I just saw an ad on TV for the Nissan LEAF, which apparently is an EV car for 2010. It has a 100 mile range, which is respectable. I think my next car is very likely to be an electric car. And a 100 mile range is probably fine, but it means we'll never take the car on a long trip.
The solution, however, is the concept of the "pusher trailer." These typically are made from old Volkwagen Rabbits. They're front wheel drive cars, which means that everything behind the firewall can be removed and thrown away. You attach a trailer hitch to the front, lock the steering, provide remote control for the throttle, etc and you're done.
With a pusher, an EV becomes a hybrid. They generally can run in a few modes:
1. The pusher can be off and in neutral for city driving.
2. The pusher can be pushing and the EV can be in neutral. This preserves the battery of the EV, and maximizes the fuel economy of the pusher.
3. The pusher can be pushing and the EV can be in drive and coasting. In this mode, the regenerative braking of the EV charges the battery with some of the energy delivered by the pusher.
Now, hackers have achieved this, so there's no reason at all that manufacturers couldn't make pusher trailers for EVs. In fact, if they were available for rent, there's no reason I'd want to buy one. If I was able to rent a pusher for taking a long trip, everybody would win:
1. I'd get to take a long trip without worrying about the batteries.
2. Whoever rents them would be able to maintain them properly, which is good for the environment.
3. I'd do the vast majority of my driving on pure electricity, which is good for both the environment and my pocketbook.
4. As fuel cell technology improves, I can foresee the pusher trailers eventually being replaced by fuel cell generators that would just plug into the car and keep the batteries topped up over a long trip.
The auto manufacturers could, in fact, create a standard for a pusher trailer interconnection with an EV. Making it different from a traditional trailer hitch would have some advantages, in fact, since it's fairly clear that the manufacturers wouldn't want to encourage folks to attempt to tow trailers with EVs (their range is short enough without adding more weight to them). Plus, there needs to be additional control signaling from the cab to the trailer. Finally, the software running the EV, were it aware of the potential availability of a pusher trailer, would no doubt make better battery management decisions when it detected one was hooked up.
The biggest problem I see with this concept being productized is not, in fact, technological at all. It's regulatory. One hacker can lop the ass-end off a VW rabbit, call it a trailer, and probably get it licensed as such simply because the DMV staff won't know how it could be anything else. But that doesn't really fly when a manufacturer tries to make n dozen thousand of them and sell them. Moreover, they would need to be able to say with a straight face that pusher trailers are safe. That means all sorts of testing and on and on and on.
Still, the concept is just too good for it not to be considered. The big question is, who will be the first auto manufacturer brave enough to embrace the concept and lead the effort to bring it to fruition?