What are the realistic prospects for hydrogen?

Over the last few weeks I’ve looked at some of the possibilities for hydrogen in the new economy, and some of the problems too. I’ll come back to the topic from time to time, but to sum up, it’s worth asking how likely all these various applications actually are. Yes, it’s possible that we’ll have hydrogen heating. Hydrogen planes are theoretically possible, eventually.

There’s a lot of theory and potential in hydrogen, and not so many visible examples. Earlier hype hasn’t delivered. Predict...