In terms of design, the most perfect ideas are often the simplest. Consider the sailplane. Combining great strenght with virtually no weight, the sailplane can travel vast distances without any sort of internal power. Its beauty stems from the fact that its form and function are inseprable. The designer-engineer
Paul MacCready
said in 1990,“as we near the end of the century with enormous human and environmental problems, our concept of beauty is bound to change. Soon we’ll be less concerned with how something
looks and more concerned with how efficiently it
works.”
Best-known as the father of the Gossamer Condor (the world’s first human-powered aircraft to cross the English Channel, in 1979), and the Solar Challenger (a unique solar-powered plane, of 1981), MacCready brought his knowledge of low-power and high-efficiency machines to the ground in 1987. That year, he designed and built Sunraycer , a solar-powered car funded by General Motors, which won the 1987 World Solar Challenge, a grueling 1,860-mile race across the continent of Australia. Averaging nearly forty-two miles per hour, sunraycer not only won; it beat the second-place finisher by more than two days.
Accounting for his success, MacCready noted, that, as far as he knew, Sunraycer was the first vehicle in the history of General Motors in which no stylist was involved. “But what good is a solar-powered car?” someone wondered, to which the designer countered, “what good is a newborn baby?”
Very good indeed. Shortly thereafter, GM commisioned the MacCready, founder and president of the California-based environmental and vehicle firm AeroVirenment, to tap the resources of twenty-three GM divisions and affiliates in a secret program to develop what marked the first major advance in personal transportation in the last century: an all-electric vehicle with the same performance, comfort, and safety as a conventional gasoline-powered sports car.
Displayed at the 1990 Los Angeles Auto Show, the GM Impact stunned spectators and experts alike. From the beginning, GM only applied proven technologies so that a ‘real world’ car could be put into production without waiting for any breakthroughs, MacCready noted at the time.
Still today the average car wastes most of its energy, owning to poor aerodynamics, internal friction (caused by drive train, brakes, tires), and engine inefficiency. Engines convert gasoline into heat of which only a fraction is converted into motion to turn the wheels.
Knowing that conventional lead acid batteries deliver only one percent of the energy obtainable from the same weight of gasoline, MacCready estimated that by pushing every other technology to the limit, he could achieve gasoline performance with battery power. Once the besic design was set, MacCready examined the Impact like a detective, methodically locating and eliminating every source of energy loss and excess weight he could find. For example, instead of using a single electric motor, requiring the use of gears, he incorporated two smaller motors, attached directly to the front wheels. Powered by thirty-two tenvolt batteries developed by GM’s Delco Remy division, the dual-motor configiration could deliver an astonishing 11 horsepower instantly, whether the car was at a standstill or traveling at highway speed.
At the time John Zwerner, director of GM’s Advanced Product Engineering division, said “the public perceives electric vehicles as slow-moving, similar to golf carts. Yet the Impact shatters that perception.” To prove the point, GM tested the car head-tohead against the Maxda Miata and Nissan 300ZX. From a standing start, the Impact outdistanced the other two cars, achieving sixty mph in eight seconds.
In fact, punching the Impact’s accelerator at sixty mph literally threw the drivers back into the seat. Why? “At sixty miles per hour the motors use only 10 percent of the car’s total power, and, with no gears to shift, the remaining 90 percent is available with no delay, “noted MacCready.
Another factor was the sleek ultralight fiberglass body sculpted at GM’s Advanced Concepts Center, in Thousand Oaks, California. Since drive shaft and exhaust system need not be accomodated, the car’s underside is perfectly smooth, allowing it to slice through the air. Its shape, wide in the front and narrow in the rear, greatly reduced the turbulence normally left in a car’s wake. In effect, nearly a third of the foreign oil we buy is spent stirring up the air when you think of the dollars involved, it’s madness.
To extent the Impact’s range further, AeroVironment developed a regenerative braking system. Every time your foot lifted off the accelerator, the motors started to convert the car’s kinetic energy into electricity, which fed back into the batteries. As a result, the car ran about 100 miles between charges both on the highway and in the city even with conventional heating or air-conditioning. Recharging time ranged from two hours at a 220-volt industrial hookup to eight hours at home, with the electrical cost averaging 1.5 cents per mile.
In 1990 MacCready predicted, that California drivers would trade-in their conventional cars for high performance, zero pollution cars. “Nationwide it’s a political question. Until we start paying the true cost of gasoline at the pump, which experts estimate at over three dollars per gallon, we will never have the incentive to conserve.”
Famous last words…and then we @#$%&* up the end game.