On the topic of hydrogen, FWIW, Iâve been going to technical conferences since the late 1990s where hydrogen was being promised as being âonly a few years awayâ, and I still hear the same promise being made at conferences today. Businesses such as BMW, Honda and Toyota have all tried to bring hydrogen vehicles to market over that time with very limited success. Why is that though?
At the moment there is very little âgreenâ hydrogen around. Even JCB admit themselves that this is a major hurdle in their proposed use of hydrogen in their machines to âbecome greenâ; and that they havenât yet identified a source of production that will meet their stated aims [1].
As already mentioned above, production of hydrogen requires large amounts of energy (usually electrical, although steam reforming is also a possibility if large amounts of heat are available), and if itâs being burned (as is the case with JCB) in an Otto cycle engine it can only be 20-30% efficient due to the thermodynamic cycle and typical losses from an internal combustion engine.
Storing and transporting hydrogen is also difficult, as its atoms are so small that they can permeate through ânormalâ welds and even âsolidâ metals, and as they transit through materials, the hydrogen atoms can cause chemical reduction reactions, and lead to hydrogen embrittlement.
Perhaps one day weâll be surrounded by hydrogen vehicles, but my experience so far suggests it wonât be very soon.
[1] Source: Q+A session following presentation by Ryan Ballard, Engineering Director â JCB, at the Future Propulsion Conference 2023