Hydrogen: out but not down

Hydrogen refuses to go away. It really ought to.

One of the most persistent misconceptions dogging future mobility policy is the idea that hydrogen has a future as a mass transportation energy system.

It does not.

The difference between hydrogen and every other motive system, including electricity, is that it requires two conversions, rather than one, to get from the original fuel source to power at the wheels.

It’s like a restaurant making a pie in the kitchen, then taking it apart, bringing the components to your table on a trolley, and then reassembling and reheating them for you.

Would you believe anyone who told you that was a cheaper and better process than simply bringing the pie straight from the kitchen to the table?

The latest person who would like us to believe this is Professor Brian Scott-Quinn from the University of Reading. In an article in today’s i newspaper, he argues that hydrogen ‘could’ be the way to turn railways green.

He rather answers his own question in the negative by acknowledging that hydrogen is produced almost entirely from fossil fuel, with a commensurate carbon footprint. He also acknowledges that hydrogen infrastructure doesn’t yet exist and there is only one hydrogen train in Europe, running on a short line in Germany.

He makes a whopping technical error in claiming that hydrogen could replace natural gas in mains pipes. You couldn’t use existing natural gas infrastructure because tiny hydrogen atoms fly straight out of joints designed to contain natural gas molecules.

And while it’s true that scaling-up the production of hydrogen and fuel cells could reduce unit costs in the long run, you will always have to pay for the extra energy losses involved. You have to convert natural gas (or water) into hydrogen, compress it, transport the heavy pressurised containers, transfer hydrogen to pressure tanks on the vehicle and then carry out another energy-losing conversion in the fuel cell to power the electric motors.

To be fair, the professor’s article does address an actual problem for railways – how to eventually replace diesel on sections of the rail network where the cost of installing overhead electric cabling is likely to be prohibitive.

His conclusion, which should get every taxpayer’s spidey senses tingling, goes:

”A government-funded experiment with hydrogen trains could help overcome this problem [lack of infrastructure] and bring the renewable economy one step closer to reality.”

Call me an old cynic if you like but I don’t for a moment believe it’s a coincidence that this pitch by a professor of finance for pork barrel spending appeared on the very day that the Institution of Mechanical Engineers published a report warning that hydrogen is not a substitute for electrification.

The same goes for road vehicles. Except that with road transport, hydrogen really does look like a solution in search of a problem.

If the government is persuaded to pour public money into chasing hydrogen-powered unicorns, it would betray a fundamental misunderstanding of the role the fleet and auto industries play in converting practical energy inputs into a viable modern economy. That’s something I’ll cover in future posts.