a silicone anode, which we've known "for ages" that it leads to higher energy density, but soaking it with lithium degrades the material very quickly, leading to cracks and thus damage after just a few charge cycles. The main innovation is some kind of nano-structuring of the anode, and that technique was published in the scientific literature in 2006.
I'm sure it was hyped as a battery break-through in 2006, and it has taken 17 years to get to market.
So, maybe we shouldn't go back 5 years, more like 20 years (OK, no HN back then :D).
Batteries do get better over time, fairly consistently so. The development lifecycle is just soooo much longer than in software.
I follow these announcements with a sense of dread, as battery limits are the main obstacle between our current situation and widespread adoption of drones and robotics for military use.
Readit News
This is a lot more credible than most of the battery stories, because CATL is already producing a ton of batteries, lending them some credibility.
This is a little under 2x the density of current batteries.
The exciting part of this announcement is that if anyone can scale manufacturing, it is them.
Reminds me of the "revolutionary battery checklist": https://news.ycombinator.com/item?id=28025930
edit: removed the paste of the checklist because of spam.
If yes, I hope they open-source it so that the fight against global warming can gain some momentum across the globe.
> What makes CATL’s announcement this week truly groundbreaking is that the condensed battery will go into mass production this year.
Wow, that's amazing, creeping up towards the energy density of gasoline at around 1200 Wh/kg
Of course you don't have to lug around the spent gasoline after you've used it, but that's really the problem too innit?
Aren't you missing a 0 there? Gasonline should be at 12 kWh/kg instead of 1.2.
[1] https://chemistry.beloit.edu/edetc/SlideShow/slides/energy/d...
It's still a problem, but batteries can already do a lot of heavy lifting (and pulling).
[brackets mine]
But the best batteries contain unacceptably high levels of cobalt. Practical EV batteries are made with nickel or iron, maybe vanadium someday, and have lower density than pure LiCoO2.
>CATL is already producing a ton of batteries, lending them some credibility.
A couple of years ago CATL claimed that they had figured out how to make durable sodium-ion batteries with a ferricyanide cathode, to be released in 2023. The press cheered about the end of lithium dependence.
Yesterday, not long before this announcement, it was revealed that CATL's "sodium-ion" battery contains lithium:
https://cnevpost.com/2023/04/20/catl-byd-sodium-ion-batterie...
"CATL and BYD's sodium-ion batteries to be put into mass production will both be a mix of sodium-ion and lithium-ion batteries, according to local media."
[sad trombone noises]
> CATL and BYD's sodium-ion batteries will both be carried in mass-produced vehicles within the year, and they [the vehicle battery packs] will both be a mix of sodium-ion and lithium-ion batteries, according to a report by local media 36kr today.
By my reading of that, and the rest of the article, it's saying that the vehicle battery will be assembled from of a mix of sodium-ion and lithium-ion battery cells, not that the sodium-ion cells contain lithium.
> With its pioneering AB battery system integration technology, CATL has achieved a mix of sodium ion and lithium ion, allowing them to complement each other and thus increase the energy density of the battery system, Huang said at the time.
Basically, a "battery system" using only sodium-ion cells does not yet have enough energy density to support their range targets, so they are using a mix of cell types to improve the energy density and increase the vehicle range.
And nothing wrong with having some lithium in their battery. The important thing is how much cheaper is it.
This has a lot of potential coming from CATL. However, there is no mention of price. I'm betting this is going to be very expensive.
At least these guys are announcing production.
News articles on breakthrough discoveries are mostly bullshit and even when they aren't, most of the time they don't affect my life in the slightest because the tech is impractical or expensive.
It may be interesting to read about science discoveries, but I don't want to take the time to sort out the bullshit from what's real just to find out that the breakthrough is irrelevant to me and society at large.
(This is especially frustrating on the EV conversion front, since the best parts are usually unobtainable except from salvage vehicles. The products specifically made for EV conversion are usually rather underwhelming compared to what the OEMs can get.)
Obviously jet fuel is what it is it wont get more dense but a more efficient engine means less fuel needed means even more efficiency and so on.
This allows the plane to land at Brisbane and refuel if the calculations are done wrong. Couldn't find stats on how many times it's had to land in BNE.
Pre-COVID, it was apparently common to try and off-load passengers to single stopover flights to reduce fuel needs (I was one of those passengers, and the crew confirmed it was a regular occurance).
Your car may not need this as much, an aircraft does.
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A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg, which is 13.2 km/l or 15.3 km/kg. Diesel has a mind-boggling 12700 Wh/kg energy density[1], which translates to an efficiency of ~827 Wh/km for the Chevy.
By contrast, the Tesla Model S, has a ~540 kg battery[2]. At 272 Wh/kg (from the posted article), that's ~147 kWh of energy storage, and the Tesla can do a rated 650km on a single charge[3]. So that's an efficiency of ~225 Wh/km, which is ~27% of the energy required to run a normal car!
It just wouldn't have been possible to run cars on batteries without this efficiency bump.
1. https://chemistry.beloit.edu/edetc/SlideShow/slides/energy/d...
2. https://blog.evbox.com/ev-battery-weight
3. https://www.caranddriver.com/tesla/model-s
So when you look at the headline "efficiency" of an electric car, you need to take that thermodynamic penalty into account first.
A modern series hybrid like a Toyota Prius is effectively an electric vehicle and a gas generator (which means it has the same efficiency gains due to regenerative braking). That gets 52 mpg, which is about 493 Wh/km. If you generated the 225 Wh the Tesla needs in even the most efficient combined cycle gas turbine powerplant you'd need 375 Wh. Less - but not nearly as drastic as it first seems.
Renewables change the picture though - once you have significant renewable generation the carbon intensity of electricity starts dropping, which means that remote powerplant vs local powerplant argument falls apart. That is when the real power of electric vehicles kicks in - they can take their energy from anywhere.
It is surprisingly difficult to get numbers on how much oil is used to extract, refine and transport oil.
The best I found was this:
https://www.speakev.com/threads/energy-required-to-refine-oi...
Does anyone have better numbers?
I fell down a rabbit hole and found this link, which gives 46% for the theoretical limit for the efficiency of the internal combustion engine.
https://physics.stackexchange.com/questions/98966/maximum-th...
While ICE are heat engines with a theoretical limit of 70%, they’re more specialised subsets described by the Otto (gas) and Diesel (… diesel) cycles, which have a much lower theoretical maximum.
Just plugging the temperature ranges into Carnot will give you a Carnot limit of 50%, and using Otto will yield 46% (https://physics.stackexchange.com/a/98992).
Add in that gas engines are not spherical and into a vacuum (losses and delays) and you’re in the 30s.
Generation can be from clean sources and is already happening in some jurisdictions.
Even if a clean source is not available, the pollution can best be controlled at the source. In this period of history, hundreds of millions of people make billions of polluting trips every day in their communities.
Although owning any car is the poorest choice of all for the environment, there are two ecological benefits to driving a BEV or a PHEV.
ICEs are most efficient under medium-low RPMs and high load. The electric motors can sustain low speed cruising, letting the engine shut off entirely if it wouldn't be well utilized, and also fill in for high torque demand to keep engine power output lower.
Wait, does a new prius or something like a hyundai ioniq (also 52-53 mpg) not have the internal combustion engine mechanically coupled to the transmission and drive wheels anymore?
Anything that doesn't require charging directly from the grid all the time, because although parts of the USA and Norway are ready for that, it's very tricky to get right globally.
Maybe hybrids like the Prius get to be so efficient that such cars will have a truly negligible impact on global warming.
Just to expound on this. Power stations turn fuel to heat, and heat to electricity via steam turbines.
In ICE cars, that heat is the main loss of power. Whole systems in cars are built to get rid of that excess heat in the engine.
How close/far would you say we are as a society on "having significant renewable generation"?
You mean thermal energy?
Both cars are converting chemical energy to kinetic. The theoretical maximum for this is 100%. But one uses a thermal intermediate step, that reduces that maximum.
Yes it usually is
My diesel 3 series (2.9 litre, late 90s design) would get 8.83 L/100 km (32 mpg UK, 26 mpg US) driving round town, stopping at traffic lights and averaging <20 mph and never getting past 3rd gear. This didn't require much care, just a question of not trying to accelerate too hard at low RPMs or doing a 0-60 run from every stop.
Engine technology will presumably have moved on in the past 25 years, and efficiency will have improved, but you'll still get crappy fuel economy for stopping and starting all the time.
https://www.advantagebmwhouston.com/2022-bmw-3-series-fuel-e...
Well, my 12 years old (gas) Honda Fit does +40MPG being very "pedal happy" and near 50 driving normally, and my dad's 20 years old (diesel) Citroen Xsara Picasso does around 60MPG
Very few people check the facts, and the only reliable way to know yourself is to take notes at the pump: gas pumped vs km travelled. I did check for a while and the numbers were quite different :-)
On a related note, for the VW ID.4, the manufacturer states 17kWh/100km which is actually achievable (much to my surprise) in city driving when it isn't cold. My real numbers are closer to 21kWh/100km. This goes up really quickly if you exceed 130km/h.
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Electric motors are very efficient, regenerative braking helps, EVs are designed to be super aerodynamic, etc.
Particularly German made ones, for some reason.
Gasoline is rather energy dense, but the ICE is rather wasteful. There is a certain base load of energy being generated by an ICE engine, regardless of if you are moving or how slow you go. This is why carmakers experimented with things like rapid stop/start engines, regen batteries&motors, etc.
ICE becomes more efficient as you reach highway speeds, which is why highway mpg is better than city mpg.
Batteries by contrast are not very energy dense, while EV motors are extremely efficient. The only energy being consumed is that which is needed to move the car, plus fight rolling & wind resistance, and power AC/heat. Wind resistance increases with the square of speed.
EVs as a result are most efficient at low speed, and at highway speeds become noticeably less efficient as you go from 55->65->75mph. This is also why running AC/heat has a noticeable impact on range in EVs.
An ICE car traveling at a constant 30mph is going to get much better fuel economy than an ICE car traveling at a constant 75mph. The difference is that <=30mph roads usually have a lot of stop-and-go.
Teslabjørn has a video where he turned his Model X into a sauna getting 40⁰C inside while it was -10⁰C outside.
The 3 and Y is even more efficient, mostly due to size. But it has a smaller battery, I can get about 69 kWh out of my AWD 3 after losses and it hovers around 170-180 Wh/km at 120 km/h and 130-140 at 90.
Are American diesels this inefficient?? Looking at pictures online the Chevy cruze doesn't seem like a bigger/heavier car than a Passat, so what gives??
Even my 15 year old diesel car had an efficiency of 1/22. Adjust you driving style and I'd get 1/25. Range: 1000km, with an ordinary sized tank.
It seems Americans haven't even started with efficiency, quite likely because there was no pressure to do so due to low fuel prices. Not in their homes, not in their cars, not anywhere.
Although I completely forgot it existed. There are not many diesel passenger cars on US roads. Diesel is consistently more expensive than petrol here.
Meanwhile, fairly common cycling parameters lead to well under 10 Wh/km at comfortable cruising speeds, and with things like velomobiles you kinda start around 5 Wh/km, and 3 Wh/km is possible without significantly compromising the practicality of the vehicle.
Sure, sure, lower speeds, lower cargo capacity, lower safety, &c. &c.
But it’s still a useful comparison to contemplate, especially when considering the nascent category Lightweight Electric Vehicles, which in its most interesting form isn’t far off “ebike minus pedals”. Cars are still pretty power-inefficient as a general concept.
All that extra energy ICE cars carry isn't actually being put to use very well. They don't have more powerful engines. They don't have more torque. They don't have more acceleration. And even their range isn't that much better. You can of course get models that take something like 100+ liters of petrol. But the per liter performance only gets worse if you do that (heavier cars are less efficient).
The reality is that yes, fuel is very energy dense but sadly most of that isn't transformed into motion when you use it. You are instead making lots of noise (vibrations) and heat. Both are actually bad for your car. So, you use most of the energy to wear out your car faster. The more powerful the car, the less efficient they are. And the faster they break down.
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For diesel, this is really really bad. Most gasoline cars will run more economic than this, let alone diesel. If your diesel runs less then 17 to 18 km/l something is wrong.
(my opinion is based on how things are in .nl, other parts of the world can and will be different of course)
Not a mark against EVs of course - it kind of just makes sense. I'm sure future generations will laugh that every vehicle used to have its own on-board power generation facility. It's too bad the dumb power-plant-under-hood way is still so much cheaper than the EV approach of course.
https://www.caranddriver.com/news/a15341744/the-prince-of-pa...
Earth's Lithium deposits.................. 88,000,000,000 Kilograms [2], [3]
@25% Viable for mining.................... 22,000,000,000 Kilograms [2], [3]
Tesla S battery weight.................... 540 Kilograms per car [4]
Lithium weight per Tesla S battery........ 63 Kilograms per battery [4]
Max Tesla S (global) production possible.. 349,206,349 units (See Edit below)
Number of automobiles running in the USA.. 102,000,000 units [1]
Number of automobiles running in the World 1,500,000,000 units [5]
So, even if we theoretically assume that the earth's entire known Li reserves are used for EV usage, we cannot replace more than 25% of the currently running cars in the world.
So, we have a bigger problem ahead of us (over the next decade) that will act as an opposing force against EV penetration and replacement of the IC engine.
Solutions possibly lie in exploring other battery chemistries while improving the efficiency of Li extraction.
Edit: As some of the comments below point out, the Li content in a Tesla Model S battery is approx. 63 Kg. That makes the Max Tesla S (production) possible to 349 million units. So, in theory, one could replace all IC engines in automobiles plying in the USA. That then leaves the rest of the world. So, the problem still remains.
[1]: https://www.fhwa.dot.gov/policyinformation/statistics/2021/m...
[2]: https://www.popularmechanics.com/science/energy/a42417327/li...
[3]: https://www.usgs.gov/centers/national-minerals-information-c...
[4]: https://blog.evbox.com/ev-battery-weight
[5]: https://www.weforum.org/agenda/2016/04/the-number-of-cars-wo...
I'm also going to say that all the car companies, battery companies, and governments in the world probably took six seconds to do basic math before investing trillions of dollars in it.
https://blog.evbox.com/ev-battery-weight
Even if they couldn't, why would you limit your analysis to Li-based batteries? It's basic economics that when a resource becomes rarer, it becomes more costly and alternatives spring up. EVs with Sodium batteries are already on the market in China. This whole Lithium fear mongering is such a red herring.
A quick google returned this ~63KG
https://electrek.co/2016/11/01/breakdown-raw-materials-tesla....
Emphasis added from your [3].
Ever think maybe your 88,000,000,000 Kilograms number isn't actually all the lithium on the planet, and maybe there's more undiscovered under the ground? Or do you think all the lithium on the planet was discovered in 2023, and now there won't be any more reserves found?
Strange how this maximum amount of lithium reserves keeps magically growing year over year over year over year. I wonder how it magically appears.
Having said that, my 13-year-old normal sized diesel car does 60mpg in normal use.
Luckily, most people don't charge their teslas with coal power.
It would be slightly worse in colder climates. I wish car manufactures would allow for easy installation for range extenders in the front trunk. I'd be a great source of heat for the heat pump. Range anxiety would be gone. No carbon tax since it would be an aftermarket solution.
It seems Mazda MX-30 r-ev is the only thing you can buy.
Range anxiety is an affliction more common among those who do not drive an EV than those who do.
This is because you're not comparing the same things: going from thermal energy to mechanical energy has a much lower efficiency than going from electricity to mechanical energy. But that electricity has to come from somewhere, and most of the losses happen at the electricity generation place instead of in the car.
> It just wouldn't have been possible to run cars on batteries without this efficiency bump.
Electric motor have always been far more efficient than ICE ones, even in the 19th. In fact, the difference was even bigger, because combustion engine sucked hard back then, whereas electric engine didn't make as much progress as combustion engine ones (that doesn't mean that they didn't make progress, they did, but there's far less of a difference between an electric engine of 1920 and the one in a Tesla, than between an ICE engine then and now).
The difference is like the difference between carburetor engines and direct fuel injection.
We should measure efficiency based on that number.
On top of that, they have more efficient components. When you compare a model S to a lightweight Carbon Fiber BMW i3, with a much smaller pack, you’ll see that the modelS still squeezes out a higher mpgE rating.
https://www.fueleconomy.gov/feg/Find.do?action=sbs&id=46207&...
The problem is that at that point liquid hydrogen already spent 70% of the energy stored in it (80% efficiency of electrolysis * 40% liquefying efficiency) .
The measurements outside North America are reciprocal, e.g. 7.7L/100km (which is awfully inefficient for a diesel, normally it should be around 5L)
So converting gallon to liter, and mile to kilometer is the wrong way to present it.
As for the efficiency in general - of course electric engines have a very high efficiency (in the 90s), unlikely diesel which can barely hit 35%.
It's better to use real world highway range which is 300 miles (482 km) in a Model S:
https://insideevs.com/reviews/443791/ev-range-test-results/
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That's not very good, my LPG car runs on average around 25km/l and around 30km/l on gas, albeit being a 10 years old model.
Modern diesel cars run on average at over 20km/l, the Citroen C3 does ~30km/l.
Porsche Taycan: 2 miles per kWh
Tesla Model 3: 5 miles per kWh
Lightyear Zero: 7 miles per kWh
Aptera: 10 miles per kWh
Source: https://www.youtube.com/watch?v=mpiH-Y-HOvE
The Aptera gets 0 miles on a 0 kWh battery because they've shipped 0 cars, right? Can I go buy one and drive it today?
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Still, your point stands.
This of course doesn't include losses in transmission from the power station and in electricity production.
mpg = miles per gallon
There are other approaches to Li-S (and Al-S and Mn-S) which will be less expensive. Grats to CATL for bringing this to market, but the race for sure isn't over yet.
It would weigh 1/3, not 1/3 less.
Get ready for passenger drones[0], delivery drones[1] and just drones in general, because this is what this breakthrough means really.
[0] https://www.youtube.com/watch?v=lw6HDgv4ekE
[1] https://www.youtube.com/watch?v=DOWDNBu9DkU
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The claims about new battery chemistry are rarely farfetched or inaccurate, but we as a society (and especially the reporters) don't do a good job of interpreting the claims, focusing on one promising sounding parameter and neglecting all others.
The manufacturers are also not helping by omitting this sort of critically important information that you have highlighted (lying by omission).
Seems like it would still annihilate the payload/range.
- 130 kW engine, Lycoming_O-360 that weighs 117 kg. For comparison, an electric motor of this range would weigh 11-13 kg (at 10-12 kW/kg, [2]). That saves 100+ kg weight immediately and we can put 50+ kWh batteries instead.
- It carries up to 200 liters of kerosene ([3]), which weighs 164 kg. We can place 82 kWh of batteries instead.
- The engine consumes around 30 liters/hour ([1]), which gives us ~6.7 hours of flight time or the equivalent of 6.7*130=871 kWh for an electric-power plane.
- The fuel tank weighs about ~14 kg (source: an LLM, sorry) and gives us another 7 kWh.
So, we can put 50+82+7=139 kWh. By using modern materials, we can probably increase it to ~180 kWh, which will give us about 1.5 hours of flight time / 300 km range. This is much less than 6.7 hours, but quite practical for recreation and short flights. And it would be much cheaper to run too.
That said, still not practical for medium and long flights.
1. https://en.wikipedia.org/wiki/Lycoming_O-360
2. https://cleantechnica.com/2021/03/25/groundbreaking-h3x-moto...
3. https://www.globalair.com/aircraft-for-sale/specifications?s...
4. https://en.wikipedia.org/wiki/Cessna_172
I also think taking out the weight of the tank is unfair if you don’t add weight for the structures for holding the batteries.
But yes, for many smaller planes, we’re close to flying electric on shorter flights being economically feasible.
Electric aircraft of the future will have half the drag or less. High aspect ratios, flush fairings, streamlined cockpits etc.
Perfectly agree with everything, but 1.5hr may be very short if you need to have 30 minutes of reserve at landing. On the saving side, you don’t have to have an alternator to transform ICE energy into energy for the dashboard instruments. On the downside, you now need to heat the cabin manually, rather than reusing the ICE heat.
https://en.wikipedia.org/wiki/Pipistrel_Alpha_Trainer#Alpha_...
324 nmi range for the regular variant. Around 65 nmi for the electric version.
This is with older batteries, probably with very bad pack-level energy density. The battery pack can even be swapped. Great to avoid having to wait for charging, but probably terrible for weight.
If you design the aircraft for electric flight from the ground up (see Maxwell X-57 for how you could do that), with a structural battery pack, and with 300-500wh/kg batteries, I'm willing to bet a 2-5 times increase in range is viable.
Consider the Eviation Alice, one of the 9 passenger prototype electrical planes that is currently undergoing test flights (i.e. it definitely works). The advertised range is 250nm. Not amazing. But far enough for a lot of regional flights.
What would happen if you double the battery capacity without increasing the weight? You more than double that range. This is counter intuitive until you realize that you are not going to need more energy for taking off, or reserves. All that extra energy goes into extending cruise range. So you get more than 250nm extra. Basically, it's probably getting closer to 600nm. That's still not amazing but there are a lot of flights every day that are much shorter than that. All of those are now doable with electrical planes. At a fraction of the fuel cost.
Most flights are short haul. And they are, well, short. Which means, all of those are in scope for electrical planes. Small planes work well for these too. You don't have to cram hundreds of people in a plane if you eliminate fuel cost as a major cost factor. That's the only reason we do that. It's not like it's pleasant or comfortable. 20 ten passenger planes can do the work of one passenger jet. But it can do it more flexible and cover more destinations too.
Electrical planes are not about doing exactly the same things that we do with traditional planes but about doing a lot more than that. Basically, less noise, less pollution, less cost, means that a whole lot of flights that would be considered decadent and obscene right now become perfectly feasible and reasonable. A ten minute hop across town. Why not? Live 70 miles from your office? Not a problem, you commute there in under 15 minutes. For the price of a few cups of coffee.
Exactly. In the EU, Eurocontrol (European Organisation for the Safety of Air Navigation) says 30.6% of flights in 2020 were 0-500km, roughly within the range of the Eviation Alice currently. A further 43.6% of flights in the EU are between 500 and 1500km.
Source [1]
> You don't have to cram hundreds of people in a plane if you eliminate fuel cost as a major cost factor. That's the only reason we do that.
Not only. Gate capacity and runway capacity is an issue too. But that might also be easier to resolve with smaller electric planes. E.g. there's Liliums approach of vertical takeoff from little more than a helipad-sized platform, but even non VTOL planes capable of taking off from short runways would be helpful.
[1] https://www.eurocontrol.int/publication/eurocontrol-data-sna...
OTOH, security costs and airport fees could be cut I guess?
https://en.wikipedia.org/wiki/Brake-specific_fuel_consumptio...
Where did you read that kerosene is at 3000Wh/kg? My googling says 12,000Wh/kg
The tweet thread from TFA and its replies just says that for aircraft, weight impact is important. See https://twitter.com/__bdimitrov__/status/1298753593638440960:
"260 to 400 Wh/kg should lengthen flight time by 90.8% --- assuming that 100% of the drone weight is from the battery."
But going from 400 to 500 Wh/kg adds another 39% on top of that, so 2.6x longer total
They don't make sense for general aviation planes that are usually a fifty year-old engine design that requires expensive overhauls and guzzles expensive fuel wrapped in a bit of aluminum.
That paper also sketches out the argument for electric flight at close to current battery densities rather than close to kerosene energy densities. It goes:
Jet fuel gets roughly 28% final efficiency while electric gets roughly 90%, so divide jet fuel by 3 to get 4,000 effective Wh/kg.
Alternate aerodynamic designs and especially distributed propulsion are much more achievable with electric engines. Imagine the difficulty of making a 14-, 24-, or even 36-turbine aircraft, yet all of those have been built and flown with electric engines already (https://en.m.wikipedia.org/wiki/NASA_X-57_Maxwell, https://en.m.wikipedia.org/wiki/Aurora_XV-24_LightningStrike, and https://en.m.wikipedia.org/wiki/Lilium_Jet respectively). Gains of 3-5x have been observed here and higher is predicted, the conservative mean is 4x, so divide again by 4 to get jet fuel to 1,000 effective Wh/kg.
That is getting close to current energy densities of batteries. You only need to find one more ~2x improvement that electric flight can obtain over jet fuel to bring it into the range of 500Wh/kg, which CATL is saying they have in production right now.
(Presumably Musk’s magic 400Wh/kg number involved another 2.5x improvement, though I don’t know where specifically he thought it would come from. The internet seems to think he said you can go higher because you don’t need oxidizer from the air to burn jet fuel, but that doesn’t sound right since you still need to push on the air with your fans and you’ll run out of that at high altitude before you run out of oxygen, so it must be coming from somewhere else. Regardless, the point is that jet fuel imposes design constraints that trap you in a local maximum of aircraft efficiency, and electric engines allow you to explore a wider space which may have much much higher maximums.)
90% likely doesn't include the efficieny of the prop?
[1] https://www.alexander-schleicher.de/en/flugzeuge/as-34-me/
[2] https://www.lange-aviation.com/antares-serie/antares-21e/
Planes tend to be very expensive to operate, due to maintenance and fuel costs. Some people would be happy to trade range for dramatically lower operating costs.
This is simply not true with electrical planes. A mega watt hour of power is about 60-100$. And much cheaper than that with renewables. Not at retail prices of course. But if you consume power by the mwh, you'd be investing in your own generation (solar + storage) pretty soon. A mwh is about what you need to move a small electrical plane a few hundred miles. The kerosene cost for a similar journey in a small jet is going to be hundreds of dollars, even for a small jet. The smallest jets burn 50-100 gallons of fuel per hour (in cruise). Depending where you get your fuel, that ranges from 3-5$ per gallon. That's why small jets are only for rich people. Even a very short flight sets you back hundreds of dollars. A simple propeller plane is cheaper. But we're still talking 5-10 gallons per hour. That's why people talk about 100$ hamburgers. Because that's what it costs to take your tiny plane out to grab a burger somewhere.
Big big jets are a bit more economical with fuel than small ones. But they only makes sense if you can distribute fuel cost among many passengers.
With electrical, you can use lots of smaller planes cost effectively rather than having to put lots of people in a few bigger ones. For the same reason, you don't need big airports either. Or worry about pollution. And even the noise of small electrical planes is not as much of a problem. And with autonomous flight, we won't even need pilots long term. Small electrical planes are good enough and much nicer for passengers, more flexible to operate, etc.
As they scale production of these, hopefully they can get 20% additional improvements at the cell/pack level, reaching potential to replace the most common flights.
tl;dr for their small kit aircraft the weight of batteries they would need to match the stored energy of equivalent fuel (even with a battery at 500wh/kg) would be 5-10x heavier, and also not get lighter during the flight. They said for long range it doesn't make sense, but that there are lots of companies iterating in the short range electric space.
- [0] https://www.youtube.com/watch?v=LdSnHQtoVTI
For the first years it will probably only be a few wierd, short routes in rich countries like Norway with 110% financial support from the state. But when they can safely fly 5-600km there is a actually quite a number of routes with a lot of passengers out there.
1: https://en.m.wikipedia.org/wiki/List_of_busiest_passenger_ai...
These batteries, if they deliver on the advertised specs and aren’t too expensive should make short-range electric aviation possible.
The electric air taxis that Joby and others are working on suddenly have a lot bigger margin to work with, as do electric regional airliners.
(They actually planned to go all the way to 350MW, which could theoretically run a transatlantic passenger jet with 2,000 passengers, assuming it’s even possible to build such an airframe.)
Still, an announcement from a big company like this is a lot more credible than from research labs or small start-ups, IMO.
Their main energy density boost is a silicone anode, which we've known "for ages" that it leads to higher energy density, but soaking it with lithium degrades the material very quickly, leading to cracks and thus damage after just a few charge cycles. The main innovation is some kind of nano-structuring of the anode, and that technique was published in the scientific literature in 2006.
I'm sure it was hyped as a battery break-through in 2006, and it has taken 17 years to get to market.
So, maybe we shouldn't go back 5 years, more like 20 years (OK, no HN back then :D).
Batteries do get better over time, fairly consistently so. The development lifecycle is just soooo much longer than in software.