In the early 1970's (first oil shortages, embargo) there was a lot of R&D and ideas were floated freely.  One I liked was an electric hybrid car. It was electric drive with storage batteries.  There was a small engine designed to run efficiently at a constant speed that would provide a charge for the batteries if needed and no charging station available. It would also charge while driving if the battery was running low. 

 

Like sex toys, build it and they will come(sp). (i think I made that up; but with 7 billion people in the world, who really knows?).