24 Briefing The hydrogen economy The Economist October 9th 2021
Airbus, a European aeroplanemaker, is
giving hydrogen its fullthroated support.
In September, it confirmed a plan to power
planes using hydrogen by 2035. Guillaume
Faury, the company’s boss, extolled its vir
tues: “Hydrogen has an energy density
three times that of kerosene...[it] is made
for aviation.”
On the basis of weight, that is true. On
the basis of volume, alas, it is not. At room
temperature and pressure, hydrogen is the
least dense gas in the universe. So although
by the kilogram it may carry three times
more energy than kerosene, by the litre it
carries 3,000 times less. The gas can be
pressurised, which helps, especially for
applications where big tanks are not a pro
blem. But to get to within a factor of three
of kerosene’s performance per litre hydro
gen has to be liquefied. That requires chill
ing it down to 253°C (423°F).
Little surprise, then, that Boeing, Air
bus’s American rival, is more guarded. Its
boffins agree that “hydrogen is fundamen
tal to all sustainable aviation fuels”. But
they reckon that flying a 747 across the At
lantic using liquid hydrogen would require
filling all its passenger and cargo space
with fuel. That is why for longer journeys,
planes may end up using cleanhydrogen
based ammonia (as many large ships may
do, too) or, more likely, synthetic hydrocar
bons. In aviation, those synthetic fuels will
have to be able to compete with advanced
biofuels, the obvious alternative.
Michael Liebreich, a cleanenergy guru,
notes that, as one moves away from appli
cations where hydrogen has clear benefits
over renewable electricity, it becomes
harder to see serious markets for the gas.
To illustrate his point he has developed a
“hydrogen ladder” which ranks uses from
indispensable to unaffordable (see dia
gram on previous page).
An intriguing borderline case is afford
ed by domestic heating. On an efficiency
basis, electrically powered heat pumps
beat domestic boilers fired by hydrogenquite handily. But retrofitting urban hous
ing already equipped with boilers to burn
hydrogen may be more attractive in some
places than trying to fit heat pumps on to
every building. Britain is likely to be a test
case for this tradeoff. In August, its gov
ernment unveiled plans for 5gwof low
carbon hydrogen production capacity by
2030 to replace natural gas in domestic and
industrial applications. Stairway to heaven
Near the bottom of Mr Liebreich’s ladder
are fuelcell electric vehicles (fcevs) used
as cars. Toyota, a Japanese automobile
giant, has longed to build them since the
early 1990s, investing billions in the tech
nology. Official visitors were ferried
around Tokyo in such vehicles during the
recent Olympic games, and the Japanese
government has plans to expand the coun
try’s fleet of fcevs, which numbered just
3,600 in 2019, to 200,000 by 2025. The Chi
nese government says it wants 1m of the
things by 2030.
But as Mr Liebreich and many others
point out, this does not seem sensible if
the competition is a batterypowered elec
tric car. Fuel cells add to an electric car's
price and complexity while offering no
benefit in performance. They are also inef
ficient. About fourfifths of the power fed
into a batterypowered electric vehicle gets
used; conversion losses mean that an fcev
is likely to manage only half that level of ef
ficiency. A veteran Japanese utility execu
tive whispers that Toyota’s stance makes
no sense: “Millions of fuelcell cars won’t
happen. Even Honda gave up. Pride is why
Toyota is sticking with it.”
That does not rule out other forms of
road transport. Many of the world’s big lor
rymakers, including Europe’s Volvo and
Daimler, are racing against startups like
Hyzon to bring hydrogenfuelled heavy
lorries to market on the basis that the
weight and recharging time of batteries
means they are not able to be used. According to dhl, a logistics company, when lor
ries with heavy loads need to travel farther
than 200km (120 miles) batteries become
unattractive.
America’s Cummins, known for dec
ades for its conventional engines, is bet
ting big on hydrogen, having acquired
firms making electrolysers, fuel cells and
hydrogen tanks. Tom Linebarger, its chief
executive, says he is highly confident that
hydrogen lorries will be “even money”
with diesel lorries on total cost of owner
ship by 2030. Customers, he says, are wor
ried about the reliability of vehicles with
batteries. “If I am a distribution company
and have fuelcell vehicles using hydro
gen, I don’t need to depend on the grid.”
As on road so, perhaps, on rail. France’s
Alstom, the biggest rail manufacturer out
side China, is already running hydrogen
powered trains in Germany. Compared
with diesel trains, these whizzy locomo
tives emit no local air pollution, make very
little noise and offer a ride as smooth as
that of conventional electric trains. The
firm thinks many of the 5,000 diesel trains
to be retired in Europe by 2035 could eco
nomically be replaced by hydrogen trains.
By 2030, hydrogen trains could make up a
tenth of those not already electrified.
The Boston Consulting Group (bcg)
reckons that hydrogen could be competi
tive on price with other ways of fuelling
trains by 2030 even with no carbon pricing.
The other big early market it sees is in con
struction equipment and other applica
tions where the high torque provided by
electric motors is useful and the long
charging time for batteries a frustration
(forklift trucks have proved to be one such
niche). bcgexpects heavy lorries, ships
and applications in the chemicals industry
will be close behind, and predicts an annu
al $200bn market for hydrogenrelated
machinery and components by 2050.
But this makes sense only if supply and
demand grow in tandem. A businessas
usual approach in which supply was not
stimulated would lead companies to dou
ble down on incumbent dirty technol
ogies, particularly in industrial applica
tions, as they update ageing capital equip
ment, leading to a pernicious lockin of
legacy equipment. But stimulating supply
will generate resistance, both from incum
bents in other fields and from finance min
istries, unless demand is visibly increasing
alongside it and delivering things which
people want.
Comparing it to the renewables indus
try, which could feed in to existing grids,
Mr Heid of McKinsey likens the hydrogen
economy to a heavy flywheel: “It takes
more to get it spinning, but once it’s going
it really goes.” He might also add that spin
ning up a flywheelisa tricky business; let it
go even a little offbalance and you risk
having it tear apart.n