Energy density, storage, and delivery are major stumbling blocks with hydrogen
Can you imagine trusting your typical backwards baseball cap wearing yoof, to fill his car up with hydrogen gas....
Hindenburg anyone
We have a storage and delivery system for liquid fuels already in place
Using carbon monoxide/dioxide pulled out of the atmosphere and hydrogen from water- both of which processes can be solar or wind powered we could have an achievable low emission low cost fuel
And what comes out of the tailpipe? Water and carbon monoxide/dioxide mostly...
https://en.m.wikipedia.org/wiki/Fischer–Tropsch_process
