Clean Power Lund solar fuel cell

Published on March 4th, 2015 | by Tina Casey


Supersonic “Solar Fuel Cell” Could Churn Out Sustainable Hydrogen

March 4th, 2015 by  

A while back, we introduced you to the artificial leaf and the bionic leaf. Now, check out this supersonic leaf. An international team of researchers headed up by Sweden’s Lund University is developing a thing they’re calling a supersonic “solar fuel cell.” Like its bionic cousin, the solar fuel cell mimics the chemical reactions in photosynthesis to produce sustainable fuel, namely hydrogen.

Right now the fuel of choice for fuel cell electric vehicles (FCEVs) is hydrogen sourced from natural gas, which comes with a huge load of environmental baggage, so if the Lund work pays off, that’s good news for all you FCEV fans out there.

Lund solar fuel cell

The Inevitable March Of The Fuel Cell

We were just talking about the inevitable march of the fuel cell the other day, and here comes another indication that despite its critics, the fuel cell electric vehicle might find a solid niche in the personal mobility market, one way or another.

Actually, we’ve had a number of lively discussions about the pros and cons of FCEVs here at CleanTechnica, but there doesn’t seem to be any doubt over at the US Energy Department.

Last summer, the agency’s ARPA-E high-tech R&D funding division threw into the fuel cell pot, and last October it announced a $1 million prize for developing low-cost hydrogen fueling stations.

Earlier, the Energy Department followed up with yet another multimillion-dollar fuel cell research funding opportunity, to the tune of $35 million. In its open call for new fuel cell ideas, the agency is particularly looking for hydrogen production through microbial biomass conversion.

We’re especially interested in the agency’s interest in using fuel cells as a range extender for light duty hybrid electric vehicles — since we were already wondering if the electric vehicle of the future might one day embrace a battery and a fuel cell in peaceful coexistence, but we digress. Let’s get back to that new supersonic solar fuel cell from the Lund University.

A Supersonic Solar Fuel Cell

The Lund team is calling its effort “artificial photosynthesis.” The reasoning goes that since plants use sunlight to convert water and carbon dioxide to energy-rich molecules, so can we.

Until now, we’ve been focusing on harnessing solar energy by converting it to electricity through photovoltaic cells, or converting it to heat in the form of from rooftop water heaters and utility-scale concentrating solar power plants.

Both of these systems lose energy as heat along the way. A solar fuel cell, on the other hand, could theoretically store all of its solar energy in the form of chemical energy within molecules. All you need is light-collecting molecules and a catalyst to do the work for you.

Simple, right?

For their solar fuel cell, the Lund team has developed a molecule with two metal atoms at its heart. One is for collecting solar energy, and the other mimics the catalyst that produces hydrogen (and potentially, in this case, methane).

Study of the new molecule has revealed that electrons “cross the bridge” between the two atoms in half a picosecond (check out the illustration above for a summary of the time scale). That rounds out to about 4 kilometers per second or about 10 times the speed of sound, hence the name “supersonic solar fuel cell.”

That’s nothing. The team also found that you can change up speeds depending on which kind of bridge you use, and another study using a different type of bridge reached a speed 100 times higher than the first bridge.

ET Come Home!

The press materials were a little thin on detail but you can find the study online at Nature Communications under the somewhat mysterious title, “Visualizing the non-equilibrium dynamics of photoinduced intramolecular electron transfer with femtosecond X-ray pulses.”

For those of you on the go, the double-hearted molecule studied by the team was based on ruthemium and cobalt. Fancyspeak for the process is ET, short for photoinduced electron transfer:

The bimetallic complex studied in this work consists of a light-harvesting, ruthenium (Ru)-based chromophore linked to an optically dark cobalt (Co) electron sink by a bridge that mediates ultrafast ET. This prototypical dyad exemplifies the wide class of synthetic and natural photocatalysts for which the coupled electronic and structural dynamics are only partially understood…

So, now that the Lund team has converted a partial understanding to a more fleshed out picture, it’s on to the next stage of R&D. In other words, don’t hold your breath for abundant solar-sourced hydrogen just yet, but things are certainly heading in that direction.

For the record, the international team included the US as well as Denmark, Germany, Hungary, and Japan.

Also for the record, the artificial leaf refers to Harvard (formerly MIT) researcher Daniel Nocera’s low cost, palm-sized photoelectrochemical cell, designed to get solar-generated hydrogen from water — even dirty water — for use in small household fuel cells.

Based partly on that work, earlier this year Harvard introduced a “bionic leaf” that combines ET with bacteria in an integrated system that produces liquid fuel, specifically isopropanol (that’s fancyspeak for rubbing alcohol).

The bionic leaf moniker actually first crossed our radar last year when the folks at Lawrence Berkeley National Laboratory used it to describe a revved-up photoelectrochemical cell using gallium phosphide (a semiconductor that absorbs visible light), and a hydrogen-producing catalyst called cobaloxime.

So. There.

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Image Credit (screenshot): Courtesy of Lund University.

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About the Author

specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. Views expressed are her own. Follow her on Twitter @TinaMCasey and Google+.

  • Carl Borrowman

    “battery and a fuel cell in peaceful coexistence”

    I see nothing wrong with that. If a plug in ICEV can receive praise today, why not a plug in FCEV in the future?

    “There have been 2.6 billion years of evolution, and… working together a year and a half (we) have already achieved the efficiency of photosynthesis.”

    • Bob_Wallace

      We could replace the ICEs in PHEVs with fuel cells. The amount of fuel required would be very small which might mean a fuel access problem away from densely populated areas. Seems like you’d need a fuel cell that ran on a more common fuel than hydrogen, say gasoline.

      If you’re thinking about a plug in FCEV I don’t think you’d get much gain. The FCEV should arrive “home” with its battery pack largely charged up most of the time. Plugging in might result in little charging from the grid.

      Then there’s cost. Navigant Research claims that hybrids of all types can’t compete against EVs with inexpensive batteries.

      • Carl Borrowman

        I’m actually more intrigued with flow cell batteries, which combine the technologies in regular batteries and fuel cells. In this regard I see the development of both fuel cell and battery technology to be mutually beneficial.

        I don’t know if fuel cells or flow cell batteries can come down enough in cost to make sense or “compete” with regular batteries in the future, but I like following the progress of technology in general regardless.

  • The Reverend Ponsenby Smythe

    No offence but you seme to be blissfully unaware of what’s going on in the Hydrogen space in Germany, Japan and the rest of the world. Germany in particular generates Hydrogen from water via wind turbines and electrolysers – they are building hydrogen infrastructure as we speak. Japan too is making huge in roads into this and are even discussing exporting it. They see Hydrogen as a highly significant to their future -I saw this for myself last year at smart energy week and was literally blown away. I’m afraid I disagree with Elon Musks views on Hydrogen. There’s lots going on with Hydrogen.

    • Bob_Wallace

      Actually people here are aware of Germany’s involvement with hydrogen. They are using surplus wind power to generate H2 and injecting it into their natural gas system.

      Germany is also building a few H2 fueling stations.

      And we’re up on what it happening in Japan. Apparently someone high up is convinced that hydrogen is the future. Probably looking at the large deposits of methane hydrates along their coast. Also likely someone who isn’t worrying their beautiful mind about climate change.

      Now, are you aware of the cost per mile to operate a FCEV and an EV?

      • The Reverend Ponsenby Smythe

        Actually the Germans are using H2 for a bit more than power to gas applications. And they are building more than a few H2 fuelling stations. ..”To date, according to press material provided by Mercedes-Benz, Linde produces half of the hydrogen for existing fuelling stations from sustainable energy sources. The gas is obtained from crude glycerol, which is a by-product of biodiesel production. Biodiesel, as the name indicates, is a carbon-neutral fuel produced from plant life and other biological sources.

        Linde also splits water molecules by passing a current through the water, with the electricity procured from wind power generation.

        The 13 new stations by the end of 2015 will take the total in Germany to 50 hydrogen stations. By 2023, the network of hydrogen stations in Germany will be up around 400.”

        Just one of the stations in Hamburg produces 750kg/day half of which is from windturbine/electrolyis and is used for buses and cars.

        I would say that a blended solution will be the likely outcome in the years to follow – FCEV and EV. Nissan have started producing a FCEV with an inverter in the boot that plugs into the home.

        I’d say basically don’t knock what others are doing – if it’s working for them (e.g. outside the US) then surely we all benefit in the long run?

        • Bob_Wallace

          I’ll ask a second time. Are you aware of the cost per mile to operate a FCEV and an EV?

          • Sheldon A Harrison

            The cost per mile for a FCEV is currently 2 – 3 times as high and will remain high until/unless scale up occurs. A fuel cell + tank etc. if manufactured at any kind of scale will see costs fall faster than batteries because it is not as materials intensive. The costs tend to scale to the square of required materials for tanks (which is the main driver of energy storage costs vs. to the cube for batteries) That is very obvious to anyone who takes an objective look at the technologies and explains why batteries are hopeless for renewable energy storage outside of diurnal to at best a few days. Additionally, platinum loadings have already been reduced to the point that this formerly major cost driver is no longer a commercial barrier. I have even heard talk of platinum free cells.

            I will also maintain that if the present batteries are not improved re true 300 mile range capability at 75mph, then people will pay a higher price for the convenience of true autonomy that EVs including the Tesla Model S do not currently possess. I do not think folks are going to be willing to trade the flexibility that is possible with ICE cars for lower running costs unless fuel prices dramatically rise. ($6+ per gallon) Of course, with more range, an EV gains more market but until the magic 300 real miles of range happens, they will remain niche (albeit increasingly large as range increases)

            Why 300 miles? Answer: That is about the range at 75 – 80 mph on interstate or similar highways in foreign lands after which folks genuinely need to take a decent break of say 30 minutes or more. It represents about 4.5 to 5 hours of driving. The so called upcoming 200 mile EV will not meet this criteria and in fact will probably represent only 160 – 170 miles of real world range or barely 2.5 hours of driving.

            I have long been a fan of EVs (cheering on NIMH, Zinc Air, LI Polymer etc. etc.) but I have come to realize why ICEVs are such a powerful technology and so stubborn to replace. Even a 280 mile Tesla (at moderate speeds to add) is not suitable for general purpose use at least for me especially considering that it takes at least 20 minutes to gain another 2 hours worth of range. In the US and to a lesser extent Canada, folks think nothing of taking a 300 to 400 mile drive, often on a whim and with little prior planning and oftentimes done several times per year. At 280 miles at < 70 mph, such a car cannot even get one from say the Florida Panhandle where I reside to Orlando without the need for a recharge stop of at least 10 to 15 minutes. Note, this is a trip that is often done non-stop in roughly 5 hours. Most folks on such a drive may make one 5 to 10 minute bathroom stop and then be back on their way. Most working folks do not have time to waste milling around waiting for a fast charge to be complete and are not prepared to alter their preferred eating/rest stop habits to fit within the requirements of the car.

          • Bob_Wallace

            “The cost per mile for a FCEV is currently 2 – 3 times as high and will remain high until/unless scale up occurs.”

            Actually, and I’ll use Toyota’s numbers, the cost per mile for an FCEV is over 5x as much as for an EV. (17 vs. 3 cents per mile) Toyota thinks that price could come down to about 3x as much eventually. (10 vs. 3 cents)


            Now, we will need to drive using low carbon fuel, not reformed methane. It takes 2x to 3x as much electricity per mile to power a FCEV as to power an EV plus the infrastructure and distribution costs.

            Can you explain how “scaling up” will make FCEVs competitive in terms of cost per mile?

          • Sheldon A Harrison

            Bob, fuel cells will drop in price faster than batteries. It has already been happening and scale up has not even started in earnest. H2 generation and distribution tech will also drop in price as experience is gained with the pumps, valves, tanks etc. at scale. It happens with every other technology. Why wouldn’t it apply to H2 tech? NG H2 from an input reagent perspective alone can today allow a $3 per kg number. renewable H2 from biomass is not far away and even electrolytic H2 from bulk electricity can at full build out be done for $5 – 6 per kg.

            I have also explained why even at higher cost per mile, there will be a role. If everybody was concerned only with cost per mile, we would take the bus. It also explains why we truck goods across the country rather than using cheaper water or rail transport and why we air freight goods. If something does not meet your needs, it does not matter that it is cheap to run, it does not meet your need and thus is not suitable.

          • Bob_Wallace

            Seldon, I was not talking about fuel cell cost. I was talking cost of H2 vs electricity.

            Do you know anything about the energy requirements for extracting H2 from water and compressing it for use in a vehicle?

            Do you know anyone producing H2 at a “3 cent per mile” price? Actually producing, not just on paper.

            As for range, we’re apparently about to get affordable 200 mile range EVs. With <30 minute 80% recharging one can drive over 500 miles a day with two stops. A FCEV driver would arrive at destination only a bit later than a FCEV driver assuming the FCEV driver ate a meal and stopped to pee at least once.

            Most people drive over 500 miles very infrequently. The extra cost of driving a FCEV all year plus the time spent visiting fueling stations would likely cause most people to choose an EV.

            Then there's the "king of the hill" problem. If EVs become established it's going to be very difficult to find the capital to build the fueling infrastructure for FCEVs. Remember, we'd need filling stations at least as frequent as today's gas stations. (FCEV range will be less than ICEVs.)

          • Sheldon A Harrison

            We shall see. I am going with my gut observation of people’s behavior, including many people breaking the speed limit to gain 15 to 20 minutes. Have you not observed these folks on the interstates; the ones doing 80+ mph at every chance and who would do 100+ mph if given the chance?

            Some folks are not going to give up the flexibility and autonomy of a fuel powered vehicle, unless the cost is outrageous. By that, I mean if costs are the same or similar to today’s existing gasoline / diesel infrastructure, there will be a market for such vehicles unless batteries improve to give the same level of autonomy. (i.e 300 true miles including cabin hotel loads like HVAC and < 10 minute recharging) I see no battery in the next 5 – 10 years on the horizon that will offer such performance at a competitive price.

            You keep mentioning the time spent going to fill up and I have already shown that this time is miniscule. It amounts to less than a minute per day for an efficient fossil powered vehicle. If the FCEV costs less to acquire than a BEV (I take it on good sources that this is a very likely outcome at any kind of scale) the calculation about operating costs versus capital cost is more complicated.

            I agree that a 500 mile trip is infrequent but a 200 – 300 mile trip is not, being made several times per year. For such a trip, most folks do not make lengthy or forced stops. A 200 mile EV is not going to be adequate without some inconvenience.

          • Bob_Wallace

            I suspect you underestimate the value of not having to stop at filling stations. It may be only a minute a day, on average, but in reality is a dozen or so 15 to 20 minute interruptions to ones routine. (Probably a lot more than a dozen stops for those who don’t like to run their tanks far below half full.)

            I don’t see how FCEVs become significantly cheaper than EVs. FCEVs need the same motor and electronics and a smaller batter pack plus the fuel cell and tanks.

            At $100/kWh (where EV batteries appear to be headed) the extra 48 kWh in a 200 mile EV would cost $4,800. Fuel cells and tanks will have some cost.

            And do remember that battery capacity is not fixed. It will almost certainly improve. Tesla is replacing its Roadster battery with a same sized battery and taking the range from 244 to 400 miles. The Roadster was built between 2008 and 2012.

  • Tycoon

    Why do you insist on saying NG is the choice of FECV’s for Hydrogen? That is just not the case. The FCEV industry doesn’t care where H comes from. But to your accurate point that carbon based H is not environmentally friendly…..there is a green option right now, being used for producing the Hydrogen needed to ‘fuel’ FCEV’s: Water.

    • Bob_Wallace


    • nakedChimp

      any idea why FF is even retracting these days? It’s not because the investors and backers found their environmental conscience.. it’s because RE is now cheaper than FF.. it’s all about the money honey.
      So if there is a cheaper source for hydrogen from NG than from RE, the NG route will be taken for the bulk of it.

  • UncleB

    Ru is not the cheapest not he easiest to find on earth? is it depleted in any way or is it simply a catalyst?
    Extreme heat available form Chinese fast neutron gas moderated reactors enough to make large amounts of H2 cheaply?

  • Tom G.

    I can express my beliefs about hydrogen as a motor vehicle fuel in just a few sentences.

    1. The cost of the infrastructure is too high and;
    2. I just want to go to work or shopping, then come home and plug in. What could be more simple.

    It will soon be so “old school” to go to a filling station. You would think after 100+ years we would have found something better to do with our time.

    In only a few more years we will be be able to:

    1. Drive our electric vehicles to work if we have one and charge there.
    2. When we get home we will most likely drive over the top of an inductive charging coil and never touch a charging cable,
    3. Many streets and highways will have built-in inductive charging eliminating range concerns and for people living in apartments, and;
    4. If you really want to take that 400 mile trip into the backcountry just rent a darn oil burner for the week.

    As someone who is quickly approaching 75 years of age I find it really hard to understand why we seem so intent on spending another 100 years going to filling stations.

    Sorry for the long posting. It took a few more words than I expected.

    • Bob_Wallace

      I agree. However I don’t think there will be places to do a 400 mile trip into the backcountry. I can’t think of anywhere one can drive in the US where there isn’t electricity within 100 miles.

      • Offgridman

        Especially when you go on the motor home camping sites and see all of the places where it is possible to find a double 20-40 amp 220 volt receptacle to access.
        Additional charging infrastructure is needed around our city and urban areas, its already available in a lot of remote vacation spots.

    • Michael G

      One scenario is that EVs are standard on smaller cars and SUVs while FC dominate in the larger SUVs, trucks, and military vehicles. The problem with current EVs is that they don’t scale well for moving large masses over long distances. For the average car existing batteries are fine, but if you are moving freight, the batteries wear out faster than desirable. Following chart (1st one) shows range vs battery/FC size (in liters):

      FC cars are standardizing on 10,000 PSI (70MPa) so the lower FC curve is more relevant.

      The second chart shows energy density and conversion efficiency where the FC is at 5,000 PSI. As I said, 10,000 PSI is where things are going for FCs so the data should be at 1500 NCV with a conversion efficiency of 50% putting it at 750 Wh/l vs. Li-ion batteries at 280 Wh/l and 90% effiicency putting it at 252 Wh/l.

      Hydrogen for fuel cells can be generated by electrolysis at home as well. Here’s one on Amazon for $220.

      Small fuel cells to be sure, but also a small electrolysis machine.

      Inductive charging seems to be the way to go for EVs but my understanding is that existing inductively charged busses have to be specially sheilded to make sure pacemakers and the like aren’t affected. Solvable problem, but not as simple as it initially seems.

      • Bob_Wallace

        Sorry, Michael, I know you don’t want anyone to disagree with you when it comes to fuel cells but I’m going to anyway.

        There’s no reason why we can’t run large trucks on batteries. That’s a perfect application for battery swapping. Battery packs can be swapped out faster than fuel tanks can be filled.

        Batteries seem to have very good cycle life calendar life may be the limiter on overall life. Being in constant use (on the road or on the charger) wouldn’t be an issue.

        We’d need swapping stations only along major shipping routes. Fuel savings would be enormous.

        And battery volume would be a much smaller issue with large trucks. Turn the tractors into rolling battery pack with a cap on top.

        • Michael G

          Disagree all you like.

          I am sure battery-swapping *could* work, but I have no idea if it will be accepted. Public accceptance is more important than theoretical “correctness”. I have seen so many technologies wither because although they were theoretically *better*, the alternative technology was “good enough” and either cheaper, or more convenient, or more familiar, or something.

          I am agnostic on this. May the best tech win. I think Wishart’s article is very good and the idea of a FCHEV (Fuel Cell Hybrid EV) is the best idea and will ultimately dominate. But I could be wrong (so could you). So make it as easy as possible for people to ditch the ICE. Fund it *ALL* and complain the DOE isn’t funded enough – it is all a pittance compared to the cost of the wars over oil and global warming (Syria fell apart because of extended drought due to climate change bringing us ISIS).

          In case you forgot, here is the article:

          • Bob_Wallace

            When it comes to hauling freight economics dominate.

            If the cost spread is 17c (or 10c, best case) to 3c per mile for FCEVs and EVs that ratio is going to hold for 18-wheelers.

            There would be a higher cost for the spare battery that is being charged while the truck is on the road but that would only reduce the spread, not reverse it.

          • Michael G

            We should see in 5-10 years, if not sooner. I can wait.

            The argument, such as it is, is how much govt. money should into exploring FCVs. “The DoE only gets so much money” is the refrain. But that amt is not a universal constant like “pi” or Coulomb’s constant. It can be cut or increased.

            No one allocating govt. funding listens to us here (I most sincerely hope) but if they did, do you think they would take the money now going into FCs and put into some other green tech – or simply cut it entirely? I would bet that the GOP congress would simply eliminate it entirely and give it to the CIA or some other worthy organization, or tax breaks for “job creators”. And while they’re at it, probably take a swipe at tax incentives for EVs, Wind turbines, and PVs.

            Best to let sleeping dogs lie.

          • Sheldon A Harrison

            Batteries are even less feasible for 18 wheelers that oftentimes have shifts of 12 hours followed by mandatory 10 hour breaks. That doesn’t even account for team driven situations where the trucks are constantly rolling with one driver sleeping while the other keeps the truck rolling down the highway. You will not get a battery (perhaps needing 500 – 600 kwhrs) that motivates an 80,000 lb vehicle fast charged in 30 – 40 minutes or a typical meal break.

            You can also safely forget battery swapping. The logistics involved are staggering and would be the equal of hydrogen infrastructure setup. A team driven hypothetical trip from LA to NY would end up needing about 5 to 6 swaps. Most intractable of all, we would need to sort out battery age (how do you sort for various stages of wear in swapped batteries etc.?) Storage space for all the swapped batteries? robotized equipment to perform the swaps (not going to be cheap)? transportation of spent and charged batteries etc.?

            Additionally, the usable load of the truck is diminished with batteries (trucks are limited in most jurisdictions to 80,000 lbs total) and a battery sufficient to travel 300 miles will weigh as much as 10,000 lbs which is a big negative. I will concede however that freight moving cross country should be on trains preferably powered by overhead catenary!

          • Bob_Wallace

            Install battery packs that will power the truck 200 miles.

            Pull in every 200 for a charged set. Battery swapping is very fast.

            Lease the batteries. Let the swapping stations own the batteries, not the tractor owner.

            Pull into a swapping bay. The front of the tractor pops open, old battery pulled out, new battery shoved in, hatch closes, Drive away. Again, battery swapping is very fast.

            10,000 pounds? You’re just making up numbers.

          • Sheldon A Harrison

            Ho heavy do you think a battery would need to be to go 300 miles? If a Tesla 85KW battery with one of the best energy densities around weighs greater than 1K lbs, is it not realistic that a 500 – 600 KWH battery will come in close to 10K.

            I notice you use a 200 mile number versus my 300. That will certainly make progressing down the road more time consuming. Many truckers drive for 4 hours or more without a single stop. You are now asking them to stop every three hours.

            And how does the swapping station get back it’s exact battery when the truck is 200 miles away or do you anticipate a network that owns all the batteries and that a truck uses only that battery supplier? I think you are seriously minimizing the scale of the logistics of battery swapping whether owned by the trucker or the station.

          • Bob_Wallace

            Battery swapping is much faster than refueling. One doesn’t even need to climb down from the cab. From the time of stopping to pulling back out should be a couple of minutes. (Tesla swaps out batteries from underneath their cars in less than three minutes.)

            The cost per mile over liquid fuel would make drivers very happy. There would be no complaints about stopping every three hours for a set of batteries for those who purchase their own fuel. Hired drivers get paid by the hour.

            With leased batteries there is no issue of getting back the original battery. You’d simply be renting a full battery and dropping off the spent battery with the leasing company. When you picked up your new tractor it would already have a battery owned by the leasing company installed.

            Basically, the battery leasing company needs two sets of batteries per tractor. One set in the truck and one set being charged or charged and waiting. Standardizing battery packs would keep inventory simple.

            Remember, battery capacity will almost certainly improve over time.

            Historically lithium batteries have increased about 8% per year over recent years. If that sort of progress continues then today’s 200 mile battery pack would double in capacity in nine years.

            I’m not saying that we’ll see 8% improvement per year, but some sort of increase in capacity is likely. Battery companies are spending a lot of money on research, far more than we’ve ever spent in the past.

          • Sheldon A Harrison

            So, you are leasing the batteries. In that case, in addition to the raw fueling cost in electricity, the trucker is now partially paying for the capacity of the battery and handling equipment. Additionally, there will be a need to occasionally reposition batteries because of the realities of unbalanced freight routings etc. My field of work is transportation planning and I have a thorough understanding of logistics. Right away, the 3c per compared to 10c per mile analogy falls to pieces. You are back to a number closer to if not more than the fuel cost of 10 cents per mile in addition to being less flexible in routing and not able to haul as much payload. It is well known that the capital storage cost of a battery is much more than the energy input cost to said battery. I stand by this statement. Long haul trucking, railroads, shipping, air will be using fuel powered vehicles for a long time to come.

          • Bob_Wallace

            10c per mile assumes no infrastructure/fuel transportation costs.

            Pieces reassembled.

            Remember, the difference per mile is a constantly recurring cost. Most long-haul, over-the-road truck drivers average from 100,000 to 110,000 miles per year. And with the lower miles per kWh/unit H2 the savings of driving with electricity is multiplied.

          • Bob_Wallace

            “in addition to being less flexible in routing and not able to haul as much payload”

            I missed this part. How much flexibility is needed if the trucks have a 300 mile range per charge and swapping stations are built along major travel route.

            ” railroads … will be using fuel powered vehicles for a long time to come.”

            “Along the route of the Trans-Siberian Railway, trains of oil tank cars extend across the landscape for miles. Each tank car, black and tarry-looking, with its faded white markings, resembles the one that follows it… a trainload of these cars defines monotony.

            The Trans-Siberian Railway covers 9,288 kilometers between Moscow and the Pacific port of Vladivostok, or 5,771 miles. In other words, if it were twenty-one miles longer, it would be exactly twice as long as Interstate 80 from New Jersey to California. Laying awake near the tracks in some remote spot at night you hear trains going by all through the night with scarcely a pause.

            (T)he Trans-Siberian Railway is all-electric, with overhead cables like a streetcar line – you find the tracks are empty of traffic only for five or ten minutes at a time.

            Besides oil, the railway carries coal, machinery parts, giant tires, scrap iron, and endless containers … just like the containers stacked five stories high around the Port of Newark, New Jersey, and probably every other port in the world.”

            Travels in Siberia by Ian Frazier (2010)

            Things change. If Russia pulled it off, so can we. The Trans-Siberian was converted from fossil fuel to electric.

          • Sheldon A Harrison

            The cost used for H2 absolutely includes the infrastructure/fuel transportation costs. It is intractably embedded in the purchase price at the pump and the quoted numbers. If it did not, the number would be lower. H2 can be done today from nat gas for < 10 c per mile equivalent in a fuel cell if transportation and distribution were magically omitted.

            I concede your point on railroads actually. In fact, I really think that is the direction we should go in for long haul overland freight. Point still stands for the others however.

            Battery swapping is less flexible than pumping fluid (whether liquid or gas). That should be obvious. You simply have to manage and move more material and it is harder for the trucker cannot to take odd jobs off the beaten path. That implies less flexibility of operation.

          • Bob_Wallace

            Yes, on reflection the 17 cents per mile that Toyota states includes distribution costs.

            When you think about the price spread remember that a long haul truck gets about 6 MPG. The difference between 3 and 10 -17 goes way up.

            Hydrogen from natural gas is not a solution. We can’t afford to keep pumping carbon into the atmosphere and at some point we run out of NG.

            Battery swapping and pumping fluid are equally flexible. Meaning that the ability to engage in either depends on whether the ‘station’ is built.

            With battery powered trucks there would be the option of using high power charging in more remote areas where a battery swapping station wouldn’t be justified. Think the ability to plug in all the power from 8 bays of a Tesla Supercharger at once.

            Battery swapping equipment needn’t be complicated. A modified fork lift could do the job in a less frequently used location. And batteries could be charged over a longer time period for that 18-wheeler that comes by once a week.

          • Shane 2

            It may be that swappable battery packs along major transport routes make more sense for 18 wheelers than for cars.

          • Bob_Wallace

            That’s my guess. Trucks run a lot of hours almost every day. Most car drivers rarely drive more than 200 miles in a given day.

            What makes the most sense to me is to use electric rail to move the long distances and battery powered trucks for “the last mile”.

            As we quit coal and oil we are going to free up a lot of rail space. Rail is an extremely efficient way to move stuff.

            And if we’re really lucky we’ll have some version of the hyperloop to move the stuff that needs to be moved very quickly. Freight could move from one coast to the other at 800 MPH in less than four hours. No need for potty stops.

  • Mephy

    “Both of these systems lose energy as heat along the way. A solar fuel cell, on the other hand, could theoretically store all of its solar energy in the form of chemical energy within molecules.”


    • Kyle Field


      • Mephy

        The Second Law of Thermodynamics.

        • Hazel

          Uh, “solar cell” produces fuel. Tank stores fuel. How does that violate the Second Law?

          • nakedChimp

            [ ] tick here if you don’t understand the laws of thermophysics and what they mean.

      • nakedChimp

        to elaborate on Mephy a bit more.. any energy conversion incurs losses from input to output, otherwise it would be perfectly possible to revert the reaction and end up with the inputs again without any further energy input into the reaction. Humans have never witnessed a reaction like that (even if some people on youtube have vids about this) – so the 2nd law of thermodynamics is here to stay and even the supersonic solar fuel cell will have to abide it’s rules – no matter what Tina writes.

        • Hazel

          Ah, so your beef is with the word “all” in that sentence? Yes, there will be losses. Does that address your concern?

          • Kyle Field

            I agree – seems like this is the sticking point. Makes sense to me…but it would be nice if comments were more constructive & specific.

  • Michael G

    Thanks for the interesting article. I always enjoy your reporting on some strange research I never heard of before. I actually do go look up the ideas elsewhere after you’ve pointed them out. Of course, relatively few research projects make it out the development stage intact but they still make a difference in that some other research feeds off it and eventually you get some synthesis of ideas no one ever expected.

    And your breezy style is always fun to read.

    • Joseph Dubeau

      Big box stores could ditch the grid, use natural gas fuel cells instead

      “The high efficiency of natural gas fuel cells means fewer greenhouse gas emissions as well. The PNNL prototype showed 56 percent electrical conversion efficiency compared to 32 percent from conventional coal plants
      and 53 percent from natural gas combined cycle plants. The study shows that the natural gas fuel cell system would produce 15 percent less carbon dioxide per kWh than a modern natural gas combined cycle power plant.”

      • Hazel

        Solid oxide fuel cells using natural gas are better for constant load applications, than for big box stores using power for about 12 hours a day. Efficiency is higher, so fuel costs are lower, but capital costs are higher than for gas turbines and other generation technology. So you want to run them all the time.

        There are a lot of fuel cells at data centers which are on 24/7, and similar constant-load facilities.

  • Joe Viocoe

    This is as much Vaporware as anything found on phys . org
    This is decades away from commercialization and likely to never make it out of the lab. There is usually some omitted detail that makes this unsuitable for the application that journalists are claiming for it. There is really no information about Hydrogen production quantity per unit area. Not even ball park estimates.

    The devil is in the details that they DO NOT SHOW.

    Other research into nano-batteries, metal-air, ultra capacitors, are all much further along and better funded.

    Governments have been throwing a few million dollars at the Hydrogen Economy every year for the past several decades.

    It isn’t so much an “inevitable march”… as it is a “death march” debacle.

    • Pete Marevich

      Joe, can I make a guess that you are pro Battery EV? You don’t explicitly say it, but your emotional response about positive news related to FCEVs goes along with a stereotype I’ve been noticing with pro BEV folks. No offense if you’re not. Just a guess on my part based on your reaction.

      • Joe Viocoe

        I do not deny that, and have often explicitly admitted to that.
        Everyone has emotional biases or some kind of preference… even/especially the commentators here that deny any such bias.

        my opinions, however, are still based on facts and backed up where ever I can. And I often debate against equally emotionally Biased pro fuel-cell advocates.. But they tend to lack in facts that are backed up by reality, But instead are speculations of future possibilities.

  • Hazel

    Neat research, sounds like a major breakthrough. Congrats to the team.

    What’s the solar → H₂ efficiency, and what’s the cost? If less than about 20% efficient, PVs + battery round trip loss gives more miles per insolation×area×time than SSL (supersonic leaf?) + hydrogen leakage and fuel cell losses. If more than $1/W, PVs + battery are still cheaper.

    There’s your target. Keep doing the research, and keep funding it. And we can start start thinking about public funding for scaling up and commercializing hydrogen fuel cell vehicles when researchers get close to that target.

    • Neptune

      Artificial leaf probably won’t be able to outcompete PV, but it could provide bulk storage for winter which batteries cannot. That’s probably the main advantage it has against PV.

      • Hazel

        Why can’t batteries provide bulk storage for winter? Flow batteries certainly can. The right kind of liquid metal battery could. Those are extremely low-cost storage options. PV + such storage is the competition here.

        • Neptune

          Too expensive, because of high capital costs.

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