Here's an interesting way to look at hydrogen fuel cell vehicles, courtesy of the California Fuel Cell Partnership. In a new blog update, the CaFCP says, "Nothing like a little exhaust from a fuel cell electric vehicle ... water so clean you can drink it."

Well, that's the picture text, any, the blog post says that this isn't really the case. After all, "It's clean, distilled water, but it will have traces of the catalyst. Plus, the tailpipe is a little dirty." Then there's this:

A fuel cell doesn't produce enough water to fill you glass. When we drink tailpipe water for a camera, like Ben is doing in the picture, it's not more than a few drops. If fact, fuel cells produce about the same amount of water as gasoline vehicle – about 1/3 cup for a full day of driving.

Not much there we didn't know already, and we've seen similar demonstrations before (see video below, starting at min. 5), but it's still interesting, no?



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    • 1 Second Ago
  • 96 Comments
      • 3 Years Ago
      The article is correct about a fuel cell vehicle producing about the same amount of water vapor as a gasoline powered vehicle, but it gets the amount wrong. Let's assume a Honda FCX Clarity: The Honda FCX Clarity is a fuel cell vehicle running on pure hydrogen. It is available for lease in southern California. It has a full sized cabin. It is EPA rated to run 240 miles on 4.1 kg of hydrogen (see http://en.wikipedia.org/wiki/Honda_FCX_Clarity). (Note that kg stands for kilogram, which is about 2.2 pounds, if you don't get technical about the distinction between weight and mass. So, 4.1 kg of hydrogen is about 9.02 pounds.) In a fuel cell, hydrogen is combined with atmospheric oxygen to produce water and electricity. 2H + O => H2O (Actually, 2H2 + O2 => 2H2O if you want to get fussy!) The atomic weight of hydrogen is 1, and the atomic weight of oxygen is 16 (see http://en.wikipedia.org/wiki/Atomic_weight). (Technically, the atomic weight is actually a measure of mass.) Therefore, by the above formula, 2 mass units of hydrogen combine with 16 mass units of oxygen to produce 18 mass units water. Therefore, 1 kg of hydrogen results in 9 kg of water so 4.1 kg of hydrogen results in 36.9 kg of water (4.1x9), when driving the FCX Clarity for 240 miles. Now, 1 kg is about 2.2 pounds, so 36.9 kg of water is about 36.9 x 2.2 = 81.18 pounds of water. So, the FCX Clarity produces 81.18 pounds of water for 240 miles. (Note that most of the mass of the water comes from atmospheric oxygen, not the original 9.02 pounds of hydrogen.) I gallon of water weighs about 8.35 pounds, so 81.18 pounds of water is about 81.18 /8.35 = 9.7 gallons. So, the FCX Clarity produces about 9.7 gallons of water for 240 miles. This is a bit more than 1/3 cup! I assume that 240 miles is considered a full day of driving. Actually, the FCX Clarity produces water vapor, not water - see http://automobiles.honda.com/fcx-clarity/fuel-cell-benefits.aspx For calculating the water from a gasoline powered car, you can start with the following (the rest is left as an exercise!) The chemical equation for burning gasoline (with atmospheric oxygen) into carbon dioxide and water is (http://en.wikipedia.org/wiki/Gasoline): 2C8H18 + 25O2 => 16 CO2 + 18 H2O
        Joeviocoe
        • 3 Years Ago
        1/3 of water is probably accurate if 'Liquid Water' was the intended term. With the heat of the fuel cell stack and the low pressure environment inside the stack. Most of the H20 will come out as a vapor and dissipate over a wide area before condensing as dew (if the atmospheric pressure and ambient temperature at that location even allow it).
        Elmo Biggins
        • 3 Years Ago
        Thats alot of green house gases. Maybe these hydrogen cars should count for negative CARB points.
          DaveMart
          • 3 Years Ago
          @Elmo Biggins
          It's the CO2 which is the greenhouse gas. Note that there is no carbon in hydrogen, and hence no CO2 emitted. Water vapour can have a temporary and localised heating effect, but does not build up over the decades the way CO2 does, and hence is not classified as a greenhouse gas.
        Dave
        • 3 Years Ago
        "This is a bit more than 1/3 cup! I assume that 240 miles is considered a full day of driving." Its hard to tell what they mean by a "full day of driving". An average day of driving is 12,000 / 365 = 32 miles. So, 32 / 240 X 9.7 gallons = 1.3 gallons per day. Looking at it another way, an average day is 1/2 kg of hydrogen and hydrogen is 11.2% of the mass of water, so we get 4.5 kg of water which is equal to 4.5 liters which is about 1.2 gallons. So, I'd say youre right - much more than a 1/3 of a cup.
        DaveMart
        • 3 Years Ago
        The Clarity FX is a fairly early and not very efficient fuel cell, so the ones in the Hyundai Tucson for instance use 1 kg of hydrogen for 72 miles. The petrol version is shown as having a combined EPA mileage of 25. That is about a 3 to 1 advantage per mile. Running your formula for petrol and with the atomic mass of carbon at 12, I come out with 2(12*8 +18) = 228 for the petrol, and 18*16 = 288 for the water emitted. So every kg (gallon equivalent, for our purposes) results in 1.26kgs of water. Multiply that by 3 and you come out to hydrogen fuel cells emitting around 2.5 times as much water vapour per mile as petrol cars. Is this amount enough to be of concern? 9kgs over 72 miles is 125 grams per mile, with comes out to .08 grams/litres of water per metre, That hardly seems likely to result in the roads becoming sheets of black ice!
          DaveMart
          • 3 Years Ago
          @DaveMart
          I was in error giving the weight of gasoline at 1 kg per gallon. http://wiki.answers.com/Q/How_much_does_a_gallon_of_gasoline_weigh It is about 6lbs. That is 2.7kgs. Therefore it is clear from the figures I have given above that there is no substantial difference in water emissions between burning gasoline or using hydrogen in a fuel cell per mile travelled.
          DaveMart
          • 3 Years Ago
          @DaveMart
          S/be 0.08 grams/millilitres, of course!
      Peter Muller
      • 3 Years Ago
      and on a cold day the water vapour freezes on the road surface and causes accidents with cars carrying czlinders full of incrediblz explosive hyfrogen gas... wow what a future, we dont Need terrorists.. we can blow ourselves to kingdom come.
        Joeviocoe
        • 3 Years Ago
        @Peter Muller
        There is about the same amount of H20 coming from gasoline engines. But I am sure you were unaware of that little fact. They call it a HydroCarbon for a reason. The hydrogen is locked up very tight in long chain molecules... but is is still there and still reacts with O2 in the air to make plenty of water vapor. None the less, whether gasoline car tailpipes or FCV tailpipes.. there are only a few drops per every few feet of travel. Most of it is vapor (even on a very cold day) and will disperse so much that no noticeable dew will form. Slippery roads is pure FUD.
        • 3 Years Ago
        @Peter Muller
        Sure.
      Elmo Biggins
      • 3 Years Ago
      Hydroflunkies distorting the truth to manipulate public perception. Shocker.
        Elmo Biggins
        • 3 Years Ago
        @Elmo Biggins
        ...and according to this video, these cars will lay sheets of black ice on the road when it gets cold. Anybody with a car and snow for Christmas will quickly learn to HATE hydrogen cars.
          Joeviocoe
          • 3 Years Ago
          @Elmo Biggins
          There is about the same amount of H20 coming from gasoline engines. But I am sure you were unaware of that little fact. They call it a HydroCarbon for a reason. The hydrogen is locked up very tight in long chain molecules... but is is still there and still reacts with O2 in the air to make plenty of water vapor. None the less, whether gasoline car tailpipes or FCV tailpipes.. there are only a few drops per every few feet of travel. Most of it is vapor (even on a very cold day) and will disperse so much that no noticeable dew will form. Slippery roads is pure FUD.
          DaveMart
          • 3 Years Ago
          @Elmo Biggins
          I don't know which bits about: '1/3rd of a cup per day' And: 'about the same as a petrol car' were too difficult for you. I suppose the true miracle is that you have learnt to type, not what you type.
          • 3 Years Ago
          @Elmo Biggins
          Not to mention: with his hardly acquired typing skills he's then usually killing digital trees every day.  Not quite green activity ;)
      • 3 Years Ago
      There ya go! Who wouldn't understand the great and green future of fuel cells / hydrogen, when a Green Angel (YES! That's Victoria Peters nickname on www.worldsnests.com) explains it to us. And if somehow even this - i.e. a Green Angel - wouldn't be enough (for some 'hard to convince' guys) to get that message, than a green "hydrogenated" hummer stretch limo will surely do the job. Here is the unfathomable magic of hydrogen fuel cells for you: it can easily convert your hummer (or whatever car you happen to have / like / dream about) to being the greenest car ever! on this planet. No more unconscious sense of guilt! Get that now?
        2 Wheeled Menace
        • 3 Years Ago
        URL too long. But let me say something rather shocking ;) It is easier to generate energy directly from the sun ( solar ), than take a bunch of steps that result in producing a gas/liquid fuel. The yield is far greater. The more steps you take to convert energy, the more you lose... always. And in the case of hydrogen, the losses are extremely high. Generating hydrogen without a fossil fuel input is amazingly expensive, the end result ( from all that i have read ) is sorta like having 6-7 dollar a gallon gas for a 30mpg car. Whereas an equivalent amount of electricity ( even from straight solar ) would be about 1-2 dollars ( not counting battery degredation per cycle, because we don't know what fuel cell degredation costs either ).
          • 3 Years Ago
          @2 Wheeled Menace
          2WM Countless study concluded already, that H2 will be WAY cheaper, than even recharging the battery (not to mention way faster as well). In the future hydrogen production most likely will be direct 'solar fuel' (e.g. like artificial photosynthesis), which will be cheaper than anything else (close to $0). #abouthydrogen
          • 3 Years Ago
          @2 Wheeled Menace
          While I agree about the efficiency issue, converting solar to hydrogen makes some sense for a fuel cell vehicle. Given that electric vehicles currently require heavy batteries to hold the charge that is only available when the car is home, and given that a solar to hydrogen station in the home can be creating more hydrogen while the vehicle is away, solar to hydrogen makes sense only to the extent that the fuel cell plus the tank weighs less and occupies less volume than the weight and volume of the battery required to cover the same distance. As a range extender a solar fueled hydrogen fuel cell makes sense if it allows a smaller less costly battery to cover the most frequent trip length.
        2 Wheeled Menace
        • 3 Years Ago
        Infinite free energy with no environmental footprint is here! Magic indeed!
          2 Wheeled Menace
          • 3 Years Ago
          @2 Wheeled Menace
          Both coal electricity and H2 from natural gas are very pollutive. Do you have numbers proving that one is worse than the other? Pollution aside, last time i checked, natural gas comes out of the earth in a vastly more destructive way. Coal acquisition is pretty bad too, but fracking is far, far worse. So let me get this straight.. your favored way to burn fossil fuels absolves all guilt, even if you are riding around in a stretch hummer? No thank you, i'll power my transport off my roof.
          Joeviocoe
          • 3 Years Ago
          @2 Wheeled Menace
          Go ahead and keep posting that C.E. Thomas paper... And I will keep mentioning how he is a number fudging shill that claims ridiculous things like "Every BEV sold must have TWO public charging stations, and each charger must have an expensive trench dug." You are just hoping that people only read the first part of the URL since it is a .gov site... and just take your word for it that it is a credible document.
          • 3 Years Ago
          @2 Wheeled Menace
          2WM, Spec First of all, what we saw on the video is a REAL ZERO EMISSION H2 generation in the 'backyard'. Also. I already posted a study to back my statement up. I know it's an evil biased study, payed by Big Oil, not to mention, can be found on a website of the "evelist" government in the entire Universe (U.S.). But still: 2.4 Greenhouse Gas Pollution "The greenhouse gas (GHG) implications of charging battery EVs with today’s power grid are serious. Since on average 52% of our electricity in the US comes from coal, and since the grid efficiency is on the order of only 35%, GHGs [Greenhouse Gas Pollution] would be much greater for EVs than for hydrogen­-powered FCEVs... [Figure 8]... http://www1.eere.energy.gov/hydrogenandfuelcells/education/pdfs/thomas_fcev_vs_battery_evs.pdf #backingupmystatement
          Spec
          • 3 Years Ago
          @2 Wheeled Menace
          "A little bit more seriously: a fuel cell car - even if the H2 was reformed from NG - has way less environmental footprint, than an EV (at the current state of electric grid in the U.S.)." You have nothing to back that up. The hummer is a big & large and thus needs a larger amount of energy. And today's natural gas isn't all that clean if it is from fracking since that often releases a very large amount of fugitive methane gas which is a much worse greenhouse gas than CO2. If the amount of fugitive methane exceeds 2%, you might as well be burning coal.
          • 3 Years Ago
          @2 Wheeled Menace
          2WM You must know it too, that even you (being a human being) has an environmental footprint (e.g.~1kg CO2 "exhaust" every day). A little bit more seriously: a fuel cell car - even if the H2 was reformed from NG - has way less environmental footprint, than an EV (at the current state of electric grid in the U.S.). #justsayin
        • 3 Years Ago
        2WM, Spec (I repeat here my reply to you for everyone else) First of all, what we saw on the video is a REAL ZERO EMISSION H2 generation in the 'backyard'. Also. I already posted a study to back my statement up. I know it's an evil biased study, payed by Big Oil, not to mention, can be found on a website of the "evelist" government in the entire Universe (U.S.). But still: 2.4 Greenhouse Gas Pollution "The greenhouse gas (GHG) implications of charging battery EVs with today’s power grid are serious. Since on average 52% of our electricity in the US comes from coal, and since the grid efficiency is on the order of only 35%, GHGs [Greenhouse Gas Pollution] would be much greater for EVs than for hydrogen­-powered FCEVs... [Figure 8]... http://www1.eere.energy.gov/hydrogenandfuelcells/education/pdfs/thomas_fcev_vs_battery_evs.pdf #backingupmystatement
          Joeviocoe
          • 3 Years Ago
          Go ahead and keep posting that C.E. Thomas paper... And I will keep mentioning how he is a number fudging shill that claims ridiculous things like "Every BEV sold must have TWO public charging stations, and each charger must have an expensive trench dug." You are just hoping that people only read the first part of the URL since it is a .gov site... and just take your word for it that it is a credible document.
      paulwesterberg
      • 3 Years Ago
      Ending your statement with ", no?" does not form a proper question. For example do not do this: This blog is teh suxor, no?
      Doug
      • 3 Years Ago
      http://www.mercurynews.com/san-mateo-county-times/ci_20935895/sfo-official-concerned-about-catastrophic-hydrogen-explosion-at
      upstategreenie
      • 3 Years Ago
      it is still more than amount of fracking fluid and biocides pro frackers drink and more than what any denialists will do with regards to ******* on their own stinking polluting tailpipes.
      • 3 Years Ago
      But to be a little bit more clear Peter. If you happened to read the ABG article above - what you clearly did not - you could have read this: "If fact, fuel cells produce about the same amount of water as gasoline vehicle ..." So, we dont Need (sic) terrorist ICE vehicles too. Now we are in great trouble. No. Calm down! You just didn't read the article. That's it.
      artwolters5
      • 3 Years Ago
      Do not disconnect from your well or city water connection. HYDROGEN will never be a fuel! It can be manufactured only using prodigious amounts of electrical energy -- or by conversion of carbon or hydrocarbons. If you have it, you can't store it as a liquid (too cold), or as a compressed gas (too light). And uniquely hazardous in either form. There's a reason you can't drill a hydrogen well (it has all reacted to something else). And if you can't drill for a natural fuel (i.e., oil or natural gas) it will never be a transportation fuel in our lifetimes.
        Chechnya
        • 3 Years Ago
        @artwolters5
        Instead, let's use precious metals and heavy battery packs for our ultra expensive battery vehicles. LOL.
        clquake
        • 3 Years Ago
        @artwolters5
        Hydrogen powered cars can't produce enough water for everyday use, that's the only reason not to disconnect from your water supply, but you don't have to drill for hydrogen. You quite literally turn on the faucet, and it comes pouring out, two hydrogens/oxygen atom. I'm not saying it's easy to split it, but your point of storing it in a non combustible form is pointless.
      goodoldgorr
      • 3 Years Ago
      Im more interrested in a fuelcell hydrogen then an hydrogen ice, it's electric, more scalable and runs more silently. That's something that you cannot do with a pure battery car. If you want a long range from a battery, you have to do like tesla and go to a huge weight and a huge price that equal with current batteries to 77 000$ because you have to put a huge battery in a huge full size weighty car and this equal to 265 miles. Or you put a small battery like the leaf and you get 90 miles range for 34 000$, that's not scalable and is unsustainable in the current market. With hydrogen you just have to put a sufficient sized tank in a small car and you have long range with a small cheap car and that should amount to 400 miles approx with 5 minutes refill for 25 000$ approx. Of course it's not proven yet because big oil, car manufacturers, cia and media, wall street speculators, journalists are still impeding hydrogen commercialisation. But scientifically it's the numbers i calculated.
        pmpjunkie
        • 3 Years Ago
        @goodoldgorr
        I can't afford 25 000$ refills, I rather charge for hours and get my fill for $6.57
        • 3 Years Ago
        @goodoldgorr
        I honestly have to say Gorr, you kinda nailed it now. (Maybe your list a little bit exaggerated, but still) Congrats
        Neil Blanchard
        • 3 Years Ago
        @goodoldgorr
        The Honda FCX Clarity (which has 4.1kg of hydrogen storage and a 4kWh battery) has a range of ~240 miles and weighs 3582 pounds: http://automobiles.honda.com/fcx-clarity/specifications.aspx I don't think you can fit another 3-4kg of hydrogen into the car; and it would weigh quite a bit, due to the crash protection the high pressure tanks require to survive a crash without exploding. The Tesla Model S has a range of ~265 miles and weighs 4647 pounds: http://www.teslamotors.com/models/specs The Tesla can be charged in an hour. The Honda can be filled in 10-15 minutes -- but the hydrogen has to be "per-compressed" to 350bar (~5,000PSI) which takes a while, so a hydrogen filling station can only fill about 15 cars a day. Compressing hydrogen to 700bar / 10,000PSI is non-trivial. Neil
          Letstakeawalk
          • 3 Years Ago
          @Neil Blanchard
          That's a great illustration of the weight, range, and refueling advantage that an FCV has over a similar BEV. But, the Honda Clarity is starting to get a little long on tooth, and doesn't really compare in terms of passenger space to the Tesla Model S. A better example would be the Toyota FCHV-adv. Five passengers, plus plenty of storage capability (like the Tesla), with a weight of 4144lbs, and a range of more than 400 miles with 6kg of hydrogen stored on board. http://unit.aist.go.jp/hydrogenius/ci/event/ihdf2012/pdf/1-2kawai.pdf http://www.toyota.com/esq/articles/2010/FCHV_ADV.html As far as refueling times, they generally run under ten minutes, even for a 6kg 700bar fill. The pre-compression you mention happens at the station, not in the car, so the car doesn't need to wait around while it's happening.
        2 Wheeled Menace
        • 3 Years Ago
        @goodoldgorr
        You are our favorite scientist, gorr. I trust your numbers to be sound.
      Dan Frederiksen
      • 3 Years Ago
      it's good sentiment to create sustainable energy but you have to appreciate some quantitative analysis and not cripple the efforts with ignorant vehicles like stretched hummers and V8 pickup trucks. the only thing you sacrifice by getting rid of such vehicles is ignorance
      fred schumacher
      • 3 Years Ago
      That low temperature water vapor exhaust would be a huge problem in a cold climate. The car would lay down a film of black ice. IC exhaust comes out at high temperature, but even so, here in Minnesota it can easily be cold enough for exhaust water vapor to turn into black ice. Fuel cell cars will need insulated, heated tanks to recover and store exhaust water vapor.
        pmpjunkie
        • 3 Years Ago
        @fred schumacher
        I think something like this: http://www.goneblue.com/mupatibehe.html to pipe the water to the driver will be sufficient
        2 Wheeled Menace
        • 3 Years Ago
        @fred schumacher
        Water is also a greenhouse gas!! Manbearpig gonna crack down on that!!
          Grendal
          • 3 Years Ago
          @2 Wheeled Menace
          I saw what you did. :-)
          2 Wheeled Menace
          • 3 Years Ago
          @2 Wheeled Menace
          Yeah, but you put out more methane! a more potent gas!!
          • 3 Years Ago
          @2 Wheeled Menace
          2WM As we already know it, your "exhaust" (CO2) exhalation is way more dangerous greenhouse gas, than water vapor. #dangerousexhaust
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