As I was catching up on the backlog of energy-related articles that accumulated over the holidays, I noticed an interesting trend. Although there are still many possible ways that we can solve the problem of providing clean and affordable energy for transportation, a growing number of experts and pundits seems to be zeroing in on the plug-in hybrid car as our best option, despite the fact that it has yet to appear in a production model for consumers. Although I remain enthusiastic about this technology's potential, we need to remember that that's all it is today: potential. Anyone suggesting that we should cease funding research into hydrogen fuel cells or any other option, based on the promise of the plug-in hybrid, is making a premature judgment that can't be validated by modeling and prototypes, but only by head-to-head competition in the marketplace.
As frustrated as many of us get with the status quo for transportation in general and cars in particular, we are blessed with a profusion of alternatives for the future, including advanced internal combustion engines, hybrids, and plug-in hybrids running variously on gasoline, diesel, hydrogen, or biofuels; fuel cell vehicles using stored hydrogen or hydrogen produced onboard from other fuels; and advanced electric vehicles with no onboard energy source other than batteries. Each of these options faces an array of obstacles on the way to attaining the scale necessary to make a difference in overall greenhouse gas emissions, oil imports, or any other criteria. These obstacles fall into three basic categories: changes to the vehicle that increase its complexity and cost, changes to the energy distribution network requiring either modifications or parallel infrastructure, and changes to underlying energy production sources (e.g., oil refineries, power plants, etc.) An option involving only one or two of these areas will have a faster, easier pathway, in general, than one affecting all three.
Compare the plug-in hybrid car to the fuel cell car in this regard. Both entail expensive and complex changes to the basic automobile, though at this point the hybrid looks cheaper to implement. While the fuel cell requires an entirely new distribution network for hydrogen, and major plant and equipment to produce hydrogen on an industrial scale, the plug-in hybrid can piggyback on existing electrical distribution infrastructure, with only modest modifications--ignoring the much trickier vehicle-to-grid, or V2G, version. But as I pointed out on Monday, mass adoption of this technology will require either a large expansion of the fuel supply for surplus off-peak electrical generating capacity--natural gas--or the construction of enormous new capacity based on renewable or nuclear power, or coal-fired capacity with carbon sequestration. This is a tall order, beating the fuel cell on complexity, but not necessarily on scale.
In the meantime, simpler technologies such as conventional hybrids will be moving down their cost curves and gaining market share and momentum. In the process, they will capture the most valuable increment of fuel efficiency, going from 20 mpg to 40 mpg. That will make it harder for either plug-in hybrids or fuel cell cars to compete, once they're ready for the mass market, because going from 40 mpg to 100 mpg is only worth a few hundred dollars a year to the average motorist, while the first 20 mpg improvement is worth over $1000, at current fuel prices.
It's tempting to view this technology competition as a NASCAR or Indy-style car race, in which all the cars are on the same track, heading for the same finish line. A better analogy, though, might be a steeplechase with each horse on a unique course, with different hurdles and distances. Like horses, these technologies also interact with each other in complex ways. For example, improved batteries that make plug-in hybrids more practical also lower the hurdle for fuel cells, by allowing developers to reduce the size of the costly fuel cell stack. While it may indeed prove easier to sell 100 million plug-in hybrid vehicles than 100 million fuel cell cars--and that's the scale we're really talking about--it's not clear that we know that, yet. Nor can we say whether either of these options can actually beat the European-style diesels or conventional hybrids that have a substantial head start on them. This race still has a few more furlongs to run, before we can declare a winner.