U.S. Trends in SF6 Consumption, Supply and Emissions Reported under the Greenhouse Gas Reporting Program

Stephanie N. Bogle and Deborah OttingerU.S. Environmental Protection Agency

Mollie Averyt and Deborah Harris, ICF

Acknowledgements

§ Neha Vaingankar, ICF International

§ Megha Kedia, ICF International

§ Rebecca Ferenchiak, ICF International

§ Dave Godwin, U.S. EPA

Outline

§ Background• F-GHG characteristics• Use of SF6 in the US• US SF6 emission trends

§ Greenhouse Gas Reporting Program• Background• SF6 emitters and suppliers• Electrical Equipment Use and Manufacture

§ GHGRP requirements and methods§ Emissions and Trends

§ Comparison of US SF6 Consumption and Supply• Methodologies for estimating consumption• Upstream and downstream estimates• Sources of differences

F-GHG Characteristics

Chemical Type GWPs Lifetimes (years) Sources

HFCs

100-15,000 1-240 Air-conditioning/refrig. and other ODS substitute uses

F-GHG production

Electronics

NF3

17,200 500 Electronics production

F-GHG production

SF6

22,800 3,200 Electrical T&D equipment

Electronics

Magnesium production

F-GHG production

PFCs7,000-17,000 2,500-50,000 Electronics production

Aluminum production

F-GHG production

Other Fluorinated GHGs

~ 0.1-10,000 Electronics production

F-GHG production

Uses of SF6

§ SF6 is most potent GHG, with 100-year GWP (AR4) of 22,800 and atmospheric lifetime of 3,200 years

§ Uses include:• Insulator and arc quencher in electrical transmission and distribution equipment

• Source of fluorine for electronics manufacturing

• Cover gas for magnesium production and processing

• Military uses (e.g., AWACs, torpedo propellant)

• Insulator in research and medical accelerators

• Other medical applications

• Tracer gas and others

US Emissions: Sources of SF6

Source: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2017. U.S. Environmental Protection Agency. April 11, 2019. EPA 430-R-19-001.

0

5

10

15

20

25

30

35

1990 1995 2000 2005 2010 2015

MMTC

O2e

Electrical T&D (SF6)

Semiconductor Prod.

Magnesium Prod. & Process

The Greenhouse Gas Reporting Program (GHGRP)

§Annual Reporting Program • For reporting year (RY) 2018, over 8,100 facilities and suppliers reported to the greenhouse gas reporting program.

• Reported direct emissions in RY18 totaled 2.99 billion metric tons carbon dioxide equivalent (CO2e), about half of total U.S. greenhouse gas emissions.

§Reporting threshold of 25,000 metric tons CO2 equivalent (CO2e) or more per year for most sources

§Reports are submitted to EPA electronically via the electronic greenhouse gas reporting tool (e-GGRT)

§Reports go through EPA verification

What’s Reported to GHGRP?

§ SF6 Users/Emitters:• ET&D: Emissions, acquisitions, disbursements of SF6

• Electronics: Emissions• Magnesium: Emissions (= consumption)

§ SF6 Suppliers:• Production• Import• Transformation• Export• Destruction

Draft Deliberative - Do Not Cite or Quote

GHGRP: Electrical Transmission & Distribution Equipment

§ Subpart DD: Electrical Transmission and Distribution Equipment Use

• For electric power systems: Report emissions and related quantities if total nameplate capacity of SF6 and PFC insulated equipment located within the facility, when added to total nameplate capacity not located within the facility but under common ownership or control, exceeds 17,820 pounds (excluding hermetically sealed pressure equipment)

• For electricity generation units (EGUs): Only report subpart DD emissions from SF6 or PFC insulated equipment if the nameplate capacity of equipment located at the EGU facility exceeds 17,820 lbs

§ Subpart SS: Electrical Equipment Manufacture or Refurbishment

• Report emissions and related quantities if total annual purchases of SF6 and PFCs exceed 23,000 pounds.

GHGRP: Electrical Transmission & Distribution Equipment - DD

§Subpart DD – Eq. DD-1

User Emissions = (Decrease in Storage Inventory) + (Acquisitions) – (Disbursements) – (Net increase in Total Nameplate Capacity of Equipment Operated)

• Inventory refers to gas inside containers or non-energized equipment. Under the annual mass-balance approach, the beginning of year inventory for a given year must equal the end of year inventory from the prior year in order for emissions to be estimated properly.

• Gas or nameplate associated with hermetically sealed-pressure equipment must be included in all of the inputs of the mass-balance formula.

GHGRP: Electrical Transmission & Distribution Equipment Manufacturers- SS

§ Subpart SS – Eq. SS-1

User Emissions = (Decrease in Storage Inventory) + (Acquisitions) – (Disbursements)

§Subpart SS – Eq. SS-6

Emissions from Equipment Installation = (Total Mass used to Fill Equipment) + (Total Mass used to charge Equipment Prior to Leaving the Manufacturer Facility) – (Total Nameplate Capacity Installed at Electric T&D

Facility)

• Emissions that occur during installation while filling the equipment off-site from the electrical equipment manufacturing facility must be calculated and reported by the electrical equipment manufacturer under

Subpart SS until the title of the equipment has transferred to the electric power T&D entity.

• Once the title has transferred to the equipment user, the subpart DD facility is responsible for reporting emissions even if third-party conducts installation.

Mass Balance in the Reporting Form

§ For the reporting form to accurately calculate a facility’s emissions, gas needs to be tracked as it moves to a new location (e.g. from the inventory into a piece of equipment) and each is reflected in two tables of the reporting form.

• e.g. acquiring new equipment, installing and/or filling equipment, retiring equipment, etc

§ Example: Equipment is removed from service and the gas is recovered and sent off-site for destruction.

GHGRP Data – Subpart DD

ØReporters in 49 States, DC and Puerto Rico

ØPercentage of US total emissions covered by GHGRP and SF6 Emissions Reduction Partnership: ~68%a

(2017)ØPercentage of US

transmission miles covered: ~67%a (2017)

a Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2017. U.S. Environmental Protection Agency. April 11, 2019. EPA 430-R-19-001.

Latest GHGRP Data

§ Subpart DD: Electrical Equipment Users2011 2012 2013 2014 2015 2016 2017 2018

Number of Reporters 121 122 121 118 105 88 77 84

Emissions (MMTCO2e) 3.89 3.24 3.26 3.18 2.47 2.96 2.52 2.43

Annual Emission Changes -16.8% 0.7% -2.4% -22.3% 19.8% -14.8% -3.5%

Total Emission Changes -16.8% -16.2% -18.2% -36.5% -23.9% -35.42% -37.4%

Avg. Emission Rate* 3.3% 2.5% 2.5% 2.4% 1.9% 2.3% 1.9% 1.6%

Ø Over the eight years of the reporting program, there has been a 37% percent reduction in emissions

Ø 14 facilities left the program after 2014; they accounted for 2.1% of 2014 emissions.Ø 20 additional facilities left the program after 2015; they accounted for 4.8% of

2015 emissions.Ø 13 facilities left the program after 2016; they accounted for 1.9% of 2016 emissions.

*weighted average, based on estimated end of year nameplate capacity

Emissions

Emission Rate

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1.0%

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2011 2012 2013 2014 2015 2016 2017 2018

Emiss

ion ra

te

Emiss

ions (

MMTC

O2e)

Latest GHGRP Data

§ Subpart DD: Electrical Equipment Users

2011 2012 2013 2014 2015 2016 2017 2018

Number of Reporters 121 122 121 118 105 88 77 84

Emissions (MMTCO2e) 3.89 3.24 3.26 3.18 2.47 2.96 2.52 2.43

Avg. Emission Rate* 3.3% 2.5% 2.5% 2.4% 1.9% 2.3% 1.9% 1.6%

Ø Most facilities now have an emission rate of 4% or lower. The highest emission rate in 2018 was 7.1%.

Ø Facilities that left the program after 2015 had an average emission rate of 1.3% (2015); Facilities that left the program after 2016 had an average emission rate of 1.7% (2016).

*weighted average, based on estimate end of year nameplate capacity

0.0%

2.0%

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6.0%

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14.0%

Emiss

ion Ra

te

Emission Rate Per Facility

2011 Emmisions / NC (EOY) 2018 Emmisions / NC (EOY)

Latest GHGRP Data – Nameplate Trends

Nameplate Capacity (Million lbs SF6)

2011 2012 2013 2014 2015 2016 2017 2018

Number of Reporters121 122 121 118 105 88 77 84

Beginning of Year10.7 11.5 12.4 12.9 12.9 12.5 12.6 13.8

New (total) 0.73 0.76 0.96 1.00 0.92 0.80 1.07 0.84

New (herm) NR NR NR NR NR NR 0.37 0.10

New (other) NR NR NR NR NR NR 0.71 0.74

Retired (total) 0.22 0.21 0.20 0.33 0.25 0.20 0.21 0.23

Retired (herm)NR NR NR NR NR NR 0.005 0.01

Retired (other)NR NR NR NR NR NR 0.20 0.21

Ø From 2011 to 2013, total beginning of year nameplate capacity increased by 13.7%Ø Net new nameplate capacity increases on average ~5% per year.Ø In 2017 and 2018, hermetically sealed equipment accounted for, on average, ~3.5% of retired nameplate capacity and 23% of new

nameplate capacity

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6.0%

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9.0%

2011 2012 2013 2014 2015 2016 2017 2018

Percentage of Total Nameplate Added and Retired Each Year

% New % Retired

Latest GHGRP Data

§ Subpart SS: Electrical Equipment Manufacturers2011 2012 2013 2014 2015 2016 2017 2018

Number of Reporters 6 6 6 7 7 7 6 5

Emissions (MMTCO2e)* 0.34 0.17 0.19 0.19 0.15 0.13 0.15 0.16

Annual Emission Changes -50.3% +12.9% -0.6% -22.0% -13.7% +19.2% +5.7%

Total Emission Changes -50.3% -43.9% -44.3% -56.5% -62.5% -55.2% -52.7%

Ø Over the seven years of the reporting program, there has been a 53% percent reduction in emissions. (Subpart SS only)

Ø One facility exited the program after 2016 and second facility exited after 2017; their emissions accounted for less than 6% of total F-GHG emissions in 2016 in Subpart SS.

Ø Combustion emissions were ~6% of emissions from the sector in 2018.

* Non-combustion emissions

0

0.1

0.2

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0.4

2011 2012 2013 2014 2015 2016 2017 2018

Emiss

ions (

MMTC

O2e)

F-GHG Emissions from Manufacture of Electrical Equipment

Inventory QA/QC Check: Comparison of US SF6 Supply and Consumption

§ Comparison of supply and consumption can assist in validating the completeness of the inventory.

§ EPA previously compared the supplies of SF6 reported for 2012 to the consumption of SF6 estimated for 2012 and found that estimated consumption accounted for 59 percent of reported supplies in that year (difference = 630 tons or 14 mmtCO2e).

§ We updated this analysis to determine if this difference still exists for the full timeseries.

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Comparison of Upstream vs. Downstream Consumption Estimates

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Estimate Based on Downstream Reporting: SF6 Emitting Facilities

Estimated based on reports by emitters of SF6

Represents subset of uses, but should account for all consumption by those uses*

Available by industry sector

Estimate Based on Upstream Reporting: Suppliers of SF6

Consumption = gas production + imports - exports -transformation - destruction

May represent subset of suppliers, but reflects all uses

NOT available by industry sector

Estimation Method:

U.S. Coverage:

Level of Detail:

*after estimating emissions of non-reporters

Scope of GHGRP Data

SourceEstimated Percentage of GHGRP GHG Emissions

Coveragea

Users / Emitters

Electronics Manufacturing (Subpart I) 96-97%

Magnesium Production and Processing (Subpart T) 73-89%

Use of Electric Transmission and Distribution (ET&D) Equipment

(Subpart DD)67-74%

Manufacture of Electric Transmission and Distribution (ET&D) Equipment (Subpart SS) ~50%

Suppliers

Importers / Exporters (Subpart OO and QQ) >95%

Production of Fluorinated Gases (Subpart OO) 100%

Percentage of GHG Emissions Accounted for by Facilities Covered by GHGRP By Source Category

a Coverage estimates include both F-GHGs and other GHGs emitted from these sources and show the range in coverage from 2011-2017.

US Consumption › Emissions

§ Consumption > Emissions for some sectors• SF6 is stored in electrical equipment (growing bank)

• SF6 is partially destroyed during electronics manufacturing

§ Magnesium and Elec. Equip. manufacturing: GHGRP SF6 emissions = U.S. SF6 consumption not accounted for by other sectors

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Estimating Consumption by Non-Reporters

§ ET&D: Extrapolate SF6 consumption from reporters to non-reporters based on length of transmission lines

§ Semiconductors: Extrapolate historical SF6 consumption reported by Partners to current U.S. consumption based on index of electronics production (substrate area x number of layers)

§ Magnesium: Use USGS estimates of production and EFs calculated from GHGRP and USGS data.

§ Elec. Equip. manufacturing: Assume GHGRP accounts for 50% of consumption

Draft Deliberative - Do Not Cite or Quote

Improvements to Downstream Consumption Method since 2014

§ Magnesium• Previous estimates overestimated production from non-reporters

§ ETD• Previously estimated consumption by non-reporting facilities based on their estimated emissions, which were based on the

length of their transmission lines (>35kV) • Now estimate consumption based directly on the length of transmission lines.

Consumption by Medium-Voltage Electrical Equipment

§ Investigated possible underestimate of SF6 consumption by low and medium voltage equipment used by non-reporting electric power systems.

• Had used transmission line (>35kV) length to estimate emissions, and from emissions, consumption, by non-reporting electric power systems.

• Is distribution line length (<35kV) a better predictor of emissions/consumption?• Analysis showed that neither transmission nor distribution line length predicted consumption very well.

SF6 Consumption Estimates by Source Category (Metric tons)

Source

U.S. SF6 Consumption Estimate

2011 2012 2013 2014 2015 2016 2017

Electric T&D729 744 827 817 786 693 876

Semiconductor Manufacturing

128 115 120 130 142 137 117Magnesium Production

75 63 56 41 43 49 46

Total 932 922 1003 988 971 879 1040

SF6 Consumption Estimates by Source Category (metric tons)26

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1990 1995 2000 2005 2010 2015 2020

SF6 Consumption by Users (Downstream Method)

Magnesium Production Semiconductor Manufacturing Electric T&D

SF6 Supply Estimates (metric tons)

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Source

U.S. SF6 Supply Estimate

2010 2011 2012 2013 2014 2015 2016 2017

Production, bulk imports, bulk exports810 1500 1500 1200 1300 1100 1100 960

Imports and exports in pre-charged

equipment -11 -11 -9.4 -7.8 -7 -6.1 -5.8 -5.2

Total 799 1489 1491 1192 1293 1094 1094 955

SF6 Supply vs. Consumption (metric tons)

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Method

U.S. SF6 Estimate

2011 2012 2013 2014 2015 2016 2017

Net Supply of SF6

(Upstream Reporting Method) 1489 1491 1192 1293 1094 1094 955SF6 Consumption

(Downstream Reporting Method)932 922 1003 988 971 879 1040

Percent supply

accounted for (downstream/upstream)63% 62% 84% 76% 89% 80% 109%

SF6 Supply vs. Consumption (metric tons)29

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2011 2012 2013 2014 2015 2016 2017

SF6

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Net Supply of SF6 (Upstream Reporting Method)SF6 Consumption by Users (Downstream Reporting Method)

SF6 Supply vs. Consumption (metric tons) Supply Estimated as Rolling Average

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SF6 Consumption by Users (Downstream Reporting Method)3-year Rolling Average of Net Supply of SF6

Uncertainties in Scaling Emissions31

Source CategoryU.S. SF6 Emission

EstimatesU.S. SF6 Consumption Estimate

Uncertainty of Consumption Estimate

Upper Bound %Magnesium Production 46 46 50 7%Semiconductor Manufacturing 32 117 139 18%Electric T&D 188 876 974 11%Total and upper bound consumption based on error propagation 267 1040 1129 9%

Potential Reasons for Inconsistency

§ Uncertainties in upstream method• Import and export reporting is threshold based

• Possible errors in reporting• Growing or declining stockpiles• Do not report sales of recycled SF6

§ Uncertainties in downstream method• Uncertainties in scaling consumption to national level• Uncertainties in trends over time (Semiconductors)• Possible underreporting by facilities• Some uses of SF6 are not captured

For Additional Information

§ For information on the GHGRP: https://www.epa.gov/ghgreporting• Information and resources for reporting facilities

§ https://www.ccdsupport.com/confluence/display/faq/FAQs

• View and/or download the latest GHGRP Data

§ Envirofacts

§ Facility Level Information on GHGs Tool (FLIGHT)

§ 2017 Data Highlights

§ Industrial Profiles

§ For Information on the 2019 Inventory of US Greenhouse Gas Emissions and Sinks: https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks

§ Contact: Stephanie Bogle (bogle.stephanie@epa.gov)