GENERATING HYDROGEN FUEL ON DEMAND from magnesium and water? Sounds too good to be true. Though I’d be happy to be wrong about that.

UPDATE: But it looks like I’m not. Various readers emailed, but this from chemist Derek Lowe is clearest:

As I’m sure several heaps of people have already emailed you about, magnesium gives off hydrogen as a matter of course when it’s submerged in water. You’re left with magnesium hydroxide, an insoluble white powder. The problem with this (and similar ideas using boron, aluminum, etc.) is that you need energy to get the free metal to start with, and plenty of energy to recycle the oxides back to the metal (when that’s practical at all – it often isn’t).

All the press-release talk about how this process doesn’t release carbon dioxide ignored the production of the metals, as far as I can see. . .

Sounds like the process is of limited utility overall.