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The case for hydrogen-powered cars

thedrive.com

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Re: The case for hydrogen-powered cars

#61

Post by vlehto »

"Most H2 is created through a technique called "cracking," which involves splitting the methane molecule (CH4) found in natural gas into two H2 molecules and a free carbon atom."

You can generate methane from rotting garbage, cow dung and whatnot. Almost anything that rots. And some of it is now torched as the transport is too expensive from far away oilfields.

But here's and idea: burn that methane directly in fuel cell?

https://newatlas.com/platinum-free-methane-fueled-fuel-cells...

People are WAY too exited about that "only water vapor from the tailpipe!" -hype.

Re: The case for hydrogen-powered cars

#62

Post by extrapickles »

FrojoS wrote: post #56
sharpercoder wrote: post #16

When discussing hydrogen cars, I particularly like the blog of Mux about this topic. Part 1: https://ssj3gohan.tweakblogs.net/blog/11470/why-fuel-cell-ca... Part 2: https://ssj3gohan.tweakblogs.net/blog/11493/why-fuel-cell-ca... Part 3: https://ssj3gohan.tweakblogs.net/blog/11556/why-fuel-cell-ca... Part 4: https://ssj3gohan.tweakblogs.net/blog/11572/why-fuel-cell-ca...

Very interesting! > Besides the battery, the biggest component(s) by weight is/are the motor(s). Current generation electric cars use still fairly heavy central motors with an actual axle to the wheels. Upcoming generations will use in-wheel or near-wheel motors that have almost no drive train associated with them: no transmission, no gearing at all, no weight lost to things that aren't necessary. This is one of the…

Increasing unsprung weight by putting the motors in the wheels will reduce the ride quality quite a bit.

You can make lower RPM electric motors that can do direct drive but they will loose efficiency, power and speed. At some point gears became better to reduce the RPM, even after accounting for gear loses. Even current electric cars really need 2-3 gears for maximum performance and efficiency, but they can get away with fixed gears which greatly simplifies things. One of the interesting things about the 4 wheel drive Tesla’s is that the 2 motor/gear assemblies are optimized for different speed bands so they can have the benefit of both without needing to shift gears, they just shift power from one motor to the other.

In wheel motors generally will only be done for low speed applications where a suspension is optional, just like airless and omnidirectional tires.

Re: The case for hydrogen-powered cars

#64

Post by ilovecars2 »

mikeash wrote: post #43

The one advantage of hydrogen cars, refueling speed, is not actually an advantage for typical driving habits. A hydrogen car takes about five minutes to refuel. On a typical day, a battery car takes about five seconds to refuel: you plug it in and you leave it overnight. Sure, the actual charging takes longer, but who cares? You’re not involved. On long trips, this reverses, but how often do you do those? Most people…

I understand what you're saying but I'm just not sure I'm prepared to wait at a service station for an hour or more to recharge my car.

Today I drove from the south east to the Lake District - a distance of about 400 miles. I made 3 5-10 minute stops en route for food, toilet and one for fuel. I found that once I'd stopped for 10 minutes I just wanted to get going again and get to my destination. I'm really not sure I would be happy hanging around a service on the M6 toll road for 1-2 hours because I needed to recharge my car.

I don't often do long trips, perhaps 2-3x a year, but when I do I really just want to get to my destination as soon as possible.

Re: The case for hydrogen-powered cars

#65

Post by chaostheory »

mikeash wrote: post #43

The one advantage of hydrogen cars, refueling speed, is not actually an advantage for typical driving habits. A hydrogen car takes about five minutes to refuel. On a typical day, a battery car takes about five seconds to refuel: you plug it in and you leave it overnight. Sure, the actual charging takes longer, but who cares? You’re not involved. On long trips, this reverses, but how often do you do those? Most people…

My time is precious. Long trips are for rentals if you have a full EV.

As an alternative I drive a Chevy Volt which has a gas run battery charger. While the battery only has a 50 mile range, the gas powered battery charger has about a 250 mile range

Re: The case for hydrogen-powered cars

#66

Post by pasbesoin »

I think we'll end up with enough "next generation" energy (renewable, whatever), that we'll be able to afford the inefficiencies in manufacturing "legacy", high-energy-density fuels -- and product precursors, e.g plastics -- where still needed. (Avoiding further extraction and all the pollution and environmental damage and unqualified and quantified future impacts.) And our overall carbon burden may be enough less (disregarding accumulated atmospheric load, in this arugment), that we can afford the corresponding limited amounts of exhaust.

So, for common transport, I don't know whether pure hydrogen still fits in. It hasn't scaled, and it's still more difficult to handle.

Re: The case for hydrogen-powered cars

#67

Post by mikeash »

chaostheory wrote: post #65
mikeash wrote: post #43

The one advantage of hydrogen cars, refueling speed, is not actually an advantage for typical driving habits. A hydrogen car takes about five minutes to refuel. On a typical day, a battery car takes about five seconds to refuel: you plug it in and you leave it overnight. Sure, the actual charging takes longer, but who cares? You’re not involved. On long trips, this reverses, but how often do you do those? Most people…

My time is precious. Long trips are for rentals if you have a full EV. As an alternative I drive a Chevy Volt which has a gas run battery charger. While the battery only has a 50 mile range, the gas powered battery charger has about a 250 mile range

My point is that the EV is a net time saver over a hydrogen or normal car, so if your time is precious then it’s a win. The Volt may be even better in that respect, of course.

Re: The case for hydrogen-powered cars

#68

Post by mixmastamyk »

ilovecars2 wrote: post #64
mikeash wrote: post #43

The one advantage of hydrogen cars, refueling speed, is not actually an advantage for typical driving habits. A hydrogen car takes about five minutes to refuel. On a typical day, a battery car takes about five seconds to refuel: you plug it in and you leave it overnight. Sure, the actual charging takes longer, but who cares? You’re not involved. On long trips, this reverses, but how often do you do those? Most people…

I understand what you're saying but I'm just not sure I'm prepared to wait at a service station for an hour or more to recharge my car. Today I drove from the south east to the Lake District - a distance of about 400 miles. I made 3 5-10 minute stops en route for food, toilet and one for fuel. I found that once I'd stopped for 10 minutes I just wanted to get going again and get to my destination. I'm really not sure…

Some cars can charge in 30-40 mins, which is a good amount of time for a meal.

Re: The case for hydrogen-powered cars

#69

Post by mikeash »

ilovecars2 wrote: post #64
mikeash wrote: post #43

The one advantage of hydrogen cars, refueling speed, is not actually an advantage for typical driving habits. A hydrogen car takes about five minutes to refuel. On a typical day, a battery car takes about five seconds to refuel: you plug it in and you leave it overnight. Sure, the actual charging takes longer, but who cares? You’re not involved. On long trips, this reverses, but how often do you do those? Most people…

I understand what you're saying but I'm just not sure I'm prepared to wait at a service station for an hour or more to recharge my car. Today I drove from the south east to the Lake District - a distance of about 400 miles. I made 3 5-10 minute stops en route for food, toilet and one for fuel. I found that once I'd stopped for 10 minutes I just wanted to get going again and get to my destination. I'm really not sure…

It’s not for everyone. If you really want to just go go go then it will be frustrating.

400 miles is pretty easy, though. In my car (Model S 85), I’d probably plan to stop once a bit past the halfway point for lunch. 20-30 minutes should get enough to finish the trip. That’s assuming I can charge at the destination. If you can’t, it’s tougher.

In a Model S 100D or a Model 3 LR, you could probably stop for only 10 minutes somewhere in the middle. They charge faster (especially the Model 3) and don’t need much extra to make that trip.

Re: The case for hydrogen-powered cars

#70

Post by terryf »

mikeash wrote: post #43

The one advantage of hydrogen cars, refueling speed, is not actually an advantage for typical driving habits. A hydrogen car takes about five minutes to refuel. On a typical day, a battery car takes about five seconds to refuel: you plug it in and you leave it overnight. Sure, the actual charging takes longer, but who cares? You’re not involved. On long trips, this reverses, but how often do you do those? Most people…

If people would be fully rational, then you would be correct. However, they are not (and shouldn't be imho, but that's another discussion).

Basically, it's about the ability or potential of going anywhere. I bought a car that technically has the ability to go off-road. The reality is that I probably never will. But it sure feels good to know that I could. Paid extra for it and all. Completely irrational, but makes me happy.

That's the reason that people worry about range and refueling time. It's not rational, it's just humane. We aspire to do more , see more and go further. Not all of us do, but it's a very human emotion. That's not a bad thing.

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