Hydrogen Fuel Cell Toyota Mirai Energy Efficiency Compared TO BEVs


Occasional InsideEVs contributor Mark Larsen assembled this graphic that compares the energy efficiency of the hydrogen fuel cell Toyota Mirai to several of today’s pure electric cars.

Recently, the official EPA figures for Mirai were released – 67 MPGe and 312 miles of total range.

Larsen Tweeted:

Mark Larsen ‏@yanquetino

Sorry, @Toyota, but your #Mirai wastes too much energy for me.

*For more of Mark Larsen’s electric vehicle related works, check out his website here.

Category: Toyota

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66 responses to "Hydrogen Fuel Cell Toyota Mirai Energy Efficiency Compared TO BEVs"
  1. offib says:

    I am going to print this, frame it and hang it on my wall!

    1. european point of view says:

      Yes print the very poor efficiency of Tesla (and the Mercedes BEV powered by Tesla) compared to its peers BMW , Nissan , Mitsu

      1. Open-Mind says:

        Full-size high-performance long-range luxury super-cars are inherently less efficient than smaller, slower, more average vehicles. It’s a simple design trade-off.

        1. jelloslug says:

          So what is the excuse for the Mirai?

      2. Mint says:

        In what universe are those vehicles considered peers of the Model S?

        That’s like saying a Prius (or at best a 320i) with a 2-gallon gas tank is a peer of the CLS 63 AMG.

      3. MDEV says:

        Yes Mercedes S Class underperform compare with Mercedes C class with way less miles per Gallon. Troll comments.

    2. Chris O says:

      I won’t.

      Per de PDF of Hydrogenics, the people that actually build these electrolysis stations it actually takes 69KWh rather than the 60KWh Larsen uses as one of his base assumptions to make one kilo on hydrogen, so hydrogen efficiency is even significantly worse than this graph suggests.

      1. finecadmin says:

        And THAT’S not including the prep and pumping energy of drinking water systems. One of the biggest single users of power in most towns.

  2. Ambulator says:

    Is this really fair? There are transmission and charging losses in a BEV. There are also electrolysis, compression and transmission losses in the Mirai. To be fair all of these need to be accounted for, and I am uncertain if they are.

    1. RS says:

      Not really, if the H2 is produced with electrolysis, it had transmission losses before and the fuel cell charges a battery, so you have charging losses as well. The only thing not fractured in are compression losses of H2, if you assume it is produced at the hydrogen filling stations.

    2. Will says:

      People always bring up transmission losses, all the time. I really don’t understand why, considering transmission losses are on average 10%, and as the other commenter said, these losses also apply to the hydrogen stations.

      Charging losses on the other hand are minimal. A decent power supply can convert AC to DC or downscale to a charge current with an efficiency close to 92%.

    3. jerryd says:

      EV charging eff is over 95%.
      But H2 takes 66kwhr’gal gasoline equivalent to make according to Toyota or only 60% to start before going in the tank, both from solar.
      So take 120 miles off of the FC car for those losses.
      Next take the distance to the H2 station from home from it.
      Next how much time does it take to get to, from the station?
      Since there are few H2 stations, real range is only 140 miles from the H2 station.
      How come they can’t sell the few available even with free fuel?
      I bet Toyota, Honda doesn’t even sell the few they will build.
      When an EV only takes 30 seconds to recharge and a full tank ever morning.
      With just 120 mile range and battery/clean fueled range extender will beat a foolcell car into the ground in every way.
      And let’s not forget how many FC moving, hot parts, systems, compressors, etc to
      I think this replacement parts sales might be why they are pushing these as EV’s kill that business by 66% or so.
      With gas cars it’s a big part of their profit marking them up 2,000% from costs studies have found.

      1. Foo says:

        Actually, EV charging efficiency is more like 80%.

        1. neptronix says:

          Depends on the EV.
          I have a newer 95% efficient charger over here. The charger i had before was 79% efficient, but that was last generation tech.

          One could consider compression to be an energy loss in hydrogen fueling. I don’t know how bad it is. But compressing a few kG of hydrogen to a 10,000 psi probably isn’t pretty.

          1. ModernMarvelFan says:

            The charger is in the car.

            Most of the charger loss at least 15% before it gets to the battery.

            EPA uses that figure.

            Transmission loss used by EIA.gov is 7%

    4. Pushmi-Pullyu says:

      No, the graph above is counting only the car’s efficiency in using onboard energy. The massive amount of energy lost in all the steps necessary to get hydrogen into the car’s fuel tank are not considered.

      To be fair, a “fool cell” car is more efficient at using energy stored on board than a gasmobile. But the massive energy loss before the hydrogen gets to the fuel tank makes it even worse, from both an environmental perspective and an engineering/efficiency perspective, than the gasmobile.

      1. sven says:

        I think you are mistaken. The second star bullet point at the top of the graph says “60kWh-per-kg using compressed electrolysis.” Either they are factoring in compressing the hydrogen after electrolysis, or they used high-pressure electrolysis (electrolyzing highly-pressurized water gives you compressed H2).


        Is Pushmi-Pullyu the new nom de guerre for the poster formerly known as Lensman?

        1. finecadmin says:

          Is sven the same nom de merde for “idee fixee”?

    5. Djoni says:

      I’ve read a very well documented comment on this site about MGPe being exactly evaluate at the plug beforre de EVSE.
      So it’s exactly what is taken from the grid to propel the car.
      Transmission loss is pretty small and vary from place to place depending of many factor, but are usually round up at no more than 15% in the worse case.
      What about leak loss from hydrogen?
      What about efficiency loss of the fuel cell?
      Sometime a valid comparison is a valid comparaison without having to explaine every insificant matter.

      1. Djoni says:

        Boy did I write badly there!
        Sorry folk!

  3. zoe-driver says:

    My Renault ZOE needs 18.8 kWh per 100km. This includes all charging losses and is a measured mix from 32,000 Km in summer/winter. Winter with winter tires of course.

    So 279.4 kWh / 18.8 = 14.86 * 100 km
    equals to 930 Miles or 1486 Kilometers

    Astounding ! Thank you for that Information. I am going to use that in my e-mobility presentations.

    Most significant drawback of Mirai:
    Cant be charged at work / home / friends.

    1. M Hovis says:

      Agreed. A very useful graph provided by Mark Larson. I think what would also help this is to pick two ICE models with largely varying MPG and finding one with poor MPG that compensates with a larger gas tank.

      Really what good is touting 300+ mile range when it will be 20+ years before you are interstate capable.

      I find it further amazing that particular new organizations hail the potential 3,000 Mirai sales over the first 3 year period, yet consider 60,000 Volts in the same period a failure. That’s fair and balanced for ya…

      1. Lustuccc says:

        Add also the price you pay, h the price to produce and the unaccountable environmental damages! lol!

    2. mr. M says:

      You forgot efficiency of transition. Actuallly it’s 279,4*0,77/18,4 = 1169 km or ~730 miles.

      This a little bit better than the Leaf and equal to the eGolf.

      1. Pushmi-Pullyu says:

        Hydrogen fueled cars are only about 25-33% efficient in well-to-wheel efficiency; far worse, and far more polluting, than either a gasmobile or a BEV.


        1. sven says:

          That article is almost a decade old and part of the analysis is flat out wrong, making the wheel-to-wheels efficiency appear lower than it is. For example the article states:

          “the pressurized tank needed to store [hydrogen gas] is very heavy, large and expensive. So if we wanted to use it in a vehicle, we would have to liquefy the hydrogen by cooling it down to about -253°C and keep it in a pressurized, insulated container instead. This process would cost another 30% to 40% of the energy in the hydrogen.”

          The Toyota Mirai, Honda Clarity, an Hyundai Tuscon FCV do not use cryogenically liquified hydrogen, and therefore the 30% to 40% figure above is invalid, as it the 25-33% WTW efficiency figure.

      2. arne-nl says:

        No he didn’t. As stated, the 18.8 kWh/100 km includes the charging losses.Your multiplying by 0.77 actually double counts the charging losses.

        My Zoe yields about the same 18.8 kWh/100 km figure, measured from the switchboard with a 1% accurate meter. When I compare that to the dash readout, charging efficiency for the Zoe is 87%.

        1. mr. M says:

          Ok, sry bout that. Cool to see that the zoe performs so well 🙂

        2. Anon says:

          The Zoe is awesome. Renault needs to sell them in the US. TO ALL STATES, not just CARBies.

  4. CDAVIS says:

    Using the MPGe metric gives FCEVs way more credit than they deserve.

    MPGe is a worthless metric especially when applied to FCEVs because the formula makes costing/efficiency assumptions of the fuel source a universal static conversion which it is not.

    Its like having a MPHBe (mile per hay bale equivalent) metric to compare horse drawn carriages against gas cars and electric cars.

    1. CDAVIS says:

      … or worse yet, using MPHBe to compare one electric car against another electric car same as being done with MPGe.

  5. Forever green says:

    Tkanks very much for the comparison chart.The Toyota Mirai is a waste of time and energy.

  6. Forever green says:

    The Toyota Mirai is also a waste of money!

  7. jmac says:

    Batteries are more efficient than fuel cells in Electric Vehicles.

    We have all known this for some time, but it’s nice to see it on paper as an easy to understand graph.

    A Natural Gas fired plant makes electricity, then sends it over wires to charge an EV battery. Clean and simple.

    With the hydrogen fuel cell however, a gas fired plant makes electricity which is then used to hydrolize water to make H2 which is stored in tanks inside EVs. The hydrogen is then reacted with O2 to make water and electricity on board the EV.

    With pure battery EVs you only generate electricity once. With fuel cells you are forced to generate electricity twice. Once at the plant and once inside the vehicle.

    Hydrogen is simply an unnecessary, additional energy transfer.

    Electricity from a Natural Gas generating plant can also be used to make steam to reform natural gas into hydrogen. Steam reformation is more efficient dollar-wise than hydrolysis but once again, we have the additional unnecessary step of producing hydrogen instead of just using that electricity from the grid to directly to charge batteries..

    1. finecadmin says:

      Yep, can’t beat the Second Law. Conversion processes always lose to no-conversion-process, including heat conversion and gas reforming.

  8. Three Electrics says:

    I think it’s very likely that EVs will eventually consume electricity generated from fuel cells. In a renewable world, using hydrogen for grid storage is at least as cheap as batteries (https://gcep.stanford.edu/pdfs/HydrogenBatteries_GridStorage.pdf)–and storing seven days of power is roughly the same cost as storing only a day. There is talk of hydrogen storage costs at $1 per kWh when using geologic formations, like salt mines, to store the gas. And hydrogen storage is effectively free when using the elastic capacity of long distance natural gas pipelines.

    1. Pushmi-Pullyu says:

      Three Electrics said:

      “I think it’s very likely that EVs will eventually consume electricity generated from fuel cells.”

      Ummm… that’s exactly how fuel cell EVs, such as the Mirai, work. Electricity is generated by the car’s fuel cells to power electric motors which propel the car.

      “In a renewable world, using hydrogen for grid storage is at least as cheap as batteries”

      The round-trip efficiency of using hydrogen for energy storage is horrible when compared to storing energy in batteries. Using hydrogen loses about 2-1/2 to 3 times as much energy. Furthermore, the price of battery storage keeps coming down, whereas the efficiency of using hydrogen for the purpose is limited by basic physics, and thus can’t ever be significantly improved.

      1. sven says:

        I think he is talking about a fuel-cell power generating station like the one in the article below.


    2. finecadmin says:

      …except such stationary fuel cells are run on natural gas, not hydrogen. Because the market’s not stupid.

      1. sven says:

        In the link I posted above, the fuel-cell power generating station steam reforms natural gas to run its fuel cells on hydrogen at 51% efficiency.

        “Fuel cells come in different types, and they use a variety of sources for the hydrogen that powers them. The large complex here runs on natural gas, which initially is heated to about 1,000 degrees to break out the hydrogen. Then the chemical process is similar to that of a standard hydrogen fuel cell.

        The fuel cell complex here is 47 percent electrically efficient, a measure of the electricity derived from the fuel source, in this case natural gas. The 650-degree to 750-degree heat coming off the fuel cell is used to generate additional electricity, which raises the units’ efficiency rating to 51 percent, about double that of a coal plant generating the same amount of electricity.”


  9. Can a Toyota Mirai actually be driven the ~360 miles from Los Angles to Sacramento (California’s capital) today?

    1. Pushmi-Pullyu says:

      …and if it can, is there a public hydrogen fueling station at or near Sacramento? Or would the fool cell car have to be towed back to L.A.?

      1. Mike I says:

        The hydrogen infrastructure plan includes a station that is already permitted and contracted in Coalinga, on I-5. It will be built by First Element Fuel, the company supported by Toyota and funded by grants from the California Energy Commission.

          1. finecadmin says:

            oh, you mean the same CA office that has EVSEs in front, but no hydrogen filling?

  10. Aaron says:

    Can we have a version that isn’t JPEG compressed so badly? Use PNG for charts and things with text; use JPEG for photographs.

  11. mr. M says:

    Actually efficiency between two fuels doesnt matter for 95% of the people. Only price counts for most, but fuel cells are even worse regarding price… So unless the sun and the wind stops, the masses will never buy.

    1. Speculawyer says:

      Yeah, I think it is worse on price . . . but we can’t seem to ever know. They don’t tell us what the H2 price is. Seems like a big red flag.

      1. mr. M says:

        True, we habe to wait…

  12. Brian says:

    It’s pretty well known that electrolysis is low efficiency. It makes for a simple comparison, and a good start. We need a calculation on other hydrogen sources for this to be comprehensive.

    1. finecadmin says:

      No, we don’t. The Second Law means that converting natural gas will always be more costly (energy and dollars) than… natural gas! Repeat this for any pathway you’d like.

      1. Brian says:

        Yes we do. There are a number of sources of hydrogen required for the fuel cell, including electrolysis, steam reformation methane and steam reformation of natural gas. A better comparison would also include more sources.

  13. Speculawyer says:

    You really gotta hand it to BMW for the efficiency of their i3. That is very impressive. That Carbon reinforced plastic is good stuff that is doing its job by making the car light.

    They just need a better car design. Something more aerodynamic and less . . . uh . . . ‘polarizing’.

    1. sven says:

      BMW just revealed a concept that is “polarizing” to the EV crowd: an i8 Hydrogen FCV that uses cryogenically compressed hydrogen (CCH2).



      1. sven says:

        BMW also partnered with Total to open a hydrogen station in Germany that dispenses both industry-standard 700 bar compressed gas hydrogen (CGH2), and cryo-compressed hydrogen (CCH2) which allows for lower pressure and smaller tanks.

        “Cryo-compressed hydrogen storage technology (CCH2). This technology, developed by the BMW Group, involves storing gaseous hydrogen at low temperature on board the vehicle at a pressure of up to 350 bar. It is currently at the advanced development stage and will only come on stream for general use over the longer time frame. CCH2 tanks offer up to 50% more hydrogen storage capacity than 700 bar tanks and can support a driving range of over 500 kilometres.”


        1. finecadmin says:

          Oh wait, I thought you just said cryogenic losses were out of date and invalid.

          YOU are out of date and invalid.

          1. sven says:

            The link below will show you the error in your ways. Maybe in the future you will learn to discuss the issue at hand without resorting to personal attacks. For now, you should chill out with some cryo-compressed hydrogen. 😀


  14. jmac says:

    As Bryan suggests, steam reforming natural gas to extract hydrogen is cheaper than electrolysis. But, it’s still more expensive than recharging an EV directly from the grid.

    But, even in the best case scenario, the hydrogen fuel cell vehicle requires at least one extra (expensive) energy transformation.

    A battery electric vehicle uses grid electricity directly and skips the unnecessary and bizarre step of converting perfectly good electricity into hydrogen first and then directly back to electricity again.

    What a snow job …. And I thought just battery salesmen were liars !!

    Listen, when you start talking with hydrogen ‘true believers’, the BS gets so deep you need hip waders.

  15. e-lectric says:

    Mirai is a new vehicle. The first gen Prius wasn’t exactly the most efficient, or beautiful, or what measure you. I’m going to sign up for a Mirai, and take delivery when my local H2 station is up and running.

    1. Djoni says:

      And we are sorry for you, but it’s your money after all.
      Since you wont pay for fuel, hope there will be some available near you.

    2. finecadmin says:

      No, the Second Law is the Second Law. No technological development or kaizen will rewrite the universe.

  16. Bill Howland says:

    I think the comparisons are pretty fair.

    I work it out to a full tank in a Toyota Mirai is around the same heat content (and assuming the work to get it there and back out again), is around 8 1/4 gallons of ethanoled gasoline.

    So my point is, why have all that complication since I can easily, and cheaply obtain 8 1/4 gallons of gas, which I very rarely have to do (none of my cars has been to the gas station in months), and thats with several trips from Buffalo to Batavia and back, and also 2 trips from Buffalo to Syracuse and Back.

    One of the cars is almost empty and needs gas, but the other one is 3/4 full.

    So why do we need new multimillion dollar hydrogen stations, or more infrastructure, when the existing with phev’s is so rarely but efficiently used?

    1. M Hovis says:

      Agreed Bill,
      The rise of EVs will take its toll on gas stations. IF that is true, then how can we ever build out a new pumping infrastructure of any kind outside of densely populated cities? I suppose at best, you could have a pumping infrastructure along interstates like a supercharger network, but there is one major difference, and that is the available charging prior to getting to the network. EVs may not be for everyone, but there is no denying that a large percentage will choose either to cut chords with the pump, or as in your case, reduce it drastically.

  17. Spider-Dan says:

    I think this graph is stating the obvious. It’s like a graph that shows the miles per minute refuel speed of H2 vs. BEV, or a graph that shows number of gas stations vs. H2 stations. Some of the advantages are implicit.

  18. Solaraficionado says:

    As a professional engineer in the renewable energy/ energy storage space, a proud volt owner and EV enthusiast, I agree the well to wheel efficiency of BEV and PHEV (running on electricity) is far more technically efficient than that of fuel cells. That being said, the aforementioned article doesn’t take into account one potential benefit of hydrogen production, e.g. the utilization of grid-scale renewable electricity generation that would have been curtailed should a variable load such as electrolysis at hydrogen fueling stations not be available. Within a real world context, seasonal storage from increased wind generation during night-time winters (which is normally curtailed) might now find a home in hydrogen storage.

    I am not arguing with the outputs of this article, but the problem with drawing conclusions from one part in a system is that it is not holistic. EV’s might have better round-trip efficiencies and through smart IoT integration and energy internet algorithms, may be able to adjust charging to be beneficial within a limited time-period, but as a load, EV’s are not flexible and thus should renewable generation not be available to fill demand, a fossil asset will be activated on the grid-scale to meet the requirement. Electrolysis for hydrogen is flexible and production on a station by station basis, depending on the volume of storage on-site, is significantly more variable and thus beneficial as a grid asset.