2007 South DC-Tie Emergency OperationTPTF
November 27, 2007
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Agenda
• Current Operations of the DC-Ties• Summary of the Schedules flows in the last 12 Months
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ERCOT DC-Ties
• ERCOT-CFE Operational DC-Ties– Eagle Pass (DC_S, 36 MW) – Laredo Variable Frequency Transformer (DC_L, 100 MW)– Sharyland Railroad (DC_R, 150MW)
• ERCOT-SPP Operational DC-Ties– North DC_Tie (DC_N, 220 MW)– East DC_Tie (DC_E 600 MW)
DC_N220 MW DC_E
600 MW
DC_S36 MW
DC_L100 MW
DC_R150 MW
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ERCOT DC-Ties -- Operations
• ERCOT/SPP DC-Ties– Open for commercial transactions and operation
• ERCOT/CFE DC-Ties– Interim agreement in place with CFE. Addresses
emergency assistance through the DC-Tie and BLT• Transmission Outages, Supply shortages, voltage
deficiencies and other– Currently only utilized under emergency conditions
• Transmission Emergency Condition• EECP
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• ERCOT received DC-Tie flows 32 times through the South DC-Ties from October 2006 to August 2007.
– Each DC-Tie flow corresponds with a declaration of an Emergency Condition.
South DC Tie Requests
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Eagle Pass DC-Tie Emergency Assistance Schedules
• Request for Emergency Assistance:– 25 Times due to Transmission Emergency Conditions
Month Days
October 06 6 (Outage)
November 06 5 (Outage)
December 06 2 (Outage)
January 07 5 (Winter Storm)
February 07 7 (Outage)
• 2 Times due to EECP, June 18th, 2007 & August 1st, 2007
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Other South DC-Tie Emergency Assistance Schedules
Laredo VFT DC-Tie Schedules• Request for Emergency Energy:
– 3 Times due to Transmission Emergency Conditions• July 16, 17, 18 of 2007• Due to a planned outage of a local RMR unit in the Laredo
area.
– 2 Times due to EECP, June 18th, 2007 & August 1st, 2007
Railroad DC-Tie Schedules• No emergency schedules in the Tie