The 2008 SGS Transmission Reliability
Benchmarking Study
The SGS Study has set the standard for benchmarking
transmission reliability since 1995.  The SGS Study utilizes 5+
years of raw transmission circuit outage data and applies
common rules to all systems to insure the highest integrity of
analysis and comparisons.

The SGS Study is the largest comparison forum for electric
transmission in the world.

Features of the SGS Study:

DELIVERABLES:  A 300+ page Study binder, customized company-
specific Summary (30+ pages) and NERC TADS Supplement, electronic
data files and a 2 day participant conference (deliverables, CD).

NEW in 2008:  NERC TADS PERFORMANCE METRICS:  The Study  
adds a complete new section utilizing 12 of the 16 NERC TADS metrics
(Transmission Availability Data System) for AC transmission lines, which
were defined in 2007.  Mandatory NERC TADS reporting for Bulk Power
systems took effect in January 2008, with the first annual reports due in
Q3-2009.  The SGS Study provides participants with over a year in
advance preview!

SIZE:    The 2008 SGS Study has 30 participating systems and
representing more assets than 2007.  In 2007, participating systems had
the following circuit totals:








2007 participants had approximately 480,645 MW peak transmission
load, serving an estimated 74 million distribution and wholesale
customers.

The 2007 SGS Study included approximately 50% of US Bulk Power
transmission (see 2007 participation map, list).

EASE OF PARTICIPATION:  Simply provide a down-load of raw
transmission outage data and circuit inventory (see data submission
example).  There are no complicated surveys or spreadsheets to
complete.  A low commitment of internal time and resources for
participants.

VALIDITY OF COMPARISONS:  The Study pools raw outage data and
uses common methods process each participants and to screen major
event days (pooling data).

TIMELY RESULTS CONFERENCE:  Results are presented at a 2 day
Conference on May 6-7, 2008 at the Turningstone Resort in Verona, NY
(central NY state) at a closed participant conference.  Includes
participant presentation about internal reliability management practices.

COMPREHENSIVE:  Comparisons by voltage class against the industry
average, quartiles, geographic regions, self-defined PEER group and
individual systems (bar chart, trend chart).

GRANULARITY:  Precise circuit-level performance measures for
reliability management decision support.  Annual and multi-year
averages of circuit level performance.

CUSTOMER and DELIVERY POINT ANALYSIS:  IEEE Std 1366 and
other reliability measures and benchmarking are provided for
transmission line outages affecting Customers or Delivery Points by
system, voltage class and individual circuits (example).

OUTAGE CAUSE ANALYSIS:  Participant classify their internal outage
cause descriptions into nine Study categories.  Analysis is provided at
the voltage class (bar charts, trend charts and tables) and circuit level
output.

CABLE:  Comparison of cable reliability performance (voltage class,
individual circuits).

COMPLETE PERFORMANCE METRICS:  The Study uses performance
metrics defined by NERC, IEEE and CIGRE working groups, plus
innovative reliability statistics (time between failures).

COST:  Participation cost is determined by system size for transmission
owners.  Participation is also available for ISOs, RTOs and Regional
Reliability Councils.

To view examples of typical SGS Study output and deliverables and a
discussion of Study applications, click on the following link to view PDF of
slides:

SGS STUDY SAMPLE DELIVERABLES and SLIDES (PDF)

There is a formal project proposal and data requirements documents
which are sent upon request in January.

The STUDY TIMELINE illustrates the data submission process, analysis
phase, conference and support.

2008 SGS Study Participant List

Listing of participants does not constitute an advertisement or
endorsement of the study.  Participants are listed to provide an example
of the size and type of systems likely in future years.

  1. American Transmission Company
  2. Arizona Public Service
  3. Dominion Virginia Power
  4. Duke Power Company
  5. Entergy Transmission
  6. Exelon Corporation
  7. First Energy
  8. Florida Power & Light
  9. Georgia Integrated Transmission System
  10. Hydro One Networks
  11. Idaho Power Company
  12. International Transmission Company
  13. Long Island Power Authority
  14. National Grid USA
  15. Nebraska Public Power District
  16. New York Power Authority*
  17. Northeast Utilities
  18. NorthWestern Energy
  19. PacifiCorp
  20. Pacific Gas and Electric
  21. Progress Energy
  22. Public Service Electric & Gas
  23. South Carolina Electric & Gas
  24. San Diego Gas & Electric
  25. Salt River Project
  26. Southern Company*
  27. Tennessee Valley Authority
  28. Tucson Electric Power
  29. TXU Electric Delivery
  30. Xcel Energy
* INDICATES NEW ENTRANT FOR 2008

There are 62+ operating companies (as defined as FERC Form 1
reporting units or public power agencies/coops)
Voltage Class
 Number of Circuits
 Circuit Miles
Load Serving (<230 kV)
 12,716
 174,962
Bulk Power (>= 230 kV)
 3604
 100,651
Total
 16.320
 275,613
The 2008 SGS Transmission Reliability
Benchmarking Study