23 Sept. 2007
SETI League
PriUPS Project

The Modular Volt

Blame it on the Times.  Not the current year or century, but the New York Times.  A few weeks ago I was declared to be a guru in its august pages, and I just realized that since then I have been writing about transcendental subjects.


  • Pastry repair

  • Bananafication of the bun

  • Turkeys and fungi

  • Scallop fraud


  • A new type of space drive

  • Why you need a gigabuck to be "rich"

  • A new type of financial instrument that can save one from chocolatic penury

  • Saving the world from carbon dioxide

I'm afraid that if I keep this up, my brain will explode.  (If I don't, it may implode.  I'm not sure if either will make a difference.)  Either way, today I was torn between saving the world yet again, or writing about the New Jersey conceit of the Uni-l-ular Michele.  My decision:  Today the world, tomorrow the "l." 

Saving the World

To be sure, just the vehicular world and the energy problems that go with it.  Although in this case, I propose to also usher in the hydrogen economy painlessly.

Let's consider the Volt.  That is the name of General Motor's proposed electric car of the future.  In this weekend's New York Times, there was an article comparing the new crop of near-term battery-powered cars.  The section about the Volt reads thus:

G.M. doesnít like the Volt to be called a plug-in hybrid, since it considers the car more of an E.V. But the concept car has a tiny gasoline engine, albeit one thatís used exclusively to pump electricity into lithium-ion batteries, not to power the wheels. And thereís definitely a cord attached, requiring eight hours to recharge from a household plug but far less with higher-voltage current.

G.M. is designing the Volt to run on electricity alone for up to 40 miles. So for more than 85 percent of American commuters, the Volt would indeed work like a pure E.V., using no gasoline and delivering up to 150 m.p.g. G.M. hopes to bring a car like the Volt to market by 2011 or 2012.

Notwithstanding G.M.'s dislike of the term, the car is a plug-in hybrid.  You charge the batteries mostly by plugging it in, but also by using its gas engine.  For normal commuting, you may not have to use gas, but it's there to provide extra range and to eliminate the fear that when your batteries are discharged, you'll be stranded.  (A perfectly reasonable fear, to be sure.)

Why A Gasoline Engine?

How about:  G.M. makes gas engines, and one can get gas at gas stations?  But there are two alternatives that don't seem to be mentioned in the discussion of the Volt:  Diesel and hydrogen.  Does it make sense to offer these instead of gasoline?  Not yet.  Diesel may not meet emission standards, and hydrogen may be too exotic for general use.


And it's a big but:  Diesel may meet emission standards by the time the Volt is available, and hydrogen, with a fuel cell to generate electricity to recharge the battery, may be practical, at least where hydrogen is available.  Both are possible variants of the G.M. Volt, each with its distinctive advantages, providing that it isn't the only variant.  What I suddenly realized is that the Volt can be offered with all three engines.  There's no good reason why it can't be made modular!

Consider the Prius, the non-plug-in hybrid that I drive every day.  It gets 50mpg, which is a big improvement over what it replaced.  But the gasoline and electric motors both power the car, and are, as the term goes, "inextricably intertwined."  Not so a "series hybrid" such as the Volt.  In this car, only the batteries and electric motors drive the car; the gasoline engine simply recharges the battery.  In fact, the gasoline engine is both small and, in the best case of short trips with charging intervals in between, supernumerary.  And, it is connected to the rest of the car with wires instead of the complicated system used in the Prius.  You can just unplug it!

Of course this is an oversimplification.  Even a small gas engine needs an exhaust system and a way to fill the gas tank, so there is some plumbing.  But I think it could be engineered to be exchangeable.  If it were, and G.M. produced a Diesel or a hydrogen/fuel-cell electric system, one could choose which he wanted to purchase.  Of course, the connections for a Diesel would be the same as for gas: wires to charge the battery, and an exhaust and fuel system.  Picking either gas or Diesel for the few kilowatts needed to recharge the battery would be pretty simple.  What about hydrogen?

The Hydrogen Solution

When we read about the hydrogen economy, most of us feel that it's more dream than reality.  There are very difficult problems to be solved:  How to distribute hydrogen throughout the country, how to effectively store it in the vehicle to get enough range, and how to make a powerful enough fuel cell to run the car.  All difficult, with no immediate engineering and economic solution in sight.  Here again the big But!  For use in the Volt, none of these problems must be solved!

  • We already have hydrogen available here and there.  As demand increases and technology improves, the infrastructure will be built out in an economical and temperate fashion.  If you can't get hydrogen where you are, just get the gasoline (or Diesel) version.

  • Nobody knows how to store 300 miles worth of hydrogen in a tank small and safe enough to work in a car.  But 50 to 100 miles worth isn't as big a challenge!  Since the car is primarily dependent on electricity, and uses hydrogen as a supplementary range extender, we can live with that.

  • Fuel cells that will drive a car, providing perhaps 100kW peak power and many kW average power are very expensive and challenging to make.  A fuel cell that will deliver maybe 5kW with no peak demands and an intermittent duty cycle should be much smaller and cheaper.

Hydrogen is a great store of energy, and one we can't run out of.  Maybe making a modular hydrogen power source for the G.M. Volt will be a good start toward a hydrogen economy, one that requires no sacrifice and no breakthrough.  How about it, General?

I've got to write something silly.  Soon.  This saving the world stuff can get tedious.

NP:  "The Wake" - IQ

© 2007
Richard Factor

Yesterday  |  Tomorrow