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. CO2e/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 CO2e 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:

X million metric tons CO2 e Y thousand MWh x 2,204.623  lbs. 1  metric ton x 1  MWh 1,000  kWh = Z lbs. CO2 e 1  kWh X = Emissions from electric power Y = Energy generated from electric power Z = 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):

11,579 mi x 1  kWh 3.60  mi x Z lbs. CO2 e 1  kWh

Plug-In Hybrid Electric Vehicle Emissions

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

11,579 mi x 56.3 100 x 1  kWh 3.03  mi x Z lbs. CO2 e 1  kWh + 11,579 mi x 43.7 100 x 1  gal 40.80  mi x 23.7  lbs. CO2 e 1  gal

Hybrid Electric Vehicle Emissions

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

11,579 mi x 1  gal 39.78  mi x 23.7  lbs. CO2 e 1  gal = 6,898  lbs. CO2 e

Gasoline Vehicle Emissions

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

11,579 mi x 1  gal 21.79  mi x 23.7  lbs. CO2 e 1  gal = 12,594  lbs. CO2 e