David Marlow
Green Machines: First Person: Green Without Envy
April 1, 2007
Physicist Amory B. Lovins is the cofounder and CEO of Rocky
Mountain Institute (www.rmi.org), an entrepreneurial nonprofit think tank that
fosters the efficient and restorative use of resources. Published in 29 books
and hundreds of papers, his work has been recognized by the "Alternative Nobel,"
Onassis, Nissan, Shingo, and Mitchell prizes, a MacArthur Fellowship, the
Benjamin Franklin and Happold medals, nine honorary doctorates, and the Heinz,
Lindbergh, Jean Meyer, World Technology, and Time magazine’s "Hero for the
Planet" awards. He advises governments and major firms worldwide, including
automakers, on advanced energy efficiency, and has led the technical redesign of
nearly $30 billion worth of facilities, in 28 sectors, to achieve large energy
savings at typically lower capital cost. The
Robb Report Collection asked him to discuss the future of
fuel.
The greatest technological
revolution in 120 years of automaking is gaining pace. Its maturation in the
next decade will let you have it all—muscular performance, refined amenity,
advanced intelligence, and environmental friendliness—simultaneously and without
compromise.
Traction is key because
an electric motor’s highest torque is at low speed. The latest motors—compact,
light, digitally controlled, incredibly powerful—easily make acceleration
traction-limited. I’ve smoked a Lamborghini in an experimental electric
roadster, equipped with heavy lead-acid batteries. Today’s lightweight lithium
batteries make acceleration even more startling. Riding in Tesla Motors’ new
lithium ion battery electric sports car, you may be innocently invited to flick
on the radio … but just as you reach forward to the switch, your driver floors
the electric accelerator, pinning you in your seat.
Hot performance can now
come with as much as double the fuel efficiency. Previously these goals were at
odds: A conventional, engine-driven car with mechanical traction can accelerate
faster only via a bigger engine that is even more oversized for normal driving
loads. A typical car today uses only one-sixth of its rated engine power in
ordinary highway driving, and just a few percent in the city. This mismatch
halves average engine efficiency to a miserable 17 percent.
In contrast, a
self-recharging hybrid gas-electric car—the modern software-rich version of Dr.
Ferdinand Porsche’s 1900 Lohner-Porsche Chaise—exploits the electric motor’s
sizzling torque without enlarging the engine. Instead, the electric torque boost
makes the engine smaller and runs it near its efficiency bull’s-eye all the
time. Now add regenerative braking: Toyota’s Prius recovers and reuses braking
energy with two-thirds efficiency. Result: up to doubled average fuel economy,
yet with peppier performance that makers like Lexus are starting to
exploit.
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1900 Lohner-Porsche Chaise. (Click image to enlarge)Performance cars already offer superior tires and aerodynamics. Some also use lightweighting at key points. BMW is making over 1,000 carbon-fiber roofs and hoods each year, for nimbler handling via a lower center of gravity and shorter yaw moment. The next big step will be making the entire car radically lighter by affordably applying the costly advanced composites previously confined to handbuilt F/1 derivatives, like the Mercedes-Benz SLR McLaren. This materials revolution will be like finding an inexhaustible Saudi Arabia under Detroit, at $16 a barrel, while saving a million auto-related U.S. jobs. Rather than importing efficient cars to replace foreign oil, and perhaps buying oil-frugal Chinese cars at Wal-Mart, American and European workers would make those cars, so their countries import neither the cars nor the oil.
Your car burns daily the gasoline derived from 100 times its own weight in ancient plants. Yet most of that fuel is wasted. Seven-eighths of a modern car’s energy is lost in the engine, idling, driveline, and accessories. Of the one-eighth that reaches the wheels, half heats the tires and road or the air that the car pushes aside. Only the last 6 percent accelerates the car, then heats the brakes when you stop. And since about 95 percent of the mass being accelerated is the car, not the driver, only about 0.3 percent of the fuel energy ultimately moves the driver. Happily, though, three-fourths of the car’s need for propulsive energy is caused by its weight, and every unit of energy saved at the wheels saves another seven units we needn’t waste on the way to the wheels. Thus, making cars radically lighter in weight has huge fuel-saving leverage.
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