NOT long ago electric cars were going to save the world. Every major automaker was developing a battery-driven vehicle that would offer both freedom from petroleum and zero emissions (at least at the tailpipe -- the power plant might be another matter). California enacted a regulation requiring the test marketing of electric cars; General Motors got there first, in 1996, with the EV1, a Jetsons-style plug-in coupe that was just the ticket for guilt-free commuting. And it was ... terrible.
Despite hundreds of millions of dollars' worth of research and development, GM's electric car could travel only fifty to eighty miles before it needed a recharge, which took four to eight hours. A drive outside Los Angeles, or even to the outer valley, would have had to include a leisurely dinner followed by a three-part German opera to pass the time while the batteries recharged for the return trip. And that was assuming an excursion without air-conditioning: with the AC on, the range of the EV1 shrank further, and tractor-trailer rigs could pass it going up hills. Once word got out about this impracticality, even trend-happy Californians shunned the electric car. GM recently "suspended" production of the EV1. Honda, long the industry leader in environmental improvements, abandoned its electric-car project; other manufacturers scaled back their efforts. A few fleet buyers may still go electric -- the U.S. Postal Service, for example, which has begun buying battery-powered vans, which are practical for mail delivery because they travel short fixed routes and always return to the same point at night, making recharge expedient. But barring a fundamental breakthrough in battery chemistry, electric transportation for the masses appears as dead as a car whose headlights have been left on all night.
Yet a funny thing happened on the way to the demise of the plug-in car. Engineers realized that they could use what they'd learned about batteries and electric-coil motors to fashion half-piston, half-electric "hybrid" cars that dramatically reduce energy consumption but run in the conventional way -- on petroleum from filling stations -- and never need to be plugged in. Driving range, the big drawback of electric designs, not only isn't a problem with hybrid vehicles but is significantly improved: hybrids get so many miles to a tank of gas that one could drive from New York to Washington and back without stopping. This is practical and attractive in an era of rising fuel prices. The market is about to be flooded with hybrid vehicles -- and they offer an example of the kind of serendipity that occurs when in the course of failing to achieve a planned goal, one discovers something of greater value.
goes the Honda Insight, the first hybrid car to hit the U.S. market, when the key is turned in the ignition. A piston engine has started up, but it's so small -- just three cylinders, making 67 horsepower -- that it's hard to hear. An electric engine sits in tandem with the internal-combustion unit, but it is almost inaudible. So quiet is the Insight that a check of the instrument panel is required to make sure the car is really on.
When a hybrid vehicle accelerates, the two engines run together, providing maximum horsepower; they also run simultaneously when the driver stomps on the throttle for a high-speed pass. But if the vehicle is cruising and power demand is low, only the piston engine operates. When the driver hits the brakes, the technological fun begins: the electric motor runs in reverse, exploiting the friction of braking to generate a current that recharges a bank of batteries. The point of this arrangement is to create a vehicle that has the same basic properties as today's conventional cars but requires only a small-displacement piston engine, which burns far less gasoline. Normally, 67 horsepower would not be enough for a modern car; assisted by an electric motor, it is.
The Insight is rated by the Environmental Protection Agency at a phenomenal 61 miles per gallon in city driving and 70 mpg on the highway. Its tank holds 10.6 gallons, meaning the car can travel about 700 miles between fill-ups. For the typical driver that's one stop a month at the gas station. And the electric assist gives the car pizzazz. Humming around in an Insight, I found myself consistently able to outrun big, powerful cars. I also found that the Insight would accelerate uphill with the air-conditioning on. In a week of local driving the car got 58 miles per gallon. I know this because the Insight's instrument panel flashes a continuous readout of gas mileage.
From an engineering standpoint, what hybrid propulsion does is combine the best aspects of electric and piston motivation while avoiding their weaknesses. The weakness of batteries is "energy density." An automobile gas tank that weighs about a hundred pounds when it is full contains enough usable energy to move the typical car 200 to 300 miles; a thousand pounds or more of chemical batteries would be needed to provide that kind of range, and there is no battery-design breakthrough on the horizon that could reduce that weight. ("Flywheel" batteries, which store power as circular motion, could in theory have roughly the same energy density as a gas tank, but making a flywheel battery practical for propulsion has stumped every engineer who has looked at the problem.) If an electric car were designed to have the driving range of a gasoline-powered car, the entire vehicle would be given over to batteries. The car would then exist to transport its own energy supply, which isn't a huge accomplishment.