# Data Sources and Assumptions for the Electricity Sources and Fuel-Cycle 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 Fuel-Cycle 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:

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