Thursday, October 25, 2007

Recharging the Electric Car

An article in yesterday's Wall St. Journal prompted some thoughts about the relative merits of entirely-electric cars (EVs,) compared with hybrids employing varying degrees of electric boost. It's interesting that Honda and GM, both of which have marketed all-electric cars in the past, should arrive at such different conclusions on the subject. Honda now apparently finds pure EVs superior to hybrids and plug-in hybrids (PHEVs,) while GM, which invested close to a billion in today's dollars in its EV-1 in the 1990s, is not convinced. Although some of the factors that led to the failure of the EV-1 might no longer apply, others look daunting, except perhaps to environmental regulators, who would naturally find zero-local-pollution EVs preferable to hybrids.

When you consider the experience of GM's EV-1, a few things stand out--after setting aside the unfounded allegations that it was killed by a conspiracy. As the testimonials from its former lessees attest, the EV-1 was a terrific car, as long as your driving needs didn't exceed about 75 miles, or you didn't need to transport more than one additional passenger. The latter was a design issue, constrained by the size of the original lead-acid battery pack and the body shape GM selected. But while the range was largely a function of the available battery technology, it also reflected the challenge of quickly recharging a partially-drained battery, even with a small number of high-voltage recharging facilities that GM and its partners installed around Southern California. How many of us would have really wanted a car that couldn't go more than 100 miles without stopping for a charge that might take an hour?

Batteries have improved a lot since the first EV-1 left the factory. If the lithium batteries around which GM is planning its Chevrolet Volt PHEV are able to deliver 40 miles of gasoline-free driving, surely a larger array of the same batteries could take an all-electric version of the same car 200 miles or more. That's the basis of the Tesla, which claims a range of 245 miles for its sleek electric roadster, running on thousands of laptop batteries.

Paradoxically, that range is both good news and bad news. Because it easily exceeds what most of us require for our daily commutes or errands, it effectively severs the chicken-and-egg infrastructure dependency that I believe really killed the EV-1: you can't sell EVs without recharging facilities but can't justify the recharging facilities without lots of EVs already on the road. A 200+ mile range eliminates the need for most recharging away from home, workplace or other predictable sources of electrical outlets and reduces the inconvenience associated with the lengthy intervals required for low-voltage recharging. In the process, though, it also eliminates most of the incentive to build a fast-recharging infrastructure to meet the needs of longer-distance travel.

It's arguable that this isn't a real impediment. When I first started looking at these issues in the mid-1990s, I saw compelling data that suggested that American motoring habits were evolving towards each household owning a mini-fleet of specialized vehicles: the commute or train car, the kid-hauler, the weekend sports car, etc. That meant that a car like the EV-1, which couldn't fill all of these roles but excelled at one, had great potential. Unfortunately, that view turned out to be wrong, or at least premature. This is still a key question today. Would millions of consumers be happy to own a car that they couldn't sensibly drive from Boston to Washington, DC, let alone from Washington to Minneapolis?

If the answer is yes, then a pure electric car looks pretty good, and the added complication and expense associated with a plug-in hybrid might not be justified, provided the cost per Watt-hour of batteries keeps falling. Personally, though, I think the flexibility of a PHEV able to run on gasoline, E-85 or electricity will appeal to more folks than a simpler battery car. I also doubt that the target market for the six-figure Tesla will tell us much about that trade-off. But isn't it nice that technology is finally providing multiple choices for our future transportation needs? EVs and the various hybrids may compete for market share, but they could also coexist nicely, all furthering the gradual electrification of automobiles.

No comments: