Volume 20, Issue 1, 1995 March/April 1995

How Clean are Electric Cars?

by Harold Garabedian

In moving to electrically powered vehicles are we just trading one source of pollution for another? No, electric vehicles (EVs) do not have tailpipes and do not emit toxic and noxious air pollutants directly into the breathing zone of humans. Further, one is not exposed to toxic and cancer-causing vapors while refueling vehicles at gasoline stations. Electric vehicles do not require oil changes so they do not generate waste crankcase oil and used oil filters. They do not have cooling systems, nor do they have exhaust systems. So there are no antifreeze, mufflers and catalytic convertors to get rid of.

But what about the pollution that might be created by generating the electricity? One of the advantages of the electric vehicle is that it doesn't care how the electricity was created. Electricity can be generated with conventional fuels in thermal electric plants, or by renewable forms of energy such as hydroelectric, biomass, wind or solar. There are issues with each of these sources that need to be addressed, but EVs provide choices that gasoline powered vehicles do not. In addition, major sources of energy for making electricity are generally more secure and available in North America. This is important as we consider our dependency on imported oil and that many sources are in insecure parts of the world.

The Solectria Force is operated by EVermont, a consortium whose mission is to demonstrate the performance of electric vehicle technology. The vehicle has averaged an energy consumption rate of 0.17 kilowatt-hours per mile. Accounting for losses of converting thermal energy to electricity and line losses for distribution, this is equivalent to better than 3.3 liters per 100 kilometers (80 miles per U.S. gallon).

So how clean are electric vehicles? Well, it depends on how the electricity is made. If it comes from wind, solar or hydro, the air pollution would be zero. If the electricity comes from a plant burning conventional fossil fuel, EVs are expected to emit 40 percent to 70 percent less nitrogen oxides and more than 90 percent less hydrocarbons to the atmosphere. Therefore, electric vehicles could make a meaningful contribution to applying a zero discharge philosophy to the transportation sector.

Revised: April 8, 1997
Maintained by Kevin McGunagle, mcgunaglek@ijc.wincom.net