Four more carmakers join diesel emissions row

nwdiver said:

Thermodynamics strongly disagrees; H2 Fuel Cells are just another type of battery... just 50% less efficient than current tech

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I suggest a refresher course in thermodynamics. Hydrogen has over 200 times the energy density of lithium ion batteries. It's also the most abundant element in the universe. Hydrogen fuel cells are not batteries, although they do both produce electricity through an electrochemical reaction. The size and weight of lithium ion batteries increases in a logarithmic curve in relation to range. H fuel cells (and petroleum fuels) have a linear size /weight relationship to range. It will take time to build the infrastructure, but some heavy hitters like toyota, honda, hyundia, and others are developing the fuel cell vehicles of tomorrow.

turbobrick240 said:

I suggest a refresher course in thermodynamics. Hydrogen has over 200 times the energy density of lithium ion batteries. It's also the most abundant element in the universe. Hydrogen fuel cells are not batteries, although they do both produce electricity through an electrochemical reaction. The size and weight of lithium ion batteries increases in a logarithmic curve in relation to range. H fuel cells (and petroleum fuels) have a linear size /weight relationship to range. It will take time to build the infrastructure, but some heavy hitters like toyota, honda, hyundia, and others are developing the fuel cell vehicles of tomorrow.

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Hydrogen isn't a fuel source; It's an energy storage medium... just like a battery... a really, really inefficient battery. H2 might be the most abundant element in the Universe but here on Earth the only sustainable source exists as H2O... where you have to add ~2x as much energy to get the H2 as it gives back when used as fuel; Thermodynamics.

Instead of using 1kWh to drive 3 miles in a BEV you would use 2 kWh to split water, harvest the hydrogen, compress the hydrogen, transport the hydrogen and at some point use the hydrogen to generate ~1kWh to drive ~3 miles....

The best-case round-trip efficiency of 2H2O + electricity=> H2 + O2 => 2H2O + electricity is <60%. It is physically impossible to drive >50% as far with an FCEV vs a BEV.

nwdiver said:

Hydrogen isn't a fuel source; It's an energy storage medium... just like a battery... a really, really inefficient battery. H2 might be the most abundant element in the Universe but here on Earth the only sustainable source exists as H2O... where you have to add ~2x as much energy to get the H2 as it gives back when used as fuel; Thermodynamics.
Instead of using 1kWh to drive 3 miles in a BEV you would use 2 kWh to split water, harvest the hydrogen, compress the hydrogen, transport the hydrogen and at some point use the hydrogen to generate ~1kWh to drive ~3 miles....
The best-case round-trip efficiency of 2H2O + electricity=> H2 + O2 => 2H2O + electricity is <60%. It is physically impossible to drive >50% as far with an FCEV vs a BEV.

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Again, I reiterate hydrogen fuel cells are not batteries. What fuel source do you suppose fuels our sun? That's substantial power right there. Think about it. Hydrogen fuel cell vehicles primary advantage over bev's is range. So you are wrong on that front as well. Do you think the electricity to charge bev's just appears magically at 100% efficiency? This has gotten way off topic. I'm in favor of any technologies that provide a cleaner, more sustainable means of transport.

If you are comparing electrolysis / fuel cell energy storage using hydrogen to thermonuclear fusion using hydrogen, you've got some studying to do.

No one is arguing that the amount of energy you can store in a vehicle is greater using hydrogen in a FCV than it is using rechargeable lithium batteries. True statement.

But it's thermodynamic insanity to use that as an excuse to use hydrogen in a fuel-cell vehicle used for daily transportation when the ability to have approx 300 km / 200 mi range at approx US$30k cost in a battery-electric vehicle is about a year away from commercial availability. It is thermodynamically more efficient (roughly double) to use electricity to charge a lithium battery and discharge it, than it is to use that electricity to generate hydrogen and use that in a fuel cell vehicle.

That's assuming hydrogen is actually produced using electrolysis. A far more likely path is to use steam reformulation of natural gas ... a fossil fuel ... which will emit CO2 ... and at that point, it's more efficient to skip the hydrogen step and use the natural gas directly; it is a WHOLE lot easier to store and transport than hydrogen is. And you CAN make fuel cells that use hydrocarbons as fuel. But the "greenies" don't like it, because it emits CO2! But it's more efficient to do that, than it is to use hydrogen ... and we don't need an entire new distribution infrastructure to do it, either.

This belongs in the EV thread.

GoFaster said:

If you are comparing electrolysis / fuel cell energy storage using hydrogen to thermonuclear fusion using hydrogen, you've got some studying to do.
No one is arguing that the amount of energy you can store in a vehicle is greater using hydrogen in a FCV than it is using rechargeable lithium batteries. True statement.
But it's thermodynamic insanity to use that as an excuse to use hydrogen in a fuel-cell vehicle used for daily transportation when the ability to have approx 300 km / 200 mi range at approx US$30k cost in a battery-electric vehicle is about a year away from commercial availability. It is thermodynamically more efficient (roughly double) to use electricity to charge a lithium battery and discharge it, than it is to use that electricity to generate hydrogen and use that in a fuel cell vehicle.
That's assuming hydrogen is actually produced using electrolysis. A far more likely path is to use steam reformulation of natural gas ... a fossil fuel ... which will emit CO2 ... and at that point, it's more efficient to skip the hydrogen step and use the natural gas directly; it is a WHOLE lot easier to store and transport than hydrogen is. And you CAN make fuel cells that use hydrocarbons as fuel. But the "greenies" don't like it, because it emits CO2! But it's more efficient to do that, than it is to use hydrogen ... and we don't need an entire new distribution infrastructure to do it, either.
This belongs in the EV thread.

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Nope, not comparing thermonuclear fusion to electolysis. If you think our current grid system is capable of charging millions of ev's, think again. I'm a huge fan of the tesla cars btw. Every electricity generation system I'm aware of has associated CO2 emissions.

... and if you are proposing to generate that hydrogen using electrolysis, that would involve using even MORE electricity from our (inadequate) electricity grid!

Granted, it could be time-shifted at will. But even battery-charging can be time-shifted (most people will charge at night, when normal utility demand is off peak anyhow). Granted, the electrolysis plant could be put next to a generating station. But either way it's subtracting electricity that could otherwise feed the grid. The reality is that TODAY, the way that hydrogen is produced commercially in large quantities is via steam reformulation of natural gas, NOT via electrolysis (which is too expensive because the overall efficiency is too poor!) ... but if you are using natural gas, where's the CO2 go? and you are still using a fossil fuel.

I don't suggest that I know more about fuel cells than Toyota does. But I do understand what their motivation is ... Politics. From Toyota's point of view, hydrogen fuel cells transfer ALL responsibility for emission control, CO2 emissions, etc to "someone else". The whole means by which the hydrogen is produced becomes "someone else's problem". It gets the regulators off their back. And on top of that, all of the auto manufacturers that have worked on hydrogen fuel cells have been receiving millions of dollars of government subsidies to do it ...

The reality is that ultimately there is likely to be more than one solution. Battery-electric vehicles with 200 mi / 300 km range (or more) for <$30k will be "good enough for most people". Fuel cells may end up being part of the picture for longer range. But they're not going to be a panacea. Hydrogen in the absence of government subsidies will end up being really expensive ... mark my words.

And the internal combustion engine is still going to be around for a long time.

You make some excellent points there. I never mentioned electrolysis as the means by which to make the H. I agree that there isn't likely to be a single silver bullet, and that ICE is here for the foreseeable future. Thank god, because I love my diesels!

turbobrick240 said:

Every electricity generation system I'm aware of has associated CO2 emissions.

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.... depends on how far back you go; I generate ~50kWh/day with zero CO2 emissions, that's enough energy to drive ~150 miles. Obviously the panels required energy to produce but that energy can also be solar and they generate more energy that was required to produce them after ~4 years with a 20+ year life span.

And yes... our grid can handle >100M EVs with only software (Demand Response) and no structural changes. Cool thing about the grid is that it has a built in 'healthy' signal. 60Hz everything is OK. 59.97Hz please stop charging.

nwdiver said:

.... depends on how far back you go; I generate ~50kWh/day with zero CO2 emissions, that's enough energy to drive ~150 miles. Obviously the panels required energy to produce but that energy can also be solar and they generate more energy that was required to produce them after ~4 years with a 20+ year life span.

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That's great. I applaud your foresight. I also have a solar array. Clearly solar is about as clean an energy source as we can hope for. There are still co2 emissions involved in the manufacturing process. Likewise, the manufacturing of bev li ion batteries results in substantial (much more than ICE drivetrain manufacturing) CO2 emissions. But yes, ev's are undoubtedly the future. I'm done with ev's in this thread, good day.

Mike_04GolfTDI said:

Someone should look into how damming rivers to generate electricity hurts the salmon population. I'll bet that's a thing.

Maybe I can get an "Electric Cars Kill Salmon" bumper sticker. Whether it's true or not, it would be a good sticker anyway.

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Where's that "Like" button....