Wednesday, February 2, 2011 06:02
I was at an auto-company-sponsored “holiday dinner,” the kind with bottomless wine bottles and menu items up to $200. I wound up in an unwelcome, uh, discussion with a representative of an American automobile club. Just like high school debate club, I found myself defending a point with which I don’t fully agree: Electric cars are the solution to our transportation problems. Those who know me, and have followed my writing are chuckling at the irony.
Despite the fact I had placed my wineglass upside down and my “opponent” didn’t, I got whupped.
He started with his position: The car club is against electric cars and for hybrids. My position: Electric cars will be a small part of the cure, and that hybrids are a cynical marketing exercise. (I don’t have room to support the latter, but that’s the belief of ex-Formula 1 designer and creator of the T-25 city car Gordon Murray, so it’s good enough for me.)
I agreed with most of my opponent’s positions and even added one: Do NOT call electric cars “zero emissions vehicles” until their electricity is made by bird-slaughtering wind turbines, desert tortoise-choking solar cells, fish-shredding ocean-tide turbines, or nuclear plants using weapons-grade uranium. More...
Wednesday, January 19, 2011 05:59
There’s a huge misunderstanding about hybrid vehicles among the general public. (I’m sure you’re shocked, shocked, mind you, to discover technical illiteracy among the masses!) Carefully phrased advertising and marketing feed this misunderstanding. (Automakers also do this to prolong the fantasy that all-wheel drive helps vehicles handle better. It doesn’t.)
The misunderstanding: Electricity is “made” when you step on the brake pedal of a hybrid. The truth: Energy that would otherwise escape as heat is recaptured as a very little bit of electricity. That electricity refreshes the batteries, assuming the battery isn’t “fully” charged. To prolong battery life, hybrid and electric car batteries are not charged beyond about three-quarters of their true capacity.
For automotive illiterates, conventional car brakes stop the vehicle by turning the kinetic energy of the car moving down the road into heat. To further your knowledge: A hybrid’s kinetic energy comes from the potential energy in gasoline. And about 70 percent of the kinetic energy in electric vehicles comes largely from burning coal and natural gas.
In a hybrid, when the driver touches the brakes or the car thinks you want to slow down, the car’s computer switches the vehicle’s electric motor into an electric generator. This isn’t magic, but if you want to believe that, it’s okay with me. Rotating the motor-turned-generator reduces the work the brakes must do. It also captures a little bit of energy that would have been wasted as heat.
How much energy is recaptured? It varies from “not very much” to “none.” If you get on a wide-open freeway and drive, say, 10 miles without touching the brake, you’ve recaptured exactly zero energy. If you coast a bit to slow for the off ramp before touching the brakes, you recapture a very small amount. If, however, you’re on a slow-and-really-go L.A. freeway, where traffic suddenly slows from 75 mph or more to 25 or less (without an apparent reason) and then returns to 75 (without an apparent reason), then you’re recapturing a fairly useful amount of energy. Understand this: To an automaker “a fairly useful amount of energy” can be a single mile per gallon (or much less) on the government’s highway driving cycle.
The bottom line: Regenerative braking is arguably a better marketing tool than it is an energy saver. But save a little bit of energy it does.
Wednesday, January 5, 2011 05:06
Ferrari, Porsche, and other exotic sports-car makers are planning, or at least thinking about gasoline-electric hybrid supercars. My first response was, “Why?”
Even a prediction by an oil company executive of $5 per gallon gasoline by 2012 didn’t answer the question: Gasoline is the cheapest thing Ferrari and Porsche owners will ever put in their vehicles, some passengers excepted.
As a neo-Libertarian, I immediately suspected the hairy hidden hand of big government. I think I’m right.
Paris (France, not Texas) is considering banning vehicles that emit more than an as-yet undecided amount of carbon dioxide per kilometer. (We fought several wars to avoid the metric system, but it’s creeping back.) It’s almost certain that every 600-plus horsepower supercar would exceed whatever level Paris might impose. The entire European Union, or, at least, crowded cities such as Zurich, Rome, and Madrid would probably follow Paris’ lead. More...
Wednesday, October 27, 2010 02:47
While writing a driving impression on the 2011 Nissan Leaf, I tripped over some unfamiliar acronyms: kW, Nm, and kWH. With hybrids, I can write about the gas engine and dodge the electric part, but the Leaf is all-electric. (Do NOT call it a zero-emissions vehicle. To make electricity, coal is burned upwind from my house. Note to EV- and plug-in hybrid advocates: If you’re not demanding the construction of nuclear powerplants or volunteering to have noisy, bird-killing wind turbines placed on your roof, you’re hypocrites.)
Anyway, my first stumble was the output of the electric motor. Nissan says its peak power is 80kW, while its maximum torque is 280Nm. “kW” is one kilowatt and is equal to about 1.34 horsepower. So the Leaf’s motor is roughly equal to a 100-horse gas engine.
“Nm” is Newton-meters. One Nm is equal to about 0.74 pound-feet of torque. Since an electric motor makes its maximum torque at zero rpm, the Leaf produces a neck-snapping, tire-squealing 207 pound-feet of torque the instant you touch the accelerator. (Don’t call it a throttle, the loud pedal, or the gas.) Unlike a gasoline-fueled car, the neck-snapping is over almost as soon as it begins, as torque, I mean Newton-meters, start dropping like a rock. Electric cars will have great 60-foot times, but don’t run the whole quartermile. More...
Tuesday, September 28, 2010 03:34
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Logical Caterpillars in the Nissan LEAF
Something’s rotten in the tree that sprouted Nissan’s LEAF. For instance, the hype behind the new electric subcompact and how it's being subsidized by Uncle Sam. Electric cars, should they become practical, need to be financially obtainable without dealership welfare. Concepts worth their salt will prove themselves in a free market, but the LEAF comes to the dinner table with $7,500 in federal tax dollars propping up each sale, plus what’s offered by the government in your state. More...