Something to keep in mind when hearing about hydrogen as a renewable or green fuel is that nearly half of hydrogen production, worldwide, comes from natural gas. Another 45% or so come from coal and oil sources. Renewable hydrogen - electrolysis, generally - is basically a blip.
Hydrogen is, in many cases, an attempt _by the fossil fuels industry_ to carry on business as usual in the face of carbon-reduction initiatives by putting the carbonaceous parts out of sight.
@owen That's exactly what it is. Well said.
If we had huge amounts of excess electricity to electrolyze water, yes. Hydrogen would be great (except for the dangers of handling it). But we don't. The way hydrogen will be implemented simply moves the pollution from the car's exhaust to the refinery where the hydrogen is produced.
