1. SF6 Management Challenges Version 2016 & Beyond
Lukas Rothlisberger
CEO
DILO Company, Inc.

2. Topics of Discussion General Info / Current GHG Reporting Legislation
Identifying Major SF6 Management Challenges
Emission Types
Tracking Problems
SF6 Alternatives

3. General Information – SF6 Properties
Manmade
Colorless / Odorless
Inert
Non Flammable / Non Toxic / Non Poisonous
Unmatched Dielectric Strength / Arc Quenching Capabilities
Great Thermal Stability / Heat Trapping
Re-Association / Self-Healing After Arcing Event

4. General Info – GWP – Global Warming Potential

5. SF6 – The Most Potent & Highly Persistent GHG
Relatively few uses
Electric power equipment – high voltage transmission and distribution pressurized equipment
Electronics manufacture – etching silicon wafers
Primary magnesium production – inert cover gas
Miscellaneous low-volume applications (tracer gas, medical applications, insulator in accelerators, AWACs)
Relatively small emissions
Less than 1% total US annual GHG emissions
Worst of the worst greenhouse gas
22,800 greater heat trapping capacity than CO2 over 100yrs “GWP100”
1 lb. SF6 = 22,800 lbs. CO2
Highly inert - 3,200 atm. lifetime

6. GHG Pollution By Sector and Gas Type

7. SF6 Equipment Lifecycle Emissions
Emission Sources – mostly inadvertent
Equipment Production
Installation
Servicing
Operation – intermittent leaks
Decommissioning – venting discouraged but not banned
Reduction strategies – best handling and management
Leak Detection and Repair
Recovery/Recycling
Employee Education/Training
Track emissions

8. US SF6 Emission Reduction Drivers
EPA
Voluntary SF6 Emission Reduction Partnership for Electric Power Systems
Emissions vary from <1% to over 12%; avg. 2.4% rate
Greenhouse Gas Reporting Program
Large emission sources only
No mandatory emission reduction requirements planned
State Regulation – 1% emission rate by 2020
2012 – California emission standards
2013 – Massachusetts emission standards

9. SF6 Environmental Regulation – US EPA
Mandatory Greenhouse Gas Reporting Rule (40 CFR Part 98) Subpart DD (Users of Electrical Equipment) and Subpart SS (OEM’s)
US EPA Requires SF6 users with at least 17,820 lbs. SF6 Nameplate capacity to report emissions annually

10. GHG Pollution Shaming http://GHGdata.epa.gov/ghgp/main.do
EPA data publication tool allows stakeholders and the public to access the key data elements and to sort data by location, sector, and by gas.
2014 data now available

11. Environmental Reg.’s – CA Air Resources Board (CARB)
Established annual emission rate of 10% compared to nameplate capacity
Requires GIE owners to reduce annual emission rate by 1% per year over a ten year period
Beginning 2020 sets max emission rate not to exceed 1%
Massachusetts passed similar Reg. starting 2013

12. Reported Emissions Actual / Hard Emissions Leakage from GIE
Handling Emissions
Tracking Emissions
Recordkeeping Inaccuracies
Nameplate Issues
Nameplate Discrepancies
Nameplate Inaccuracies

13. Major Challenges for SF6 Users
Additional reporting requirements
Operational / Procedural
Inexperience / Infrequent SF6 handling
Handling / Measuring equipment
Missing info on work orders
Tracking / SF6 Management
Nameplate issues
Data transfer not in real time
Patchwork of different customized programs and Excel spreadsheets to monitor inventories and emissions
Disconnect between E&H and field personnel
Cylinder tracking / Multiple entry points for cylinders

14. Real World SF6 Emission Tracking Problems
4/14/2016 – Substation personnel removes SF6 from GIE containing 340 lbs per nameplate. Upon completion, 245 lbs. is stored in cylinders.
5/10/2016 – Environmental questions discrepancy – Substation personnel blames inaccurate nameplate
Problems & Possible Errors:
Long delay between work being performed and records being updated
Density was not checked/recorded prior to gas recovery
Recovery blank-off pressure unknown – incomplete recovery
Residual SF6 in recovery system not accounted for
Weighing inaccuracies (weight scale and/or cylinder TW)
SF6 emission on the pressure side of equipment (i.e. recovery system/hose leak)
Nameplate Inaccuracy
All of the above

15. Eliminating SF6 Recovery Emissions

16. Impact of Blank-off Pressure on SF6 Recovery
GIE containing PSIG
Recovery to 0 PSIG / 760 Torr lbs removed / 60 lbs lost
Recovery to 200 Torr lbs removed / 14 lbs lost
Recovery to 50 Torr lbs removed / 3 lbs lost
Recovery to 5 Torr lbs removed / 0.3 lbs lost
Personnel recovering should be instructed to always reach a blank-off pressure of 5 Torr / for GIE containing < 50 lbs 35 Torr

17. Step by Step SF6 Recovery – Verifying Nameplate
Verify Temperature/Pressure for proper density
Any deviation in pressure will result in nameplate discrepancy
Recover to < 5 Torr (< 35 Torr for GIE containing < 50 lbs)
Difference in recovered SF6 not measurable in GIE containing < 50 lbs
Use calibrated mass flow scale or weight scale
Mass flow scale preferred as it eliminates cylinder TW inaccuracies
If using weight scale verify that residual SF6 has been removed from recovery system
Document blank-off pressure

18. Real World SF6 Emission Tracking Problems
Sample Utility - Equipment Owned
CB Nameplate 100 lbs.
TOTAL NAMEPLATE lbs.
Cylinder A Empty
Cylinder B lbs.
TOTAL SF6 IN SYSTEM lbs.

19. Real World SF6 Emission Tracking Problems
Calendar Year SF6 related work to be performed
2016 CB1 to be maintained
2017 CB1 to be decommissioned
2016 CB1 maintenance
Recovered 100 lbs. from CB1 and stored in Cylinder A
Filled CB1 from Cylinder B – it required 115 lbs. to get to proper density

20. Small Errors = Potentially Huge Impact
What went wrong during SF6 Recovery?
Temperature/Pressure was not checked prior to SF6 Recovery
Personnel unaware of remaining SF6 in Recovery System
Incomplete recovery
Nothing
How could this have been avoided?
Real Time Tracking System immediately alerts to discrepancies
Utilizing mass flow scale
Better understanding of SF6 Recovery System (Training)
What went wrong filling CB 1?
Nothing (assuming CB1 was filled to proper density) 
Why does any of this matter?

21. Status 12/31/16 Sample Utility - Equipment Owned
CB Nameplate 100 lbs. / Real 115
TOTAL NAMEPLATE lbs.
Cylinder A
Cylinder B Empty
TOTAL SF6 IN SYSTEM lbs.

22. How is this event reported?
User Emission = (Decrease in storage inventory) + (Acquisitions) – (Disbursements) – (Net increase in total nameplate capacity of equipment operated)
Calculating without nameplate adjustment:
(15) + (0) – (0) – (0) = 15 lbs. Emission
Calculating with nameplate adjustment:
(15) + (0) – (0) – (15) = 0 lbs. Emission
USEPA Currently does NOT allow nameplate adjustments at time of maintenance for the purpose of calculating emissions, but requires this at decommissioning and to calculate emission rate
CARB allows nameplate adjustments if confirmed by OEM

23. (-115) + (0) – (0) – (-100) = 15 lbs. (negative emission)
2017 CB 1 decommissioned – How is this reported?
Without nameplate adjustment in 2016
Status 1/1/ Status 12/31/2017
CB lbs. Decommissioned
Cylinder A 100 lbs lbs.
Cylinder B Empty lbs.
(-115) + (0) – (0) – (-100) = 15 lbs. (negative emission)

24. (-115) + (0) – (0) – (-115) = 0 lbs. emission
2017 CB 1 decommissioned – How is this reported?
With nameplate adjustment in 2016
Status 1/1/ Status 12/31/2017
CB lbs. Decommissioned
Cylinder A 100 lbs lbs.
Cylinder B Empty lbs.
(-115) + (0) – (0) – (-115) = 0 lbs. emission

25. How much SF6 did Sample Utility release in this time period?
Comparing 1/1/2016 with 12/31/2017
Status 1/1/ Status 12/31/2017
CB lbs. CB1 decommissioned
Cylinder A Empty Cylinder A lbs.
Cylinder B 115 lbs. Cylinder B lbs.
TOTAL 215 lbs lbs.
How much SF6 did Sample Utility release in this time period?
Following EPA’s reporting rule, Sample Utility shows a 15 lbs. emission for 2016, and 0 emission for 2017
Following CARB’s reporting rule, Sample Utility shows either a 15 lbs. emission for 2016 and a negative 15 lbs. emission for 2017, or a 0 emission for both years.

26. Necessary Changes to Minimize SF6 Emission Tracking Problems
Tracking should be in real-time
Will immediately alert personnel of potential problem (Incomplete recovery, nameplate issues, weighing issues)
Improve work instructions
Field personnel needs detailed specs as opposed to “Remove SF6 from GIE”
A) Check and record temperature/density
Will immediately identify possible discrepancy with nameplate info
B) Stop recovery only after achieving blank-off pressure < 10 Torr
C) Record blank-off pressure
Will eliminate recovery emission and can be used to document nameplate inaccuracy
Utilize highest accuracy weighing tools
Use mass flow scales whenever possible
Will eliminate discrepancies due to incorrect cylinder TW and residual SF6 remaining in recovery equipment and hoses

27. EPA SF6 Partnership Emission Rates

28. Subpart DD – Use of Electric Power Equipment
2011
2012
2013
Total # Reporters
110
114
108
Total Emissions* (MMTCO2)
3.5
4.0
3.3
Electric power systems with a total nameplate capacity of SF6 and PFCs containing equipment exceeding 17,820 lbs.
Several systems with emissions over 200,000 MTCO2e
Note: EPA data now reported using IPCC 4th Assessment GWP100 values - SF6 = 22,900

29. EPA SF6 Partnership Emission Rates
EPA Partnership Utilities showing much lower emission rates
Domestic usage has increased
Atmospheric concentration of SF6 raising faster than expected
Possible Emission Sources
SF6 used for other applications
Actual emissions by partners higher than reported
Anecdotal Evidence suggests a lot of GIE being slightly over-filled
Entities not reporting have higher emissions as estimated (miles of transmission lines)
Too much virgin SF6 being purchased vs using recycled SF6

30. Virgin vs Recycled SF6 Why use recycled SF6?
Recycled SF6 works just as well – even in new GIE – provided it meets purity standards established by CIGRE / IEEE / IEC
What if OEM requires virgin SF6?
Ask to talk to somebody else
Provide comparative test result (GIE filled with virgin vs recycled SF6)
Substantially lower cost
Lowers our domestic carbon footprint
Keeps government / regulators from demanding use of alternative gases

31. Alternative Gases

32. Alternative Dielectric Gases vs SF6
Alternative Gases currently tested cannot be used in existing GIE
Do not have the ideal characteristics (Arc quenching AND dielectric) compared to SF6
More difficult to handle / on-site mixing requirements
Multiple alternatives are currently being tested by different OEM’s
Cost
Require different handling and test equipment
Much lower GWP
Only benefit of alternative gases currently tested is the much lower GWP

33. Alternative Gases vs SF6 – Future Developments
Environmental Regulators extremely interested in alternatives to SF6
Collectively (GIE OEM’s / Recyclers / Service Providers / Users) our industry needs to do a better job eliminating SF6 emissions – including Phantom Emissions
Ensures that a potential switch to alternative gases will be decided by the market (i.e. SF6 Users / Electric Utilities) based on a number of factors (Economics / Ease of handling AND environmental impact) and NOT simply due to environmental regulations

34. Lessons Learned
Despite most low hanging (GIE with known large leaks replaced or repaired) fruit picked, most utilities still report emission rates > 1%
Anecdotal evidence suggests > 90% of GIE currently installed contains a different amount of SF6 (deviation > 1%) compared to nameplate
Accidental SF6 emissions due to personnel not understanding residual pressure / blank-off pressure still extremely common
Entities routinely report “Phantom Emissions” due to tracking problems
Entities reporting should immediately establish TMM (True Mass Monitoring) for all their GIE
True Mass Monitoring = Measuring and recording the SF6 weight (Mass) for every gas event with 1% or better accuracy for the complete life-cycle of the GIE.

35. Thank you for your attention!
Lukas Rothlisberger
CEO
DILO Company, Inc.