Quantifying the benefits of hybrid vehicles

Motor vehicles are a core technology of our modern life and economy. But motor vehicles, motor fuels, and the road system unfortunately pollute our air, soil and water, depend on limited oil supplies and are implicated in warming the earth’s climate. In response, some car companies have introduced the biggest change in automotive technology since early in the last century. Hybrid electric vehicles (HEVs) reduce emissions and fuel use through increased fuel economy. So far, full-HEV technology has been used to reduce automotive fuel use by up to 40% and reduce emissions to meet California’s (and thus, the nation’s) most stringent air quality standards. The following study measures such benefits. Americans are currently buying over 20,000 HEVs per month; one model, the Toyota Prius has reached sales volumes of over 100,000 units per year. However, total HEV sales are still small compared to annual sales of all vehicles and the total number of vehicles on the road. HEVs account for about 1.6% of the annual US market of 17 million new light-duty vehicles, and only 0.2% of the total US fleet of 230 million light-duty vehicles. The numbers of makes and models offered as HEVs are small, and sales are just getting started. To spread hybrid technologies across the entire market, and replace most vehicles on the road will take decades. Still, HEVs are making an impact beyond their incipient number, primarily by being the first “green” cars on the market and setting a standard of achievement for high fuel economy and low emissions. HEV sales and their halo effect on Toyota and Honda have spurred a contest between automobile makers to supply the latest high-tech, clean, and green technologies. In the California market, hybrids account for 3% of total new light duty vehicles sales, and hybrid sales growth outpaces that of conventional models (Automotive News Data). If this contest is noticed by more car and truck buyers, it may well transform the automotive market, accelerating the introduction of alternative fuels and other electric drive technologies such as plug-in HEVs and full electric vehicles to market. In the following sections, we review the problems motor vehicles cause, then describe the varieties of hybrid technologies. Then we analyze what difference HEVs are making right now and can make in the future for our air, water, security, and climate.