The 2012 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 independent benchmarking
comparison forum for electric transmission reliability in the world.

In 2011 the SGS Study represented:

  • 25 Transmission Systems (24 US, 1 Canada)

  • 50.9% of the US and 46.9% of the North American bulk power
    grid, based on NERC TADS mileage

  • Represents 58% of total non-coincident total US peak MW load
    in 2007 (the all time US peak, EIA statistics)

Features of the SGS Study:

DELIVERABLES:  A 300+ page Study, customized company-specific
Summary (30+ pages), Extended Summary and NERC TADS
Supplement, electronic data files and a 2 day participant conference
(
deliverables, CD).  More than 30 different reliability performance
measures are provided at a circuit-, voltage class- and system-level.

NERC TADS PERFORMANCE METRICS:  The Study  has a complete
section utilizing 12 of the 16
NERC TADS metrics (Transmission
Availability Data System) for AC transmission lines.  The SGS Study
provides your system an advance view of its performance under NERC
TADS with benchmarks to the industry and your peers, which are not
provided in any NERC reports  
View sample NERC TADS report.

SIZE:   The completed 2011 SGS Study had 25 participating systems and
had the following circuit totals:









2011 participants had approximately 499,000 MW peak transmission
load, serving an estimated 70 million distribution and wholesale
customers.

The 2011 SGS Study included approximately 51% of US Bulk Power
transmission based on NERC TADS bulk power mileage (
see
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 8-9, 2012 at the Seneca-Niagara Hotel in Niagara
Falls, NY at a closed participant conference.  Includes participant
presentations 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).

LOAD LOSS: MW and MWh impacts from transmission line and station
outages are a new feature of the SGS Study.  IEEE Std 1366 and other
reliability measures and benchmarking (
load loss statistics).

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.

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.

2011 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. International Transmission Company
  12. Long Island Power Authority
  13. National Grid USA
  14. Nebraska Public Power District
  15. Northeast Utilities
  16. NorthWestern Energy
  17. Oncor Electric Delivery
  18. PacifiCorp
  19. Pacific Gas and Electric
  20. Progress Energy
  21. Salt River Project
  22. Southern Company*
  23. Tennessee Valley Authority
  24. Tucson Electric Power
  25. Xcel Energy

There are 60+ 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)
12,757
177,522
Bulk Power (>= 230 kV)
3518
94,734
Total
16,275
272,256
The 2012 SGS Transmission Reliability
Benchmarking Study