One problem that hydrogen fuel has is the efficiency of the system by which it is produced, mainly electrically or chemically, but what if there was a naturally-occurring source of hydrogen?
This is one reason why some believe that hydrogen fuel cell vehicles aren’t a good idea. On the other hand, a lot of current infrastructure can be easily adapted for use with hydrogen. Still, the problem with production remains, since it doesn’t occur naturally, mostly. Researchers in France have been focusing on deep sea hydrothermal vents, which produce hydrogen when superheated seawater flows up and mixes with near-freezing seawater.
The heat of the magma near the surface superheats seawater, which reacts with peridotite to produce hydrogen. Working 10,000ft below sea level isn’t convenient or cheap, so this particular source of hydrogen may not be feasible. [The water 10,000ft below sea level is just over freezing and the pressure is nearly 4,500psi.] Fortunately, peridotite formations are also found in some areas on land which are easier to access but are also very rare, since they react easily with water. These rare sources of peridotite could be a natural source of hydrogen fuel if sufficient deposits can be found that haven’t already completely converted to other types of rock.