Industry Brainstorm on increasing Export Capacity From Alberta to B.C. January, 2006

Who participated? CompanyParticipants ATCO PowerCarl Fuchshuber PowerexGordon Dobson-Mack TransAltaJim Paton Ron Strem TransCanadaBill Hosie Dan Levson Larry Sibbald AESOJeff Palermo (consultant) IndependentTrent Coroy (consultant)

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

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

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

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 Urgent Project 1

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

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)

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

Other Priority-1 Projects 1.Tie tripping export shedding scheme –Automatically ramp down exports when voltages fall below predetermined levels 2.New 500 kV reactor breaker at Langdon –Reactors can be switched out pre and post events to support southern Alberta voltage 3.Encourage more north south capacity increases 4.Explore BC side solutions 5.BCTC AESO coordination

Other Priority-1 Projects – cont. 6.Rebalancing north-south corridor lines –use phase shifters, new switching stations 7.Increase conductor capacity –Use new high capacity conductor technology on critical lines 8.Over-frequency generation shedding scheme (over 800 MW) 9.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

Other Priority-1 Projects – cont. 10.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 11.Use real time current measurements –Replace proxies like MW, use actual current 12.Operate systems on Live database of system conditions –Use pre-calculated limits under various conditions –Flows limited on pre-calculated contingencies, not settings

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

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