I amost missed the part about 300km in 10 hours which is less than 19 MPH.

Energy is energy. Every time you move it, change it's form or even try to store it, you lose some. You can use grid electricity to charge batteries that will run an electric motor, or you can use grid electricity to run an electric motor to compress air that runs an air motor.

Hydrocarbons are just such a darn convenient way to store energy for mobile use that most everything else pales in comparison.

As Don Lancaster points out, there's more hydrogen in a gallon of gasoline than there is in a gallon of liquid hydrogen.