EV, HEV, PHEV, E-REV, FCV, CAV, Acronyms That Confuses Consumers

Tesla's Model S, all electric sedan

It's not easy being a consumer these days.  Fear, uncertainty and doom (FUD) are rampant in the news and to top it all, car makers love to throw acronyms at us.  So what's in an acronym?

It All Started Innocently.  It all started innocently enough when the industry needed to differentiate an internal combustion engine, ICE to an electric vehicle, EV but somewhere along the lines, things got complicated.  Call it the incessant powerhouse marketing machines of companies trying to wow potential clients, but all the sudden new acronyms popped up.  PHEV, series PHEV, parallel PHEV, series and parallel HEV, FCV, CAV, etc. 

Sorting Out The Confusion.  Instead of blaming an over-zealous marketing blitz from car makers, let's get down to the basics.  What is an EV?  An EV, in its strictest sense is a vehicle that uses an electric motor as a means of propulsion.  OK, but then what is a hybrid, HEV?  According to the Oxford American Dictionary, the word hybrid means: "a thing made by combining two different elements; a mixture" and a hybrid car: "a car that combines a gasoline engine with electric motors."  Notice there is no mention of who moves the car.

Series?  Parallel?  So an HEV is a car that uses two sorts of engines.  G&E has been building diesel electric locomotives since the early 40s and are rightfully called hybrids.  Within the hybrid drive technology, you will find two layouts, parallel and series.  In the parallel system, used by most manufacturers such as the Toyota's Prius and Ford's Hybrid Escape, both a regular ICE and electric motor are used as a means of propulsion.  The ICE will also be used to recharge an on-board battery pack to power the electric motor.  In a series layout, only the electric motor is the only means of propulsion, relegating the ICE as a generator to recharge the battery pack that feeds the electric motor. Simple. no?

Plug It In!  Just when you thought you had figured it out comes out left field the plug-in hybrid, PHEV system.  PHEVs can either either have a series or parallel layout, meaning the ICE and electric motor push the car or only the electric.

Blurring The Lines.  At this tie, it would be good to introduce the extended range electric vehicle, E-REV.  So what is an E-REV?  According to GM it is an EV that has an extended range  in the shape and form of an on-board ICE used as a generator.  For all intent and purposes, GM's Volt is a series PHEV.  So why not call it such?  Because GM thought it would sound more advanced to call it an E-REV.  It could as well have been called an S-PHEV, where S could have been for series or why not, Super.

FCV And CAV.  FCV stands for Fuel Cell Vehicle, mostly vehicles using hydrogen as a means of producing electricity when combined with air.  The technology is difficult and very, very expensive.  As a side note, transporting the equivalent of one gas tank would be the equivalent of 25 hydrogen tank.  Since hydrogen have to be cooled off to almost absolute zero, −459.67° F, it also uses one third of its energy keeping cold.  To complicate things a little more, creating hydrogen uses a lot of energy, usually electricity made most of the time with coal burning power stations and you get the gist, we need to fine a more sustainable way of producing hydrogen.  Well look into that more in upcoming posts.  Lastly, FCV use 10,000 per square inch hydrogen tanks on-board.  The thought of 10,000 psi people driving around cities and neighborhood, they way they currently do is blood curling to some.  Building hydrogen dispensing stations is currently around the vicinity of $2 to 3 million.  Does that mean hydrogen is hype?  Probably not, just decades away from being financial viable. 

Lastly the CAV, meaning compressed air vehicle.  Compressed air is pumped into a tank, which is is then delivered to a piston engine and through an elaborate heat exchange system, the compressed air expands in the cylinder and drives the pistons.  We'll look more into that later, as I have had the privileged to test drive that technology that might end up in the Tata Nano cars.

Did we miss anything?  Oh yes, electric vehicles, EV.  Finally, the EV is simply put a car that only uses electricity as an energy source, using only batteries as a storage.  Famous EVs are the Tesla Roadster, and the upcoming Mini E, ZENN and other such vehicles.

Next, we will look at the benefits and drawbacks of each systems.