[This article was written by Bonne W. Posma, who can be reached at Saminco Inc., 10030 Amberwood Road, Fort Myers, FL 33913.] In early 1996, GM announced that its first production electric car, the 2-passenger EVI (formerly called the Impact) would go on sale during the fall of 1996.
Priced at about $35,000, the car's curb weight is 3,000 lbs, including a 320V battery weighing almost 1200 lbs - 40% of the vehicle's weight. The EVI's specifications claim a range of 70-90 miles per charge, requiring 3 hours to charge the battery from a 220V, single phase supply. Initially, the car will only be sold in southwestern states where "the climate is most favorable for EV operation,'' that is, where no energy-hungry heaters will be required.
GM is not claiming that the EVI will be a substitute for all gasoline-powered vehicles, and the car will most likely sell to well-heeled electric car enthusiasts who require a second car for short-range city driving.
Most battery-powered electric vehicle programs have been prompted by California's ill-considered "Zero Emission'' laws (now modified), which mandate that 2% of all vehicles sold in 1998 produce no emissions. Without this coercion and generous tax rebates, it is unlikely that an expensive, heavy car, with a short driving range, requiring 3 hours to recharge, would have ever been developed.
The EVI's biggest problem is its energy source - the 320V battery, which has a rather small energy content of only 16.2 kWh (kilowatt hours). The EVI's electric drive converts about 90% of this energy (14.6 kWh) into the mechanical energy which propels the vehicle.
In comparison, one gallon of gasoline contains 45 kWh of energy, of which about 25%, or 11 kWh, is converted into useful mechanical energy, given the same driving conditions for which the EVI's battery energy content is rated. The rest of this energy is converted to heat (34 kWh), and some of this heat is used to heat the gasoline vehicle's interior during cold weather conditions (see Figure 1).
Today's average car's tank contains between 1.5 to 2.5 gallons when its fuel gauge reads "EMPTY,'' and the EVI, with its battery fully charged, does not have much greater range than that of an ordinary car when "driving on empty.''
There are two other points worth noting:
During 1890 to 1900, a number of electric cars were produced, of which the Riker Electric Victoria (Figure 2) was one of the better designs. It was powered by a 40 cell, 80V lead-acid battery, weighing 800 lbs, which had an energy density of 10 Wh/lb (watt hours per pound), compared to 13.5 Wh/lb for the EVI's battery. It is obvious that the lead acid battery has not improved much over the past 100 years.
Second, suppose that, miraculously, a battery was invented which had the same usable energy content as that contained in a typical car's 16-gallon fuel tank (about 180 kWh), and which could also be recharged in the same time that it would take to fill up this fuel tank. A gas station's pump delivers fuel at about 4 gallons/minute, so it would take 4 minutes to fill up the tank. Now let's assume that this 180 kWh battery could also be recharged in 4 minutes. The rate of energy delivery, or power output, would then be (180 kWh)/4 minutes = (180)(3600) kWh/(4)(60) seconds = 2,700 kW or 2.7 MW (2.7 megawatts). < /FONT >
Suppose that, in a city of 5,000,000 people, 2,000 cars were refueling during peak refueling hours (based on 400 cars/million). This would require an electric power system capable of providing the enormous amount of (2,000)(2.7) MW = 5,400 MW of extra generating capacity.< /FONT >
Considering that a medium-sized power plant is capable of generating about 500 MW, a total switchover to electric cars would require the construction of about 11 extra power plants for each one of our larger metropolitan areas - a situation clearly not anticipated by the advocates of battery-powered electric vehicles!
The beautiful, sleek EVI contains some of the finest 20th Century electric propulsion technology, married to a cumbersome, obsolete 19th century energy source. The EVI represents a shotgun marriage, doomed to fail, forced on us by elitist bureaucrats. It is sad that, when promising alternative electrical energy sources such as fuel cells or cold-fusion generators become economically feasible, the general public may well be soured on electric vehicles, delaying the widespread use of this technology.
Ed note: Referencing
History of the Electric Automobile by E. Wakefield, p 43, Bonne Posma, a specialist in electric traction drives, points out that successive improvements in lead acid batteries led to energy densities of 3.7 Wh/lb in 1859, 5.7 Wh/lb in 1881, 10.8 Wh/lb in 1888, and 13.5 Wh/lb in 1995.Generating pollution-free power for their electric cars will, of course, lead the enviros to advocate nuclear power. Right? Wrong, because most of them are actually antitechnologists in enviro trappings.
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Vol. 23, No. 9
Newsletter: Access to Energy Newsletter Archive Volume: Issues Issue/No.: Vol. 23, No. 9 Date: May 01, 1996 03:17 PM Title: Correlation and Causality
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