The continuing rise in the price of gasoline has sparked a renewed interest in alternatives to the traditional gasoline-powered automobile. As I read and listened to several of these reports this week, the following question occurred to me: does the technology for plug-in hybrids already exist?
The answer is, I think, "yes and no." The technology exists, but it is still just a bit too expensive to deploy on a large scale. Nevertheless, the time is very near when plug-in hybrids will be widely available and will become a common sight on American roads.
Consider the Tesla Motors electric roadster.
The Tesla roadster uses 1,000 pounds of lithium-Ion batteries to propel it about 220 miles on a single 3.5 hour charge. The energy cost for this performance is estimated to be about 2 cents per mile when the source of the energy for charging the battery is an ordinary household electrical outlet. That's about $4.00 for 200 miles, or, to put it another way, 200 miles for the cost of a single gallon of gasoline.
The Tesla roadster is already in production, but has several drawbacks that prevent it from being a complete solution. The Tesla is small, expensive, and can only be recharged by plugging into an external source of electricity. What the Tesla does offer is a practical battery pack that can hold a useful charge.
Now, I'm no engineer, but it seems to me like it might be possible to mate the technology of the Tesla roadster with a slightly larger platform and include a small gasoline powered generator. The resulting vehicle would have both energy efficiency and flexibility. As long as such a car was used close to home, it would never need to use its gasoline powered generator, it could simply return home for a full charge. If the car's owner wanted to take a longer trip or was unable to return home for an extended period, the onboard generator could then be used to recharge to battery pack and keep the vehicle moving.
All the necessary technological elements for a practical plug-in hybrid already exist. The question is no longer how to make it work. The challenge is to find a way to mass produce these vehicles at an affordable price.
Update: This diary from Daily Kos provides a great roundup of the current state of electric vehicle technology.