Energy Resources for State and Local Governments

Avoided Emission Factors Generated from AVERT

AVERT Emission Factor Version History

Release date	Key changes
July 31, 2017	Original release, containing emission factors from 2007 through 2016. Emission factors calculated using a default displacement of 5% of each region’s fossil generation.
May 30, 2018	Added emission factors for 2017. Revised all emission factors to reflect a default displacement of 0.5% of each region’s fossil generation. Added contextual information about capacity factors and emissions accounting and claims.
June 1, 2018	Corrected a minor methodological issue that arose when generating the 2017 emission factors.
May 30, 2019	Added 2018 emission factors and revised all years to reflect year-specific transmission and distribution line loss factors generated by the Energy Information Administration (EIA).
September 15, 2020	Added emission factors for offshore wind and distributed solar photovoltaic. Revised with emission factors for 2017–2019 using the new AVERT regions associated with AVERT v3.0.

AVERT uses a peer-reviewed methodology to analyze electric power sector impacts on an hour-by-hour basis, but it can also produce average emission factors for each AVERT region. EPA has used AVERT to produce marginal emission factors for each AVERT region and a weighted average for the nation each year from 2007 to 2019. These emission factors can be used for quick estimates of avoided NO_x, SO₂, CO₂, and PM_2.5 emissions and are divided into six categories: onshore wind, offshore wind, rooftop-scale photovoltaic, utility-scale photovoltaic, portfolio energy efficiency, and uniform energy efficiency.

On June 1, 2018, EPA updated AVERT-generated emission factors to represent a more commonly used EE/RE scenario. They now reflect a 0.5% displacement of the existing regional demand. On May 30, 2019, EPA added 2018 emission factors and revised all years to reflect year-specific transmission and distribution line loss factors (where appropriate) from the U.S. Energy Information Administration. On September 15, 2020, EPA added 2019 emission factors and revised 2017 and 2018 emission factors to reflect the new regions in AVERT v3.0. You can download the emission factors in Excel format below.