What oil savings will PHEVs provide?
A PHEV environmental analysis calculates air pollutants from gasoline consumption and electrical generation and is called a well-to-wheel analysis. Numerous factors can increase or decrease the pollution estimates, including fuel efficiencies of PHEVs and time of day for charging. A basic assumption for an environmental analysis of PHEVs is that the majority of charging is done off peak. In September 2006, the American Council for an Energy Efficient Economy released a study on PHEVs that included an assessment of environmental impacts.16 They used projections by the US Energy Information Agency’s National Energy Modeling System to determine the mix of electric generation sources over time including the Western States Coordinating Council/Northwest Power Pool Area (WSCC-NPP). Based on the ACEEE study, a PHEV 40 operating under a 2005 Northwest power generation mix, would reduce CO2 emissions by 55% over today’s hybrid [2006 Toyota Prius hybrid]. This compares to a 15% reduction of CO2
