The head of the Air Resources Board on her beloved Mirai

For what it's worth, this article is claiming 14.34 kg of CO2 equivalent to produce 1 kg of hydrogen, which will get a Mirai 66 miles. Looks like that's steam reforming, though, so this number's actually useful, but California requires 1/3 to be renewable - let's say there's zero CO2 emissions for the renewable portion, so we'll use 2/3 of it - 9.56 kg CO2e per kg of H2.

A Prius Two Eco will put out 10.5 kg of CO2 for the same 66 miles (using EIA figures for CO2 per gallon of gasoline - and that's not considering ethanol, although ethanol doesn't have that much impact due to the embodied CO2 in its production). That's right, ICE without a plug is actually competitive here. (Note that the Mirai does have a long tailpipe, however, which does improve some things like smog-forming emissions in cities, something very relevant to California's environment. Actually, now I wonder how much smog-forming emissions are produced with steam reforming... But, then, there's fracking pollution to consider, and the Mirai contributes to that in ways that an ICE vehicle does not.)

Meanwhile, the worst coal produces 2.17 pounds of CO2 per kWh, the best Model S (70D) - I figure that's about the closest I can get to a Mirai, and this comparison benefits the Mirai to use the heavy Model S - gets 33 kWh/100 mi, so about 21.8 kWh for the 66 mi that the Mirai is going, for 21.5 kg of CO2 to get the same 66 mi. But, that's on the worst coal you can get, and the Mirai isn't running on coal, it's running on 2/3 natural gas, 1/3 renewable sources.

So, let's use natural gas instead... and now the Model S is only puts out 12.1 kg of CO2 to go 66 mi. That's right, BURNING the natural gas and generating electricity with it is better than steam reforming it. And, if 1/3 of the electricity is zero CO2, that drops the Model S to 8.0 kg of CO2.

 

Those stats work - but why not count the many (in Cali) who recharge via home solar? Of course your home hydrogen reformer is one of those maybe someday off in the distant future thing. But since so many (locally) DO in fact recharge at home, it drops the CO2 significantly.
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I was being as kind to the Mirai as possible, to show how unsustainable it is even with those handicaps for the EV (using a much heavier EV, and powering it off of the same fossil fuels the Mirai is, rather than the more accessible renewables that an EV can be powered off of).

And, even if home hydrogen production with solar power becomes feasible, it'll take more solar panels to do it than it will to charge a battery. Even the losses of charging a battery during the day, then charging an EV from that battery at night, wouldn't be as high.

And, I mean, an ICE hybrid comes close, too.

 

I don't have the "energy" right now to check all your numbers, but on the surface it does not make sense to me. Steam reforming is not a very bad way to make H2, rather it's a very good way. Not too much CO2 is made because (1) natural gas is used and (2) about half the H2 comes from water (the "steam" in steam reforming). You're quoting an anti-FCEV political article as your proof.

 

It's worth noting that NREL is actually using more pessimistic estimates of the CO2e emissions, of 14.99 kg CO2e/kg H2 for California, than the source I used, though. (The source I used cited the NREL studies.) That would mean 14.99 kg CO2e/66 mi for the Mirai. Edit: Not counting the 1/3 renewable requirement. The California estimate by NREL is only considering electricity input, not the renewable requirement.

And, they're using 0.238 kg CO2e/kWh for California, so 5.19 kg CO2e/66 mi for the Model S when charged from California's grid, even better than my estimate earlier in the thread.

 

steam reforming on site of a large volume station (1500 kg/day) is the least expensive way to make hydrogen according to NREL. That "anti-hydrogen" site actually is a pro low green house gas site, so I don't think the charge applies. The science is rather anti-hydrogen right now if we focus on green house gasses.

Indeed when the pro hydrogen sites crunch the numbers SMR hydrogen which is all hydrogen available today in retail hydrogen stations produces more ghg in a fcv than a very efficient hybrid. That is why CARB is requiring the renewable portion, so that the numbers can work out better than a prius Many of us don't believe that a nationwide network of renewable hydrogen will be built unless entirely funded by tax payer dollars, so reject rosy scenarios. CARB is behind at building their renewable hydrogen, and actually doesn't require it with so few fcv on the road. A good place to check will be in 2021 to see what gets built and how much ghg per mile. One thing is certain, fcv are much less efficient than they were promised in 2009 by CARB which screws with their ghg numbers.

Definitely breakthroughs can happen, but its much cheaper filling a plug-in with renewable electricity than converting the electricity to hydrogen, liquifying it, trucking it to stations then dispensing it. That is why I would prefer the test be done with the least expensive hydrogen. Maybe there will be breakthroughs. Right now a Lexus ES hybrid looks like a lot more car for the money than a mirai in terms of luxury, acceleration, attractiveness, passenger room, and trunk volume. It only loses out slightly in terms of ghg.

I believe currently california is about 20 kg co2/kg of hydrogen which is much worse than cleanteca's estimates, but everyone expects future stations to be less ghg intense.

 

Well credit that to the CA grid as Model S is not the epitome of MPGe. Anyways you are in OH, and the only way you can match CA is import hydro from Canada (which CA imports from up north).

 

Yes, but I also cannot run a Mirai period, so there is that.

(Also, with Ohio's Energy Choice program, and generation suppliers that purchase renewable energy credits, I can have 100% renewable energy, and as of my next meter reading, I will be moving from 83% fossil (74% coal, 9% natural gas), 15% nuclear, and 3% renewable (1% hydro, 2% wind) - yes, I know, that equals 101%, so there's rounding errors in that disclosure - to 100% renewable (the plan I'm moving to can include wind, solar, hydro, biomass, and landfill gas, but the latest environmental disclosure says 100% wind).)

I'm also using the Model S for this comparison because if I used an actually high MPGe car, the argument would flip to the Mirai being a bigger car so of course it's less efficient. I'm giving the Mirai advantages in my comparison, not disadvantages, and it still loses.

 

I'll remember the OH renewables next time I fly into Cincinnati. yikes. But I lived I Cleveland when I was 3, then Pittsburgh.

 

I mean the S was already competitive without adjusting for CA grid; with CA grid, it blows the Mirai out of the water. Which is just fine, since the Mirai can only be purchased in, you know, CA.

In other news, I'm not sure where you're getting the idea that the S is not the "epitome" of MPGe. It's literally the most efficient car of its size class. 101 MPGe is nothing to sneeze at. But I did just notice that the Mirai is classified as a "subcompact", which would mean that we should compare it to an i3. Which gets 124 MPGe, can be recharged anywhere in the country today, and will beat 1/3 "renewable" hydrogen on 100% coal any day of the week.

 

Interesting that it counts as a subcompact, although I suspect that's because it's a 4-seater, which will likely affect how much hip room is measured. This would massively reduce measured passenger volume, forcing it down into the subcompact class, even though it's really more like a Camry in size (I looked at exterior dimensions (including wheelbase) when deciding to compare it against the Model S, instead of something like an i3 - 192.5" vs. 190.9" long, 71.5" vs. 71.7" wide, 60.4" vs. 57.9" tall, 109.4" vs. 109.3" wheelbase, so the Mirai is actually a little bigger than the Camry.)

Also, if the i3's on 100% coal, it does still lose if the Mirai's on NREL or CleanTechnica's estimates of hydrogen, although not on the 20 kg CO2e/kg H2 estimate that austingreen claimed (I would like a source on that, though). 124 MPGe is 27 kWh/100 mi, or on lignite coal, 17.5 kg CO2e/66 mi (to compare to the Mirai's 1 kg H2 performance).

 

Keep in mind CA original goal was smog control having ZEV for that purpose. Believe me, I never said that I agree with changing the CA goal to CO2 instead of smog and mandating ZEV for CO2 control. Not sure how we got here.

 

For smog control, the Mirai does work, as it lengthens the tailpipe, at least.

However, balancing smog control with CO2 control is important, and the Mirai utterly fails at CO2 control compared to BEVs in California's environment (which are at least as good at smog control), and barely wins given optimistic estimates against ICE hybrids.

 

Size classes are determined based on combined passenger + cargo volume. I suspect the Mirai ends up being a subcompact due to a tiny trunk.

 

Since neither Toyota nor the EPA post any interior measurements for the Mirai, we can only speculate as to whether the subcompact size class for it is based upon the actual interior volume or simply the default when the manufacturer doesn't submit the measurements to the EPA.

 

Out of curiosity do we have the equivalent of Fuelly for EV to be able to look up real world MPGe?

 

Not to my knowledge.
I've made that request to Fuelly actually.
However, part of the difficulty is in how you bring in that data.

Some people have a separate meter that measures the power being sent to a car. Some people don't though.
And since most EV owners simply plug in overnight and start with a full "tank" each morning, there really isn't a natural break for an owner to record the kWh used, even if they are monitored.

You could go off the car's displays, but some will point out that isn't necessarily as accurate.

 

First there are less than 200 copies in north america at this time. I doubt that is enough to get any kind of good sample on a fuelly. Second with the drivers not paying for fuel, I;d be suprised if they even tracked it well.

I have no idea if these cars have telematics like the leaf or volt, but if they do, then toyota should be able to provide data like gm does, but.... I would only expect them to show data if it looks good.

 

he was asking for EVs, not Mirai, and there are definitely way more than 200 Model S's on the road Tesla obviously has the data but I don't think they've ever shared it.

 

Well on fuelly YMMV, and does quite a bit so its hard to use. Tesla uses their data to give you range depending on your own personal trips in a easy to use calculator. It includes temperature, speed, your wheel choice, etc. This is way better than fuelly. It doen't provide the same data though, you need to divide the range by gge in a full charge which may vary depending on temperatuere (more energy needed for a full charge if its very cold as energy must be used to condition the pack), but someone could take their driving temperature profile and get an average mpge. Someone in califonia staying under 70 on the highway is going to do much better than epa, someone in Montana going in high speeds in cold weather will do much worse, but the numbers are there. GM makes volt data available but its nationwide.