44 | New Scientist | 6 February 2021
Features
Hope or Hype?
1 1
Hydrogen has long
been a candidate for
a clean fuel revolution.
Can it finally make the
grade? Adam Vaughan
investigates
I
F HYDROGEN is the future, it has been
for quite some time. In his 1875 novel The
Mysterious Island, Jules Verne imagined
the element replacing coal as a fuel, split out
of water to “furnish an inexhaustible source
of heat and light”. Similar noises were made
in the 1970s oil crisis, when hydrogen was
touted as an alternative fuel for cars. And
then there was US president George W. Bush
in 2003, latching on to a new enthusiasm for
hydrogen vehicles during the first wave of
real concern about climate change. “We can
make a fundamental difference for the future
of our children,” he said.
Now hydrogen is back – again. From
the US to Australia, and the European
Union to China, the past year has seen an
almost daily torrent of multibillion-dollar
government funding pledges, tests of new
technologies from trains and planes to
domestic boilers, industry statements and
analyses, and championing by leaders such
as UK prime minister Boris Johnson. “We’re
finding it hard to keep up with,” says Simon
Bennett at the International Energy Agency.
“The idea of a hydrogen economy is
not new,” says Martin Tengler at analysts
Bloomberg New Energy Finance. “Now
we’re in another hype cycle. The question
is: is it different, or not?”
Tengler is one of many who thinks it is.
Meanwhile, another question hangs much
heavier than hydrogen in the air: is it really
a clean, green fuel to help combat climate
change? Or does the significant lobbying
of fossil-fuel interests for a hydrogen
economy indicate other priorities? >1
TRAINS, PLANES AND...
The glossiest of many new uses
touted for hydrogen is in transport.
Hydrogen cars have faltered before,
as oil prices yo-yoed and battery
powered electric cars emerged as a viable
technology. But for larger vehicles, the
batteries required are big and heavy,
possibly creating an opening for hydrogen.
Two hydrogen fuel-cell trains built by
the firm Alstom were put into commercial
service in Germany in 2018, and one in
Austria in 2020. The UK has also been
trialling this approach on its rail network.
Hydrogen’s high energy content in relation
to its weight has also caught the eye of
plane-makers. In the UK, 2020 saw the flight
of a six-seater hydrogen passenger plane,
while European aerospace firm Airbus
unveiled three concept hydrogen planes.
“When we go to larger commercial
aircraft-type applications, we see the need
for hydrogen, because in very simple terms
it has thousands of times more energy per
kilogram than even the best batteries today,”
says Glenn Llewellyn at Airbus. Julian Renz
at green aviation company ZeroAvia, which
undertook the six-seater test flight, says he
thinks hydrogen-powered planes will be
cheaper to maintain than battery ones,
because of the limited life cycle of batteries.SIX USES
FOR HYDROGEN