The thing about hydrogen…..

Development efforts will need to face well-known and unavoidable energy losses in applications of synthetic Green hydrogen. All hydrogen production methods consume energy. When that hydrogen is put to use it yields less energy, often much less, than was consumed in its production.

Such efficiency penalties are well understood, in the literature at least. They were crisply summarised over 20 years ago by Dr Ulf Bossel, a Swiss engineer who pioneered hydrogen fuel cell research: "If renewable electricity is converted to hydrogen, and hydrogen is subsequently reconverted to electricity, then…only about 25% of the original electrical energy may be recovered by the consumer".

So in this primary application of hydrogen, synthesis of a Green fuel by electrolysis and subsequent use to generate clean electricity, three quarters of the initial energy may disappear (as waste heat). Bossel claimed, rightly, that it was much more efficient, where possible, to make direct use of the original electricity rather than go through the hydrogen stage. So, a battery-driven EV should be more efficient and desirable than a fuel cell EV.

Efficiencies may well have improved since Bossel's work. The EV market seems already to be reflecting the position he took. The fundamental fact of energy losses in all Green hydrogen applications must always be kept in mind.

As for hydrogen replacing all or most of the world's natural gas, none of the above is cause for optimism. It will be interesting to see if the new Australian R&D effort changes that perception.