Wednesday, May 21, 2008

What about electric cars?

Reader & sometimes poster Brian Compton put a couple of links to prototype/production electric cars, and I figured that it might be a public service to give a little opinion on them. Now as a EE myself, I ought to love the idea. You have a flat torque curve, very few moving parts, no emissions from the vehicle, no "bomb" below the back seat (gas tank), and you can dispense with both an engine and transmission with multiple gears. There is a reason we use electric drive for things like golf carts and forklifts.

When it comes to passenger automobiles, however, I'm yet to be convinced--though as Brian's links showed (look in comments past couple of posts), there are certainly a lot of smart people working hard to prove me wrong.

Why will it be difficult? Look at a periodic table of the elements, and view the atomic weights of hydrogen, lithium, and nickel. Hydrogen is the main energy source in gasoline, ethanol, and natural gas. Lithium and nickel are the main energy sources in high tech batteries--and given that lithium is the lightest metal, it's extremely unlikely that we'll find a way of making a battery that's much lighter than lithium ion technology. Lithium is also fairly rare, and is electrolytically isolated from solutions "rich" in the element--it's really quite a difficult element to get, and cost $38/lb back in 1998, according to Wiki.

The end result is that when you use batteries instead of gasoline for energy, you need about ten times the weight for your power source. Hence, any vehicle that needs to go a serious distance is going to need hydrocarbon fuels, and it's also likely that any vehicle that needs to be inexpensive will be using ordinary, hydrogen based fuels for the foreseeable future.

Don't get me wrong; I wish those developing these vehicles all the best. I just don't know that physics and chemistry are likely to cooperate.

4 comments:

Jim Peet said...

How about overhead electric?

Bike Bubba said...

I'd have some serious safety concerns about routing the 500V and up that they power that kind of bus to a car that's only 4'- 6' tall; there are reasons it's appropriate for a bus, but not a car.

Plus, overhead electric more or less ties drivers into...well, the overhead electric grid. Again, appropriate for a bus on a fixed route (sort of), but not for a passenger car.

Anonymous said...

As a major appliance technician, I see a trend toward ever more complicated and computerized appliances. Consumers love them, but the end result is that more and more independent servicers are dropping out of the field, leaving repairs to only the largest companies with the deepest pockets for warehousing parts, training techs, and just getting the job done. Hence, the only ones who will benefit from this trend are the companies that sell the machines, and the larger companies that fix them.

I see this going on in lot of industries, and the electric and hybrid car could just be one of them. I can imagine a day when vehicles are so complicated, only a dealer will know how to fix them. What does that mean for a consumer? Just less competition and higher costs for the consumer. These higher costs could completely negate the benefits of new technology.

Bike Bubba said...

Good point--that said, it actually turns out that a lot of people are figuring out how to work with even the most complex cars--look up folks turning the Prius into a plug in hybrid, for example.

Now it actually turns out that the plug in hybrid is environmentally bad, but it does suggest that we can, with a bit of effort, still figure out the new things.