Why hydrogen won’t be the fuel of the future, but it will be a vital chemical input

Since the invention of the Grubb–Niedrach fuel cell in 1958, which was used in NASA’s Gemini missions, hydrogen has been touted as the fuel of the future. Advocates of hydrogen bemoan the lack of investment, but they are convinced that hydrogen vehicles are just around the corner and every electric utility will be generating hydrogen for energy storage within a decade. Despite all the hoopla, the imagined hydrogen boom never seems to arrive. Instead, it remains the perpetual domain of venture capitalists and vague long-term plans that are unlikely to ever come to fruition. It is necessary to do the math to understand why businesses aren’t investing in hydrogen in a major way despite decades of generous government subsidies and grandiose plans.

The fundamental problem with hydrogen is the amount of energy which is lost in its creation and conversion back to usable energy. If creating hydrogen from water, first between 30% and 37% of the energy is lost in the electrolysis to split H2O into H2 and O. Then roughly 10% of the energy is lost in compressing and storing the H2 and even more is lost if the H2 is liquefied by cooling it to under −253°C (−423°F). If compressed and transported via truck to a hydrogen fueling station, roughly 20% of the energy will be lost. Then, the hydrogen is passed through a fuel cell, such as a proton exchange membrane (PEM) in an automobile, an alkaline fuel cell (AFC) in a submarine, a phosphoric acid fuel cell (PAFC) in a commercial building’s generator or solid oxide fuel cell (SOFC) at a power utility that also needs both electricity and heat. The fuel cell splits the H2 molecule into two hydrogen protons (H+) and two electrons (e-). Then combines them with oxygen (O₂) molecules from the air to create water and free electrons. One O₂ molecule and two H₂ molecules will generate 4 free electrons for electricity:
   2H₂ + O₂ → 2H₂O + 4e-
In this conversion from hydrogen + oxygen to water + electricity, phosphoric acid fuel cells lose 60% of the energy, molten carbonate fuel cells lose 50%, and alkaline and solid oxide fuel cells lose 40%. Proton exchange membrane fuel cells lose between 30% and 40% of the energy, so the fuel cells in automobiles are relatively efficient, but the membranes are expensive and they wear out too fast for use in a power plant.

Just the basic operations in a power plant of electrolysis, compression, storage and electric generation in a fuel cell will lose roughly 65% of the original energy. In a vehicle, the losses are even greater because of the need to transport the hydrogen to a fueling station and the losses in the motor. Concawe, which researches environmental issues for the leading oil and gas companies, estimates that a hydrogen vehicle is only 27% energy efficient. This estimate may be optimistic, considering that Ulf Bossel of the European Fuel Cell Forum calculated in 2003 that a hydrogen fuel cell vehicle (HFCV) is only 22% efficient if the hydrogen is stored as compressed gas or 17% efficient if the hydrogen is liquefied.

Well-to-Wheels energy efficiency (according to Concawe)
	Electricity	e-Hydrogen	e-Hydrogen	e-fuels
	BEV	Fuel Cell	ICE	ICE
Transmission eff.	95%	95%	95%	95%
Electrolysis eff.		63%-70%	63%-70%	63%-70%
Fischer-Tropsch eff.				70%
Transport eff.		80%	80%	95%
Battery eff.	90%
Fuel cell eff.		60%-70%
Motor eff.	85%	85%	30%	30%
Mechanical eff.	95%	95%	95%	95%
Total efficiency	69%	27%	15%	13%
Concawe (Jan 2020) Role of e-fuels in the European transport system – Literature review, report no. 14/19, https://www.concawe.eu/wp-content/uploads/Rpt_19-14.pdf

A number of the auto makers have looked at the complexities of hydrogen fuel cell vehicles, and have decided that it will be far simpler to burn the hydrogen in a traditional internal combustion engine (ICE), but combustion loses 70% to 75% of the potential energy stored in the hydrogen, so it makes even less sense than using a fuel cell. Concawe calculates that 85% of the original energy is lost in a hydrogen combustion vehicle, meaning that it takes nearly twice as much energy per mile as a hydrogen fuel cell vehicle.

Toyota, which is the leading global car manufacturer, has been working on developing hydrogen combustion vehicles since 2017. Toyota has demonstrated prototypes of the Yaris GR, Corolla GR Sport and HiAce van with hydrogen combustion engines. While existing gasoline combustion engines can be adapted to work with hydrogen, they become much less powerful when burning the light gas. Toyota found that its 3.4-liter twin-turbo V6 engine produces 409 hp and 650 Nm when burning gasoline, but only 161 hp (120 kW) and 354 Nm when burning hydrogen, so there is a significant reduction in power. To counter this problem Toyota is now prototyping a liquid hydrogen motor which burns the hydrogen in a more concentrated form, but the hydrogen pump quickly wears out, because it can’t use lubricating oil with liquid hydrogen. A liquid hydrogen vehicle is also significantly heavier, because it needs refrigeration equipment and insulation to hold the H2 at −253°C.

Toyota isn’t the only automaker pursuing hydrogen combustion. Mazda has developed its rotary RENESIS engine since 1991 that can burn either hydrogen or gasoline. Hyundai/Kia along with the Korea Institute of Machinery and Materials have developed a hydrogen motor that injects hydrogen at 30 times normal pressure during combustion. Mitsubishi says that it plans to develop hydrogen combustion engines with 6, 12 and 16 cylinders.

Tata Motors just opened two R&D facilities in October 2023 in Pune, India to develop hydrogen combustion motors. Girish Wagh, Executive Director at Tata Motors, explains the logic for investing in wasteful hydrogen combustion: “For fuel cell electric, a very high level of purity in the hydrogen is required, and hydrogen ICE can work at a lower level of purity. Secondly, hydrogen ICE allows using the current available infrastructure that has been in place for decades. Hence, in a way, it can also keep that value chain for longer.” Obviously there isn’t much hydrogen fueling infrastructure in place in India, so the “infrastructure” that Girish refers to is its existing ICE motor manufacturing that Tata Motors doesn’t want to lose. The attraction of hydrogen combustion is that it allows automakers to keep making similar vehicles to what it is already making, even if hydrogen combustion is extremely wasteful and expensive.

Cummins, which makes internal combustion engines for trucks, boats and generators, has developed 6.7 and 15 liter hydrogen combustion motors, which it plans to produce starting in 2027. The company views hydrogen combustion as a way to continue its current business operations with minimal disruption. The company’s web site explains: “Hydrogen engines are built upon today’s modern and reliable internal combustion engines. For vehicle manufacturers, it is a familiar technology to use in their vehicle design and production. Similarly, for fleets, it is a familiar technology to operate, maintain, troubleshoot, and service.”

Sadly hydrogen combustion isn’t the most wasteful idea being pursued by the auto industry when it comes to hydrogen. Instead of passing hydrogen through a fuel cell or internal combustion engine, Porsche plans to take hydrogen and CO₂ and turn them into methanol, which is then converted into a synthetic liquid electro-fuel (or “e-fuel” for short) that will burn just like gasoline, so that the luxury automaker can continue to sell ICE vehicles after the EU bans the sale of new gasoline-burning cars starting in 2035. Porsche has already invested US$100 million in the development of e-fuels, including $75 million in April 2022 in HIF Global, which plans to produce e-fuels in Chile, Australia and Texas. It opened a pilot plant in December 2022 to produce 130,000 liters (34,342 gal.) of e-fuel from wind energy in Punta Arenas, Chile. Porsche estimates that e-fuel will cost $10 euros per liter ($45 per gallon) to produce, making it unlikely that anyone except the rich will ever use it.

Likewise, BMW announced in June 2020 an investment of $12.5 million into Prometheus Fuels, a Silicon Valley e-fuels startup that aims to pull CO₂ from the atmosphere. BMW is also participating in Germany’s Copernicus Project, which is researching e-fuels in its P2X (power to everything) project. Among other things, the P2X program is trying to develop water-splitting electrolyzers that reduce or eliminate expensive iridium without sacrificing conversion efficiency that is currently around 65%. P2X is currently aiming to be able to produce a liter of e-fuel with 625 watts (or a gallon with 2.36 kW).

Like Toyota, BMW refuses to accept the obvious fact that battery electric vehicles will dominate in the future because they simply require less energy to operate than all the other types of vehicles. BMW began testing its iX5 Hydrogen vehicles on European roads in February 2023, but BMW recognizes that the use of expensive platinum group metals as catalysts in the proton exchange membrane will limit the scalability of hydrogen fuel cell vehicles. For this reason, BMW, Airbus and Quantinuum are investigating the use of quantum computing to discover new catalyzers that can be used in place of platinum, which has limited global reserves.

All these plans to use hydrogen in automobiles will inevitably come to naught, since they will require tremendous amounts of energy, which will make them far too expensive to ever compete with battery electric vehicles. The Intergovernmental Panel on Climate Change’s Sixth Assessment Report (2022) calculates that a hydrogen fuel cell vehicle consumes between 1.14 and 1.39 megajoules per km, which is 7 times more than a battery electric vehicle (BEV). Given how little energy it takes to operate a BEV compared to all other types of vehicles, it becomes apparent that BEVs will inevitably dominate the light-duty vehicle market, because other types of vehicles simply can’t compete with their energy costs per km. As the selling price of new BEVs approaches the selling price of traditional ICE vehicles, it is hard to see how hydrogen vehicles have any chance of ever succeeding in the marketplace.

Energy efficiency of light-duty vehicles in megajoules per km
Fuel	Powertrain	Low	High	Medium	Times diff.
Gasoline (spark ignition)	ICEV	1.37	2.88	2.13	11,7
Diesel (compression ignition)	ICEV	1.34	2.60	1.97	10,9
Gasoline (spark ignition)	HEV	1.22	2.05	1.63	9,0
Diesel (compression ignition)	HEV	1.15	1.51	1.33	7,3
Electricity	BEV	0.12	0.24	0.18	1,0
Hydrogen	FCV	1.14	1.39	1.27	7,0
Source: Intergovernmental Panel on Climate Change (2022) Sixth Assessment Report, Working Group III, Mitigation of Climate Change, p. 1146, https://www.ipcc.ch/report/ar6/wg3/downloads/report/IPCC_AR6_WGIII_FullReport.pdf

Even if only using excess renewable energy to make “green hydrogen” when the wind blows or the sun shines, so the price of the electricity is close to zero, hydrogen as a medium of storage still doesn’t make sense, because the price of grid storage keeps dropping, so it is going to become cheaper to store that energy as electricity in a battery than as hydrogen. For example, LFP batteries in China now cost between $70 and $75 per kWh, and they will last 10,000 cycles at a 60% depth of discharge (which is 27.4 years if cycled daily). Even more promising are the sodium ion batteries being developed by CATL, BYD, Gotion Hi-Tech and EVE Energy, which only use iron, aluminum and manganese, so their metal costs are much lower than lithium ion batteries. CATL projects that it will be able to produce sodium ion for 30% cheaper than LFP, so they should retail for roughly $50 per kWh once their production reaches scale.

With salt water flow batteries, there are no expensive membranes and no resources being consumed with limited reserves like copper, lithium, cobalt and nickel or even resources with high energy costs like aluminum and synthetic graphite, so salt water flow batteries are infinitely scalable since they only require the construction of stainless steel tanks, and do away with expensive exchange membranes. Salgenx currently sells its salt water flow batteries at $100 per kWh, but projects that its production costs will be as low as $5 per kWh. Many of the other ideas for future grid storage are also infinitely scalable, such as iron and salt water batteries, compressed air, compressed CO2, molten salt, molten metal batteries, gravity batteries, etc. Even at current grid storage prices, hydrogen energy storage makes no economic sense, and future storage tech promises to make hydrogen storage even less viable.

Another major problem with hydrogen is the high cost of transporting and storing it, because it requires building a whole new infrastructure. The H₂ molecule is so tiny that it is very hard to contain over time. Between 1% and 4% of compressed hydrogen leaks and liquefied hydrogen can have energy losses of 10% to 20%. Hydrogen causes metal embrittlement when diffuses into its metal containers and pipes, so leaking becomes a major problem and its infrastructure has to constantly be renewed over time. In contrast, we already have an existing electric grid, and building an EV fast charging station costs about a fifth of the price of building a hydrogen fueling station. Most people already have the electric infrastructure to charge EVs at home (although they often have to add an additional 230-240 volt AC outlet in countries that use 110-127 volts). BEVs are far more convenient than hydrogen vehicles, because they can be charged at home and work. The International Energy Agency estimates that there were 2.7 million public EV chargers worldwide at the end of 2022, of which 900,000 were constructed in 2022, for a 55% annual growth rate.

In contrast, at the end of 2022, 814 hydrogen fuelling stations were in operation worldwide, with 120 being constructed in 2022, for a 17% annual growth rate. There are 37 countries with hydrogen fueling stations, but most countries only have a handful in a few cities, so hydrogen isn’t really an option for long-distance driving, since hydrogen stations can’t be found along the major highways. Only in a few places, such as Germany, the Netherlands, Belgium, Switzerland, southern Japan, South Korea, coastal California, and a few urban centers in Eastern China (Shanghai, Beijing and Guangdong) are there enough stations to use a hydrogen vehicle for long-distance driving.

I doubt that hydrogen vehicles will ever gain the critical mass necessary to drive down the costs and reach the mass market. The International Energy Agency’s (IEA) estimates that 20,500 new HFCVs were sold worldwide in 2022, which is a 40% annual growth rate. In comparison, EV Volumes estimates that 10.5 million new EVs (BEVs + PHEVs) were sold worldwide in 2022, which represents 13.0% of global light-vehicle sales and a 55% annual growth rate. EV sales are expected to reach 14.1 million in 2023, which represents 16% of the global market, but the percentages are much higher in China and Europe, which are the two largest vehicle markets in the world. 39% of new light-vehicle registrations were EVs in China and 25% were EVs in the European Union in October 2023. EV adoption hasn’t been as fast in the US, but pockets of the US are adopting EVs in record numbers, such as in California where EVs represented 25.4% of the light vehicle market in Q2 of 2023. It is hard to see how HFCVs will be able to compete with the falling cost curves of the EV market. Batteries which represent roughly 40% of the cost of an EV were reported to cost between $70 and $75 per kWh for LFP and $80-$90 per kWh for NMC in October 2023, whereas the global price of all types of lithium ion batteries was reported to be $98.20 / kWh in August 2023, which represents a 90% drop over the last decade.

A hydrogen tanker truck can only hold between 500 and 1100 kg of gaseous H2 (depending on the degree of compression), which would fuel between 100 and 220 compact cars (assuming 5 kg of H2 per car). In contrast, a large tanker truck in the US typically holds 9300 gallons of gasoline, which would fuel about 930 compact cars, so a hydrogen station would need to pay for roughly 6 times more fuel trucks than a comparable gasoline/diesel station to fuel the same number of vehicles. In comparison, EV fast charging stations typically require no human labor to run (except for maintenance), which is one of the reasons why fast charging an EV is so economical.

Retail H2 at the pump currently costs around $20 per kg ($10.33 in S. Korea, $16.87 in Germany and $36 in California), so filling up a HFCV car like the Toyota Mirai would cost about $100, whereas 50 kWh of electricity costs about $10 at home and about $20 at a DC fast charger, so a hydrogen fuel cell vehicle is 2.5 to 5 times more expensive per mile than a BEV. The Mirai needs to change its air filter ever 10k miles and its ion filter every 35k miles, and new FC stack coolant needs to be periodically added, so it has higher maintenance costs than a BEV.

Hydrogen proponents believe that the price of hydrogen will drop dramatically in the future to as little as $2 per kg. It may be possible to get prices that low if hydrogen is generated from renewable energy at times when there is an excess, so electricity is essentially free. However, hydrogen storage will never be cheaper than storing that same renewable energy in grid batteries, because roughly 70% of the original energy is lost in converting to hydrogen and then converting back to electricity with a fuel cell, whereas roughly 14% of energy is lost in storing electricity in grid batteries. Anybody who argues that hydrogen will cost as little as $2 per kg in the future is not taking into account that power from batteries charged with that same renewable electricity will be even cheaper.

Hydrogen is often presented as an environmental solution, but the H2 used in fuel cells and combustion actually causes global warming, because it leaks into the atmosphere, where H2 combines with OH radicals to create more methane (CH4) and ozone (O3) in the troposphere and more stratospheric water vapor, which are all greenhouse gases. Leaked H2 will stay for roughly 2 years in the atmosphere before 70%-80% is absorbed by the soil and 20%-30% reacts with OH radicals. The extra ozone created by H2 only stays in the atmosphere for a few hours to a few weeks, but during that time a molecule of ozone produces as much warming as 1000 molecules of CO2. The methane created by H2 stays in the atmosphere for an average of 12.4 years. While a gram of H2 stays in the atmosphere, it will cause roughly 100 times more warming than a gram of CO2, before the H2 is absorbed by the soil or it reacts with OH. H2 has a GWP-20 (global warming potential over 20 years) of 33, meaning that a gram of leaked hydrogen will cause as much warming over 20 years as 33 grams of CO2. Most carbon accounting is done over a 100 year timeframe, where H2 has a GWP-100 of 11.6. It is estimated that between 3% and 6% of H2 will leak when used in hydrogen vehicles, because it is so hard to contain, so the climate impact of using hydrogen on a massive scale will be significant.

Of course, proponents of hydrogen argue that switching to green hydrogen will significantly lower the greenhouse gas emissions, which is true if comparing hydrogen with today’s energy, which mostly comes from fossil fuels. According to Carbon Fund, electricity in the US emitted an average of 371 g CO2-e per kWh in 2021, so BEVs which are charged from the grid are still polluting, but the electrical grid is getting much cleaner. Over 60% of global electricity generation in 2023 came from fossil fuels, but only 3.8% of new global electricity generation in H1 2023 was based on fossil fuels, so the world is transitioning rapidly to low-carbon electricity. At current trends, over 95% of global electricity should be low-carbon (renewables or nuclear) by 2050, and there are indications that this transition could happen much faster, because by the mid-2030s, it should be cheaper to build new solar/wind plus storage than keep running old coal and gas power plants. In other words, grid electricity is going to keep getting cleaner and the GHG emissions from operating BEVs in the future will be significantly lower than HFCVs using green hydrogen.

Hydrogen proponents often argue that hydrogen vehicles can be fueled faster than an EV can be charged, so hydrogen vehicles are more convenient. Although it takes time to drive to a hydrogen vehicle to an H2 fueling station, they can be fueled in about 5 minutes. However, DC fast charging for EVs is improving at such a rapid rate, that it soon won’t take any longer to fast charge an EV than to fuel a hydrogen vehicle. CATL, which is the biggest battery maker in the world, announced in June 2022 its Qilin battery whose integrated cooling in the cells allows an 80% charge within 10 minutes, and this has been improved in its upcoming Shenxing LFP battery, Because CATL will offer both NMC and LFP versions of its Qilin battery, it can cover the entire market from high-end to low-end EVs. DC fast charging standards are rapidly improving to allow EVs to be charged in a matter of minutes. The different DC fast charging standards now support a max of 250 kW with GB/T, 350 kW with CCS, 350 kW with NACS (Supercharger V4), 1.0+ MW with Megacharger, 1.2 MW with ChaoJi-1/CHAdeMO 3.1 and 3.75 MW with MCS. The battery industry is already talking about 5 minute charge times for EVs, so expect even faster charging in the future. Polestar is testing StoreDot’s battery with silicon anodes and thinner pouches for better cooling that can charge 100 miles in 5 minutes.

The cheapest way to currently obtain hydrogen is from methane steam reforming, which is known as grey hydrogen. The production of a kg of grey hydrogen emits 9 kg of CO2, so it is hardly an environmental solution. Producing electricity from grey hydrogen is little better than burning diesel in generator. The lifecycle emissions of grey hydrogen is between 0.23 and 0.33 kg of CO₂ per kWh, compared to 0.27 kg/kWh for diesel. However, if the effects of leaked H2 is included in the calculation, electricity from grey hydrogen causes more warming than a diesel generator. The International Energy Agency (IEA) estimated that grey hydrogen costs between $1.0 and $2.5 per kg of H2 in 2021, whereas green hydrogen made from electrolysis using renewable energy cost between $4.0 and $9.0 per kg in 2021. After Europe’s supply of cheap natural gas from Russia was restricted due to the war in Ukraine, the IEA calculated that the cost of grey hydrogen rose to $4.8 – $7.8 / kg in 2022. The IEA estimates that hydrogen production consumes 6% of the world’s natural gas production and 2% of the world’s coal.

The fossil fuel industry eagerly promotes hydrogen, partly to clean up its dirty image, but also as a Trojan horse for stimulating more fossil fuel extraction. Between January and September of 2023, 32 oil and gas companies spent a total of $41.3 million on federal lobbying in the U.S. for hydrogen, according to OpenSecrets. The fossil fuel companies claim that they will produce blue hydrogen made from fossil fuels whose carbon emissions are captured and stored. Howarth and Jacobson (2021), however, have calculated that even with carbon capture and storage (CCS), blue hydrogen made from natural gas will cause 20% more greenhouse warming over a 20 year period than simply burning natural gas and coal for heat. Howarth and Jacobson estimate that roughly 3.5% of extracted natural gas ends up leaking into the atmosphere, where a gram of methane causes 82.5 times more warming than a gram of CO2 over 20 years, which totally outweighs the effect of capturing the carbon dioxide released during steam methane reforming.

Rational people who have looked at the numbers admit that hydrogen cars won’t be economically viable, but they often point to heavy trucks, ships, rail and airplanes as areas where hydrogen does make sense. However, the energy consumption of hydrogen trucks, ships, trains and airplanes is not any better than for hydrogen cars. According the estimates from the IPCC, hydrogen fuel cell heavy trucks consume between 5 and 8 times more energy than battery electric heavy trucks per tonne-km. Hydrogen fuel cell buses consume between 8 and 11 times more energy per passenger-km than battery electric buses. Hydrogen fuel cell passenger rail consumes 6 times more energy per passenger-km than electric rail. Lest anyone advocate for another type of fuel, such as biodiesel, concentrated natural gas, ammonia or direct air capture Fischer-Tropsch e-diesel, their energy consumption is even worse.

Energy efficiency of heavy-duty trucks, buses and rail in megajoules (MJ)
Fuel	Powertrain	Heavy-duty truck (per tonne-km)		Bus (per passenger-km)		Passenger rail (per passenger-km)		Freight rail (per tonne-km)
		Low	High	Low	High	Low	High	Low	High
Diesel	ICEV	0.38	0.93	0.16	0.52	0.36	0.40	0.11	0.78
Concentrated natural gas	ICEV	0.48	1.45	0.25	0.61
Liquid natural gas	ICEV	0.43	1.00	0.27	0.37
Biodiesel	ICEV	0.38	0.93	0.16	0.52	0.36	0.40	0.11	0.78
Ammonia	ICEV	0.38	0.93
DAC FT-Diesel	ICEV	0.38	0.93	0.16	0.52	0.36	0.40	0.11	0.78
Diesel	HEV	0.34	0.59	0.11	0.37	0.33	0.33
Liquid natural gas	HEV	0.46	0.51
Electricity	BEV	0.03	0.09	0.01	0.04	0.03	0.03	0.01	0.12
Hydrogen	FCV	0.25	0.43	0.11	0.31	0.18	0.18	0.10	0.10
Ammonia	FCV	0.25	0.43
Note: Assuming an 80% occupancy rate for buses and passenger rail and 100% occupancy for heavy-duty trucks and freight rail. Source: Intergovernmental Panel on Climate Change (2022) Sixth Assessment Report, Working Group III, Mitigation of Climate Change, p. 1146-7, https://www.ipcc.ch/report/ar6/wg3/downloads/report/IPCC_AR6_WGIII_FullReport.pdf

A number of heavy truck and bus manufacturers are now offering hydrogen options. Hyundai started delivering its XCIENT Fuel Cell Truck in July 2020 in Switzerland, and has expanded its sales to the rest of Europe, USA and China. Toyota’s Zero Emissions Powertrain was approved for sale by the California Air Resources Board (CARB) in May 2023 to convert existing ICE trucks/buses to a hydrogen fuel cell engine. In July 2023, Nikola started production at its Coolidge, Arizona factory, which is capable of producing 2400 heavy trucks which have either battery electric or fuel cell powertrains. Nikola reports that it has received 223 preorders for its TRE FCEV, a hydrogen fuel cell class 8 semi with a 500 mile range. In Europe, Scania will deliver its first hydrogen fuel cell trucks, which are between 40 and 70 tonnes, to customers in Switzerland in 2024 and 2025. Volvo and Daimler, which began their cellcenter joint venture in 2020 to produce fuel cells for heavy vehicles, are now testing prototypes of their fuel cell trucks, which should hit the market in 2025.

However, the sale of heavy-duty electric trucks and buses has a head start over hydrogen trucks, and battery electric trucks are likely to dominate due to their superior economics. Tesla’s class 8 Semi, which has a range of 500 miles, a recharging time of 70% in 30 minutes and a gross combination weight of 82,000 lbs, promises to revolutionize the long-haul trucking market due to its lower costs per mile. The Tesla Semi will consume roughly 400 kWh to haul a load 200 miles. At $0.12 per kWh, that works out to an average cost of $0.24 per mile. In contrast a class 8 diesel truck consumes an average of 6.5 gallons per mile, so it would consume 30.8 gallons to make the same trip. At $4 per gallon for diesel, it would cost $0.62 per mile, which is 2.5 times more than the Tesla Semi. We don’t know the final pricing of the Tesla Semi, but the price per mile is still less even if the Tesla Semi costs twice as much as a comparable diesel truck. It will take a while for a network of ChaoJi stations to be built in China and Supercharger and MCS stations in the US and Europe, but once the charging infrastructure is in place, the trucking industry will quickly switch to electric trucks because they are far cheaper than anything that hydrogen and fossil fuels can offer.

The same economic logic applies to shipping over water. Electric ships will be far cheaper to run than ships running on dirty bunker fuels, and certainly cheaper than hydrogen ships, so all short-range shipping will quickly switch to electric. People argue that the lack of charging stations in the oceans will force long-distance ships to run on hydrogen or toxic ammonia which is made from hydrogen. However, a ship loaded with LFP batteries can go a long way since ships don’t have the same weight limits as ground transport. Shipping companies can build charging stations at every island port. Eventually I expect that the major shipping companies will lay HVDC (high voltage direct current) lines along the major shipping routes to power floating charge stations located every 1000 km. HVDC lines only lose 3% of their energy per every 1000 km, so the energy loss of an HVDC line from the coast of China to the middle of the Pacific would only be 15%, which is far less than the 70% energy loss in converting electricity to hydrogen. In a highly-competitive industry where profits are measured in a fraction of a penny per shipping mile, it makes no sense for the shipping industry to opt for expensive hydrogen with 3 to 4 times the operating cost of electric ships.

Hydrogen advocates also love to say that hydrogen airplanes are the future, but that is also a highly dubious proposition. First of all, it will be very difficult to even engineer a plane with large enough hydrogen tanks to fuel a long-haul flight, as Micheal Barnard points out. Even with the energy losses in jet fuel combustion and assuming that liquid H2 will only cost $8 per kg, Barnard calculates that a hydrogen airplane will cost double the price per passenger or cargo mile than a conventional jet.

The other issue is the danger of flying with such a flammable fuel that is prone to leakage. The liquid hydrogen tanks can’t be stored underneath the passengers due to the risk of leakage into the cabin, and they need to be large and roundish to maintain the temperature below -253 C, so planes need to be redesigned with extra wide wings to hold large hydrogen tanks.

It is clear that all short-haul flights in the future will become electric, because battery electric planes are projected to have far lower costs per passenger mile than conventional jets. With new battery chemistries coming onto the market with much higher energy densities, electric short-haul planes are going to become viable both in terms of the engineering and economics. Eviation’s Alice, which is an electric turboprop with room for 8 people or 2500 lbs of payload, is currently using conventional NMC batteries with pack energy density of 220.4 Wh per kg. However, much better batteries should be available for aviation in the near future. Amprius plans to start mass production in 2024 of its batteries with silicon nanowire anodes, which have cell energy densities of 500 Wh per kg and 1300 Wh per liter. CATL also announced its “condensed battery” with 500 Wh/kg in April 2023 and says that it “is cooperating with partners in the development of electric passenger aircrafts”. With that greater energy density, mid-sized passenger planes for short-haul flights should become possible.

According to Lee et al (2021), 56.9% of the radiative forcing from aviation comes from condensation trails (contrails) produced by airplanes, so eliminating CO2 emissions from airplanes won’t solve the majority of the problem, and H2 emissions have their own warming effect. Hydrogen planes will emit more water vapor than conventional jets, so it is possible that their warming effect will be even greater than conventional airplanes burning jet fuel. However, contrails only are formed under certain atmospheric conditions, so it is possible to avoid most of the contrail formation by changing flight routes, although this will cause chaos in flight schedules and increase costs for the airlines.

A far better solution is to create airplanes with hybrid electric and biofuel/e-fuel motors that use their battery electric motor when flying through atmospheric conditions where contrails are likely to be formed and burn biofuels or e-fuels when not under those conditions. That way airplanes don’t have to change their flight plans to avoid contrail formation. Since they are burning carbon-neutral biofuels or e-fuels, their CO2 emissions will be close to zero. Biofuels do take food from humans which causes more deforestation for agriculture, and the creation of e-fuels from hydrogen and CO2 is extremely energy inefficient. The Research Center for Energy Networks and Energy Storage calculates that e-fuel vehicles consume 5 times more energy per mile than battery electric vehicles, so a plane fueled by e-fuels will likely have even higher costs than a hydrogen plane, but larger percentages of flights will be run on battery power as battery energy densities keep improving. We are also likely to see long-distance flights being broken into multiple flights to stop for recharging. Direct flights to the other side of the globe will become luxuries for the rich.

If you care about the environment or just want to lower the cost of electricity and transport, it makes no sense to promote hydrogen as the fuel of the future. Investment in hydrogen pulls funding away from far more useful investment in solar, wind, geothermal and hydroelectric and batteries, which will get the world to a low-carbon economy far faster and for less money. Solar and wind plus LFP grid battery storage is already the cheapest source of electricity in most places on the planet, and it will only get cheaper, so it makes no sense to invest in hydrogen storage, which requires massive investment in new infrastructure, has high leakage rates and costs far more than today’s LFP batteries.

Hydrogen doesn’t make sense as a medium for energy storage or transport, but it does make sense as a chemical input that can be used to make green steel, fertilizers, plastics, chemicals and e-fuels, which are currently made with fossil fuels. We do need lots of R&D into how to use hydrogen and CO2 to make all the things that we currently make with coal, natural gas and petroleum, so hydrogen will play a big role in the future green economy, but not as means to store energy or fuel vehicles. The difference is that the hydrogen used in future industrial plants will be generated on site when it is needed and it won’t be stored or transported. That way the factories of the future won’t have to worry as much about the leakage of H2 and all the concomitant problems of storing H2. We will need hydrogen to decarbonize 100% of our future economy, but it won’t be in the way that many of the proponents of hydrogen imagine, since hydrogen will be embedded in our steel, fertilizers, plastics and chemicals, rather than storing our energy and powering our vehicles.