Gary,
Based on the theory that it takes X amount of energy to move a (semi) load a given (1500 miles) distance, and this now requires a large diesel motor to accomplish this feat, - internal combustion engine --> transmission --> power to wheels, how can a MUCH smaller motor turn a generator shaft --> generate electricity --> charge battery --> turn motors on wheels to accomplish the same thing? While there are energy savings in "leveling" the load - level power production to the battery buffer - while more energy needed to start / accelerate a load and less energy to maintain speed, how does this make a major change in the total energy required to move the load?? For long OTR trucks, the amount of power available from the grid would be pretty small. The generator must provide the rest. I feel this is the real stumbling block for large loads and long distances.
I have a friend with a hot rod Tesla that accelerates like a rocket! However, he must stop every 150 - 200 miles for nearly an hour to recharge, and this is for a nice passenger car!