Why Not Hydrogen Cars?

Some, particularly Japanese automakers, are pushing hydrogen as a “better” energy source than electric cars. Is that a good idea?

First, we need to talk about the two kinds of hydrogen-powered cars. The “conventional” approach would be a vehicle with an internal combustion engine powered by hydrogen instead of gasoline. This approach makes no sense whatsoever. While you get a cleaner exhaust (mostly just water) you have all the same problems as with a gasoline or diesel engine. They include:

  • Lots of moving parts which can mean lots of maintenance issues
  • Inefficiency — internal combustion engines are inherently inefficient so most of the hydrogen fuel will be converted to heat rather than motion
  • As the power curve for any internal combustion engine is limited a transmission will be needed meaning lower efficiency

This approach to a hydrogen-powered car seems like no more than a welfare program for the internal combustion engine car industry.

The second approach is a fuel cell system. The fuel cell combines hydrogen with oxygen from the air to produce electricity with water as the byproduct. So far this seems like a better approach. But, what this really is is an electric car that uses tanks of pressurized hydrogen for energy storage instead of batteries. Overall efficiency (tank to wheels) will be lower than that of a true battery electric vehicle but much better than the internal combustion engine approach covered above.

To power your hydrogen vehicle you need hydrogen. There are multiple ways to produce hydrogen with various levels of efficiency and pollution. Even if you use “free” solar energy to produce it the overall efficiency will be lower than just using that free energy to charge the batteries in an EV.

Finally, unlike your EV which you can plug in at home to charge it, you will need to go to a hydrogen station to fill your tank. Seen any hydrogen stations? I haven’t. Sure, they can be built and then something — mostly likely a truck — will need to fill up the hydrogen station. Building a hydrogen station network will be much harder and much more expensive than building out public electric vehicle chargers.

While there may be a use case for hydrogen-powered commercial vehicles in some places, I don’t see hydrogen as a good alternative to electric cars.

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