# Data Sources and Assumptions for the Electricity Sources and Emissions Tool

The following data sources and assumptions were used to calculate the emissions, fuel use, and electricity sources for conventional and electric-drive vehicles in the Electricity Sources and Emissions Tool.

## Electricity Sources

These assumptions were used to show electricity sources.

Parameter | Value | Unit | Year | Source |
---|---|---|---|---|

Electricity fuel mix | varies by state | thousand MWh | 2021 | U.S. Energy Information Administration's Open Data API for Electricity Net Generation |

## Annual Vehicle Emissions

These assumptions were used to calculate the annual vehicle emissions for an average conventional, hybrid electric, plug-in hybrid electric, and all-electric vehicle.

Parameter | Value | Unit | Year | Source |
---|---|---|---|---|

Gasoline emissions | 23.7 | lbs. CO_{2}e/gal |
2019 | Well-to-wheels greenhouse gas emissions factor derived from Argonne National Laboratory's GREET model |

ICE gasoline efficiency | 21.79 | mi/gal | 2019 | Weighted average of projected vehicle sales from EPA Automotive Trends Report and mpg from the Fuel Economy Guide |

HEV gasoline efficiency | 39.78 | mi/gal | 2019 | Weighted average of vehicle sales from U.S. HEV Sales by Model and mpg from the Fuel Economy Guide |

PHEV gasoline efficiency | 40.80 | mi/gal | 2019 | Weighted average of vehicle sales from U.S. Plug-in Electric Vehicle Sales by Model and mpg from the Fuel Economy Guide |

PHEV electric efficiency | 3.03 | mi/kWh | ||

PHEV electric range | 27.74 | miles | ||

BEV electric efficiency | 3.60 | mi/kWh | ||

PHEV % electric VMT | 56.3 | % VMT | 2010 | SAE J2841, Appendix B, MDIUF based on PHEV electric range |

Average annual VMT | 11,579 | miles | 2019 | Oak Ridge National Laboratory's Transportation Energy Data Book Edition 39, Table 4.3 |

Emissions from electric power | varies by state | million metric tons CO_{2}e |
2021 | U.S. Energy Information Administration's Electric Power Annual |

Energy generated from electric power | varies by state | thousand MWh |

### Average Emissions from Generated Electricity

The following equation is used to calculate average emissions from generated electricity at the state and national level:

$$\frac{{\mathrm{X\; million\; metric\; tons\; CO}}_{2}e}{\mathrm{Y\; thousand\; MWh}}x\frac{\mathrm{2,204.623}\mathrm{lbs.}}{1\mathrm{metric\; ton}}x\frac{1\mathrm{MWh}}{\mathrm{1,000}\mathrm{kWh}}=\frac{{\mathrm{Z\; lbs.\; CO}}_{2}e}{1\mathrm{kWh}}$$ $$\mathrm{X}=\mathrm{Emissions\; from\; electric\; power}$$ $$\mathrm{Y}=\mathrm{Energy\; generated\; from\; electric\; power}$$ $$\mathrm{Z}=\mathrm{Average\; emissions\; from\; generated\; electricity}$$The result of this equation is used to calculate annual vehicle emissions for BEVs and PHEVs.

### All-Electric Vehicle Emissions

The following equation is used to calculate emissions for all-electric vehicles (EVs) also called battery electric vehicles (BEVs):

$$\mathrm{11,579}\mathrm{mi}x\frac{1\mathrm{kWh}}{3.60\mathrm{mi}}x\frac{{\mathrm{Z\; lbs.\; CO}}_{2}e}{1\mathrm{kWh}}$$### Plug-In Hybrid Electric Vehicle Emissions

The following equation is used to calculate emissions for plug-in hybrid electric vehicles (PHEVs):

$$\left(\mathrm{11,579}\mathrm{mi}x\frac{56.3}{100}x\frac{1\mathrm{kWh}}{3.03\mathrm{mi}}x\frac{{\mathrm{Z\; lbs.\; CO}}_{2}e}{1\mathrm{kWh}}\right)+\left(\mathrm{11,579}\mathrm{mi}x\frac{43.7}{100}x\frac{1\mathrm{gal}}{40.80\mathrm{mi}}x\frac{23.7{\mathrm{lbs.\; CO}}_{2}e}{1\mathrm{gal}}\right)$$### Hybrid Electric Vehicle Emissions

The following equation is used to calculate emissions for hybrid electric vehicles (HEVs):

$$\mathrm{11,579}\mathrm{mi}x\frac{1\mathrm{gal}}{39.78\mathrm{mi}}x\frac{23.7{\mathrm{lbs.\; CO}}_{2}e}{1\mathrm{gal}}=\mathrm{6,898}{\mathrm{lbs.\; CO}}_{2}e$$### Gasoline Vehicle Emissions

The following equation is used to calculate emissions for gasoline vehicles also called internal combustion engine (ICE) vehicles:

$$\mathrm{11,579}\mathrm{mi}x\frac{1\mathrm{gal}}{21.79\mathrm{mi}}x\frac{23.7{\mathrm{lbs.\; CO}}_{2}e}{1\mathrm{gal}}=\mathrm{12,594}{\mathrm{lbs.\; CO}}_{2}e$$