Puget Sound Area Northern Intertie (

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Puget Sound AreaNorthern Intertie (PSANI)
Transmission History

• ColumbiaGrid
• September 24, 2007
• Snohomish County Public Utility District
• John D. Martinsen

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PSANI History

• Historical BPA Plans
• April 2003 Curtailments
• Meeting of the Minds
• Current Status

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Historical BPA Plans

• Excerpts from the BPA 1991 2000 Transmission
  System Facilities Ten Year Development plan
• King County System Reinforcements (second Monroe
  to Echo Lake 500kV)
• Planned energization in 1997
• Puget Sound Area Reinforcement (double circuit
  Chief Joseph to Monroe upgraded to 500kV tie to
  Snohomish )
• (Planned energization in 2000)
• Little support for new transmission during this
  period due to regulatory uncertainty NEPA 1992

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King County System Reinforcements

• New Monroe to Echo Lake 500kV line
• Reinforcement is required to eliminate the heavy
  loading on the underlying 230kV system during an
  outage of the existing Monroe-Echo Lake

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King County System Reinforcements
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Puget Sound Area Reinforcement

• Replace existing Chief Joseph Monroe 345kV
  double circuit lines with a 500kV double circuit
  line to Monroe and Snohomish
• ..capacity may not be sufficient beyond 2000 if
  load growth is higher than expected or the
  Canadian Entitlement return must be delivered to
  Blaine

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Puget Sound Area Reinforcement
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April 2003 - Curtailments

• April 2003 the Canadian Entitlement return
  increased from 630MW to 1,149MW
• Curtailments and curtailment notices became a
  regular occurrence for Puget Sound utilities and
  Powerex

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Meeting of the Minds

• Soon after April 2003 BPA, Puget Sound utilities,
  and Powerex met
• A short-term Redispatch was agreed to by the
  Puget Sound and Powerex parties
• The Puget Sound Area Study Group (PSASG) was
  formed under the Northwest Power Pool (NWPP)
  Northwest Transmission Assessment Committee
  (NTAC)
• Puget Sound Area Upgrade Study Report was
  completed by the PSASG -November 2004

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Current Status

• The Canadian Entitlement may increase to 1500 MW
• Puget Sound Area loads are growing
• Both wire and non-wire alternatives have been
  reviewed
• Most of the major Transmission reinforcements
  reviewed would take eight to ten years to
  complete
• Incremental upgrades and operating procedures
  have resulted in reduced curtailment risk
• No major (i.e. 500 kV) Puget Sound area
  transmission expansion is currently moving
  forward

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Canadian Entitlement Returns
Entitlement Capacity (MW) Entitlement Capacity (MW)
Year Returned to BC
2001-02 768
2002-03 630 then 1149
2003-04 1,154
2004-05 1,154
2005-06 1,195
2006-07 1,221
2007-08 1,217
2008-09 1,222
2009-10 1,327
2010-11 1,291
2011-12 1,289