Industry Brainstorm on increasing Export Capacity

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Industry Brainstorm on increasing Export Capacity

• From Alberta to B.C.
• January, 2006

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Who participated?

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Purpose of Brainstorm

• Identify as many quality ideas as possible that
  can increase Export capacity on B.C. Alberta Tie
  Line
• Brainstorming temporarily suspends critical
  processes
• Time frame for ideas 6 months to 5 years
• Long lead times on some projects
• Need early identification and initiation
• E.g. A solution for 2011 may need initiation now

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Purpose of Prioritization Process

• Develop consensus on prioritizing projects based
  on their cost and benefits in increasing export
  capacity
• Criteria used to prioritize projects
• Time to implement
• How proven is the technology
• Approximate cost versus magnitude of export
  capacity
• Issues that the technology addresses
• Projects prioritized into three groups
• Analysis based on Jan 06 industry knowledge of
  transmission limitations

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Summary of Results

• Three urgent and important projects
• Twelve more important Priority-1 projects
• Consider for approval and immediate resourcing
• Three Priority-2 Projects
• Need further study and evaluation
• Thirteen Priority-3 Projects
• Park these ideas for review at a later date

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Urgent Project 1

• Thermal capacity assessment and upgrades strategy
  for limiting elements
• Thorough inventory of each element of
  transmission backbone
• Transmission lines (ground clearance, conductor
  replacement)
• Breakers
• Current transformers
• Busses, jumpers
• Identify lowest cost options to solve limits
• Identify database errors, if any, that could
  create artificial constraints
• Start work immediately as thermal constraints
  rather than dynamic constraints are currently
  limiting exports

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Urgent Project 1b

• Create transmission limitations document
• Limiting operating criteria
• Limiting contingencies by facility
• Consequence of each contingency
• Action required to mitigate limitations
• Cross references to support studies

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Urgent Project 2

• Expanded Remedial Action Schemes
• Develop a North South GRAS (underway?)
• Triggered by loss of ATC limiting double circuit
  or single circuit line outages
• Develop a 500 kV BC Tie RAS to mitigate loss of
  ATC limiting double or single circuit line
  outages
• Expand the use of undervoltage relays in a RAS to
  prevent voltage collapse
• Develop Generator MW ramp down scheme to
  automatically respond to thermal line overloads
  (which have a longer response time)

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Urgent Project 3

• Thermal Monitoring Indirect Sensors
• Use indirect sensors such as weather stations to
  monitor weather, sunlight, temperature and wind
• Use these indications to create a real time
  assessment of thermal limits on the system
• Proven technology
• Capacity should be higher during
• Cooler days, night time, windier conditions
• Risks are higher during storm conditions

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Other Priority-1 Projects

• Tie tripping export shedding scheme
• Automatically ramp down exports when voltages
  fall below predetermined levels
• New 500 kV reactor breaker at Langdon
• Reactors can be switched out pre and post events
  to support southern Alberta voltage
• Encourage more north south capacity increases
• Explore BC side solutions
• BCTC AESO coordination

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Other Priority-1 Projects cont.

• Rebalancing north-south corridor lines
• use phase shifters, new switching stations
• Increase conductor capacity
• Use new high capacity conductor technology on
  critical lines
• Over-frequency generation shedding scheme (over
  800 MW)
• Saskatchewan Tie enhancements
• Sask Tie can modulate voltages, RAS to increase
  exports to Saskatchewan on a BC Tie trip,
  increase imports for southern Alberta
  undervoltage concerns

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Other Priority-1 Projects cont.

• Use weather adjusted criteria
• Use N-2 criteria only during adverse weather
  conditions (when almost all contingencies occur),
  otherwise use N-1 with safety nets
• Use real time current measurements
• Replace proxies like MW, use actual current
• Operate systems on Live database of system
  conditions
• Use pre-calculated limits under various
  conditions
• Flows limited on pre-calculated contingencies,
  not settings

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Lower Priority Projects

• Three - Priority 2 Projects
• Need further study and evaluation
• Twelve Priority 3 Projects
• Park these ideas for review at a later date
• Key caveat on prioritization
• If AESO sees more merit in any of these 16
  projects, priority could be increased

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Conclusion

• Process was worthwhile
• Will likely be the first of many over the next 5
  years as north south capacity becomes tighter
• Based on current knowledge of the cause of
  limitations on the system
• Thanks to AESO for its support of this
  brainstorming process