Saturday, February 27, 2010

Some Thoughts on Electric Cars

I was thinking about getting a pure electric vehicle (EV) like the Tesla sedan or the Nissan LEAF, since my wife does a lot of around town driving. One of the things that usually comes to mind when car shopping is gas mileage, but mpg is meaningless for an EV. What is more relevant for an EV is the battery system's energy storage capacity. Storage capacity will affect the range of the vehicle as well as its cost to recharge. Knowing the vehicle's storage capacity in kilowatt hours (kwh) helps give you a handle on these things.

For a round numbers example, if your vehicle has a storage capacity of 30kwh, and the cost of your electricity is $0.10/kwh, it will cost you $3.00 to fully charge the vehicle. If you can drive 100 miles before fully recharging, your energy cost will be $0.03/mile. (If fuel was $3.00/gal, for comparison, it would be like having a vehicle that gets 100mpg, but only has a one gallon tank.)

Getting a handle on the range is a little trickier. Although it depends on the design of the vehicle and the driving habits of the operators, published figures from the manufacturers will likely only be achievable under "ideal" conditions (downhill with a tailwind). Independent testing by organizations like Consumer Reports will probably be more realistic. Needless to say, YMMV and living with the vehicle for a while will be a learning experience in that regard to see how far you can go and still get home with a comfortable amount of reserve power.

One of the psychological stumbling blocks for EVs will be the fear of a flat battery while on the road. Battery failure notwithstanding, a dead battery may be a little more traumatic an experience for the EV driver than running out of gas in a regular car. Towing may eventually be replaced by mobile recharge services that can supply a high voltage "quick charge" to get you home or to a charging station.

Technology should also come to the rescue here by keeping you apprised of the amount of energy left in your system and, via GPS, letting you know when you are in danger of not being able to make it home or to the nearest charging station.

Another thing about EVs is that, since the government can't collect road taxes via the fuel they consume, they may eventually incur recovery tax(es) to help pay for road use. This policy might change, however, in the interest of having an incentive for the public to move away from the high pollution and carbon emissions of conventional vehicles. Incidentally, pure electrics are not the only EVs in this space. Plug-in hybrid vehicles like the Chevy Volt are too.

It will be interesting to see how the pure electric vehicle space develops as their numbers increase and especially if they become a significant portion of the overall marketplace.