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The Lowdown on Hydrogen, Part 1: Transportation

Roger Arnold's picture
Director Silverthorn Institute

Roger Arnold is a former software engineer and systems architect. He studied physics, math, and chemistry at Michigan State University's Honors College. After graduation, he worked in...

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  • Apr 3, 2017

After more than two decades of hype about the imminent arrival of a transformative “hydrogen economy”, many veteran technology watchers — myself included — had concluded that hype was pretty much all it was. Hydrogen fuel cell vehicles, in particular, looked like a failed dream. Bright innovators like Canada’s Geoff Ballard had attacked the problem and burned through serious investment money trying to develop a product that could stand up to the rigors of the automotive market. All with little success. And beyond the cost and durability issues of fuel cells themselves, the hydrogen storage issue stubbornly resisted commercially practical solutions.

In recent years, hybrids and battery electric vehicles have appeared to hold the inside track for low carbon and zero carbon transportation. Tesla has reshaped perceptions of what is possible for battery electric vehicles. The cost of lithium-ion battery packs has been driven down, while capacity, performance, and reliability have increased dramatically. To be sure, government programs have continued to fund fuel cell R&D. If nothing else, fuel cells still hold broad appeal for military programs. But to those of us who felt we understood the issues, the barriers to broad use of hydrogen as an energy carrier looked pretty fundamental. We — or at least I — didn’t really expect to see them fall anytime soon.

In the face of that expectation, a spate of announcements and news articles over the past year relating to hydrogen have come as a shock. Most prominent have been recent announcements by Toyota, Honda, and Hyundai of new FC vehicles for production release in markets where hydrogen refueling stations are available. Toyota announced the Mirai, Honda announced the Clarity Fuel Cell, and Hyundai announced the Tucson Fuel Cell SUV. But those were just the commercial announcements backed by ad campaigns. When one starts digging, scores of significant news stories and announcements from around the world turn up. The whole idea of the hydrogen economy — which never quite went away — seems to be resurgent.

So what is it that happened while I wasn’t paying attention? A thorough review seems in order. Since battery vs. fuel cell EVs are at the eye of the storm, I’ll start there. Then, time permitting, I’ll go on to look at some of the broader issues of energy storage and hydrogen production.

The EV technology race

Despite disappointing progress in the early years of the Bush “Freedom Car” initiative, fuel cell R&D never dried up. It has been ongoing, and not all of it has been politically driven. There has always been genuine promise in FC technology. The problems have been cost and durability. As far as I can tell, there have been no singular technology breakthroughs behind the resurgence of interest in hydrogen. But persistence and general advances in materials and manufacturing have begun to pay off. A small example: automated machinery able to make reliable gas-tight welds between thin sheets of metal. That turns out to be crucial for fabrication of efficient bipolar plates in PEM fuel cells.

Analysis by DOE’s Fuel Cell Technologies Office puts present cost of automotive FC stacks at $53 per kW for manufacturing volumes of half a million units annually. That’s half of what was projected for the state of the art in 2006.

Ironically, one thing widely seen as needing to change before FCEVs could become practical has stubbornly not changed: technology for carrying hydrogen on-board the vehicle. Despite a plethora of promising lab developments, there seems to have been no practical breakthrough in hydrogen storage. The new FC vehicles all use high pressure gaseous hydrogen stored in polymer-lined, fiber-wound pressure tanks. Similar tanks were made by Quantum in the 1980s. The tanks remain heavy, bulky, and costly. However, with better manufacturing methods and stronger, cheaper carbon fibers, their cost now measures in the low thousands of dollars rather than the high tens of thousands.

FC Advantages: weight, capital cost, refueling time

From Toyota’s product sheet for the Mirai, the fuel cell system delivers 2.0 kW/kg with a power output of 114 kW max. That implies a FC system weight of 57 kg. The hydrogen tanks hold 5 kg H₂ at a weight percentage of 5.7%. That implies a tank weight of 83 kg. So, 145 kg total for tanks + FC system + 5 kg hydrogen, delivering an EPA estimated range of 312 miles. That compares to 540 kg for the battery pack in a Tesla Model S with a rated range of 265 miles.

It appears that despite the heavy and bulky pressure tanks, the Mirai delivers a greater driving range than the Model S, with roughly a 4:1 weight advantage for the energy delivery system. More important for most buyers, however, will be the system cost per kWh to the drive motors. That’s harder to nail down, because manufacturers don’t normally release cost data publically.

There’s a small cottage industry devoted to guessing and predicting the cost of Tesla’s battery packs. GTM Research projects that by 2020, Tesla’s average cost for packs will be $217 / kWh. Using that figure, the 85 kWh Model S battery pack would come to $18,500. That’s less than some estimates, but more than the $12,000 that Tesla itself is willing to guarantee to Model S owners as the replacement cost after 8 years. Everyone agrees that costs are on the way down as production from new battery “gigafactories” kicks in, so $18,500 is probably a reasonable figure to use for near term comparisons between battery and fuel cell vehicles.

On that basis, fuel cells appear to come out ahead of batteries on cost as well as weight. At $53 per kW, the Mirai’s 114 kW fuel cell system would cost just over $6000. The high pressure storage for 5 kg H₂ is probably around $3000. So the capital cost of the Mirai’s energy delivery system with longer range looks to be roughly half that of the battery pack for the Model S.

Of course, FC vehicles are also much faster to refuel. That’s widely considered their strongest market advantage. But it presumes a network of public hydrogen refueling stations that for the most part does not yet exist.

Normally a “chicken and egg” problem like that would be lethal for a new product introduction. It may prove to be so in this case as well. However, there are some special factors for hydrogen that could potentially enable it to break through. We’ll get to those. First, though, we should look at other issues on the flip side of fuel cells relative to batteries.

FC disadvantages: efficiency, carbon emissions, fuel cost

There are many ways to produce hydrogen. For electrification of transport, the green vision is that it would be by electrolysis of water. That vision is promoted for hydrogen fueling stations. The H₂ to be dispensed each day would be produced on-site the same day or the day before by electrolysis. That reduces on-site H₂ inventory, enhancing safety, and minimizes the capital cost of the station. It also avoids the need for new and costly infrastructure to distribute hydrogen. No need to either dig up the streets to lay hydrogen pipelines, or have liquid hydrogen tanker trucks mixing with city traffic.

In that scenario, the relatively low efficiencies of PEM fuel cells and electrolyzers put fuel cells at a distinct disadvantage relative to batteries. For each kilowatt-hour delivered to the drive motors of the vehicle, the electrolyzer / fuel cell system requires roughly twice the kilowatt-hours of energy input as the battery system.

The rough 2:1 difference in electrical load that FCEVs impose is bad enough, but it also carries over to the indirect carbon emissions of the two classes of vehicles. In terms of what they emit on the road, both BEVs and FCEVs are zero emission vehicles. Both, however, inherit indirect emissions via the power grid. If the grid were supplied entirely from carbon-free power sources, then both BEVs and FCEVs would be carbon-free as well. But that’s far from the case today. A 2:1 difference between FCEVs and BEVs electrical load means that an FCEV will have double the indirect carbon emissions per mile of a BEV.

The actual difference in fuel cost per mile will be quite a bit greater than the 2:1 difference in electrical load suggests. For BEVs, the fuel cost is just the cost of the electricity consumed in charging. There is no capital equipment of any significance between the vehicle and the power grid. For FCEVs, however, there’s the electrolyzer, hydrogen storage, dispensing system, and the commercial property hosting the station. There is also the daily operational overhead of running the station. Those elements raise the retail cost of hydrogen dispensed well beyond the cost of electricity to the electrolyzer.

Solid estimates of what can be expected in the near future are hard to come by. A jumble of subsidies confuse the picture, and estimates for future costs are sensitive to assumptions about rates of adoption, size of refueling stations, and the technology used for supplying H₂. DOE’s aspirational goals for 2020 are a wholesale production cost of $2.00 or less / gge (gallon of gas equivalent; ~1 kg of H₂). The goal for price at the pump, exclusive of taxes, is $4.00 or less (ref. here).

The bottom line is that fuel costs for an FCEV will be at least 5 to 10 times more than for a BEV for some years to come. I doubt that zero-carbon electrolytic hydrogen will ever be less than 4x as expensive. However for context, the fuel costs for a BEV are a fraction of those for a gasoline vehicle and are usually considered negligible. If the cost of hydrogen in an FCEV were 4 times higher than the per mile cost of electricity in a BEV, most drivers would find it acceptable. Fuel would still be a small part of the overall cost of owning and driving a vehicle. Witness to that is the fact that manufacturers of FC vehicles can afford to bundle free hydrogen into the purchase price or lease terms for the vehicles in their California test markets.

Situation in flux

The relative advantages and disadvantages cited above for FCEVs vs. BEVs are mostly soft. They’re subject to changes in technology, design approach, and use patterns. For example, developments in battery technology and manufacturing will almost certainly trim the upfront cost and weight disadvantages of BEVs. At the same time, changes in hydrogen production methods could reduce the per-mile cost disadvantages of FCEVs. There’s also an easy FCEV design change that would substantially reduce their cost of driving and mitigate the H₂ infrastructure challenge. (See below.)

Perhaps most significantly, the arrival and spread of autonomous vehicle capabilities will transform the automotive market in ways that significantly affect the tradeoffs between hydrogen and batteries. I’ll talk about that later.

Universal hybrids?

Controversy over batteries vs. fuel cell aside, there’s consensus on one aspect of future vehicle technology. Electrical motor-generators and solid state power controllers will increasingly be at the heart of drive systems. They make for cheaper, more reliable, and higher performance than mechanical transmissions and engine-coupled drive shafts. Ultimately, all future vehicles will be either pure BEVs or hybrids.

It’s not touted, but the new FC vehicles are, in fact, already hybrids. Toyota’s Mirai is built atop the Prius’ drive system. The two share many components, including traction battery and power controller. That enables regenerative braking and instant throttle response. It also buffers the FC system and reduces its cost. Commonality of components with Prius and a more benign FC environment are key parts of how Toyota limited its costs in fielding a new FC vehicle class.

All it would take to produce a plug-in hybrid version of the Mirai would be addition of a plug-in charging port. The same is likely true of Honda and Hyundai FC offerings as well. But batteries and fuel cells are competing for mindshare in the EV marketplace; it’s understandable that companies backing an FC play don’t want to expose the HEV roots of their flagship FC vehicles. It wouldn’t make marketing sense. A charging port does make technical sense, however. Local miles could be driven mostly in battery electric mode. The cost per mile would be low. Hydrogen consumption for a typical driving profile could be cut by half or more. In Europe, Symbio FCell has in fact taken that approach for a range-extended Nissan e-NV200 van for the taxi market.

A plug-in hybrid capability mitigates the hydrogen infrastructure issue for FC vehicles. They remain drivable even in areas without hydrogen refueling stations. The limited plug-in battery range might be a pain, and drivers would still want to have hydrogen refueling available near their home base. But they wouldn’t be tightly tethered to that base. The plug-in capability would provide flexibility, drawing from on-board hydrogen to extend range between plug-in chargings, or drawing on plug-in charging to extend range between hydrogen fill-ups.

The switch to electric drive changes the tradeoffs between batteries and fuel cells. It’s no longer a stark either-or choice. If electric drive and at least a modicum of battery capacity are givens, then the issues become how much battery capacity to have and what technology to employ for delivering extended range beyond what the hybrid drive battery supports. If the latter is enough to let local miles be driven mostly in battery electric mode, then the optimal solution for extended range is one that minimizes added vehicle cost. That holds even at the expense of higher fuel costs for times when the extended range capability is tapped.

Alternative fuels

It’s possible that neither large batteries nor hydrogen fuel cells are optimum choices for range. With large batteries, capacity above and beyond the needs of local driving may be a costly way to achieve an infrequently tapped range capability. And while future batteries will be lighter and cheaper, that also makes it attractive to offer more capacity for local driving. Increased capacity in the basic battery pack reduces the frequency of resort to the extended range capacity. The conceptual simplicity of having a single large battery may not be worth the cost. Separate subsystems could deliver greater range at lower vehicle cost, while enabling fast fueling as a bonus.

The separate subsystem for extended range might or might not be hydrogen. The added vehicle cost of the hydrogen approach looks like it would be about $9,000; that’s not small, but it’s not all that far above the cost of an IC engine and the various subsystems around it. The question is, what would it be buying?

With a fully decarbonized electricity grid and electrolytic hydrogen, the HFC approach would be buying carbon-free transportation. Yet if addition of easy and ubiquitous plug-in capability with larger hybrid drive batteries has already enabled most local miles to be driven in battery electric mode, then carbon emissions have already been slashed. If average fuel consumption for new plug-in vehicles is already 150 mpg or better, then the incentive to use hydrogen will be weak.

Barring a major breakthrough in hydrogen storage technology and further reductions in fuel cell cost, the default competitor to both batteries and fuel cells for extended range driving will likely be gasoline or compressed natural gas. Perhaps, if the price of fossil carbon emissions gets high enough, a carbon-neutral synthetic fuel might prove cheaper and more competitive. The energy cost of producing synthetic fuels from CO₂ and H₂ isn’t much greater than that of H₂.

Heavy Transport

The discussion so far has been about passenger cars. For a broader view of the hydrogen economy, we need to consider heavy transport as well: trucks, buses, trains, ships, and airplanes. Not to mention farm and heavy construction machinery. For the sake of brevity, I won’t cover any of the latter here. But trucks and buses play big roles and warrant comment.

For trucks and buses, the factors favoring hybrid electric drive systems are at least as strong as they are for passenger vehicles. The ability to deliver smoothly controlled torque for acceleration and uphill driving across the full speed range, with attendant capacity for regenerative braking, are attractive. Electric drive can deliver performance and safety advantages, along with fuel economy, clean air, and quiet operation. Low production volume for the heavy duty batteries, power control units, and motor-generators have hampered widespread adoption so far, but things are changing.

For energy supply to the electric drive system, there are different tradeoffs and different options that may be favored, depending on the application sector. All-battery approaches are attractive for metropolitan buses and utility trucks. Metro buses spend hours parked each day, either in their barns at low service times or at route ends while drivers change or take rest breaks before starting their next scheduled runs. It should be relatively easy to provide fast recharging at those points. The on-board batteries should never have to deliver more than about 25 miles in regular service.

For long-haul trucking and inter-city buses, all-battery approaches are currently impractical — and likely to remain so. Hydrogen has potential opportunities there. The recent unveiling of the prototype for the Nikola One electric semi (pictured below) has, in fact, caused quite a stir.

Credit: Nikola Motors

The truck is a hydrogen FC model, and its specs are quite impressive. 1000 horsepower (twice that of a diesel semi), 2000 ft. lbs torque, range of 1,200 miles, … If Nikola Motors can deliver on its promises, it will have a winner. Production deliveries aren’t scheduled to start until 2020, but truckers have already been plunking down $1500 deposits for reservations.

The high cost of electrolytic hydrogen will still make the per-mile fuel cost for a Nikola One relatively high — assuming that Nikola Motors is even able to deliver on ambitious plans to build solar farms for supplying its trucks with zero-carbon hydrogen fuel. The financial case for the vehicles would probably be stronger if they ran on compressed natural gas rather than H₂. They would still be hybrids — the Nikola One is planned to carry a 315 kWh battery that will give it the power to maintain 65 mph up a 6% highway grade and soak up the energy of descent from a mountain pass without touching the brakes — but it would lose its cachet as a hydrogen fuel cell vehicle.

It could retain some of that cachet if the Nicola One used high temperature SOFC fuel cells that run directly on methane. That’s an approach recently demo’d by an alliance between Ascend Energy and Atrex Energy. High temperature SOFCs are at least as efficient as PEMFCs, and if their high temperature waste heat is used to power a Brayton cycle turbine, they are a lot more efficient. The combination would certainly make for a low-carbon vehicle. To be zero-carbon, however, the methane burned would need to be from a carbon-neutral source.

Further topics

I haven’t yet covered the likely impact from autonomous vehicle developments, nor have I talked about different technologies for hydrogen production, or the use of hydrogen for energy storage and backing of intermittent renewables. Those are important topics, but I’ll leave discussion of them for part 2, next week.

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Bob Meinetz's picture
Bob Meinetz on Apr 3, 2017

Roger, your lowdown on hydrogen transportation avoids some key problems with H2, assuming we’re considering it as an alternative to gasoline to prevent GHG emissions. If we hop on the Trump Train and make emissions/climate change our descendants’ problem, there’s no reason to stop burning gasoline.

97% of commercial H2 is the result of steam-reforming methane – using heat to break down CH4. Left over is an atom of carbon which, ejected it into the atmosphere, quickly joins with a free atom of oxygen to make carbon monoxide, then soon thereafter another to make CO2. We could sequester it in salt caverns or silicates using massive trains bridging deposits in California to the Pacific, but that’s another article.

Raising the question of whether building a half-$trillion H2 refueling infrastructure leaves us with any environmental benefit at all. A well-to-wheels analysis using Argonne National Labs’ GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model shows FCVs only marginally better than purpose-equivalent parallel hybrids (Priuses) on GHG emissions, and 31% worse than electric vehicles in California. These results are using default inputs for the model, but there are many (you can download it from in MS Excel format, and try some of your own).

Not long ago I was forwarded an email from the California Fuel Cell Partnership (CAFCP). The group, financed by oil/methane companies and eager to find a way to sell something from thousands of gas stations as internal combustion cars are replaced by EVs, has seized upon the idea the public might be fooled into thinking FCVs are more environmentally-friendly than Priuses. When I challenged the CAFCP rep on this point in a reply email, he replied with another, claiming oil companies haven’t been involved with CAFCP for a decade. I replied back, pointing out Chevron and Shell Hydrogen are still heavily-invested in CAFCP. That was the end of our discussion.

Though high-temperature gas (nuclear) reactors are capable of separating hydrogen from water, convincing anyone H2 is more green than battery EVs once it’s compressed, chilled, and transported would be a tough sell. Then again, maybe not – hard to underestimate a public gullible enough to elect Donald Trump.

Engineer- Poet's picture
Engineer- Poet on Apr 3, 2017

Your TDS is showing.

Generally speaking, the people who care about hype-drogen as either an environmental solution (which we agree it actually isn’t) or their key to remaining relevant 30 years from now are not the ones who voted for Trump; their fix was in with Hillary, until it wasn’t.  You really need to look at your own camp to find those who are to blame.

Schalk Cloete's picture
Schalk Cloete on Apr 3, 2017

If current technology at scale can deliver the fuel cell and H2 tank for around $9000, it is not hard to see why there is a lot of interest. When adding $3000 for the motor and power electronics, the powertrain becomes quite attractive with standard EV subsidies. Marketing as an EV that you can fill up in 5 minutes like a regular car should be quite successful.

Regarding fuel costs, H2 production through methane reforming adds about $1/gge to the price of natural gas. In the US, natural gas currently costs only about $0.4/gge, making hydrogen fuel significantly cheaper than gasoline. Transport and storage will probably add another $1/gge to bring the cost up to around the cost of gasoline. Fuel costs should then be similar to a Prius and up-front costs only a few thousand more.

Even if all CO2 is released to the atmosphere during methane reforming, the CO2 intensity will still be lower than gasoline. Methane reforming is also a promising target for CCS, especially with H2-perm selective membrane technology.

Most importantly, fuel cell vehicles will be applicable to nearly all modes of transport, unlike BEVs that are best suited to cars primarily used for city driving (10-20% of transport energy consumption). Hydrogen therefore offers a true practical alternative to oil in the transport sector. Let’s see what happens…

Bob Meinetz's picture
Bob Meinetz on Apr 3, 2017

EP, plenty of blame to go around. Liberal Joe Romm made a solid contribution on the topic with The Hype About Hydrogen; he remains a fervent antinuke.

Liberal activist Michael Shellenberger is at war with liberal ideologues Jerry Brown and his corrupt hierarchy in California over their push to close Diablo Canyon.

Conversely, Republican John McCain has been pro-nuclear for his entire adult life. In 2007, before politely but briefly acknowledging hydrogen, he said this in remarks at the Center for Hydrogen Research:

We have in use today a zero emission energy that could provide electricity for millions more homes and businesses than it currently does. Yet it has been over twenty-five years since a nuclear power plant has been constructed. The barriers to nuclear energy are political not technological. We’ve let the fears of thirty years ago, and an endless political squabble over the storage of nuclear spent fuel make it virtually impossible to build a single new plant that produces a form of energy that is safe and non-polluting. The Savannah River Site has been instrumental in the development of new reactor technology that is more fuel efficient and safe. If France can produce 80 percent of its electricity with nuclear power, why can’t we? Is France a more secure, advanced and innovative country than we are? Are France’s scientists and entrepreneurs more capable than we are? I need no answer to that rhetorical question. I know my country well enough to know otherwise.

So unfortunately, it has little to do with political party and a lot to do with intelligence. What do all of the above have in common? 1) They’re not climate deniers, and 2) they all recognize Donald Trump as a simpleminded, non-partisan huckster.

There was rumored to be some support for nuclear energy in Trump’s incoming Department of Energy, run by that oil company CEO. How’s that playing out?

Roger Arnold's picture
Roger Arnold on Apr 4, 2017

Guys, please don’t steal all my thunder. I’ll have plenty to say in Part 2 about different options for producing hydrogen, and why electrolysis mostly sucks. For now, I’m more interested in comments on the thesis that all vehicles are headed in the direction of electric drive supported by at least some degree of battery storage. The issues are:
(1) how much battery storage:
(2) whether to make it accessible for plug-in charging; and
(3) whether and how to provide for extended range beyond what the hybrid battery will deliver.

All bearing in mind, of course, that we’re not constrained to live in a “one size fits all” world. There will certainly be a diversity of vehicle types introduced and slugging it out in the market. Where would you put your money?

Rick Engebretson's picture
Rick Engebretson on Apr 4, 2017

If you want to play with hydrogen gas (H2), go ahead. If you want to exploit hydrogen bearing molecules for energy there are plenty of options. Oxidation-reduction reaction options are available in batteries, fuel cells, or internal combustion engines. It’s hard to think of energy systems that don’t use hydrogen. Even the nuke-heads rely on boiling water. Perhaps wind and solar PV can be excluded.

Hydrogen is interesting because it has strong electric properties and virtually no mass or volume. IIRC, the O-H bond stretch vibration frequency has an optical wavelength in vacuum of 3 microns, and overtones into the near infrared. Thus, excitation of vibration modes is very improbable, of the order 10 to the -14. This is how we get neutral pH (-log) of 7.

An interesting opportunity is doing acid-base chemistry with the intense solar wavelengths we get for free. Biology does it.

Having seen Ronald Reagan “make America great again” in California when Minnesota was computer central and Walter Mondale leftists killed science, it is worth wondering where the next generation of science will emerge.

Just give hydrogen more credit than being H2 gas.

Nathan Wilson's picture
Nathan Wilson on Apr 4, 2017

… the default competitor to both batteries and fuel cells for extended range driving will likely be gasoline or compressed natural gas.

Good point with respect to cost, but cng tanks are bulky; why allocate space for them if the cng system is only occasionally used (for plug-in hybrids)? It seems better to pay the carbon tax and burn gas (or biofuel) for range-extension, and get more usable trunk space.

… if the price of fossil carbon emissions gets high enough, a carbon-neutral synthetic fuel might prove cheaper and more competitive.

Not so fast. If there is a price on CO2 emissions, and it is large enough to 1) cover the cost of CO2 capture from fossil fuel combustion, and 2) cover the cost of sequestration (presumably the minimum CO2 emissions cost that results in deep decarbonization), then a climate neutral synthetic hydrocarbon fuel must also reflect the cost of CO2 emissions. This is because any CO2 which is captured, even from biomass, can be sequestered, and the resulting emissions credit can be sold for cash. So carbon-free fuels (e.g. H2, NH3) will still gain an advance when there is a carbon tax/fee.

… if the Nicola One used high temperature SOFC fuel cells that run directly on methane.

It’s worth noting that SOFCs have also been tested with ammonia fuel (NH3), and found to have good efficiency, plus the exhaust was found to be effectively free of NOx. Yes, (fossil) methane is cheaper than ammonia, but ammonia is a much better solution when the objective is deep decarbonization. Why should government incentivize a roll-out of methane infrastructure which is only an interim solution?

Ammonia has not been hyped like hydrogen, but it does have advantages: it has triple the energy density of 5000 psi H2, and it can be stored without high pressure tanks. This makes the vehicle side easier, and the infrastructure. Because ammonia is easily and in-expensively transported by truck or rail, it works well with centralized production (which reduces retail cost). It’s relative ease of storage also means it’s a much better solution for using off-peak electricity, even for seasonal usage; this means it will have much lower up-stream CO2 emissions than H2 which is produced at the point-of-sale with only a few hours of storage (electricity costs are lowest when sustainable electricity production exceed grid demand). Retail ammonia dispensers (using truck-delivered NH3) should also be cheaper than H2 systems that include equipment for on-site fuel generation; this helps with the chicken and egg problem.

The main drawback of ammonia, toxicity is less of an issue for professionally operated heavy duty vehicles compared with personal cars. So it actually complements personal BEVs rather than competing with them as personal FCV would.


Roger Arnold's picture
Roger Arnold on Apr 4, 2017

.. any CO2 which is captured, even from biomass, can be sequestered, and the resulting emissions credit can be sold for cash.

Ah! Good point. So even though being made from captured CO2 means that there’s no back end carbon tax on synthetic hydrocarbons, full accounting needs to add a front-end “opportunity cost” for the carbon credits that the captured carbon could have produced, had it been sequestered.

OTOH, if the synthetic fuel being produced is ammonia, then there won’t be any carbon captured as part of the manufacturing process. So the choice really comes down to the comparative cost of isolating atmospheric nitrogen from the air and reacting it with hydrogen to make ammonia, versus the cost of capturing CO2 from whatever source is handy and reacting it with hydrogen to make synthetic hydrocarbons. All independent of carbon credits or emissions pricing.

That’s versus the third option of using the hydrogen as-is. Given hydrogen, the cost of making either ammonia or synthetic hydrocarbons trade against the storage and handling advantages of the liquid (or easily liquified) fuels. (I can’t think of any ways to make either ammonia or synthetic hydrocarbons that don’t start with production of hydrogen. Perhaps electrolytic production of ammonia would do so, but that’s a process I know little about.)

Engineer- Poet's picture
Engineer- Poet on Apr 4, 2017

Liberal Joe Romm made a solid contribution

Yes, LIBERAL Joe Romm.  Not a Trump voter.  Yet you try to place blame where it manifestly does not belong.

Stop projecting your own wrongs and faults onto others.

Republican John McCain has been pro-nuclear for his entire adult life.

Juan McPain should have been washed out of the Navy after losing several aircraft, and played the Vietnamese equivalent of Tokyo Rose.  He was one of the Keating Five, yet somehow survived that scandal to become one of the Gang of Eight trying to gut US immigration law.

McCain being pro-nuclear is like a serial killer also being part of an Adopt-a-Highway crew.

How’s that playing out?

Ask me after the Russiagate fraud has blown up and taken out the media and Obamacrat forces behind it, preferably prosecuted for felony violation of the FISA act and sedition.  Right now the new administration has far more serious things to deal with.

Bob Meinetz's picture
Bob Meinetz on Apr 4, 2017

Even if all CO2 is released to the atmosphere during methane reforming, the CO2 intensity will still be lower than gasoline. Methane reforming is also a promising target for CCS, especially with H2-perm selective membrane technology.

Schalk, you’re only counting carbon released to the atmosphere during the reforming stage. For a true well-to-wheels analysis, add the carbon penalty in cooling/compressing hydrogen to 700 bar and transporting it, and you end up with 20% more GHGs (418g/mi) than a comparable grid-independent hybrid electric/gasoline car (334g/mi):

Who would spend more money for a car, powered by a fuel dirtier than gasoline, with less range, and a tiny fraction of the locations at which to fuel it?

In the news today Tesla’s market cap surpassed that of Ford Motor Co. at $48.2 billion, cementing the role of EVs in US transportation and trapping FCVs right where they’ve been for the last thirty years: “a great idea that’s only ten years away.”

Schalk Cloete's picture
Schalk Cloete on Apr 4, 2017

Wow, I did not know that additional lifecycle emissions are so large. For a 60 mile/gge FCV, greenhouse gas emissions from methane reforming amounts to less than 150 g/mile. It is hard to see this number being tripled by other lifecycle emissions. Could you send me the source of the tables you posted? I’d like to have a look.

Bob Meinetz's picture
Bob Meinetz on Apr 4, 2017

Schalk, the image is a screenshot from the Excel version of the US Dept. of Energy’s GREET model installed on my own computer. Inputs are default ones with which you may disagree; fortunately, you can download it yourself, input your own values (among hundreds), and run your own model:

I attended a free GREET workshop at Argonne National Laboratory in October, 2015. Besides learning how to work the Excel install – there are thousands of macros which perform the calculations – there were lectures by DOE researchers and many other energy advocates wtih whom to engage, mostly from the renewables community. While wandering the grounds of the lab I bumped into Roger Blomquist, Director of Nuclear Outreach, and got a personal tour of their History of Nuclear Energy museum.

I highly recommend both the download and the workshop, but I’m not sure the download is still available – ANL.GOV, like all DOE sites, has changed significantly since Trump took office. The useful Electricity Data Browser disappeared from EIA.GOV for about a week; after complaints from me and others, it magically reappeared one day. I’d like to think my thorn in their side played a part.

It will be up to all Americans to be a thorn in the side of our anti-science, anti-climate administration, which becomes more irrational and unpredictable by the minute. Some of that on display on this very page.

Nathan Wilson's picture
Nathan Wilson on Apr 5, 2017

There is a process call solid-state ammonia synthesis which creates ammonia from water and nitrogen, without a gaseous H2 intermediate. It is still experimental, and is chronically underfunded.

The demonstrations of the technology to date have used reversible fuel cells which use a proton-conducting ceramic (PCC) membranes, at around 500C. This temperature (which counts as medium for ceramic fuel cells) is actually high enough (with the right catalyst) to open the nitrogen bonds and allow ammonia to form. The benefit to using PCC ceramics instead of more common SOFC w/ oxygen-conducting ceramics is that with PCC, the ammonia is produced on the nitrogen side of the cell, instead of the steam side, which makes ammonia separation trivial.

Solid-state ammonia synthesis is supported mainly by advocates of the small-is-beautiful concept, since it would scale easily down to the 10 kW range. Separating nitrogen from the air is really easy, as demonstrated by home medical oxygen generators (which work by pumping air through a nitrogen adsorption bed).

For the 300 MW+ utility scale, the conventional approach (electrolysis followed by Haber-Bosch ammonia synthesis) apparently works fine, and has an efficiency/cost in the same range as electrolysis followed by liquefication and modest storage.

On the H2 versus NH3 storage question, here is an article about the work of a team working on a technology to let retail outlets stock ammonia, which gets converted to H2 for use in FCVs. The conversion could happen either at the point of sale, or in the vehicle. 99% purity is easy to achieve with a hot catalyst, but their technology seeks to achieve the high purity needed for PEM FCVs.

“From now on,” Kambara is quoted as saying, “hydrogen will be stored as ammonia.”

Ronald Chappell's picture
Ronald Chappell on Apr 7, 2017

Do any of these approaches make sense when the low carbon imperative disappears?

Ronald Chappell's picture
Ronald Chappell on Apr 7, 2017

Do any of these approaches make any sense when the low carbon imperative disappears as it surely will?

B W's picture
B W on Apr 14, 2017


hydrogen is an essential to all major fuel sources sans Uranium. Whether dispensed commercially in its elemental form or not, Hydrogen will inevitably play a large role in the future of energy.

B W's picture
B W on Apr 14, 2017

I would like to add in addition Schalk, that hydrogen offers great utility for a variety of industrial uses, and that if used in stationary fuel cells Combined Heat and Power efficiencies are very good. Regarding long term bulk storage of energy, hydrogen offers unique scalability and low capital cost compared to alternatives like batteries or pumped hydro.

B W's picture
B W on Apr 14, 2017

Bob, the reality is that compressing hydrogen to 10,000 psi doesnt take a major amount of energy (electricity). 2.5 kwh/kg is the average requirement including cooling and compression. The transportation requirements are highly uncertain and could be minimal – I can elaborate.

B W's picture
B W on Apr 14, 2017

$190/kwh is not competitive with fuel cells much less ICEs.
neither is a partial charge in 30 minutes.

finally the 100D models are far too expensive for a mass market solution.

Sean OM's picture
Sean OM on Apr 18, 2017

GM is only paying 145/kw for their Bolt batteries. Even if you multiply that times the 33% for the battery pack itself. They at less then the 217/kwh for the assembled battery pack itself. You know Tesla isn’t paying more.

Even lowly VW has said battery capacity will double within 10 years. Samsung is saying 5 as they have a solid state battery, that won’t start fires, charges slightly faster and has a lifetime of several thousand charge cycles. They already have the tech, they just have to test and mass produce it. It cuts the weight in half. IThere are at least 3 major markets for batteries right now. Utility, transportation and portable electronics, so it ups the ante for research because you can possibly hit one of 3 markets.

Hydrogen -may- make sense for larger vehicles. But for the normal person, it doesn’t offer any advantages, and in fact a disadvantage over using gas. With gas, if you run out, you grab a gas can which you can use for all your other toys like the lawnmower. With hydrogen, you have to get towed or have some tow truck that is transportable. With electric there is a -chance- you can push it to a plug somewhere or someone has an onboard generator on their tow truck. The hydrogen FC tech converts directly to electric, so in reality, you are still using an electric drivetrain, the differenc is what is supplying the power.

The faster refueling time is really the only advantage, but if you can charge at home, shopping or at the bar, etc. It offers little advantage.

We already have to pay for the electric infrastructure and it is a much needed tool for our communications network and it is only like 50% more load at most. It already needs to be revamped.

Last, since hydrogen is almost exclusively made from NG, it doesn’t offer any benefits over oil as NG, oil and coal prices tend to move in unison on the market. So we are screwed by having to pay more at the pump and no recourse of action to combat rising oil prices for the 3rd time. With electric, you at least have the option of installing solar panels. Which creates a market force to keep prices low.

Sean OM's picture
Sean OM on Apr 18, 2017

You can actually charge to 80% within 5 minutes with current lion tech. It requires bigger/heavier and more expensive components. it also requires the charging stations has the ability to deliver the current, which isn’t typically the case. It also can affect battery life.

The charging stations are becoming available that have the ability to deliver. They also have optional battery packs so they can store the needed current waiting for the next customer. Which brings us back to batteries, supercaps, and possibly FCs, but for delivery stations.

I totally agree it is kind of an overblown issue. The ability to put charging stations at places you frequent, makes it far less of a hassle then having to make a separate trip to the gas station even if it takes 15 minutes longer to charge.

Mark Heslep's picture
Mark Heslep on Apr 19, 2017

The faster refueling time is really the only advantage, but if you can charge at home, shopping or at the bar, etc. It offers little advantage.

From MIT’s On The Road 2050 report, BEV achieves only 5% of the new car market by 2050.


…One of our specific findings on the use of electricity in transportation is that, without additional technological breakthroughs, pure BEVs are likely to be limited to modest sales volumes. One major reason is the long recharging time for this technology, which better vehicle batteries will not significantly reduce. Drivers are accustomed to refueling gasoline vehicles for more than 400 miles of travel in about five minutes. Gasoline refueling occurs at a rate of chemical energy transfer through the pump outlet of about 10 MW. For the equivalent recharging rate (400 miles of range in five minutes) 2–3 MW of electrical power would be required.40 This power requirement is more than an order of magnitude higher than even the fastest (Level 3) charging stations (~100 kW). Even if the associated battery cooling and durability challenges could be overcome, rapidly switching on 2–3 MW of charging power would place significant demands on the electricity distribution system: equivalent to the average power demand of more than 2,000 homes or 1 million square feet of commercial building space.

Mark Heslep's picture
Mark Heslep on Apr 19, 2017

Sean OM's picture
Sean OM on Apr 19, 2017

without additional technological breakthroughs,

It is -extremely- impressive that with no technological advances from -2009- (when the information they are quoting is from), BEVs could garner 5% of the market by 2050.

It is a different conversation today, since modest improvements have been made across the board even between 2009 and 2015 when the MIT report was published. The EIA even has increased it’s forecast for EV market penetration by like 10x since 2014. The stated there are multiple factors involved. For instance, if gasoline prices wouldn’t have dropped, EVs would have a lot stronger sales then the 3.24%(combined) of the market they are currently holding. And the flatline also means they arent guessing gas prices will rise again, which is projected for 2020s.

It isn’t a simple linear equation like projections in the MIT report are showing, but it is extremely difficult to make projections with multiple factors involved of new technology over a 40 year timeframe.

You are just quoting a best guess from 2009. I would suggest updating your information. The market changes.

Mark Heslep's picture
Mark Heslep on Apr 19, 2017

The MIT report was published 16 months ago.

The 5%/2050 figure is 800K cars sold in the US, anemic. Tesla alone claims it can sell a million globally by 2020.

Sean OM's picture
Sean OM on Apr 19, 2017

The mit report was published 16 months ago. The data they are using for the chart is from 2009. If you read the article.

Bob Meinetz's picture
Bob Meinetz on Apr 19, 2017

aration, the low carbon imperative won’t disappear for at least another 100,000 years, so don’t hold your breath.

Darius Bentvels's picture
Darius Bentvels on Apr 20, 2017

With technical progress and the increase of the market for solar, wind and storage,
the unsubsidized cost price is widely expected to decrease below that of classic fossil power plants (and of course far below that of nuclear).

– PV solar panels now have efficiencies of ~20% that will increase to ~30%, while the costs will decrease further as production will be automated thanks to the increased market. So the costs will decrease towards levels of 2 – 3 cent/KWh in insolation poor Germany.

– Wind offshore will become cheaper than onshore as offshore allows for the construction of big wind turbines of 16-20MW, which will increase the CF towards 60% and decrease the costs per KWh towards levels of 2 – 3 cent/KWh.

– Storage using batteries (for evening to a few days) & Power-to-Gas (for seasonal dips) are also on a long term price decrease path, though I know not enough about those.

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