Back in 2003, President George W. Bush announced the Hydrogen Fuel Initiative. At the time, people criticized the effort as an attempt by the oil industry to shift attention away from electric cars. The oil industry knew that hydrogen power wasn't going to be viable anytime soon, while electric cars were already a direct threat to their profits, so they pushed the US government towards hydrogen power.
Not to disparage the talented scientists and engineers working on hydrogen power, but now that 20 years have passed I believe it was designed to fail.
Huh. I kind of thought that batteries had comprehensively won in this market, tbh.
I still can't quite get used to the electric buses. A 20 tonne double-decker bus should sound like it might explode at any moment; it is unnatural for them to move around more or less silently.
In Tompkins County we were early adopters of the electric bus, at least for the American market. We bought them from a startup which had trouble with the structural aspects and eventually they fell apart
Five months before the company filed for bankruptcy, Proterra's CEO was appointed to the President’s Export Council (PEC), "the principal national advisory committee on international trade."
Batteries have won this so hard (if you ignore CNG busses, which have existed forever and are "almost as good as hydrogen could be") - because even when they hadn't won it, you just needed more busses.
Is it nice if the bus can do a driver's entire shift without a recharge? Sure! But if it can't, you just design the route so that the driver can switch busses and buy another bus. That means the technology problem is now a money problem.
Busses are also already quite heavy, so battery weight doesn't affect them as much as it might in a small car.
The stop-start nature of city busses makes them a real low hanging fruit for battery electrification, benefiting from instant torque to start and regen to stop and, as you say, fixed known routes within larger fleets.
The only nation that seems to have capitalised on this basic fact is China which bootstrapped its EV industry on busses, pulling ahead from 2010 and hitting 90% of global market share for EV busses in 2020, and now a big exporter.
For the same reason the electric mail trucks are a good idea. You can probably expect UPS and FedEx to start replacing their fleets over time as the existing vehicles age out, now that all electric vans are starting to become available.
(At least in King County Metro) the newer diesel-electric buses are series hybrids that use electric motors for traction, and diesel generators to power a small battery. So the low hanging fruit of electric traction was already “picked”. You can look up the bus model online - New Flyer XDE class
> But if it can't, you just design the route so that the driver can switch busses and buy another bus
Oof, that's a huge 'just' in many cases.
That said, current electric buses have sufficient range that this mostly isn't an issue. The unnervingly silent double-deckers I mention have a claimed range of 320km, which, at least here, is sufficient.
The big problem with Dublin's electric buses, ridiculously, was that the operator was late in applying for planning permission for the substations required to charge them. With the result that for about a year, there were about a hundred of them stored and unusable.
This depends a lot on local climate and topography.
Seattle has kind of been a bust with them because the hills really reduce the amount of charge, and on top of that the existing bus depots are already full, so switching to electric only would mean having to find and locate space for more bus depots, which is quite difficult.
Hills should never reduce the range, because the energy lost during climbing up is recovered when going downhill.
This is one of the great advantages of electric vehicles with batteries, when properly designed.
Electric buses with batteries are even more suitable for cities with hills than for cities without hills, because they provide greater energy savings over buses with ICEs.
While I have never used buses with batteries, I have lived in cities with electric trolley buses. Even with the primitive technology of many decades ago, they were doing great in cities with hills, recovering most of the energy when going downhill, unlike the buses with ICEs, which had excessive fuel consumption because of the hills.
Regenerative breaking is not perfectly efficient, so you may loose a significant portion of the additional energy needed. Better EV systems are what, 70-80% efficient on the breaking efficiency?
Okay, but gasoline is far more energy dense than batteries and a gas tank is a whole lot cheaper than a battery pack, so vehicles can have a gas tank big enough that that doesn't cause range problems. I don't know about buses, but you can buy a pickup with a 48 gallon tank. Even after assuming only about 1/3 efficiency, that's still equivalent to some 500 KWhr, which is several times more than any consumer EV I'm aware of.
That's efficiency, not range. Suppose hilly terrain reduces range by a third for electric vehicles and half for diesel. The diesel bus just fills up twice as often. The electric bus needs a 50% bigger battery in order to finish the same route without stopping to charge, and then it becomes 70% because it has to lug the bigger battery up the hills.
You can just... do that, but that doesn't mean it's not a thing you have to do, and it's not free.
It is impossible for a hilly terrain to reduce the range by a third for well-designed electric buses.
The efficiency of regenerative braking increases with the power of the vehicle. The electric efficiency should be well over 90%, perhaps even 95%. The mechanical losses will lower the total efficiency to much smaller values, but even so, the total efficiency should be over 80%.
A bus with an ICE will consume 5 times more extra energy for climbing the hill and it will also consume energy while going downhill.
Values like a 50% greater battery are unrealistic, and a heavier battery adds much less to the consumption than by how much it is heavier, even when going up the hill (because most of the extra energy consumption is also recovered).
In a certain city, it may happen that the bus routes are so long that batteries are not competitive with ICEs, at least for now. However, the presence of hills in any city can only make electric buses more advantageous, not less advantageous, due to much greater cost savings for fuel and maintenance. Buses with ICEs that are operated on hilly routes also need extra maintenance, besides increased fuel costs. Well-designed electric buses do not care whether they are operated in conditions requiring higher torque.
Regenerative braking is nice but as sibling pointed out it doesn't nearly recapture everything. Another factor is that the additional load whether accelerating up a hill or braking down one puts more current through the system. In fact nearly every part of the drivetrain will experience accelerated wear under those conditions, mechanical or electrical. Cooling systems, too. Properly spec'd, it's of course very doable, but it's true hilly terrain is more difficult.
This is a weird multi-paragraph evangelical lecture seeing as any EV owner that’s driven in a hilly climate will tell you that this isn’t how things work.
Many bus routes have a 5-10ish min break at some point (usually the main station) in the route. If you can utilize those ten minutes to do a top-up, you can go a lot further on the same sized battery.
No bus route should be more than 15 minutes between full and empty. That is you start at some station, go 15 minutes, then turn around and go back. There are many systems that attempt to do more, but there is no point: people have places to be: on the bus is not on that list. That 15 minutes means an average of 7 minutes, now they walk to some other express bus that gets them nonstop (at faster speeds) to someplace, but you still only get 15 minutes to get there before it isn't worth the bother, than 7 more minutes on some other bus. Add in 5 more minutes of walking time (and transfer time!) and we are at 45 minutes - this is unreasonably long for normal trips already, but it is the best you can do!.
In short there are plenty of places to switch buses if you need to.
There are two critical aspects to the bus routing problem. One is that no matter how well you design your system, there is always variance in the arrival times of a bus at any given stop. If you expect people to switch buses, then you need to account for this variance, and this means adding buffers. Nothing makes people stop using buses faster than missing your connection because your bus was late.
The other aspect is the what city topology you are dealing with. In square grid cities, you can probably put a tram on every road, and with one switch over, get to where ever you need to get to.
But many organically grown cities end up using the hub-and-spoke model, where there are main stations where many different buses meet. People switch over to the next connection (and you need a buffer here). Critically, you need all the buses to meet at roughly the same clock time, say every 30 min. Now, one thing you realize immediately is that not all routes are equal. One route might be only 25 min, Either you make it longer and waste fuel, and time for everyone sitting on the bus, or you wait an extra 5 min at the main station.
Bus scheduling is very difficult problem in real cities with weird topologies and real traffic issues. Buffers are a necessary part of any reasonable solution.
I'm coming from a different perspective: regardless of all else (all those issues you raised are very real), people need to get where they are going in a reasonable amount of time. Most bus service fails to account for that, but if you can't get people there in a reasonable amount of time there is no point in trying.
Sorry, but, what the hell? This is Hacker News at its finest: completely talking out of its ass.
This isn’t how bus routes work, and this isn’t how people ride busses, on most if not all of the…many PT systems I’ve used in multiple states / countries.
There is a reason people complain about buses and prefer to drive in so many cases. Operators try to compromise on cheap and end up with service for those who after 5 DWIs can't get their friends to drive them anymore.
CNG buses were about a 10-year experiment in Toronto. There were a number of bus terminals where CNG vehicles were prohibited, either due to clearance or because of the associated explosion risk.
A second batch of buses were converted to diesel so that the fuelling station could be decommissioned.
Why do transit agencies keep falling for hydrogen busses? From the perspective of the US, it’s pretty simple:
1. Transit agencies have no way to reasonably validate what the future holds. From the standpoint of today, a hydrogen bus can be expected to replace a diesel bus 1 to 1, while battery electric is a 2 to 1 replacement. This might not be a huge issue except:
2. FTA regulations have strict requirements on how many spare busses may be kept at any time (defined by the ratio of peak vehicle usage vs the size of the overall fleet), doubling the size of the fleet blows this ratio out of the water.
3. It doesn’t matter what BYD offers or what’s possible in China, US transit agencies are required (FTA regs again!) to buy busses made in the US. American manufacturers do have somewhat decent battery electric products, but they are clearly not at the leading edge. With the proterra banktrupcy, there are limited competent suppliers in the market. To a large degree, gillig et al do get to decide what gets pushed into the market.
Answer to the question: political reasons and lobbying.
Hydrogen is produced by the big oil and gas companies. By pushing hydrogen vehicle instead of battery electric vehicles they stay in business.
They market hydrogen as a green alternative to oil, although most hydrogen is currently produced from fossil sources, and this won't change soon (next 10 years).
Transit agencies don't have the technical expertise to distinguish truth from lies in cleantech marketing. They aren't the only ones, see the over-inflated valuations of both Nikola and Tesla as two (very different) stories of companies successfully lying to investors and the general public about the magical capabilities of their novel transportation platforms.
I've ridden both hybrid and electric buses and I prefer the latter, as those huge engines still produce a lot of vibration.
I drive a Toyota hybrid and while it's a step up from a purely combustion propelled car, I still have to do oil changes and its fumes still smell bad when it's running rich for whatever reason.
(At least in King County Metro) their newer diesel-electric buses are series hybrids that use electric motors for traction, and diesel generators to power a small battery. The drivetrain seems smart but maybe other agencies use it less? You can look up the bus model online - New Flyer XDE class
Here in SE Michigan, one local transit authority ditched its new hybrid busses and returned to diesel ~15 years ago - because the TCO for the hybrid busses was so much higher that fixing the hole in their budget proved impossible.
> The ideal drivetrain was invented over 20 years ago by Toyota and apparently nobody but me and Honda noticed it!
The problem is hybrid drivetrains are complex. You don't save anything on the complexity of a combustion engine and exhaust train (over 1000 individual parts that have to be machined at extremely low tolerances), but add a more complex transmission (it needs to be able to work with two distinct inputs) and an electric drivetrain on top of that.
It is worth it in terms of energy efficiency and acceleration stats since even a small electric motor can supply a lot of torque at low speeds until the high-horsepower combustion engine catches up (virtually all modern cars have a turbocharger that needs time to spin up), but it's technically challenging to actually build into a modern car design - unlike 90s cars with ample space available to stuff components in, in a modern car every cubic centimeter is accounted for due to crash resistance.
As a simple driver of cars, I've never understood why no one has mass produced an EV with a built-in generator. That would avoid the complexity of the hybrid drive train, allow easy plugin and short range electric-only travel, and could even be offered as an optional attachment. So what am I missing? Is the efficiency gained by the generator offset by losses through the EV system?
That is called a series hybrid and the reason they're not popular is that the power split device in common hybrids is simply better.
The power split device isn't an ordinary transmission, it's a set of planetary gears with a fixed gear ratio between three shafts. One goes to the wheels, the other two to the engine and the electric motor respectively. The ratio of the engine speed to the wheel speed is then set by the speed of the electric motor connected to the third shaft, which gives you a CVT with no belts, clutches, torque converters or even synchros.
The transmission is "more complicated" only in the sense that it contains electric motors. In every other respect it's simpler, more efficient and more reliable than an ordinary transmission. Meanwhile those electric motors mean you don't need a starter motor or an alternator because the engine can be started by the electric motor through the transmission and an electric motor is a generator when operated in reverse.
A series hybrid still requires you to have a gas engine with all that entails, but now the gas engine needs its own dedicated electric generator/motor and you can't deliver power from the gas engine directly to the wheels, so the traction motors have to be bigger in order to supply 100% of the torque used in acceleration instead of the gas engine and electric motors both contributing. That makes series hybrids heavier, slower and more expensive, so they're basically useless.
Most BYD PHEVs work like that - with the additional option of connecting the engine directly to the wheels via a clutch at highway speeds. I think Honda has a similar system.
This was the GM Volt, predecessor to the Bolt: https://en.wikipedia.org/wiki/Chevrolet_Volt GM ceased production in 2019. The answer to your question can probably be found there, but IIRC [from GM's perspective] the consumer market preferred ICE + battery over electric + generator, especially after the all-electric options came to market and siphoned demand from the latter.
It just turns out not to be worth it. The generator is a lot of weight to add, and a whole bunch of new parts to maintain.
It's a lot easier to add enough batteries to match the range of an ICE car. Range anxiety is largely manufactured at this point. The cars know how far they can go and where the chargers are. A gasoline powered generator would be a huge extra cost with no real upside other than averting a non-problem.
Edison Motors is working on a system like this. They're looking to sell kits for retrofitting it onto pickup trucks, & a larger scale semi truck cab version for use with logging trucks. It looks great in their videos, although I'm not sure if they're selling to the public yet - probably a ways to go before it's really mass produced.
That undersells it. The data on hybrid drivetrains is pretty clear--it's definitely more reliable. Even mechanics will tell you that; certainly mine did, and he's not a masochist. Start+stop is hell on mechanical drivetrains. It's a no-brainer when purchasing a new car except that there's still a premium for hybrid, so the RoI might not be there given baseline reliability and depending on your preferences. Though the premium gap is closing, at least for non-plugin hybrids. Plugin hybrids are the new premium option in model lineups, so traditional hybrids are moving down market.
My plugin hybrid (I just bought it 2 weeks ago) is on track to save me $200/month over the others similar vehicle it replaced (minivan with the same engine, but 10 years difference in years, so lots of other differences).
That goes for anything hydrogen and wheels pretty much.
It's actually pretty simple to figure out. Making hydrogen takes energy. You lose some of the energy making the hydrogen. This is not a fixable problem. At least not unless you break the laws of thermodynamics.
When you have created hydrogen, you lose more energy compressing the energy. Then you have to transport it to wherever it's going to be pumped into the vehicle ... both of which take more energy. Then it goes into a fuel cell, which loses more energy. All these losses multiply. And if you know your maths, you know that multiplying numbers smaller than 1 means the result gets smaller and smaller. These losses are significant.
And we're comparing it with putting the energy into a battery directly. It has inherently better round trip energy. Even if hydrolyzers, and the infrastructure to store, compress, and transport hydrogen were free (which they are not), using hydrogen would still be more expensive than that. Because it wastes more of the energy that goes in. So, in addition to the energy losses, you also need to deal with infrastructure cost. On top of regular energy infrastructure.
Anyway, that's all theory. For practice, just look at market price of hydrogen. Most of that stuff is of the dirty grey hydrogen variety creating that wastes a lot of methane. So much, that it would be cleaner to just use the hydrogen in a combustion engine in the bus and you'd have less CO2 emissions. Expending more methane to make hydrogen to have less emissions makes no logical sense.
If you are using grey hydrogen, it is more expensive per mile than methane. Nothing can change that. If you are using green hydrogen, it is more expensive per mile than battery electric. Nothing can change that either. That's just physics and simple economics. Yes there are some innovations in this space happening that reduce the gap a little. But it's never going to be enough.
Right now it's not even close. Unless somebody is subsidizing the hydrogen fuel, you'd be paying way more per mile than with diesel. And not just a little bit. And a common reason to switch from diesel to BEV is that it actually costs way less per mile than diesel. So, instead of saving money, you are spending more money.
Subsidies are hiding the true cost of hydrogen. That's the only reason there are some vehicles on the road. As soon as the subsidies dry up, hydrogen transport use cases evaporate. There are of course plenty of other use cases where hydrogen is needed that make much more economical sense. Using scarce and expensive hydrogen for transport is a poor use of resources. The utopian world where we have vast amounts of hydrogen surpluses does not exist.
If the goal is anything-but-diesel-or-gasoline/petrol, the use of propane (a fossil fuel that is a byproduct of oil and gas refining) is a well-understood, well-implemented practice. I am not advocating for propane as a primary solution, but rather as part of the journey towards truly clean vehicle emissions and the ramp-down of heavily polluting fossil fuel refining. Propane and the equipment to operate engines with it are available today, and we have the knowledge going back over a century to implement it successfully.
BTW, I wish I could find the article from the 1970s discussing how Ford Motor Company engineers had converted a brand-new 1960s Lincoln to propane and ran it with 100% synthetic motor oil, never changing the oil or filter. After 500,000 miles of daily use, they stripped the engine down to its parts and found it to be shiny and not exhibiting the expected amount of wear seen in usual engines of those years with much lower mileage. I'd have to pour through old magazines for that story, but life gets in the way, so let's treat my recollection as apocryphal.
There isn't any point to propane now. Electric busses got good enough to do the job. Propane reduces pollution, but the goal is to reduce CO2 emissions. Buying propane means buying electric in decade or two.
A local airport shuttle service converted some of their vans to propane. They told me the benefit is that they go about 3-4x longer between oil changes. (I suspect they aren't brave enough to go 500,000 miles.)
> Fuel cell buses do produce sufficient waste heat, but here’s the problem: it’s exceptionally expensive heat. Every degree of warmth comes from hydrogen — a fuel that’s costly to produce, store, and transport. Unlike diesel, heating with hydrogen’s waste heat is technically easy but economically painful.
Thanks, you beat me to it. While it is more expensive per watt, that's a sunk cost: you've already paid it when you were consuming the hydrogen to make the bus move.
Yeah, I just find the framing very weird. It's talked about as if it's somehow worse than diesel. But then isn't the issue that hydrogen fuel is less economical than diesel in general, regardless of whether the fuel is used for locomotion or for passenger heating? In the context of passenger heating specifically, waste heat is either free for both diesel and hydrogen, or equally non-free for both.
Also the article appears to be arguing for electric instead of hydrogen buses, but for some reason seems to try to frame "winter range" as being an issue for hydrogen buses specifically, and then says "electric buses face a different challenge" -- winter range.
I feel like there are two separate points that can be made:
- Hydrogen fuel is more costly than diesel or electric (not even sure how true this is, but it's what the article seems to indirectly imply).
- Hydrogen fuel doesn't have winter range issues the way electric buses do, but regardless electric is still better for other reasons.
The mechanism through which fossil fuel interests work is "grey hydrogen" which is hydrogen produced through processing of fossil sources with no eye towards carbon capture. Grey hydrogen is as polluting as just burning the fossil feedstock but works with an established hydrogen infrastructure.
This lets the producers "green wash" their production pipeline by stating in a lies-through-omission manner that their hydrogen is "clean burning". See no carbon out of the tailpipe! It's clean! It's the same lie as EVs claiming to be "green" in places where fossil fuel sources dominate electricity production. It's just moving the tailpipe somewhere else rather than eliminating it entirely.
There's also "blue" hydrogen that's manufactured with fossil fuels but claims/intends to capture the carbon produced in the process. It can still feed into a hydrogen infrastructure so fossil fuel companies love it due to the same greenwashing.
The only carbon neutral hydrogen is "green" hydrogen which uses a renewable source and electrolysis of water to generate hydrogen. But even that is wildly less efficient on net than just using renewables to charge battery EVs. Electrons are far easier to move long distances than hydrogen or hydrogen feedstocks (including water).
> It's the same lie as EVs claiming to be "green" in places where fossil fuel sources dominate electricity production.
This is just anti-ev propaganda.
First, its kind of a chicken-egg situation:
'its not worth going green for the power grid, all the cars are still ICE' 'oh its not worth building EV cars, the power grid is dirty anyway'.
Second, there are lifecycle analyses that show that even if your powergrid is entirely fossil fuels, EVs are still a win. This is because powerplants are really efficient in ways that a car engine can't be because of scale/weight. iirc the only exception was if your power-grid was still like 50%+ coal?
The electric airplane is another myth. There is no known battery technology, or one on the horizon, that can provide a large enough power/weight to make them practical.
I feel there is an unaddressed market for a hybrid gas/electric or diesel/electric powerplant.
Size the battery for takeoff/climbing/go-around/diversion use-cases. Size the fossil-fuel engine for cruising power, which should improve efficiency. During takeoff and climbing power, the two motors work together. During cruise and descent, the electric motor regenerates the battery. I imagine that for general aviation, you would maintain one propshaft and not even bother with a clutch pack, since the gas engine is needed in all phases of flight, and freewheeling an electric motor is simple. Perhaps have the fossil-fuel engine keyed to the shaft with a shearing pin, so that if the engine seizes, the electric motor still turns the prop.
This has the advantage that you now have two independent motors, which could eventually help with ETOPS rating, but would initially improve safety/reliability for general aviation.
Yes, you are still fossil-fuel dependent, but you burn much less of it, first by offsetting some takeoff energy to the electrical grid, and secondly by reducing reserve power in the fossil fuel engine to improve efficiency.
They use electric seaplanes at Harbour Air for regional flights across the Georgia Strait between Vancouver, Seattle, and Victoria. Electric makes a lot of sense for short-range flights.
No, the eBeaver has never flown a commercial flight. Harbour Air is aiming for certification in 2026. Additionally, it only holds four passengers and is more a proof of concept than anything else. It is a cool effort but battery technology needs to come a long way first.
Firstly: I'm a fan of Harbour Air's work and their electrification. Have flown that airline.
Retrofitting electrical flight to a 1950s airframe will be, in the long run, not a great use of the technology.
Those planes were designed around having a single heavy powerplant up front driving the propeller, and fuel largely distributed along the center of gravity (in the wings) so as not to adversely alter flight characteristics over the trip. The electrified Beaver stores its batteries in the fuselage; of course there is no change in mass/CG over the flight with electric, but all that fuel tank space in the wings is going to waste. The fact that these are floatplanes make charging/battery replacement tasks at the dock challenging and restrict options.
A clean sheet design, with multiple distributed smaller motors and more options for battery placement, will be a significant improvement.
They're great for trainers. Short hops with immediate control, low maintenance and operating cost, and you can save the magneto/ignition/etc workload for a different lesson series.
Edit: although maybe there's a good idea: catapult or winch launch for electric aircraft would massively reduce the power and energy storage requirements to be carried onboard.
Being constrained to a ship makes things harder though. If it was simply very long (runway length), I reckon an abort would be fine. There are probably a lot of different ways to do it.
But yeah, much harder than a regular runway. Probably not economical.
Really? The Beta Alia CX300 just completed a coast to coast journey (Vermont - Santa Monica). Range of about 338 miles using 200kwh of completely unremarkable ~150wh/kg batteries. With 500wh/kg batteries being announced from multiple manufacturers now, that range should improve pretty quickly.
> There is no known battery technology, or one on the horizon,
> There is no known battery technology, or one on the horizon, that can provide a large enough power/weight to make them practical.
Small aircraft are already there. I'm looking into starting my pilots license this year, the local flight school recently acquired an Elektra Trainer [1], that apparently has 2.5 hours worth of flight time [2].
Big transoceanic widebodies obviously will be fossil fuel based for a long time to come, but I think a lot of the GA market and bush pilot/island hoppers can and will be done by electric planes sooner than later - alone because the noise and lead emissions are all but gone, and I think that in a few years, when experiences on failure modes are a bit richer, electric planes will also be cheaper to maintain - similar to cars, there are less parts involved in the first place that can break down.
It is, because it's easier to get started with certification and experience in ultralights than in full-size planes. It won't be long until we see bush capable Cessnas, I think.
Back in 2003, President George W. Bush announced the Hydrogen Fuel Initiative. At the time, people criticized the effort as an attempt by the oil industry to shift attention away from electric cars. The oil industry knew that hydrogen power wasn't going to be viable anytime soon, while electric cars were already a direct threat to their profits, so they pushed the US government towards hydrogen power.
Not to disparage the talented scientists and engineers working on hydrogen power, but now that 20 years have passed I believe it was designed to fail.
Huh. I kind of thought that batteries had comprehensively won in this market, tbh.
I still can't quite get used to the electric buses. A 20 tonne double-decker bus should sound like it might explode at any moment; it is unnatural for them to move around more or less silently.
In Tompkins County we were early adopters of the electric bus, at least for the American market. We bought them from a startup which had trouble with the structural aspects and eventually they fell apart
https://www.ithaca.com/news/ithaca/tcat-pulls-all-electric-b...
Established bus manufacturers make good electric buses now but we don't have the money to buy replacements.
Five months before the company filed for bankruptcy, Proterra's CEO was appointed to the President’s Export Council (PEC), "the principal national advisory committee on international trade."
[delayed]
Batteries have won this so hard (if you ignore CNG busses, which have existed forever and are "almost as good as hydrogen could be") - because even when they hadn't won it, you just needed more busses.
Is it nice if the bus can do a driver's entire shift without a recharge? Sure! But if it can't, you just design the route so that the driver can switch busses and buy another bus. That means the technology problem is now a money problem.
Busses are also already quite heavy, so battery weight doesn't affect them as much as it might in a small car.
The stop-start nature of city busses makes them a real low hanging fruit for battery electrification, benefiting from instant torque to start and regen to stop and, as you say, fixed known routes within larger fleets.
The only nation that seems to have capitalised on this basic fact is China which bootstrapped its EV industry on busses, pulling ahead from 2010 and hitting 90% of global market share for EV busses in 2020, and now a big exporter.
For the same reason the electric mail trucks are a good idea. You can probably expect UPS and FedEx to start replacing their fleets over time as the existing vehicles age out, now that all electric vans are starting to become available.
(At least in King County Metro) the newer diesel-electric buses are series hybrids that use electric motors for traction, and diesel generators to power a small battery. So the low hanging fruit of electric traction was already “picked”. You can look up the bus model online - New Flyer XDE class
> But if it can't, you just design the route so that the driver can switch busses and buy another bus
Oof, that's a huge 'just' in many cases.
That said, current electric buses have sufficient range that this mostly isn't an issue. The unnervingly silent double-deckers I mention have a claimed range of 320km, which, at least here, is sufficient.
The big problem with Dublin's electric buses, ridiculously, was that the operator was late in applying for planning permission for the substations required to charge them. With the result that for about a year, there were about a hundred of them stored and unusable.
This depends a lot on local climate and topography.
Seattle has kind of been a bust with them because the hills really reduce the amount of charge, and on top of that the existing bus depots are already full, so switching to electric only would mean having to find and locate space for more bus depots, which is quite difficult.
Hills should never reduce the range, because the energy lost during climbing up is recovered when going downhill.
This is one of the great advantages of electric vehicles with batteries, when properly designed.
Electric buses with batteries are even more suitable for cities with hills than for cities without hills, because they provide greater energy savings over buses with ICEs.
While I have never used buses with batteries, I have lived in cities with electric trolley buses. Even with the primitive technology of many decades ago, they were doing great in cities with hills, recovering most of the energy when going downhill, unlike the buses with ICEs, which had excessive fuel consumption because of the hills.
Regenerative breaking is not perfectly efficient, so you may loose a significant portion of the additional energy needed. Better EV systems are what, 70-80% efficient on the breaking efficiency?
Sure, but you lose 100% in the case of combustion...
Okay, but gasoline is far more energy dense than batteries and a gas tank is a whole lot cheaper than a battery pack, so vehicles can have a gas tank big enough that that doesn't cause range problems. I don't know about buses, but you can buy a pickup with a 48 gallon tank. Even after assuming only about 1/3 efficiency, that's still equivalent to some 500 KWhr, which is several times more than any consumer EV I'm aware of.
That's efficiency, not range. Suppose hilly terrain reduces range by a third for electric vehicles and half for diesel. The diesel bus just fills up twice as often. The electric bus needs a 50% bigger battery in order to finish the same route without stopping to charge, and then it becomes 70% because it has to lug the bigger battery up the hills.
You can just... do that, but that doesn't mean it's not a thing you have to do, and it's not free.
It is impossible for a hilly terrain to reduce the range by a third for well-designed electric buses.
The efficiency of regenerative braking increases with the power of the vehicle. The electric efficiency should be well over 90%, perhaps even 95%. The mechanical losses will lower the total efficiency to much smaller values, but even so, the total efficiency should be over 80%.
A bus with an ICE will consume 5 times more extra energy for climbing the hill and it will also consume energy while going downhill.
Values like a 50% greater battery are unrealistic, and a heavier battery adds much less to the consumption than by how much it is heavier, even when going up the hill (because most of the extra energy consumption is also recovered).
In a certain city, it may happen that the bus routes are so long that batteries are not competitive with ICEs, at least for now. However, the presence of hills in any city can only make electric buses more advantageous, not less advantageous, due to much greater cost savings for fuel and maintenance. Buses with ICEs that are operated on hilly routes also need extra maintenance, besides increased fuel costs. Well-designed electric buses do not care whether they are operated in conditions requiring higher torque.
Approximately 100% but not exactly, given that engine braking downhill drives the accessories without any fuel. (Alternator, aircon, pumps, etc.)
Do you know which conversation you’re replying to?
The original point was: hills do not matter, because what goes up must come down, and regen will get all the energy back.
This is categorically untrue, at the very least because regen doesn’t capture at 100% efficiency. It being “more than ICE” doesn’t mean anything.
Regenerative braking is nice but as sibling pointed out it doesn't nearly recapture everything. Another factor is that the additional load whether accelerating up a hill or braking down one puts more current through the system. In fact nearly every part of the drivetrain will experience accelerated wear under those conditions, mechanical or electrical. Cooling systems, too. Properly spec'd, it's of course very doable, but it's true hilly terrain is more difficult.
This is a weird multi-paragraph evangelical lecture seeing as any EV owner that’s driven in a hilly climate will tell you that this isn’t how things work.
Regen isn’t 100% efficient, for starters.
I think it depends more on the regulatory climate.
Seattle also has (or had) trolley busses which fixed that problem.
Everything is cost, it's all cost, not the ability to actually solve the problem.
Many bus routes have a 5-10ish min break at some point (usually the main station) in the route. If you can utilize those ten minutes to do a top-up, you can go a lot further on the same sized battery.
No bus route should be more than 15 minutes between full and empty. That is you start at some station, go 15 minutes, then turn around and go back. There are many systems that attempt to do more, but there is no point: people have places to be: on the bus is not on that list. That 15 minutes means an average of 7 minutes, now they walk to some other express bus that gets them nonstop (at faster speeds) to someplace, but you still only get 15 minutes to get there before it isn't worth the bother, than 7 more minutes on some other bus. Add in 5 more minutes of walking time (and transfer time!) and we are at 45 minutes - this is unreasonably long for normal trips already, but it is the best you can do!.
In short there are plenty of places to switch buses if you need to.
There are two critical aspects to the bus routing problem. One is that no matter how well you design your system, there is always variance in the arrival times of a bus at any given stop. If you expect people to switch buses, then you need to account for this variance, and this means adding buffers. Nothing makes people stop using buses faster than missing your connection because your bus was late.
The other aspect is the what city topology you are dealing with. In square grid cities, you can probably put a tram on every road, and with one switch over, get to where ever you need to get to.
But many organically grown cities end up using the hub-and-spoke model, where there are main stations where many different buses meet. People switch over to the next connection (and you need a buffer here). Critically, you need all the buses to meet at roughly the same clock time, say every 30 min. Now, one thing you realize immediately is that not all routes are equal. One route might be only 25 min, Either you make it longer and waste fuel, and time for everyone sitting on the bus, or you wait an extra 5 min at the main station.
Bus scheduling is very difficult problem in real cities with weird topologies and real traffic issues. Buffers are a necessary part of any reasonable solution.
I'm coming from a different perspective: regardless of all else (all those issues you raised are very real), people need to get where they are going in a reasonable amount of time. Most bus service fails to account for that, but if you can't get people there in a reasonable amount of time there is no point in trying.
Is there any bus route anywhere that never goes more than 15 minutes from the depot?
Not that I know of - but there shouldn't be.
How do you get somewhere which is 20 minutes from the depot, or in general between any two points that are more than 15 minutes apart?
Sorry, but, what the hell? This is Hacker News at its finest: completely talking out of its ass.
This isn’t how bus routes work, and this isn’t how people ride busses, on most if not all of the…many PT systems I’ve used in multiple states / countries.
There is a reason people complain about buses and prefer to drive in so many cases. Operators try to compromise on cheap and end up with service for those who after 5 DWIs can't get their friends to drive them anymore.
CNG buses were about a 10-year experiment in Toronto. There were a number of bus terminals where CNG vehicles were prohibited, either due to clearance or because of the associated explosion risk.
A second batch of buses were converted to diesel so that the fuelling station could be decommissioned.
Why do transit agencies keep falling for hydrogen busses? From the perspective of the US, it’s pretty simple:
1. Transit agencies have no way to reasonably validate what the future holds. From the standpoint of today, a hydrogen bus can be expected to replace a diesel bus 1 to 1, while battery electric is a 2 to 1 replacement. This might not be a huge issue except:
2. FTA regulations have strict requirements on how many spare busses may be kept at any time (defined by the ratio of peak vehicle usage vs the size of the overall fleet), doubling the size of the fleet blows this ratio out of the water.
3. It doesn’t matter what BYD offers or what’s possible in China, US transit agencies are required (FTA regs again!) to buy busses made in the US. American manufacturers do have somewhat decent battery electric products, but they are clearly not at the leading edge. With the proterra banktrupcy, there are limited competent suppliers in the market. To a large degree, gillig et al do get to decide what gets pushed into the market.
> US transit agencies are required (FTA regs again!) to buy busses made in the US
BYD makes electric buses in California: https://en.wikipedia.org/wiki/BYD_K_series
I'm just waiting for flywheel powered buses to make a return: https://en.m.wikipedia.org/wiki/Gyrobus
Answer to the question: political reasons and lobbying.
Hydrogen is produced by the big oil and gas companies. By pushing hydrogen vehicle instead of battery electric vehicles they stay in business.
They market hydrogen as a green alternative to oil, although most hydrogen is currently produced from fossil sources, and this won't change soon (next 10 years).
Transit agencies don't have the technical expertise to distinguish truth from lies in cleantech marketing. They aren't the only ones, see the over-inflated valuations of both Nikola and Tesla as two (very different) stories of companies successfully lying to investors and the general public about the magical capabilities of their novel transportation platforms.
There are some hydrogen busses working in the UK.
>34-bus expansion, jointly funded by Brighton & Hove Buses and Surrey County Council, bringing their total hydrogen fleet to 54 vehicles – the largest hydrogen bus operation in the UK. https://drivinghydrogen.com/2025/02/04/hydrogen-buses-34-new...
I'm not sure how cost effective it is compared to battery though.
Because people are allergic to hybrids and I don't know why
"Electric is short range, fuel is expensive, guess I have to pick one"
The ideal drivetrain was invented over 20 years ago by Toyota and apparently nobody but me and Honda noticed it!
I've ridden both hybrid and electric buses and I prefer the latter, as those huge engines still produce a lot of vibration.
I drive a Toyota hybrid and while it's a step up from a purely combustion propelled car, I still have to do oil changes and its fumes still smell bad when it's running rich for whatever reason.
(At least in King County Metro) their newer diesel-electric buses are series hybrids that use electric motors for traction, and diesel generators to power a small battery. The drivetrain seems smart but maybe other agencies use it less? You can look up the bus model online - New Flyer XDE class
Here in SE Michigan, one local transit authority ditched its new hybrid busses and returned to diesel ~15 years ago - because the TCO for the hybrid busses was so much higher that fixing the hole in their budget proved impossible.
What is TCO?
Total Cost of Ownership.
It includes fuel & upkeep costs.
Total Cost of Ownership
> The ideal drivetrain was invented over 20 years ago by Toyota and apparently nobody but me and Honda noticed it!
The problem is hybrid drivetrains are complex. You don't save anything on the complexity of a combustion engine and exhaust train (over 1000 individual parts that have to be machined at extremely low tolerances), but add a more complex transmission (it needs to be able to work with two distinct inputs) and an electric drivetrain on top of that.
It is worth it in terms of energy efficiency and acceleration stats since even a small electric motor can supply a lot of torque at low speeds until the high-horsepower combustion engine catches up (virtually all modern cars have a turbocharger that needs time to spin up), but it's technically challenging to actually build into a modern car design - unlike 90s cars with ample space available to stuff components in, in a modern car every cubic centimeter is accounted for due to crash resistance.
As a simple driver of cars, I've never understood why no one has mass produced an EV with a built-in generator. That would avoid the complexity of the hybrid drive train, allow easy plugin and short range electric-only travel, and could even be offered as an optional attachment. So what am I missing? Is the efficiency gained by the generator offset by losses through the EV system?
That is called a series hybrid and the reason they're not popular is that the power split device in common hybrids is simply better.
The power split device isn't an ordinary transmission, it's a set of planetary gears with a fixed gear ratio between three shafts. One goes to the wheels, the other two to the engine and the electric motor respectively. The ratio of the engine speed to the wheel speed is then set by the speed of the electric motor connected to the third shaft, which gives you a CVT with no belts, clutches, torque converters or even synchros.
The transmission is "more complicated" only in the sense that it contains electric motors. In every other respect it's simpler, more efficient and more reliable than an ordinary transmission. Meanwhile those electric motors mean you don't need a starter motor or an alternator because the engine can be started by the electric motor through the transmission and an electric motor is a generator when operated in reverse.
A series hybrid still requires you to have a gas engine with all that entails, but now the gas engine needs its own dedicated electric generator/motor and you can't deliver power from the gas engine directly to the wheels, so the traction motors have to be bigger in order to supply 100% of the torque used in acceleration instead of the gas engine and electric motors both contributing. That makes series hybrids heavier, slower and more expensive, so they're basically useless.
Most BYD PHEVs work like that - with the additional option of connecting the engine directly to the wheels via a clutch at highway speeds. I think Honda has a similar system.
This was the GM Volt, predecessor to the Bolt: https://en.wikipedia.org/wiki/Chevrolet_Volt GM ceased production in 2019. The answer to your question can probably be found there, but IIRC [from GM's perspective] the consumer market preferred ICE + battery over electric + generator, especially after the all-electric options came to market and siphoned demand from the latter.
BMW i3 and Chevrolet Volt both had that option: https://en.wikipedia.org/wiki/Range_extender
And of course, there are plug-in hybrids: https://en.wikipedia.org/wiki/Plug-in_hybrid
It just turns out not to be worth it. The generator is a lot of weight to add, and a whole bunch of new parts to maintain.
It's a lot easier to add enough batteries to match the range of an ICE car. Range anxiety is largely manufactured at this point. The cars know how far they can go and where the chargers are. A gasoline powered generator would be a huge extra cost with no real upside other than averting a non-problem.
Edison Motors is working on a system like this. They're looking to sell kits for retrofitting it onto pickup trucks, & a larger scale semi truck cab version for use with logging trucks. It looks great in their videos, although I'm not sure if they're selling to the public yet - probably a ways to go before it's really mass produced.
Some hybrid drivetrains have fewer moving parts than a traditional ICE and are more reliable.
That undersells it. The data on hybrid drivetrains is pretty clear--it's definitely more reliable. Even mechanics will tell you that; certainly mine did, and he's not a masochist. Start+stop is hell on mechanical drivetrains. It's a no-brainer when purchasing a new car except that there's still a premium for hybrid, so the RoI might not be there given baseline reliability and depending on your preferences. Though the premium gap is closing, at least for non-plugin hybrids. Plugin hybrids are the new premium option in model lineups, so traditional hybrids are moving down market.
My plugin hybrid (I just bought it 2 weeks ago) is on track to save me $200/month over the others similar vehicle it replaced (minivan with the same engine, but 10 years difference in years, so lots of other differences).
My ROI is in how I can slam in reverse when I'm rolling forward or floor it whenever without concern for the drivetrain.
Sounds counterintuitive.
Any references?
https://www.rav4world.com/threads/how-the-ecvt-operates-with...
That goes for anything hydrogen and wheels pretty much.
It's actually pretty simple to figure out. Making hydrogen takes energy. You lose some of the energy making the hydrogen. This is not a fixable problem. At least not unless you break the laws of thermodynamics.
When you have created hydrogen, you lose more energy compressing the energy. Then you have to transport it to wherever it's going to be pumped into the vehicle ... both of which take more energy. Then it goes into a fuel cell, which loses more energy. All these losses multiply. And if you know your maths, you know that multiplying numbers smaller than 1 means the result gets smaller and smaller. These losses are significant.
And we're comparing it with putting the energy into a battery directly. It has inherently better round trip energy. Even if hydrolyzers, and the infrastructure to store, compress, and transport hydrogen were free (which they are not), using hydrogen would still be more expensive than that. Because it wastes more of the energy that goes in. So, in addition to the energy losses, you also need to deal with infrastructure cost. On top of regular energy infrastructure.
Anyway, that's all theory. For practice, just look at market price of hydrogen. Most of that stuff is of the dirty grey hydrogen variety creating that wastes a lot of methane. So much, that it would be cleaner to just use the hydrogen in a combustion engine in the bus and you'd have less CO2 emissions. Expending more methane to make hydrogen to have less emissions makes no logical sense.
If you are using grey hydrogen, it is more expensive per mile than methane. Nothing can change that. If you are using green hydrogen, it is more expensive per mile than battery electric. Nothing can change that either. That's just physics and simple economics. Yes there are some innovations in this space happening that reduce the gap a little. But it's never going to be enough.
Right now it's not even close. Unless somebody is subsidizing the hydrogen fuel, you'd be paying way more per mile than with diesel. And not just a little bit. And a common reason to switch from diesel to BEV is that it actually costs way less per mile than diesel. So, instead of saving money, you are spending more money.
Subsidies are hiding the true cost of hydrogen. That's the only reason there are some vehicles on the road. As soon as the subsidies dry up, hydrogen transport use cases evaporate. There are of course plenty of other use cases where hydrogen is needed that make much more economical sense. Using scarce and expensive hydrogen for transport is a poor use of resources. The utopian world where we have vast amounts of hydrogen surpluses does not exist.
Please also electrify garbage trucks
Here in Barcelona Spain they are electric!
Look into propane (a.k.a. LPG or Autogas).
If the goal is anything-but-diesel-or-gasoline/petrol, the use of propane (a fossil fuel that is a byproduct of oil and gas refining) is a well-understood, well-implemented practice. I am not advocating for propane as a primary solution, but rather as part of the journey towards truly clean vehicle emissions and the ramp-down of heavily polluting fossil fuel refining. Propane and the equipment to operate engines with it are available today, and we have the knowledge going back over a century to implement it successfully.
BTW, I wish I could find the article from the 1970s discussing how Ford Motor Company engineers had converted a brand-new 1960s Lincoln to propane and ran it with 100% synthetic motor oil, never changing the oil or filter. After 500,000 miles of daily use, they stripped the engine down to its parts and found it to be shiny and not exhibiting the expected amount of wear seen in usual engines of those years with much lower mileage. I'd have to pour through old magazines for that story, but life gets in the way, so let's treat my recollection as apocryphal.
There isn't any point to propane now. Electric busses got good enough to do the job. Propane reduces pollution, but the goal is to reduce CO2 emissions. Buying propane means buying electric in decade or two.
A local airport shuttle service converted some of their vans to propane. They told me the benefit is that they go about 3-4x longer between oil changes. (I suspect they aren't brave enough to go 500,000 miles.)
I tell you hwat!
that site never loads for me - 403 forbidden
> Fuel cell buses do produce sufficient waste heat, but here’s the problem: it’s exceptionally expensive heat. Every degree of warmth comes from hydrogen — a fuel that’s costly to produce, store, and transport. Unlike diesel, heating with hydrogen’s waste heat is technically easy but economically painful.
Isn't waste heat pretty much free by definition?
Thanks, you beat me to it. While it is more expensive per watt, that's a sunk cost: you've already paid it when you were consuming the hydrogen to make the bus move.
Within one technology, that'd be true. But not if you have the option to choose another technology that produces a lot less waste heat.
Yeah, I just find the framing very weird. It's talked about as if it's somehow worse than diesel. But then isn't the issue that hydrogen fuel is less economical than diesel in general, regardless of whether the fuel is used for locomotion or for passenger heating? In the context of passenger heating specifically, waste heat is either free for both diesel and hydrogen, or equally non-free for both.
Also the article appears to be arguing for electric instead of hydrogen buses, but for some reason seems to try to frame "winter range" as being an issue for hydrogen buses specifically, and then says "electric buses face a different challenge" -- winter range.
I feel like there are two separate points that can be made:
- Hydrogen fuel is more costly than diesel or electric (not even sure how true this is, but it's what the article seems to indirectly imply).
- Hydrogen fuel doesn't have winter range issues the way electric buses do, but regardless electric is still better for other reasons.
The obvious answer is that government incentives and policies are corrupted by fossil fuel interests.
The article only makes this claim via a link to another article:
> the Canadian Urban Transit Research and Innovation Consortium (CUTRIC), is riddled with conflicts of interest and bias toward hydrogen.
In which they reveal gas pipeline companies and fuel cell manufacturers are members of that org and on its board.
The mechanism through which fossil fuel interests work is "grey hydrogen" which is hydrogen produced through processing of fossil sources with no eye towards carbon capture. Grey hydrogen is as polluting as just burning the fossil feedstock but works with an established hydrogen infrastructure.
This lets the producers "green wash" their production pipeline by stating in a lies-through-omission manner that their hydrogen is "clean burning". See no carbon out of the tailpipe! It's clean! It's the same lie as EVs claiming to be "green" in places where fossil fuel sources dominate electricity production. It's just moving the tailpipe somewhere else rather than eliminating it entirely.
There's also "blue" hydrogen that's manufactured with fossil fuels but claims/intends to capture the carbon produced in the process. It can still feed into a hydrogen infrastructure so fossil fuel companies love it due to the same greenwashing.
The only carbon neutral hydrogen is "green" hydrogen which uses a renewable source and electrolysis of water to generate hydrogen. But even that is wildly less efficient on net than just using renewables to charge battery EVs. Electrons are far easier to move long distances than hydrogen or hydrogen feedstocks (including water).
> It's the same lie as EVs claiming to be "green" in places where fossil fuel sources dominate electricity production.
This is just anti-ev propaganda.
First, its kind of a chicken-egg situation:
'its not worth going green for the power grid, all the cars are still ICE' 'oh its not worth building EV cars, the power grid is dirty anyway'.
Second, there are lifecycle analyses that show that even if your powergrid is entirely fossil fuels, EVs are still a win. This is because powerplants are really efficient in ways that a car engine can't be because of scale/weight. iirc the only exception was if your power-grid was still like 50%+ coal?
Also this: https://en.wikipedia.org/wiki/Trolleybus
Trolleybusses are surprisingly expensive to operate. Battery electric busses seem to be much cheaper to operate and often good enough.
Sadly my town of Santa Cruz is going through this right now: https://lookout.co/carmageddon-when-will-santa-cruz-metros-n...
The electric airplane is another myth. There is no known battery technology, or one on the horizon, that can provide a large enough power/weight to make them practical.
The investors are getting bilked.
I feel there is an unaddressed market for a hybrid gas/electric or diesel/electric powerplant.
Size the battery for takeoff/climbing/go-around/diversion use-cases. Size the fossil-fuel engine for cruising power, which should improve efficiency. During takeoff and climbing power, the two motors work together. During cruise and descent, the electric motor regenerates the battery. I imagine that for general aviation, you would maintain one propshaft and not even bother with a clutch pack, since the gas engine is needed in all phases of flight, and freewheeling an electric motor is simple. Perhaps have the fossil-fuel engine keyed to the shaft with a shearing pin, so that if the engine seizes, the electric motor still turns the prop.
This has the advantage that you now have two independent motors, which could eventually help with ETOPS rating, but would initially improve safety/reliability for general aviation.
Yes, you are still fossil-fuel dependent, but you burn much less of it, first by offsetting some takeoff energy to the electrical grid, and secondly by reducing reserve power in the fossil fuel engine to improve efficiency.
They use electric seaplanes at Harbour Air for regional flights across the Georgia Strait between Vancouver, Seattle, and Victoria. Electric makes a lot of sense for short-range flights.
No, the eBeaver has never flown a commercial flight. Harbour Air is aiming for certification in 2026. Additionally, it only holds four passengers and is more a proof of concept than anything else. It is a cool effort but battery technology needs to come a long way first.
Firstly: I'm a fan of Harbour Air's work and their electrification. Have flown that airline.
Retrofitting electrical flight to a 1950s airframe will be, in the long run, not a great use of the technology.
Those planes were designed around having a single heavy powerplant up front driving the propeller, and fuel largely distributed along the center of gravity (in the wings) so as not to adversely alter flight characteristics over the trip. The electrified Beaver stores its batteries in the fuselage; of course there is no change in mass/CG over the flight with electric, but all that fuel tank space in the wings is going to waste. The fact that these are floatplanes make charging/battery replacement tasks at the dock challenging and restrict options.
A clean sheet design, with multiple distributed smaller motors and more options for battery placement, will be a significant improvement.
https://harbourair.com/going-electric/?tab=Specification
Storing the weight in the wings significantly reduces the stress in the wings over storing it in the fuselage.
Makes me wonder about their design tradeoffs.
Beta Technologies is already shuttling cargo between bases/depots for the US military with their eVTOL aircraft.
Demonstrated range of over 300 nautical miles. Significantly higher reliability than helicopters previously used for the same task, and much cheaper.
They're great for trainers. Short hops with immediate control, low maintenance and operating cost, and you can save the magneto/ignition/etc workload for a different lesson series.
I can see that. Although managing the engine is a major part of learning to fly.
Silly idea, but if the power is needed for takeoff then the aircraft could be plugged in with a cable up until it reaches cruising altitude.
It sounds ridiculous but I’ve been in aircraft that take off while attached to a cable thousands of feet in length — a winch launched glider!
The risk assessments are a teeny bit different.
Edit: although maybe there's a good idea: catapult or winch launch for electric aircraft would massively reduce the power and energy storage requirements to be carried onboard.
Look at all the effort that goes into launching an airplane with a catapult on an aircraft carrier.
There are other issues - like you cannot abort a catapult in progress.
Being constrained to a ship makes things harder though. If it was simply very long (runway length), I reckon an abort would be fine. There are probably a lot of different ways to do it.
But yeah, much harder than a regular runway. Probably not economical.
> The electric airplane is another myth.
Strong disagree. Short range eVTOL craft will blow open the market for all kinds of use cases.
I've heard that story for 40 years. Invest in it if you like. I'll pass.
Really? The Beta Alia CX300 just completed a coast to coast journey (Vermont - Santa Monica). Range of about 338 miles using 200kwh of completely unremarkable ~150wh/kg batteries. With 500wh/kg batteries being announced from multiple manufacturers now, that range should improve pretty quickly.
> There is no known battery technology, or one on the horizon,
The planes and batteries are getting there.
> There is no known battery technology, or one on the horizon, that can provide a large enough power/weight to make them practical.
Small aircraft are already there. I'm looking into starting my pilots license this year, the local flight school recently acquired an Elektra Trainer [1], that apparently has 2.5 hours worth of flight time [2].
Big transoceanic widebodies obviously will be fossil fuel based for a long time to come, but I think a lot of the GA market and bush pilot/island hoppers can and will be done by electric planes sooner than later - alone because the noise and lead emissions are all but gone, and I think that in a few years, when experiences on failure modes are a bit richer, electric planes will also be cheaper to maintain - similar to cars, there are less parts involved in the first place that can break down.
[1] https://de.wikipedia.org/wiki/Elektra_Trainer
[2] https://www.br.de/nachrichten/bayern/elektrisch-fliegen-in-l...
It appears to be an ultra-light.
It is, because it's easier to get started with certification and experience in ultralights than in full-size planes. It won't be long until we see bush capable Cessnas, I think.
You're assuming these investors actually believe it, and not that they can sell it to a greater fool.
VC will invest in snake oil if they think they'll get out at a profit.
I thought they might make sense for trainer aircraft that flight schools would use.
Also saw this:
https://harbourair.com/going-electric/?tab=Specification
> to make them practical.
..practical to replace commercial airliners, sure. There have been plenty of slow electric planes.
In the future, net-zero air travel can only be done by producing jet fuel in a carbon neutral way.
The plane, of course, flies anyway becuase planes don't care what humans think is impossible
/j
Opening image: ChatGPT.
I'm just gonna assume the rest of the article is from the same source and close this tab.
Linked also an interesting read : https://cleantechnica.com/2024/12/22/heat-pumps-for-electric...
I have flagged for the 403 - Forbidden - at a site level.