# EV Versus FCV- Calculating CO2 Emissions and Volumetric Energy Density

3 years ago by George Bower 69

We Caught This Cutaway Of Toyota’s Fuel Cell Sedan In China Last Year

Slide 2

This is an EV site. It is called InsideEVs and it is for EV enthusiasts. Some have argued that FCV articles shouldn’t be posted here. I disagree. I’m an EV enthusiast but I also want to know what the competition is up to and how the vehicles compare.

We’ve heard these kinds of comments on previously posted articles about Toyota’s FCV:

“The hydrogen used in Toyota’s FCV will be made by steam reformation and therefore the FCV is just as bad as an ICE car when it comes to CO2 emissions.”

Toyota’s Fuel Cell Sedan

In order to test the validity of that statement I have put together some calculations that should bring light to the comparison.

Have you ever read a detailed well to wheels comparison? It can be a dizzying discussion. Do we need to include the CO2 that was emitted from making the tires on the transport truck? Are all the energy losses from transmission of the electricity included? What power plant did you assume when calculating your EV’s emissions…….and on and on.

The presentation I have put together is fairly simple. The numbers are easily checked by the reader. The only engineering calculations that need to be made are some unit conversions.

The EV and the FCV energy consumption numbers are included. The EV power plant emissions are included.CO2 emissions from the steam reformation process of making hydrogen are included. Transportation losses and line losses are not included. Leaving out the transportation and electric line losses would affect the absolute value of the numbers presented here. However, since the transportation and line losses are not included for both the FCV and the EV the RELATIVE values should still be valid for purposes of this discussion.
What are the CO2 emissions of the steam reformation process used to make the hydrogen? Reference 6 shows that a good round number is 10 lb of CO2 emitted for each pound of hydrogen produced.

We also need to know how much hydrogen Toyota’s FCV uses per mile ie miles/kg of H2.

It took some searching to answer the miles/kg of H2 question for the FCV. Probably the best source is an actual test done on Toyotas 70 Mpa Hylander- adv FCV. (see ref 5) (hat tip to Mr. Martin).

Slide 1

A value of 70 miles/kg of hydrogen is probably a reasonable H2 consumption rate for Toyota’s soon to be produced FCV.

Knowing the hydrogen consumption and the reformer CO2 the emissions are easily calculated as shown in slide 2. The CO2 calculation for the Prius and an EV are also presented as a comparison in slide 2.

Slide 2

However, comparing a FCV using steam reformation hydrogen is not really a fair way to compare the FCV because the California Air Resourced Board (CARB) has passed legislation that required 1/3 of all hydrogen to come from renewable sources as shown in slide 3.

Slide 3

Slide 4 includes the CO2 emissions calculated for the FCV with 30% renewable hydrogen.

Slide 4

One should note that both the EV and the FCV have low CO2 foot prints. Therefore it is the author’s conclusion that, from a CO2 emissions point of view, there are really no issues when it comes to EV versus FCV.

## Volumetric energy Density Comparison:

One would think that Hydrogen is a fairly dense fuel BTU wise. After all we used it in the space shuttle. The difference is that a FCV doesn’t use liquid hydrogen. It uses compressed hydrogen at 70 Mpa (10,000 psi). Ten thousand psi is pretty a high pressure but, even at 10,0000psi, hydrogen is not all that energy dense compared to gasoline on a volumetric basis. As shown in slide 5it is 1/7th the density of gasoline.

Slide 5

## Conclusion

Personally, I’ll take an EV. I live in a sunny climate and solar PV works well and integrates nicely with my Volt. However, if one lived in a colder climate with not much sun and had access to hydrogen made from renewables then a FCV might be a good choice.

### 69 responses to "EV Versus FCV- Calculating CO2 Emissions and Volumetric Energy Density"

1. DaveMart says:

Many thanks for an informative article, George.

My own position is that the two technologies go together very well, and the precise mix will be determined by how they progress relative to each other, which we can’t know.

What we can know though is that if you live in, say, Chicago, a BEV will suffer really badly in winter for range, and that you are going to be pumping in a lot more electrons for a mile of range.

If you had a 30kw fuel cell on board you would not have that hassle, as the battery (and you) would be kept at optimum temperature by the ‘waste’ heat from the fuel cell, whilst the range would be comparable with a petrol tank at very modest weight.

In turn, your 12kwh or so battery pack would mean that most of your running round would be on electricity anyway.

What conflict?

None at all, in my view, and all sorts of synergies can be found.

1. Mint says:

The conflict is cost.

PHEV has synergies. Low cost range extender, infrastructure is ubiquitous and a sunk cost.

FCPHEVs requires building massive new infrastructure for maybe 20% of their mileage, and everyone would have to pay thousands more over a PHEV.

The final nail in the coffin is that nobody is going to build this for you either, Dave. No FCV manufacturer wants its customers plugging in.

1. GeorgeS says:

@ Mint
@Nick

You have a point on compression losses. I have updated figures 2 and 4 to include 10% compression losses.

The revised numbers don’t change my conclusion though. CO2 emissions of FCV versus an EV are not an issue.

1. Mint says:

Compression losses only scratch the surface.

Your figure of 10 kgCO2/kgH2 is wholly unrealistic for SMR. It’s not 10% off. It’s over 60% off.

Check NREL’s study:
http://www.nrel.gov/docs/fy14osti/60528.pdf

And if you’re going to bring up CA’s 1/3 renewable H2, then also use CA’s grid carbon intensity.

Every comparison you make is based off that faulty 10kgCO2 figure. Your whole presentation needs to be revamped, because with realistic figures you will not arrive at this conclusion.

1. GeorgeS says:

Mint,

I wanted SMR emissions that don’t include transport losses. Your numbers from that report include transport losses. I stated right up front in the article that transmission losses and transport losses were left out of both sides of the equation. So the absolute values are optimistic but the relative values are reasonable.

Did you read reference 6? It’s an EPA report on CO2 emissions for hydrogen production. 10/1 is a decent number based on that EPA report.

As to Ca emissions: OK you got me on that one. I used .826 and reference 2 shows LA at 611. The national average is 1.2 so in fact I used a pretty clean number. It assumes the US cleans up the grid by 30%. I think that is a fair assumption as well.

So your 16/1 one number doesn’t apply here. You’ve done the classic apples to oranges comparison.

I still say my conclusion is valid and CO2 emissions of EV versus FCV isn’t where the issue’s are.

If they were an issue, why would California be backing fuel cell vehicles?

And the most important point in this whole FCV vs EV argument is this:

Hydrogen can be used as a storage medium for renewables. If you are a renewables fan then you better start liking hydrogen. They are making renewable hydrogen in Germany and they are legislating it in Ca as shown in slide 2 of this presentation.

1. Mint says:

First of all, you ignoring transport losses makes YOU the one doing an apples-to-oranges comparison. Your grid numbers include transportation losses getting electricity from generator to the battery.

But the difference in 16/1 and 10/1 is not just transportation. 16.6 is from central SMR with pipeline delivery (only 3% loss). 16.7 is from on-site SMR, which has no transportation emissions.

Your reference 6 cites a 2001 NREL report. My reference is a 2013 NREL report.

You’re using old and flawed H2 production numbers.

1. GeorgeS says:

Emissions are not an issue.

Just increase the renewable part to make the FCV cleaner.

You are arguing the same argument as anti EV people use when they criticize the fuel source of an EV …ie a dirty coal plant.

The FCV is still zero CO2 if you feed it renewable hydrogen.

If you want to criticize FCV’s. CO2 is an illogical place to start.

2. Mint says:

Let me do some calculations for you about the how much you pay for the environmental benefits of your solution.

Take a PHEV that goes 200k miles over its life, and does 20% on gas at 40 MPG. That’s 1000 gallons of gas, and assuming WTW emissions of 11kgCO2/gal, that’s 11 tons of CO2.

Toyota’s non-plugin FCV will cost \$50k more than a non-plug-in Prius, but I’m going to make life easy for you with magical assumptions:
-a mere \$5k premium for that 30kW FC
-renewable H2 costs the same as gasoline per mile
-no CO2 emissions to build H2 infrastructure

Even with all these assumptions helping your case, your solution to eliminate a PHEV’s CO2 emissions costs…

\$454 per tonne.

It’s a complete waste of resources. We can easily clean up the grid for 1/10th of that price.

3. Djoni says:

No conflict at all!
The only synergie is that a FCV absolutely need a battery as a buffer, and a BEV only need a battery, an nothing else.
Why bothers with something you don’t need?

4. Mark H says:

Still waiting for the FCEREV solution. Then I will believe the manufactures are serious about solving the issues. A FCEREV makes the most sense to me for the part time long distance traveler. Such a solution that allowed you to choose energies, especially when the hydrogen infrastructure is trying to evolve. I could consider such a solution. Still prefer AER drive when I can get it. Like George, the Volt EREV matches my need, but a 200 mile BEV with proper infrastructure would also suffice.

1. Priusmaniac says:

If a fuel cell has to be used as a range extender, then it would be much more convenient to use a direct bioethanol one rather then an Hydrogen one.

2. Josh says:

Great article George!

Someone needs to follow it up with an economic comparison along the same lines.

3. Nick says:

One missing consideration in this analysis is the energy efficiency of generating and compressing hydrogen vs charging a battery.

It takes much more energy to move a FCV a mile vs an EV.

You’d reduce CO2 much more by using the renewable energy you would have used to fuel an H2 vehicle and instead send it to the grid to replace fossil fuel generation. You’ll even have enough energy left over to charge your electric car. 🙂

1. DaveMart says:

Losses wall- battery ~10%
Compression costs ~10%

1. Jsmay311 says:

Efficiency ratings for BEV’s include charging losses.

Hydrogen FCV consumption ratings (presumably) do not include energy used for compression, since that process would not consume any H2.

1. DaveMart says:

I personally as well as far more august people and organisations like the DOE have gone through extensive calculations and any way you cut if FCEVs and BEVs are pretty much level pegging on CO2 emissions and energy consumption down to very low levels.

Out on interest though the compression losses for hydrogen using ionic compression now approach 5%.

1. Mint says:

Yes, there have been more rigorous calculations of CO2 emissions from SMR based H2 production. And they come up with numbers like 16.7 kgCO2/kgH2:
http://www.nrel.gov/docs/fy14osti/60528.pdf

That’s 67% higher than the 10kgCO2/kgH2 that George is using.

2. Mint says:

The battery losses are already included in the EV numbers.

Compression and a whole bunch of other losses are not included in his 10kgCO2/kgH2 number.

3. Nick says:

Your response fails to refute my point.

4. offib says:

Very good article! It’s certinally worthy of any reference to the subject. What I would like to know is, in Slide 2, how much would the g/mile figure differ if the Model S-like 2.8 miles/kWh was 3.8 miles/kWh? A realistic figure for the likes of the LEAF, Zoe and e-Golf.

5. Rob Stark says:
6. scott franco says:

“The hydrogen used in Toyota’s FCV will be made by steam reformation and therefore the FCV is just as bad as an ICE car when it comes to CO2 emissions.”

Hard to address this kind of stupidity if you don’t quote a source.

Nobody is saying FCVs are equivalent to ICE, but they are equivalent to CNG vehicles, since they simply move emissions down the street to the reformer.

There’s nothing wrong with CNG vehicles, either. They are far cleaner than ICE, and you could equivalently argue that EVs move their emissions to an LG burning power plant in the best of cases (that is indeed how it works in california).

I don’t see FCVs as practical at the moment on cost grounds. The proponents say they will improve, but so will EVs, and FCVs are looking at the same 300 to 400 mile limits because of the need to carry a big pressurized can in the trunk.

That’s why my money is with EVs. If there were a decent light truck that ran on CNG I would take that as my long distance car as well. An aluminum Ford 150 burning CNG might be a good idea.

The one thing I AM sure of is no more straight ICE vehicles for me. I don’t care if american car makers wake up to the new reality in time to avoid their next bankruptcy.

1. DaveMart says:

Even after reforming losses fuel cells are considerably more efficient than CNG.

2. Priusmaniac says:

Actually making electricity by burning fossil gas is the worst case scenario. Making electricity by burning efficiently encapsulated, striped from its Oxygen and safely stored deep underground CO2, also called by some coal, is not a worst case, it is a crime against the global climate and by that a crime against all living things including humans.

7. Rob Stark says:

100 kWh for BEVs gives us

Transmission lines are 94% efficient not 90%.

AC-DC conversion charging is 85% efficient.

EV with regen braking is 90% efficient.

100 kWh of renewable energy gives us 72 kWh of forward motion.

100 kWh of renewable energy for Hydrogen

Gives us 95% AC-DC conversion efficiency.

Electrolysis is 75% efficent.

Transport is 90% efficient.

Fuel Cell is 50% efficient.

FC drivetrain is 90% efficient.

100 kWh of renewable energy gives us 26 kWh of forward motion.

72 kWh > 26 kWh

Fuel cells are bovine feces.

1. DaveMart says:

10% is losses in charging the battery in addition to the 6% losses in transmission.

Your figures also take no account of storage losses for the renewables, which hydrogen solves.

1. Rob Stark says:

I account for AC-DC charging.

Hydrogen “solves” energy storage by wasting 29% of it.

Batteries in and out of BEVs store renewable energy.

Fuel Cells are no where near as efficient.

Fuel Cells are bovine feces.

2. Ambulator says:

Fine, use hydrogen to store solar and wind power if you want. (I’d prefer nuclear, and so would you.) Don’t try and ship hydrogen all over the country, though, just use it to produce electricity. Then we can still fill up at home.

3. Mint says:

Learn to read. He already put 15% loss going from the grid to the battery.

EVs mostly charge at night, and can charge faster or slower depending on wind output.

Read up on grid integrated vehicles. High EV penetration makes the storage problem go away not only for renewable energy used to power themselves, but for the entire grid. You accidently brought up a point that favors EVs.

8. Peder says:

Here’s my perspective after 6 years and 110,000 miles of pure ev driving powered by sunshine. It has nothing to do with well to wheel.

If you can imagine for a moment that the Laundromat had this incredible upgrade in technology that could wash your cloths, dry your clothes in half the time half with half the cost, using 25% of the energy with the remaining 25% generated by wind or solar……

Would you stop doing the laundry at home and return to the Laundromat?

Once you’ve had the experience of no longer needing to go to a station to pump gas or hydrogen, why on earth would you go back.

At home if you were able to crack Nat gas into hydrogen and then compress it to the levels needed for the hydrogen car, I’m guessing that the system would cost a bit more than a \$450 clipper creek L2 charger.

It just makes no sense at all in my mind.
Cheers!

1. DaveMart says:

‘Here’s my perspective after 6 years and 110,000 miles of pure ev driving powered by sunshine.’

Except you do no such thing.
You provide power to the grid from your solar array, and charge your car from the good old grid.

You just like to misstate this.

That is all fine in San Diego, as the power to the grid comes in about when it is wanted, but is not much use in Chicago in the winter.

At average yearly temperatures in Chicago you would be fine going out in shirt sleeves.

Don’t try it in January though, as whatever the yearly average is you will still find it chilly.

1. vdiv says:

A wind turbine farm would do just fine in Chicago.

2. Peder says:

Here we go again DaveMart 🙂 I think we have a difference of opinion that is well defined over many emails.

I make 13,000kWh of electricity via our Solar PV system. I use 13,000kWh of electricity to power my home and my two cars. Of course each and every exact kWh does not get used by my house or cars as I produced more during the day and I choose to charge my cars at night because it is cheaper and better for the grid, even though I could charge them during the day.

When I overproduce some lucky person near me is using the clean energy that I have generated via Solar PV.

Said a different way, I make \$13,000 and then over the course of the year, I spend \$13,000. Is it the exact same dollar bill? No. Is it my money that I have earned? Yes.

The dollar bill is not exactly the same, but it is still my dollar bill and I call it my dollar, not someone else’s or the banks.

You seem to not want this to count this unless the \$13,000 was stored in a mattress and each and every paper dollar bill spent was exactly the same one that I earned.

When storage comes on line and I can put my energy in my “storage mattress” so to speak, I wont do that. In cities it will still be better to be connected to the grid to be shared, especially the more valuable energy produced during the day via Solar PV, than off grid with energy storage.

Grids are giant sharing system which are more efficient than each of us having our own mattresses stuffed with money.

I’ve mixed metaphors enough but I think most, if not you will get my point.

It’s my money even if it’s in a bank, and it’s my energy made by harvesting sunshine even if I give and take from the grid.

I live and drive on the sunshine that I harvest and it is a very awesome feeling to be able to that.

Cheers!

3. We can move to 100% renewables. We need to move to 100% renewable energy – in fact, we must do this.

Just because the whole grid has not got there yet, doesn’t mean that what Peder is doing less than he claims.

There is way more potential for generation of all the electricity we use from renewable energy.

And we need electric cars to be able to make full use of renewable electricity.

The irony of hydrogen is that there is NO infrastructure, and there are tiny supplies of hydrogen, and there are a whopping dozen or so public hydrogen filling stations, and the cars are always “coming soon”.

We cannot have our modern lives without electricity, and we have an electrical infrastructure in place. Lets improve it, and switch over to renewable generation, and use it in the most efficient way we can.

That is *not* FCEV’s – it is EV’s.

9. Omar Sultan says:

How come every discussion of EVs and FCEVs in some way depends on comparing the current state of EVs vs the future state of FCEVs. This statement is a perfect example:

“However, comparing a FCV using steam reformation hydrogen is not really a fair way to compare the FCV because the California Air Resourced Board (CARB) has passed legislation that required 1/3 of all hydrogen to come from renewable sources as shown in slide 3.”

First, it is “fair” as steam reformation is the way most H2 gets made and simply because CARB mandate it does not mean its going to magically appear and be at an economically feasible price point. Second, the law only talks about publicly funded H2 stations, not all H2 stations, unless you want to argue all H2 stations should be publicly funded.

I could just as easily argue that we should compare FCEVs against EVs that are 100% powered against renewables as that is actually happening today. Either compare current state for both technologies or future state for both technologies, anything else is flawed analysis.

1. Khai L. says:

+1

2. Exactly. Getting that much hydrogen from renewable energy sources and then is transported to all the filling stations – is not likely to happen any time soon.

If the same quantity of electricity that was used to make the hydrogen – was used in EV’s instead – it would move more cars much farther. The losses in making hydrogen with electrolysis and transporting the hydrogen and then compressing the hydrogen vs grid losses (which are typically just 8%), mean that FCEV’s are not nearly as efficient as EV’s.

10. jmac says:

Thank you Omar Sultan. Apples to apples and oranges to oranges.

Cost to operate:

Gas ICE 10 cents/mile
FCEV 10 + per mile steam H2

Pure BEV 02 cents/mile

1. A typical 23MPG vehicle costs ~15¢ / mile.

Plus the costs of regular maintenance – ICE’s cost up to 3.5¢/mile for regular maintenance. EV’s have virtually no regular maintenance costs.

11. Assaf says:

George, thanks for a well-invested article.

My position as argued elsewhere, is that we should look at the forest rather than the trees.

Forest meaning, the role of EVs or FCVs a couple of decades down the road. In order to arrive anywhere 20 years from now, either type of vehicle needs to colonize the market rapidly now, meaning adoption across the board in more and more localities.

From that perspective, today’s specific local electricity mix, or the method of converting your particular FCV’s H2, matters less, especially if there’s a clear roadmap towards making either source renewable.

IMHO it seems that there might not be enough renewable H2 for the entire global fleet. Conversely, BEVs might not be able to cover each and every ground transportation need even after production capacity, range, etc. are there. So a certain proportion of plug-in FCVs, in an overall fleet dominated by BEVs, might be useful. OTOH it might be just as easy to keep PHEVs for that sub-fleet as argued above.

Also, two specific corrections regarding source mix and BEVs:

– The current US power source mix is around 30-35% coal and continually dropping. The 45% you have in your figure is probably from a few years back. That’s beside the fact that even in an coal-dominated region, charging at night means using waste electricity b/c most (all?) US coal plants cannot adjust their output between day and night.

– The current crop of BEVs (2013+) has an efficiency of ~4 miles/KWh or more. 2.8/KWh (again in your figure) is perhaps the efficiency of a Tesla P85, not a plain-vanilla compact one.

1. vdiv says:

39% from coal last year.

http://www.eia.gov/tools/faqs/faq.cfm?id=427&t=3

It went up this year because of the cold winter.

Both BEV and FC efficiencies decrease with lower temperatures. While we know that Li ion batteries do work, it remains to be seen how FCEVs operate in the cold Chicago winters that DaveMart talked about.

12. JakeY says:

The best comparison I have seen right now is the GREET model:
https://greet.es.anl.gov/results

And if you are going to use California FCV emissions, I’m not sure why you didn’t use California electricity emissions, which come in at 0.524 lbs CO2 per kWh according to PGE, which works out to 87g/mi for the EV.

And the biggest problem is we do not have data on the *real world* emissions of hydrogen generation. For electricity the EIA is already collecting real world emission data, but we do not have the same for hydrogen. Therefore we only have theoretical numbers to go by for hydrogen and these typically end up optimistic.

13. JakeY says:

Also for the volumetric energy density, you have to account for the relative efficiencies to see how much useful range you actually get out of that density.

And for the hydrogen side, you must also include the volume of the tank(s), the fuel cell, air intake and exhaust, buffer battery, because that is all equipment is necessary to have an equivalence with what a battery does in an EV.

And in terms of volumetric density, the Volt pack is a low density pack in the first place.

All of these factors is why unlike what your numbers of suggesting (that hydrogen FCVs have 10x the range of EVs), the range is actually about the same.

1. We cannot forget the protective structure that is required to protect the high pressure hydrogen tank(s) in a crash, and to prevent any hydrogen from leaking in a crash.

Having an air tank at 10,000psi would be potentially dangerous in a crash. Hydrogen at 10,000psi is more dangerous, because hydrogen is acidic and explosive.

14. Jeff N says:

“Slide 4 includes the CO2 emissions calculated for the FCV with 30% renewable hydrogen.”

If you assume this California mandate for renewable H2 then you should likewise assume the EVs run on California grid electricity and its 33% renewable source mandate for 2020 (which is in addition to the existing 10% large hydro power).

15. Anon says:

How corrosive are the materials in these new fuel cells? Corrosion was a BIG issue with early hydrogen fuel cells… What’s the reasonable real world lifespan of the units Toyota is using? How well do they cope with impurities and moisture from underground storage tanks, vibration from road use, and hold up over a lifetime of refueling? There are a lot of reliability and replacement (TCO) issues that are just not being addressed with these early hydrogen vehicles…

1. Excellent question! Hydrogen is incredibly acidic. H₂ is the second smallest molecule and it leaks right through many “solid” materials.

Last I’ve heard fuel cells last ~75,000 miles. And they ain’t cheap.

16. jmac says:

I already have an electric chain saw. It cost me less than the 2 cycle ICE chainsaw.

Now, the H2 people are telling me I need to buy a hydrogen-electric chain saw ?
——————————————-

I think that’s what is known as an oxymoron.

Diesel-electric trains actually run on diesel fuel, just as fuel cell vehicles will run on hydrogen.

Please don’t tell me that “FREE” H2 will come from excess renewables production. It will not be free.

The companies hydrolysing H2 will have to buy it from the renewables providers.

The idea that electrically split hydrogen will suddenly become “cheap” just because there sometimes exists sporadic excess production from renewables is nonsense.

17. BraveLilToaster says:

Even with CARB’s renewable for H2 mandate, it’s still just as clean to actually *burn* CNG in an ICE as it is to reform it into H2 for use in a fuel cell vehicle.

The difference is that it’s *way* cheaper to make an ICE burn it than it is to do all that crap that makes a FCV go (including the part where you have to build the fuel cell). Especially with CARB’s mandate.

1. Agreed.

Nobody who is advocating for the use of hydrogen in cars – has said HOW hydrogen will be made and transported over the entire country. Who will pay for the infrastructure? How much will hydrogen cost?

18. Kosh says:

Maybe someone has said this already, but it seems to me the real market niche for FCV should be in semi-trucks. They really need the range and it will clean them up greatly.

Kinda like Bob Lutz said… electrify (or hydrogenate) the right end of the spectrum.

1. GeorgeS says:

This is an excellent point and the main reason I included the fuel density chart.

Yes hydrogen is more dense volumetrically than a battery….but still 1/7th of gasoline or diesel.

I think this must be part of the reason that we haven’t seen a lot of proposals for FC’s in large trucks.

I can picture a hybrid truck though. You would use diesel fuel for the open road and switch to FC’s in town.

Or here is another interesting idea:

We know that large trucks are now using LNG (liquid natural gas).

We saw in another article here that Germany is already “spiking” natural gas with hydrogen from renewables at concentrations up to 20%.

http://insideevs.com/using-hydrogen-battery/

Perhaps one could use “spiked” LNG in long haul trucks. That would drop the CO2 emissions to even lower than LNG which already has a low CO2 footprint.

19. A couple of points: a fuel cell vehicle (FCEV) is an electric drivetrain. It has a battery. Just not as large a battery as a BEV.

And yes, a FCEV can be run with hydrogen made with renewable energy – but it takes a lot more energy than does a BEV.

The energy overhead formulas need to include transportation of the hydrogen (and the grid losses for EV’s) and the compression of the hydrogen; which is not trivial.

Similarly, gasoline doesn’t appear out of thin air – there is a very long chain to find the oil, drill / frack the oil, extract the oil, transport it, refine it, transport it some more, and then finally pump it into the car.

ALL the energy used along that long chain, then has a chain of supply for *it*, including water, electricity, natural gas and other materials using in the drilling / fracking. Extraction and refining stages are very energy intensive.

It takes as much – or more – electricity to make gasoline, than it takes to run an EV. This whole “long tailpipe” issue is moot.

1. mike w says:

+1 I have seen the calc you mentioned on another web site but nobody seems to understand how long and how energy intense it is to produce gasoline and the Hydrogen model would be pretty much the same.

20. Nand says:

I did the math on Carbon foot print calculation for Electric vehicle(EV) vs Internal
combustion cars(ICE) aka Petrol, Gasoline cars taking into the account of all the
energy source carbon footprint for US. I found that ELECTRIC CARS PRODUCE ONLY 33% OF
THE CARBON FOOTPRINT FOR AN EQUIVALENT PETROL(GASOLINE) CAR. For simplicity sake I am
comparing Honda Civic vs Nissan Leaf.

———————————————————-
Here is the calculation.

01) Amount of CO2 emitted by using 1 US Gallon (3.78Litres) in a car = 8.88 KG of CO2
a. Reference A

02) Approx amount of CO2 emitted by refining 1 US Gallon (3.78Litres) = 4.4 KG of CO2
a. Reference B

03) Total amount of CO2 emitted by using & refining 1 US Gallon (3.78Litres) = 13.28 KG of CO2
a. From point 1, 2

———————————————————-

04) Total miles driven by most fuel efficient Gasoline(Petrol) car like Honda civic for 1 gallon = 33miles
a. Reference C

05) Amount of energy taken by a Nissan leaf to cover 84 miles = 21 KWH
a. Reference D (Only 21 KWH of 24 KWH Leaf battery is used)

06) Amount of energy taken by a Nissan leaf to cover 33miles = 8.25 KWH
a. From point 5

07) Amount of CO2 emitted to produce 1 KWH using Coal power plant = 0.97 KG of CO2
a. Reference E
b. Approximately 39% of the electricity production is from coal

08) Amount of CO2 emitted to produce 1 KWH using Natural Gas plant = 0.55 KG of CO2
a. Reference E
b. Approximately 27% of the electricity production is from Natural Gas and rest coming from non-carbon source like Nuclear, Hydro, Wind, Solar

09) Approx amount of CO2 emitted to produce 1 KWH in US = 0.53 KG of CO2
a. Approximately 67% of the electricity production is from coal powered, natural gas and rest coming from non-carbon source like Nuclear, Hydro, Wind, Solar
b. Reference F

10) Approx amount of CO2 emitted to produce 8.25 KWH in US = 4.35 KG of CO2

11) Approx amount of CO2 emitted to run a Nissan leaf for 33 miles in US = 4.35 KG of CO2

12) CARBON FOOT PRINT PERCENTAGE OF NISSAN LEAF/ HONDA CIVIC FOR RUNNING 33 MILES = 32.73%

1) Savings in foreign exchange money that goes to adversary countries in Middle east

2) Shifting of the pollution from densely populated cities to less densely populated areas

3) As Coal plants are in decline and non-carbon emitting energy source like Wind, Solar, Nuclear increase their share, the carbon foot print of electric car will improve further

4) Electric cars provide regenerative braking which gives lot of energy savings in congested city traffic driving

Reference:

1. sven says:

Thanks for showing the calculations to backup your conclusion!

Here’s a map showing how the CO2 emissions of ICE cars compare to EVs on the various US regional electric grids. As expected, there’s a vast difference between the dirty and clean grids.

http://www.greencarreports.com/image/100440262_electric-car-wells-to-wheels-carbon-emission-equivalencies-in-mpg-union-of-concerned-scientists

2. Jeff N says:

You lost me at step 2…. You’re quoting a YouTube video as your authoritative source for CO2 refining overhead per gallon of gasoline?

Unfortunely, you are referencing a grossly inaccurate FullyCharged episode called “Volts for Oil” which I debunked at the link below. Briefly, he claims in the episode that UK refineries use 10-15x more grid electricity per gallon of refined gasoline than they actually use. He claims that there is an oil company conspiracy that blocked the UN from reporting their grid electricity use several beginning several years ago but in reality the UN continues the publish that data. The entire episode has no credibility. See details here including links to the online UN data and the fact-based basic calculations showing grid electricity per gallon of UK gas:

http://www.mynissanleaf.com/viewtopic.php?f=13&t=16852&p=368701&hilit=Llewellyn#p368701

“02) Approx amount of CO2 emitted by refining 1 US Gallon (3.78Litres) = 4.4 KG of CO2
a. Reference B”

The U.S. Argonne National Labs GREET estimate for upstream CO2 on a gallon of gas including refining is about half of your refining CO2 estimate. I haven’t looked up the most recently updated GREET value for the total tailpipe plus upstream CO2 but I think it is approximately 24-24.5 pounds per US gallon and tailpipe is 19.4 pounds (8.8 kg) so the GREET upstream component is 4.6-5.1 pounds (2.1-2.3 kg) versus your 4.4 kg.

3. Jeff N says:

And again at step 5….

“05) Amount of energy taken by a Nissan leaf to cover 84 miles = 21 KWH
a. Reference D (Only 21 KWH of 24 KWH Leaf battery is used)”

That implies 25 kwh per 100 miles but the actual 2015 Nissan LEAF EPA rating equivalent to your Honda Civic example is 30 kwh per 100 miles. You forgot about AC/DC battery charging overhead. The 25 kWh number is energy already in the battery — 30 kwh is electricity from the wall socket which is what you need to be using.

See fueleconomy.gov for details.

1. Nandakumar says:

Will definitely look into the links and get back to you folks

4. Jeff N says:

This report has that handy table which lists the energy used in the refining process by type, absolute amount, and by its percentage of the total energy used. This document reports that 5.2% of the refining energy is grid electricity. Other reports that I have seen are as low as 3.5%. The amounts vary by year, refinery, and type of crude oil being processed but 3.5-5.2% seems like a typical average for grid electricity.

See Table 3 on page 5 of this 2011 ANL report on petroleum refining efficiencies in the United States.

https://greet.es.anl.gov/files/petroleum

The total energy of all kinds listed in the table typically makes up 5-7 kwh of energy (not electricity) for every gallon of gasoline.

21. Ryan says:

If California would drop any and all support or ZEV credits concerning hydrogen; so too would Toyota.

1. I would simply argue that hydrogen is not “zero emission”, and not eligible for the program.

But, of course, virtually EVERY auto maker would drop their battery electric cars, too, if the ZEV program went away (again, like 2003).

Only Tesla, Mitsubishi, and maybe Nissan would survive.

22. Loboc says:

CNG fuel cell comparison may be needed as well. If you’re reforming NG anyway, why not do the whole thing on board.

23. shawn marshall says:

more CO2 is beneficial. Don’t be fuelish. EVs must be economic.

1. Bill Howland says:

Yeah, just throwing some moral support your way, Shawn.

I’ve asked several times, but no one can give me a realistic, everyday, minimally subsidized, roaduse tax included H2 GGE price per GGE at the pump.

Or who is going to buy these cars other than fleets.

Although there are a few problems, I see most of the country going the LNG/CNG route for large vehicles. I have my ear to the ground and I hear the former, not H2 vehicles.

Granted this could change, but in the meantime I would like to know pricing, since thats what the vast majority of sales is going to depend on.

By the way, I’ve always used 125,000 and 140,000 btu/US gallon for gasoline and oil, respectively.

1. Bill Howland says:

Maybe 116,900 btu/ US gallon includes that crappy ethanol which is the vast majority of gasoline sold here.

1. sven says:

It looks like the average US btu per gallon of gasoline in 2013 was 120,500 btu, down 4% from 124,500 in 1993.

http://www.greencarcongress.com/2014/10/eia-us-gasolines-average-energy-content-per-gallon-declined-3-from-1993-2013-due-to-increasing-ethanol-fraction.html

1. sven says:

Oops. It’s down approximately 3%, not 4%.