From the end of the article cited in the opening post -

...extraction and crushing of rock to extract the trapped hydrogen is...prohibitively expensive....

> you missed a rather important "snip" here. The above is true ("prohibitively expensive")

The most promising source...may be geological "traps" similar to those now drilled for natural gas. Professor Freund said: "One of these natural hydrogen fields is already known to exist in North America, and extends from Canada to Kansas."

> not quite, mon brave. What the professor said in the original was that a field of hydrogen occurence *in bedrock* (my emphasis) is already known...

There is not, repeat NOT, repeat *NOT* a natural hydrogen field that stretches across all these states. What the professor is saying boils down to this:-

1) Hydrogen occurs at ppm levels in crystalline rocks

2) Crystalline rocks occur through the mountainous spine of the USA - the Rockies - from Canada to Kansas.

3) Therefore ppm levels of hydrogen occur over such a large area that if we pretend we could reclaim it all, it would be a huge volume.

4) We can't.

5) BTW, just one of the 30,000 onshore USA gasfields consists predominantly of hydrogen, rather than natural gas.

Draw your own conclusions, based on the above, for a serendipitous hydrogen economy.

Natural gas-type geological traps of hydrogen are offered as an alternative to extracting hydrogen gas directly from Earth's crust. That last line describes a pretty big trap. So it does seem a hydrogen economy is feasible.