Grills are the least of Lexus' problems going forward. However, it is one of the superficial and outwardly visible contrasts with Tesla vehicles.
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Toyota 'Mirai' Fuel Cell Sedan
- Thread starter ivog
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I guess that's all about perspective. Compared to a comparable gas car, the FCEVs are likely significantly more efficient.
If you're powering both from natural gas, the FCEVs will be close to the same efficiency as an EV, using the efficiency of a modern combined cycle power generator and grid vs stream reformation and compression/transport.
Then there's the third perspective, where you start from renewable electricity and have to use that to split water. As several posts have noted, in that case the FCEV is somewhere between half and one quarter of a grid charged EV in efficiency, depending on the exact assumptions used.
So which is the right perspective? Most of the world is still driving gas cars. Renewable energy is still a small fraction of total generation. There are renewable sources for methane.
I mostly object to FCEVs because of the costs of developing a whole new infrastructure and the increased risks of both that infrastructure and the cars themselves - and because I see them as a deliberate spoiler attempt for the EV transition.
(You can build a PHFCEV for much less than a traditional FCEV, because the fuel cell is the major expense, and you could build the car with a cell stack with a quarter of the output if you had a Volt sized battery to handle all the acceleration and only needed to match highway steady state power needs. At the same time, you'd only need a fraction of the infrastructure because they'd do 80% of their miles on gone charged electricity like Volts do. The fact that no one has ever offered such a car and only one such has ever been shown as a concept is proof to my mind that the folks pushing FCEVs aren't looking for cost effective solutions - they're looking to slow EVs.)
I don't think that's the reason. I think the reason FCVs are pushed has it's roots in a time when batteries weren't good enough for long range in reasonably priced cars. Roughly before 1995-2000. And it's just managed to maintain momentum since then.
And the reason why PHFCEVs haven't been favoured in recent years is probably twofold. First, it adds cost and complexity, you need a big battery, charge port, and such. But more interestingly, it adds to the challenges on the fueling side. For a hydrogen fueling infrastructure to make any sort of commercial sense, you need something like 50,000 FCVs in Norway, paying the same as they would for gas. That puts enough money into the system that it could be somewhat workable. Now, what happens if you drop the hydrogen consumption per vehicle by 80%? Well, you need five times as many vehicles for the hydrogen infrastructure to make any sense, or 250,000 vehicles. Going form ~100 to 250,000 hydroegen vehicles is a lot more challenging than going from ~100 to 50,000. Which means that more subsidies are needed and/or losses will have to be sustained for a longer time.
The added cost and complexity of the bigger battery pack are very small compared to the cost of the bigger fuel cell and associated cooling systems.
The other half of your argument seems to be that we should make cars that are much harder for the owner to use and cost more in order to force the government to throw more taxpayer money into building infrastructure now. While the logic hangs together, I really don't think that's a sensible choice.
nwdiver
Well-Known Member
What's the benefit to picking that path that we know ends halfway to our destination? If we're going to use FCEVs why not just use methane? Hydrogen makes zero sense.
gavine
Petrol Head turned EV Enthusiast
Hydrogen makes sense to people who don't understand EVs and are stuck in the "fill-up at a station once a week" paradigm, but who want to go zero emissions.
nwdiver
Well-Known Member
Methane does that too... why Hydrogen? That's what I don't understand... Methane is cheaper, safer and easier to transport.
I agree with you. You could even use renewable methane like Bio-Methane. However, if you used a fuel cell that takes methane directly, you're now emitting CO2 at the point of use. Not zero emissions.
If you look at end-to-end efficiency... no, they're really not. You have to manufacture hydrogen, usually from natural gas (not a carbon-free source), or by (extremely) inefficiently cracking it from water. Then you have to spend about 1/3 more energy compressing the gas to extreme pressures so it will fit in a tank on the vehicle. And only then do you get to the conversion efficiency of the fuel cell.
Even with all those inefficiencies, it's still probably an improvement over ICE on a well to wheels basis if you include all the petroleum processing energy inputs. You also have the benefit of no point of use emissions.
My humble opinion, if you want to improve on ICE and don't want to depend on electric charging infrastructure away from home, a long range (~50 mile AER) PHEV is the best solution. The annual gas use is very low for most people and manufacturers can make many more vehicles from the same GWh of battery production than long range BEVs. However, for light vehicles for personal use, BEV is still the best solution.
nwdiver
Well-Known Member
Ahhh the illlustrous Toyota Mirai. I'd forgotten about those things. Wonder how that whole fuel-cell thing is working out for them. Mwahahaha. Fuel cell cars were Dead on Arrival I'm surprised they even got far enough to build one and it took him this long to figure it out.
At the moment in the Los Angeles area the hydrogen stations are short on fuel according to Green Car Reports (I am not sure if I am allowed to link articles from other sources). Apparently the Hydrogen supplier has been unable to deliver fuel to the stations.
I do see Toyota Mirai s on the road now and then. Someone on the other side of our neighborhood has one parked in their driveway. I think most of the owners are Toyota employees who can fuel in Torrance near the Toyota offices.
I do see Toyota Mirai s on the road now and then. Someone on the other side of our neighborhood has one parked in their driveway. I think most of the owners are Toyota employees who can fuel in Torrance near the Toyota offices.
And generally you have to use diesel fuel to truck the hydrogen to the filling station.
( There are very few "hydrogen pipelines" around to move it.)
It is way easier to get electricity from the generation source to the plug...
( Don't have to tie up the roads and risk traffic accidents either... )
JohnSnowNW
Active Member
FCEVs are the embodiment of greenwashing. The best course of action for both consumers and combating AGW is the requirement of ALL vehicles to be electrified. For those without access to home charging a hybrid makes FAR greater sense than an FCEV, as:
- The infrastructure already exists
- The cost is considerably cheaper
- The efficiencies are similar (Prius Eco 56mpg vs Mirai/Clarity 66/67 mpge)
roblab
Active Member
But compared to solar with battery backup, I find it difficult to believe that FCEVs are near as efficient. Since EVs are only about four times more efficient than gas cars, I'm curious how much is "significantly". Most anything not powered with gas is significantly more efficient than a gas car.
I feel like we're getting into apples and oranges here, unless you're proposing solar as a way to move a car directly (which will never happen to mainstream cars of current design styles/safety requirements - even with theoretically perfect panels the energy demands are too high.)
Any time you put solar or wind into an efficiency discussion, you have to stop and think carefully about what you care about and what you want to measure.
Conventional efficiency discussions are about how much of the feedstock energy you can carry over to the end activity - but unless you're constrained by space, solar and wind don't care, because the feedstock is free. So usually it's more important to harvest them cheaply instead of efficiently.
But, if you have PHFCV, not only do you not need as much infrastructure, as with BEV, you don't need infrastructure to be as conveniently located since you'd be using it more sparingly, and you be able to fill up when you're in that area.
PHFCV is more of a cost and packaging problem. Same as PHEV, really: two powertrains technologies will always be more expensive and complicated than one. At least with PHFCV it's just a bigger battery and the additional charger and port.
Nevertheless,
Mercedes-Benz GLC F-Cell EQ Power plug-in hydrogen crossover launches at Frankfurt
Potentially, the downsizing of the fuel cell stack and supporting systems would make the space for the bigger battery just like it makes the money available. The charger is neither big nor expensive in the grand scheme of things.
Interesting article, I'd somehow missed that. The original concept from a couple years ago was the lone example I'd mentioned before; none of the articles I saw then suggested it was even a candidate for production. I'm still not sure it makes sense overall - but it makes much more sense than any other FCEV.
Reforming and catalyzed electrolysis are both relatively efficient. 65-75% and 70%. Then you need compression and use. If the vehicle needs 1/3kWh to move a mile, and a typical equivalent gas vehicle needs over 1kWh to move, then even at 65% reforming efficiency, you'd only need around 50% fuel to power efficiency for compression and fuel cell and you'd still beat gas (or CNG).
HFCV's problem is simply one of cost. (Safety is just a cost challenge) That's why it found favor at a time when plug-in tech didn't seem to have a chance of meeting expectations. But now we have lithium batteries dense enough to allow long-range BEVs, DCFC and hybrids, so plug-ins are also now primarily a cost challenge. The difference is that the PEV cost challenge is primarily about the battery, and success there has synergies with the (already low) cost and sustainability of fuel production; HFCV fuel is an additional cost challenge.
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