Impacts of plug-in hybrid vehicles and grid generation mix on emissions in the South Coast Air Basin

The transportation sector is the number one consumer of energy and the principal source of CO2 greenhouse gas emissions in the world. Together with electricity generation, the two sectors are responsible for more than half of greenhouse gas (GHG) emissions. The introduction of plug-in hybrid vehicles (PHEVs) will impact both sectors. Tail-pipe emissions of GHG and criteria pollutants will be transferred to electricity generating units (EGU). To study the net impact of PHEVs on emissions, a grid dispatch model is developed and applied in this research for various PHEV penetrations, mix of EGUs, and charging scenarios. The state of California South Coast Air Basin (SoCAB) is selected as the region of focus.The Western electrical grid serving the SoCAB is modeled with both spatial and temporal resolution at the individual power plant level. Electricity load is calculated and projected for future years, and the temporal electricity generation of each power plant within the SoCAB is modeled based on historical data and knowledge of electricity generation and dispatch.Due to the efficiency and pollutant controls governing the performance of the Western Grid, PHEV deployment results in a reduction in GHGs and an improvement in air quality. The extent of improvement depends on the time of day and charging scenario. In addition, charging PHEVs using wind energy that would otherwise be curtailed can result in a substantial emissions reduction. Smart control will be required to manage PHEV charging.