Published: August 05, 2008 11:48 am         

STUMPTALK: Are electric cars the solution to weaning us off oil?

In the mid-1960s I shared an office at Hughes Space & Communication with a senior mechanical engineer who had a passion for electric race cars. His home town of Riverside, California accommodated his car club by closing off some downtown streets weekends for some fun-racing. One day he asked, “You’re a control engineer; maybe you can help me.”

He explained that mechanical brakes were ineffective in making the tight turns around city streets. I gladly dug into my design trick-bag and provided a couple of tips: (1) use of the motor’s back emf (counter voltage produced by its spinning) to bring the motor to a screeching halt and (2) an advanced motor control (battery-powered cars use DC serial motors because of their higher torque but which are inefficient when applying anything less than full voltage). The solution I provided was a duty-cycle modulated controller that switches the motor voltage from full on to full off a 1000 times per second while regulating the duty cycle (time on verses time off), a technique with virtually no power loss. He came in gleefully the Monday after, “We beat the competition by two blocks and the media even sent out spies to discover the secret behind this mystery car.”

This is old technology today, but replacing gas-guzzlers with electric cars unfortunately is more wishful thinking than realistic. There are a lot of problems yet to solve and you can’t bend the laws of physics. A major stumbling block is reliable batteries. Batteries right out of the box have less than full capacity. Even the expensive high-tech batteries take months of computer-controlled charge and discharge before they are ready for use. Today’s craze is hybrids – electric/gasoline. But according to J.D. Powers performance tests on the popular hybrids fell well short in meeting manufactures’ advertised specifications. These vehicles are expensive and seldom does anyone mention the fossil fuel expended in charging their batteries.

A number of years ago a story circulated that General Motors had developed a battery-powered car that could go 300 miles between charges. Then GM mysteriously pulled the car causing a ruckus among some celebrities like Ed Bagley, Jr., Martin Sheen, and Tom Hanks who were fortunate enough to have one. It sparked rumors among embittered fans that Big Oil was involved, but these fans never bothered to learn the truth. Indeed GM unveiled the EV1 at the Detroit International Auto Show in 1996. The company never sold it but only leased the cars and then seven years later demanded every EV1 be returned. GM’s Ken Stewart explained that the majority of the least-holders were disappointed by the performance of the EV1 in comparison with their gas-guzzlers. Few people wanted a car that had to be plugged in every hundred miles or so. After ten years and investing over a billion dollars, GM conceded that the EV1 was not ready for the market.

Decades ago the French developed an electric train that could reach 250 MPH. The train was propelled by a motor armature spinning over a “field” track excited by an electrical grid. It’s possible to develop a French-style rail system here for individual travel. The car would be powered by the track for long hauls, but run on its own battery when leaving the track. The problem is that states, lobbied by trucking firms, have laws against electricity for private rail-type transportation. Trolleys of course are public. If government does it, it’s OK.

One transportation solution, says oil-man Pickens, is to convert autos to natural gas (methane), an energy source which is abundantly available in America. If it works it would be significant since transportation represents 70 percent of all U.S. energy consumption. Meanwhile Americas suffer $4 gas while Congress sleeps.

Stumptalk is published weekly in the Crossville Chronicle. The opinions expressed in this column are not necessarily those of the Chronicle publisher, editor or staff. Phil Billington serves as coordinator of this column. He may be reached at 484-2766.