Industry News
Data: 2020-08-06
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At
least twice in the past 50 years—in the 1970s, after the oil crisis,and in the
1990s, when climate change started to acquire political salience—there has been
excited talk of replacing hydrocarbons with hydrogen.
It
didn't happen.
There
were several reasons for this.
For
a start, ripping up and replacing the world's fossil-fuel infrastructure is a
huge job.
And
even were that an easy thing to accomplish, hydrogen itself has drawbacks.
Though
better than batteries, it stores less energy in a given volume than fossil
fuels can manage.
More
important, it is not a primary fuel.
You
have to make it from something else. This can be done by a chemical reaction
called steam reforming but, besides steam, the other ingredient of that process
is a hydrocarbon of some sort, which rather defeats the object of the exercise.
Or
it can be done by the electrolysis of water.
This
has appropriate green credentials as long as the electricity is either from
renewable sources or a nuclear-power plant.
But
the laws of thermodynamics mean that the energy content of the hydrogen which
comes out of the process is less than the electricity that went in.
This
inbuilt inefficiency raises the question "why not simply power the enduse
electrically, rather than using hydrogen as an intermediary?"
To
counter these arguments those who believe that things hydrogen-related really
are different this time around can point to two things in their favour.
Several
of the relevant technologies, notably electrolytic equipment, are now at a
stage where it is possible to believe they might soon become cheap enough to do
the job.
And
the idea that economies need to be decarbonised fully in order to curb climate
change is gathering speed.
Until
2019, for instance, Britain had planned to cut carbon emissions by 80% from
their levels in 1990 by 2050.
It
then, however, upped the ante to become the first big economic power to commit
itself to a 100% cut.
This
has implications for hydrogen.
Electrification
using renewable sources such as wind and solar power would probably have got
the country to 80% observes David Joffe, a member of the Committee on Climate
Change (CCC),an organisation that advises Britain's government on how to bring
the transformation about.
But
full decarbonisation, he says, is a much bigger task, and one for which
hydrogen may prove necessary.