Just what effect could widespread use of plug-in hybrid electric vehicles have on emission levels? Researchers at the University of Colorado, Boulder and the National Renewable Energy Laboratory believe they have the answer.
They modelled the impact of plug-in hybrid electric vehicles replacing light duty petrol vehicles in the Denver, Colorado, area since the summer of 2006 – Denver currently violates federal air quality standards for ozone and is home to several large electricity generating units.
The impact was assessed under a wide range of meteorological conditions and modelled a single urban area with a finer grid resolution than has been considered in previous studies.
So what of the results?
According to the study, published in the ACS journal Environmental Science and Technology, with 100 per cent plug-in hybrid electric vehicle penetration, nitrogen oxides would have been reduced by 27 tons per day from a fleet of 1.7million vehicles and would have increased by three tons per day from power plants. Meanwhile VOC emissions would have been cut by 57 tons per day.
The emission changes reduced modelled peak eight hour ozone concentrations by approximately two-three ppb on most days.
