John Higson comments

Japan's population declining IS A GOOD THING!

Until a country can feed it's population from it's own resources it is 'overpopulated'. Japan can feed maybe 40 million. QED.

'emissions-free energy source'

For the million, millionth time, Hydrogen is not an energy source! It is an energy carrier. H2 is an energy loser, in that it takes more energy to produce that you get from it when it burns. It's that simple.

It is of use to store excess electricity from renewables when that energy is not needed(from wind power at night, excess solar during the day etc), but nobody is suggesting this or planning to use it this way, why not use the electricity in a battery and avoid the combustion step in the first place? More efficient and less complicated as you don't need a combustion chamber and all the wasteful other steps, losing energy at every one!

The Hydrogen economy is an illusion and a con. It'll never happen. Hydrogen fuel cell car will exist only as long as there is petroleum to subsidise them.