Saturday, December 25, 2010

It's harder than it looks

Converting a car to run on electricity seems pretty straightforward.  Get rid of the smelly gasoline-powered parts and replace them with an electric motor, some batteries, and the electronic controllers to make it all work.  Sounds like something a person could do in his garage on weekends.

And it would be except for one MAJOR problem--the amount of energy stored in a small amount of gasoline is more than the energy stored in hundreds of pounds of the best batteries we can make.  Well, that shouldn't be such a problem--simply make the rest of the car lighter to compensate for those heavy batteries.

Putting the whole car on a diet seems like such a virtuous exercise.  The lighter the car, the less energy it requires to run.  And some elements of a modern car could simply be discarded--the premium sound system, the 8-way powered seats, the GPS-nav system, etc.  But a lot of the "frivolous" weight in the modern automobile is for things mandated by law such as the airbags.  Ok, then cut the weight out by replacing the steel in the structure with something lighter.

Using aluminum gets you some weight savings but to get a significant weight reduction, carbon fiber is the way to go.  Unfortunately, mass-producing carbon fiber parts is nearly impossible and the affordable automobile requires mass-produced parts.  And while fabricating carbon-fiber parts can be a garage project, doing it for profit is so difficult, very few auto makers will even try.  BMW claims to have made progress but the carbon-fiber car is still incredibly expensive--even by BMW standards.

Carbon Fiber Cars
BMW's Electric Automobile Revolution
By Christian Wüst 12/24/2010 
BMW is hoping to revolutionize the electric car industry. Whereas most manufacturers rely on traditional -- and heavy-- steel car bodies, the German company hopes that carbon fiber components could lead electric cars into the future.
Cars may have conquered the world, but they didn't do it overnight. Decades after its invention in 1886, the passenger car was still too expensive and too impractical to be anything more than a rare sight on the streets. Gas stations didn't even exist in those days.
The spread of electric cars in the 21st century seems to be proceeding at a similar slow pace. The first models from major manufacturers are now hitting the market, but as a form of transportation, these vehicles face much the same acceptance problem as Gottlieb Daimler's horseless carriage did. These cars have a high price tag but offer low performance.
Mitsubishi has released its first electric car series under the rather uninspiring model designation i-MiEV. It's a simply furnished compact car with an oval body and lithium-ion batteries under the floor panel. With one charge of the battery, the vehicle can travel 100 kilometers (62 miles) in summer or 60 kilometers (37 miles) in winter. It costs €34,390 ($45,240).
Nissan's electric car, the Leaf -- set to hit the German market next year -- faces the same cost-benefit plight. Even so, European automobile journalists saw fit to name the Leaf their "Car of the Year."
It doesn't take extensive market research to see that something doesn't add up here. What customer is willing to pay the price of a luxury sedan for a spartan vehicle whose operating radius barely extends beyond the range of commuter trains?
Too Weak and Too Heavy
All car manufacturers face the same problem -- even the most modern rechargeable batteries are too expensive, too weak and too heavy to power conventional cars, which are already excessively heavy even without the batteries.
"Integrating electric power into existing vehicle concepts is the wrong way, a dead end," declares Rainer Kurek, head of the Munich-based MVI Group, which develops car bodies and other components for the automotive industry. In his recently published book, Kurek urges vehicle manufacturers to take a completely new approach. "The current hype surrounding electric vehicles," the engineer writes, "is obscuring the fact that today's auto bodies have become far too heavy over the course of the last decades." more

No comments:

Post a Comment