The electrical equipment manufacturers and use sector emits sulfur hexafluoride (SF6) and perfluorocarbons (PFCs) from the manufacture, refurbishment, and use of electric transmission and distribution equipment. SF6 and PFCs are used as electrical insulators and interrupters in electricity transmission and distribution equipment. The reported emissions from this sector decreased from 4.3 million metric tons of carbon dioxide equivalents (MMT CO2e) in 2011 to 2.3 MMT CO2e in 2020, a decrease of nearly 47 percent. The emissions have varied from a high of 4.3 MMT CO2e in 2011 to a low of 2.3 MMT CO2e in 2020. The decrease in emissions observed for this sector since 2011 is likely driven by electric utilities replacing leaking equipment and improving SF6 handling practices. [1]
About 90 percent of the emissions for this sector come from the use of electric transmission and distribution equipment, rather than from equipment manufacturing and refurbishment. The emissions originate from fugitive equipment leaks; equipment installation, servicing, decommissioning and disposal; and storage cylinders. Although PFCs and other fluorinated F-GHGs may also be used, SF6 is emitted in the highest volumes.
The emissions for the sector decreased by 0.41 MMT CO2e (15 percent) in 2020 compared to 2019, due to a 0.51 MMT CO2e (20 percent) decrease in emissions from the use of electric transmission and distribution equipment. Emissions from equipment manufacture and refurbishment increased in 2020 by about 0.1 MMT CO2e, continuing a trend of increasing emissions for this subsector observed since 2016. The emissions for electrical utilities decreased in 2020 despite small increases in the number of transmission miles and nameplate capacity. However, the number of new units installed and number of old units retired decreased. In 2020, only 7,438 new units that were not hermetically sealed were installed (1,806 less than 2019) and 2,479 old units that were not hermetically sealed were retired (6,225 less than in 2019).
Although emissions from equipment manufacture and refurbishment increased in 2020, only one of the five facilities reported higher emissions.
[1] Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2018. U.S. Environmental Protection Agency. April 12, 2018, page 4-135. EPA 430-R-20-002. Available at: https://www.epa.gov/sites/production/files/2020-04/documents/us-ghg-inventory-2020-main-text.pdf.