Self-powered Electric Car Possible?

[phillgt2002]

It's possible, but it'd be pretty expensive to develop. Remember, mostly anything is possible with the right amount of money and the smartest people working with you.

 

[Griffith500]

Note, however... this is good for hybrids, for avoiding use of the engine at a stop.

But for a battery-electric vehicle, there is some debate on whether regenerative braking is worth it.

As with gasoline cars, actually coasting to a stop typically uses less gasoline/electricity than wasting momentum via engine braking/regenerating.

-

Fission-powered cars would be amazing. Huge. But amazing.

The efficiency gain in coasting is a driving style thing - you cannot always coast to a halt.

The gain comes around from not having to sustain a constant speed for as long - i.e. either brake to a halt in 10 metres, or coast to a halt in 100 metres. In starting to slow down early, that's 90 metres' worth of speed-sustaining juice saved straight away. Assuming you have that extra 90 metres available to stop within. (Totally made-up figures, by the way).

It should be obvious that if your journey is all constant speed, the savings from coasting are minimal - better just to travel at a slower speed (depending on the efficiency relationship of the power draw). Alternatively, stop-start, busy traffic requires a more reactive approach, and braking is probably unavoidable. Better to be regenerative than not if it doesn't add too much weight or extra heat load (frontal area / drag / fans).



I think a nuclear-powered car would at this point basically be a steam car, with the boiler "fired" by the released "nuclear heat" instead of burning stuff. I love steam power, so I'm in!
Of course, for efficiency, it'd have to be a turbine, not a piston engine, so now I'm not so sure...

 

[mustafur]

What about an Ultra Light car used in a similar way to how the hybrid bike works.

Half pedal powered car, then maybe slap some Regenerative braking and Solar Panels to boost the range a bit.

 

[SniperRed3]

 

[ExigeEvan]

@Imari - As you stated that everything else is a battery, then so you should state Hydrogen is too. It's a chemical battery. We have to use electricity to make hydrogen, and then use that hydrogen in a fuel cell to release that electricity.

Which is why hydrogen has its pros/cons. It needs new infrastructure to make it viable, but also needs large amounts of electricity to support that infrastructure.

Whilst all electric already has that infrastructure.

 

[Tyger]

I love this thread because the OP is so naive (in a nice way though), and the replies, well people aren't quite sure how to take it.

Some basic laws of physics apply here, there is the law of conservation of energy sure but making a vehicle move expends a ton of this energy in the form of friction, heat, wind resistance and so forth. People have been looking into viable methods of perpetual motion for centuries, and for more efficient fuel sources almost as long. Of course fans of the Illuminati and lizards may argue that such fuel sources already exist and are being hidden from us, and so on, ad infinitum.

View attachment 300768

I know that's the Hammerhead from Top Gear but why is that smug SOB Steve Sutcliffe driving it?

 

[SniperRed3]

Why is that smug SOB Steve Sutcliffe driving it?

For the challenge it had to be reviewed by Autocar.

 

[Tyger]

For the challenge it had to be reviewed by Autocar.

Ah memory failed me there!

 

[Griffith500]

@Imari - As you stated that everything else is a battery, then so you should state Hydrogen is too. It's a chemical battery. We have to use electricity to make hydrogen, and then use that hydrogen in a fuel cell to release that electricity.

Which is why hydrogen has its pros/cons. It needs new infrastructure to make it viable, but also needs large amounts of electricity to support that infrastructure.

Whilst all electric already has that infrastructure.

Any free Hydrogen has a habit of escaping to space, too, which isn't so clever. Clamp down on those leaks, boys and girls!

Just use the electricity directly and cut out a conversion step. Assuming we can get the energy density where we need it...

 

[niky]

More to the point, a Hydrogen fuel cell vehicle still needs a battery pack to take advantage of regenerative braking and to power accessories without draining the tank.

 

[Imari]

@Imari - As you stated that everything else is a battery, then so you should state Hydrogen is too. It's a chemical battery. We have to use electricity to make hydrogen, and then use that hydrogen in a fuel cell to release that electricity.

Yes and no.

There's a difference between something like hydrogen or petrol and a traditional lead/acid or lithium ion battery. I think of a battery as something that accepts or outputs power as required. A battery will recharge. Hydrogen fuel cells can't (not the way I've seen them designed, anyway), and petrol engines definitely can't. They're one way by design, the only way to "recharge" them is to add more of the reagent that makes them work.

That's the difference. The reaction in a battery is reversible. The reaction of hydrogen or petrol is not, at least not by the car itself.

You're right that all these things are energy storage, but that's obvious. The whole point of a vehicle is to take energy from one source and turn it into kinetic energy. Of course there needs to be storage. But I think that there's a worthwhile distinction between something like a lead/acid battery that will charge and discharge many times, a "chemical" battery like hydrogen that will discharge once then need to be replaced, or a nuclear battery like a fission reactor that discharges once but has such a staggeringly high potential output that it will likely never need recharging.

 

[Beeblebrox237]

@maxi25 I highly, highly recommend you read and make an effort to understand this:

First_law_of_thermodynamics.

It will tell you, albeit in fairly complicated terms, that the answer to every one of your questions is no.

 

[Griffith500]

Yes and no.

There's a difference between something like hydrogen or petrol and a traditional lead/acid or lithium ion battery. I think of a battery as something that accepts or outputs power as required. A battery will recharge. Hydrogen fuel cells can't (not the way I've seen them designed, anyway), and petrol engines definitely can't. They're one way by design, the only way to "recharge" them is to add more of the reagent that makes them work.

That's the difference. The reaction in a battery is reversible. The reaction of hydrogen or petrol is not, at least not by the car itself.

You're right that all these things are energy storage, but that's obvious. The whole point of a vehicle is to take energy from one source and turn it into kinetic energy. Of course there needs to be storage. But I think that there's a worthwhile distinction between something like a lead/acid battery that will charge and discharge many times, a "chemical" battery like hydrogen that will discharge once then need to be replaced, or a nuclear battery like a fission reactor that discharges once but has such a staggeringly high potential output that it will likely never need recharging.

And within that discussion needs to be an account of full lifecycle costs, energy balance etc. Extra ancillaries at point of use, supply methods etc.

Remember that you cannot currently efficently convert heat directly to motion without something like a turbine. Direct from heat to electricity exists, but doesn't look promising yet.

So a nuclear reactor is no replacement for a battery, because the kind of energy output is different; whereas the hydrogen fuel cell is comparable, because its output is the same. And both can be recharged (as can a fuel tank).

So it is fair to compare batteries to fuel cells, on a thermodynamic basis; chemical reversibility in situ is irrelevant when it's all thermodynamically irreversible anyway, and chemically reversible ex situ (full cycle analysis).

 

[ExigeEvan]

@Imari - Your origin post stated that compressed air, flywheels and capacitors were different kinds of battery, hence my point that Hydrogen is effectively a battery too as its potential energy is a result of energy used in its manufacture. To such an extent that the useful energy is less than what you put in.

 

[Imari]

@Imari - Your origin post stated that compressed air, flywheels and capacitors were different kinds of battery, hence my point that Hydrogen is effectively a battery too as its potential energy is a result of energy used in its manufacture. To such an extent that the useful energy is less than what you put in.

Read how I described a battery.

The compressed air systems, flywheels and supercaps are all designed to accept energy from the vehicle as well as supply it. A hydrogen fuel cell is not. It only supplies energy, it cannot be recharged by the vehicle.

That's the difference, and it's a significant one. By the definition that I used when writing that post, which I've explained to you twice now, a hydrogen fuel cell is not a battery.

I don't find it useful to define it as a battery, I find it useful to have separate definitions for energy sources that can be recharged by the vehicle and those that cannot. This is the point of language, to convey useful concepts.

The useful concept that I was trying to impart is that traditional batteries, compressed air, flywheels and supercaps all share some similar features, which are not shared by hydrogen, petrol and other similar fuel sources. Those differences are great enough that they have significant impact on the design of the car, and I think it's worthwhile to make sure that those differences are clear by not muddying the water with an overly broad definition.

Your definition of battery seems to be a synonym for "energy source", which I don't find terribly useful.

 

[jimipitbull]

A wind up car, no batteries required. All you need is some big springs, a large key and a few magnets.

 

[Griffith500]

Read how I described a battery.

The compressed air systems, flywheels and supercaps are all designed to accept energy from the vehicle as well as supply it. A hydrogen fuel cell is not. It only supplies energy, it cannot be recharged by the vehicle.

That's the difference, and it's a significant one. By the definition that I used when writing that post, which I've explained to you twice now, a hydrogen fuel cell is not a battery.

I don't find it useful to define it as a battery, I find it useful to have separate definitions for energy sources that can be recharged by the vehicle and those that cannot. This is the point of language, to convey useful concepts.

The useful concept that I was trying to impart is that traditional batteries, compressed air, flywheels and supercaps all share some similar features, which are not shared by hydrogen, petrol and other similar fuel sources. Those differences are great enough that they have significant impact on the design of the car, and I think it's worthwhile to make sure that those differences are clear by not muddying the water with an overly broad definition.

Your definition of battery seems to be a synonym for "energy source", which I don't find terribly useful.

The energy used to recharge the "battery" came from the battery.

A battery could collect some of the energy released by the fuel cell, via regeneration. That regeneration is essential if it is to be anything like efficient enough.

If you separate and collect the waste product from the fuel cell in situ, you can re isolate the hydrogen to feed back in and recharge it. Obviously, that requires energy, and reduces the apparent efficiency. (It was always there, just outside the point of use: full cycle analysis!)

Quiz: Which came first?

Isn't language fun?

It is not unreasonable to call a fuel cell a hydrogen battery. Not all batteries are electrically rechargeable. Chemically, on the other hand...

 

[ExigeEvan]

Read how I described a battery.

The compressed air systems, flywheels and supercaps are all designed to accept energy from the vehicle as well as supply it. A hydrogen fuel cell is not. It only supplies energy, it cannot be recharged by the vehicle.

Um, yes it can. You make hydrogen through hydrolysis. That electricity would be generated from the wheels just like the compressed air you gave as an example.

The useful concept that I was trying to impart is that traditional batteries, compressed air, flywheels and supercaps all share some similar features, which are not shared by hydrogen, petrol and other similar fuel sources. Those differences are great enough that they have significant impact on the design of the car, and I think it's worthwhile to make sure that those differences are clear by not muddying the water with an overly broad definition.

You can't compare hydrogen with carbon fuels.

Hydrogen requires more energy to produce than it releases on use. Simply through manufacturing efficiencies.

Carbon fuels are not manufactured, and so the only energy we use is for refining and distribution.

You shouldn't muddy the water by confusing them.

 

[Imari]

Um, yes it can. You make hydrogen through hydrolysis. That electricity would be generated from the wheels just like the compressed air you gave as an example.

But a hydrogen fuel cell can't do hydrolysis. You need an entire additional system to make that happen.

You can't compare hydrogen with carbon fuels.

Sure I can. They have a lot of things in common.

Hydrogen requires more energy to produce than it releases on use. Simply through manufacturing efficiencies.

Carbon fuels are not manufactured, and so the only energy we use is for refining and distribution.

You shouldn't muddy the water by confusing them.

Except that in all these examples, I haven't been mentioning anything external to the vehicle. I'm talking about the vehicle itself, and how it gets and uses the power. In that sense, hydrogen and petrol and ethanol and diesel and nitromethane and coal dust all have a lot of things in common. They're irreversable chemical sources that are placed in the vehicle and consumed. It doesn't matter to the vehicle where they come from or how they're made.

If you want to talk about things external to the vehicle as well, then go ahead. There's probably an interesting post to be made about that, and maybe you're the person to do it. I'm not saying how you should define these things, I'm explaining how I referred to them in my post that was entirely about the vehicle and the fuel sources it carried or could carry.

You know, the whole thread being about a self-powered car.

 

[TexRex]

 

[Griffith500]

But a hydrogen fuel cell can't do hydrolysis. You need an entire additional system to make that happen.



Sure I can. They have a lot of things in common.



Except that in all these examples, I haven't been mentioning anything external to the vehicle. I'm talking about the vehicle itself, and how it gets and uses the power. In that sense, hydrogen and petrol and ethanol and diesel and nitromethane and coal dust all have a lot of things in common. They're irreversable chemical sources that are placed in the vehicle and consumed. It doesn't matter to the vehicle where they come from or how they're made.

If you want to talk about things external to the vehicle as well, then go ahead. There's probably an interesting post to be made about that, and maybe you're the person to do it. I'm not saying how you should define these things, I'm explaining how I referred to them in my post that was entirely about the vehicle and the fuel sources it carried or could carry.

You know, the whole thread being about a self-powered car.

Dude, I know you have me on ignore, but neglecting the stuff outside the car is foolish. It matters just as much, probably more, when it comes to what is "better" and what the overall logistics need to be.

So making "definitions" in respect of future efficent technology that completely ignores the most important aspect of that efficiency (full lifecycle) is to be missing most of the big picture context, resulting in less useful definitions for that big picture work.

A "Hydrogen car" is no more self propelled than a Diesel one, or most electrics for that matter (i.e. anything that's not solely solar powered, for example).

Also, batteries don't charge themselves, you need a separate bit of kit for that. With time and development, that's been reduced to a single special controller on a single motor / generator unit.

For hydrogen, purity is a problem, but in theory there is nothing stopping hydrogen recycling on the car itself. So you could have a hydrogen generator to recharge the fuel cell - especially if membrane based separation techs mature.

 

[Beeblebrox237]

You make hydrogen through hydrolysis.

While you can make hydrogen through hydrolysis, that's not how most hydrogen is made. 96 percent of hydrogen is made from fossil fuels, while just 4 percent comes from hydrolysis.

 

[Griffith500]

While you can make hydrogen through hydrolysis, that's not how most hydrogen is made. 96 percent of hydrogen is made from fossil fuels, while just 4 percent comes from hydrolysis.

Is that from cracking? The very thing we need to do in order to increase the yield of the roughly "octane" sized fractions from crude?

I'm sensing a pattern here...

set Tinfoilhatmode 1

Hydrogen requires a distribution network
Hydrogen is a fossil fuel by-product.
Fossil fuels are "endangered", no matter which way.
Fossil fuels already have an established supply network.
All-electric transport would replace fossil fuel, and would outperform hydrogen on everything but energy density at point of use.

Is hydrogen being pushed (by conveniently ignoring full life cycle costs, and long term implications) to prevent a shift in the balance of power?

Not that I really want the electricity companies to get all that extra "power"...

set Tinfoilhatmode 0

Why don't the petrochems switch to supplying the grid, and the power companies focus on upgrading that grid, specifically for transport?

Petrochem is already branching out into bio-stuff, which would get the water (treatment) companies in on things, too.

 

[Beeblebrox237]

Is that from cracking? The very thing we need to do in order to increase the yield of the roughly "octane" sized fractions from crude?

Do you by any chance mean fracking? Because around 50 percent of hydrogen comes form natural gas, the main product of fracking.

On a side note, fracking is really, really horrible. Why it's allowed anywhere in the world is beyond me.

 

[Griffith500]

Do you by any chance mean fracking? Because around 50 percent of hydrogen comes form natural gas, the main product of fracking.

On a side note, fracking is really, really horrible. Why it's allowed anywhere in the world is beyond me.

Ah, no I meant "cracking" long chain hydrocarbons (e.g. bitumen) down into smaller chains (like Diesels and petrols / gasolines) - it turns out that's a "hydrogen neutral" process, which I ought to have remembered, no free hydrogen generation there.

But if most of it comes from natural gas, then it's the same tinfoil situation.


Fracking only really scares me on a geological basis, much as "carbon sequestration" does; the contamination aspect should be controllable - legislators need to make sure that happens, because profit machines won't shoot themselves in the foot. Thankfully, petroleum products are in our face, meaning petrochem has to manage its image directly, so they probably will tow the line there.

Mining (e.g. for "rare earth metals") is an altogether different matter, and is all-electric's second-biggest problem (after energy / power density). The direct products of mining aren't as "in our face", in that "we" don't buy anything from mining companies. Add to that the fact that "technology" prices are pushed down constantly, so mining is not at all profitable enough to spend money on doing silly things like cleaning up after yourself - which is not to say that some companies don't try.

 

[Beeblebrox237]

Fracking only really scares me on a geological basis, much as "carbon sequestration" does; the contamination aspect should be controllable - legislators need to make sure that happens, because profit machines won't shoot themselves in the foot. Thankfully, petroleum products are in our face, meaning petrochem has to manage its image directly, so they probably will tow the line there.

My great uncle, who worked as a petroleum geologist for over 40 years, says it's possibly the scariest thing he's ever seen. And having grown up in Pennsylvania, I can back that up. When people can light their tap water on fire then something is terribly, terribly wrong. There's no regulation and the oil companies don't even disclose what chemicals they use, and fracking in the USA isn't required to comply with the clean air, water, or drinking water acts.

Anyway, the fact remains that hydrogen is a pretty stupid fuel for cars, given that it leaks through any material, must be vented out mechanically to relieve pressure, requires a tank much harder to package than a battery pack, and delivers energy efficiency that is poorer than a purely electric vehicle. It's also a far more complicated system to put in a car and would require a much greater change in infrastructure.

 

[Griffith500]

My great uncle, who worked as a petroleum geologist for over 40 years, says it's possibly the scariest thing he's ever seen. And having grown up in Pennsylvania, I can back that up. When people can light their tap water on fire then something is terribly, terribly wrong. There's no regulation and the oil companies don't even disclose what chemicals they use, and fracking in the USA isn't required to comply with the clean air, water, or drinking water acts.

Anyway, the fact remains that hydrogen is a pretty stupid fuel for cars, given that it leaks through any material, must be vented out mechanically to relieve pressure, requires a tank much harder to package than a battery pack, and delivers energy efficiency that is poorer than a purely electric vehicle. It's also a far more complicated system to put in a car and would require a much greater change in infrastructure.

The US is / was notoriously poor when it comes to legislation of geological activity, historically mostly due to ignorance (limited specialist knowledge on legislative side of things) and social pressures ("protected industries"), weirdly - maybe things have changed. Here in the EU, we are subject to the same pitfalls, but we tend to be "nannied" a bit more.

"Chemical containment" of hydrogen may help, but you've got to expend energy in switching between contained and free "states" at both ends of the transport process. Physical containers remain a challenge, membranes likely being the key once again. I agree that electric is better, especially if we can clean up the raw materials and / or research different materials.

@jimipitbull mentioned mechanical drives, and they are actually quite interesting.
Horrendously unsafe in the case of flywheels, when they let go (as could a fuel tank be), but I wonder how efficient a "wind-up" or "clockwork" car could be.

 

[niky]

I recall the rubber band Bonneville record being around 5 mph.

I think.

Clockwork... Well, my Pop jerks going on about clockwork cars... One of these days, I'm going to ask him for a domain to test the theory out.

A clockwork car is just like a rubber band car... Only the elastic energy storage is metallic instead of rubber. And in terms of potential energy, if you thought a flywheel was scary...

*Okay, googled it... Rubber band car was supposedly good for 30 mph over a more, but never did the time, officially.

 

[ExigeEvan]

While you can make hydrogen through hydrolysis, that's not how most hydrogen is made. 96 percent of hydrogen is made from fossil fuels, while just 4 percent comes from hydrolysis.

Learn something new 👍

However, given the need for fossil fuels and CO2 created (and captured), hopefully it wouldn't be the prime option in a Hydrogen economy.

 

[Beeblebrox237]

Learn something new 👍

However, given the need for fossil fuels and CO2 created (and captured), hopefully it wouldn't be the prime option in a Hydrogen economy.

I think part of the reasoning behind said production figures is the fact that it's cheaper to get it from fossil fuels than from water. And of course, it's a bit silly to convert water to hydrogen using electricity if you're only going to later reverse that reaction to make electricity.