Last updated on Wednesday June 08, 2005 09:49:22 AM -0700

Descriptions of the Transmission Paths Available for Reservation

Summary
This document is meant to summarize Sierra paths for reservation and their Total Transfer Capability (TTC). This document also describes Sierra's import capability and how it is managed within the OATi Available Transmission Capability (ATC) calculation methodology.

A system map, under Transmission Information, showing all the available paths is also available.

An outage, whether forced or scheduled, can change a path or import limit at any time. Please check the Outage report for and changes.

If no outages are listed, customers can assume that all path ratings and import limit are as described in this document.

The path ratings described here are all firm capabilities. All real-time and day-ahead non-firm ATC is based upon schedules and counter-schedules. Non-firm ATC beyond day-ahead is equal to the firm capability.

Path Ratings
Following is a list of the ratings for all of Sierra's path segment:

Path Index
Import Limit
From Bonneville Power Administration...
From Idaho Power Company...
From Pacific Gas & Electric Company (PG&E)...
From PacifiCorp's Utah Division...
From Los Angeles Department of Water and Power (LADWP) and the Intermountain Power Project...
From Southern California Edison (SCE)...

Import Limit

The import limit for Sierra Pacific defines the simultaneous interaction between a path and all Sierra's other paths. It defines the safe operating region factoring in the single largest contingency and the requirements listed in the "WECC Planning and Operating Standards." The import nomogram is found at http://www.oatioasis.com/SPPC/SPPCdocs/Import_Nomograms_Scheduling_Summer_2004.xls. The curves are for all lines in-service.

If an outage occurs that can effect the import limit, forced or scheduled, the details and its effect are posted at http://www.oatioasis.com/SPPC/SPPCdocs/outage.html. Those postings will have any new import limit required by the outage.

Any time the total system import is below 700 MW, the tie flows are such that the import nomograms are not needed. Above 700 MW, Sierra's pre-schedule and real-time scheduling staff will examine all schedules to ensure they are within the import nomograms. Sierra will utilize the "WECC Minimum Operating Reliability Criteria" (MORC) rules for phase shifter operation to balance the import capability. Essentially, the MORC gives phase shifter operators great leeway in establishing actual power flows such that the Alturas and PG&E ties can be controlled to optimize import capability..

Sierra can adjust the Alturas and PG&E phase shifters between zero MW actual path flow and 20 MW beyond (40 MW for Alturas) the path schedules. Those schedules are listed on the Intertie and Netloading page.

From Bonneville Power Administration to:

• Sierra Pacific Network: A TTC of 300MW is provided from Sierra's interconnection with BPA (at Hilltop substation) to the Sierra Pacific Network. Available transmission capacity for this path is posted on the OASIS under the path name HILLTOP345 / SPPC.
• Idaho Power Company: A (TTC) of 262MW is provided from Sierra's interconnection with BPA (at Hilltop substation) to Sierra's interconnection with Idaho Power Company (at Midpoint substation). Available transmission capacity for this path is posted on the OASIS under the path name HILLTOP345 / M345.
• Pacific Gas & Electric Company (PG& E): A TTC of 105MW provided from Sierra's interconnection with BPA, at the Hilltop substation, to Sierra's interconnection with PG&E at the Donner Summit Metering Station. Available transmission capacity for this path is posted on the OASIS under the path name HILLTOP345 / SUMMIT120..
• PacifiCorp's Utah Division: A TTC of 235MW provided from Sierra's interconnection with BPA at the Hilltop substation to Sierra's interconnection with the PacifiCorp's Utah division on the Gonder-Pavant transmission line. Available transmission capacity for this path is posted on the OASIS under the path name HILLTOP345 / GON.PAV.
• Los Angeles Department of Water and Power (LADWP) and the Intermountain Power Project: A TTC of 200MW provided from Sierra's interconnection with BPA at the Hilltop substation to Sierra's interconnection with LADWP and other Intermountain Power Project Parties on the Gonder-IPP transmission line. Available transmission capacity for this path is posted on the OASIS under the path name HILLTOP345 / GON.IPP.
• Southern California Edison (SCE): A TTC of 17MW provided from Sierra's interconnection with BPA at the Hilltop substation to Sierra's interconnection with the SCE a the Control substation. Available transmission capacity for this path is posted on the OASIS under the path name HILLTOP345 / SILVERPEAK55..
  

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From Idaho Power Company to:

• Sierra Pacific Network: A TTC of 500MW is provided from Sierra's interconnection with Idaho Power Company at Midpoint substation to the Sierra Pacific Network. Available transmission capacity for this path is posted on the OASIS under the path name M345 / SPPC.
• Bonneville Power Administration: A TTC of 300MW is provided from Sierra's interconnection with Idaho Power Company at the Midpoint substation to Sierra's interconnection with Bonneville Power Administration at the Hilltop substation. Available transmission capacity for this path is posted on the OASIS under the path name M345 / HILLTOP345.
• Pacific Gas & Electric Company (PG&E): A TTC of 105MW is provided from Sierra's interconnection with the Idaho Power Company at the Midpoint substation to Sierra's interconnection with PG&E at the Donner Summit Metering Station. Available transmission capacity for this path is posted on the OASIS under the path name M345 / SUMMIT120.
• PacifiCorp's Utah Division: A TTC of 235MW is provided from Sierra's interconnection with the Idaho Power Company at the Midpoint substation to Sierra's interconnection with PacifiCorp's Utah division on the Gonder-Pavant transmission line. Available transmission capacity for this path is posted on the OASIS under the path name M345 / GON.PAV.
• Los Angeles Department of Water and Power (LADWP) and the Intermountain Power Project: A TTC of 200MW is provided from Sierra's interconnection with the Idaho Power Company at the Midpoint substation to Sierra's interconnection with LADWP and other Intermountain Power Project Parties on the Gonder-IPP transmission line. Available transmission capacity for this path is posted on the OASIS under the path name M345 / GON.IPP.
• Southern California Edison (SCE): A TTC of 17MW is provided from Sierra's interconnection with the Idaho Power Company at the Midpoint substation to Sierra's interconnection with SCE at the Control substation. Available transmission capacity for this path is posted on the OASIS under the path name M345 / SILVERPEAK55.
  

From Pacific Gas & Electric Company to:

• Sierra Pacific Network: A TTC of 100MW is provided from Sierra's interconnection with PG&E at Summit metering point to the Sierra Pacific Network. Available transmission capacity for this path is posted on the OASIS under the path name SUMMIT120 / SPPC.
• Bonneville Power Administration: A TTC of 100MW is provided from Sierra's interconnection with PG&E at the Donner Summit Metering Station to Sierra's interconnection with Bonneville Power Administration at the Hilltop substation. Available transmission capacity for this path is posted on the OASIS under the path name SUMMIT120 / HILLTOP345.
• Idaho Power Company: A TTC of 100MW is provided from Sierra's interconnection with PG&E at the Donner Summit Metering Station to Sierra's interconnection with the Idaho Power Company at the Midpoint substation. Available transmission capacity for this path is posted on the OASIS under the path name SUMMIT120 / M345.
• PacifiCorp's Utah Division: A TTC of 100MW is provided from Sierra's interconnection with PG&E at the Donner Summit Metering Station to Sierra's interconnection with PacifiCorp's Utah Division on the Gonder-Pavant transmission line. Available transmission capacity for this path is posted on the OASIS under the path name SUMMIT120 / GON.PAV.
• Los Angeles Department of Water and Power (LADWP) and the Intermountain Power Project: A TTC of 100MW is provided from Sierra's interconnection with PG&E at the Donner Summit Metering Station to Sierra's interconnection with LADWP and other Intermountain Power Project Parties on the Gonder-IPP transmission line. Available transmission capacity for this path is posted on the OASIS under the path name SUMMIT120 / GON.IPP.
• Southern California Edison (SCE): A TTC of 17MW is provided from Sierra's interconnection with PG&E at the Donner Summit Metering Station to Sierra's interconnection with SCE at the Control substation. Available transmission capacity for this path is posted on the OASIS under the path name SUMMIT120 / SILVERPEAK55.
  

From PacifiCorp's Utah Division to:

• Sierra Pacific Network: A TTC of 370MW is provided from Sierra's interconnection with PacifiCorp's Utah division on the Gonder-Pavant line to the Sierra Pacific Network. Available transmission capacity for this path is posted on the OASIS under the path name GON.PAV / SPPC.
• Bonneville Power Administration: A TTC of 370MW is provided from Sierra's interconnection with PacifiCorp's Utah division on the Gonder-Pavant line to Sierra's interconnection with Bonneville Power Administration at the Hilltop substation. Available transmission capacity for this path is posted on the OASIS under the path name GON.PAV / HILLTOP345.
• Idaho Power Company: A TTC of 262MW is provided from Sierra's interconnection with PacifiCorp's Utah division on the Gonder-Pavant transmission line to Sierra's interconnection with the Idaho Power Company at the Midpoint substation. Available transmission capacity for this path is posted on the OASIS under the path name GON.PAV / M345.
• Pacific Gas & Electric: A TTC of 105MW is provided from Sierra's interconnection with PacifiCorp's Utah division on the Gonder-Pavant line to Sierra's interconnection PG&E at the Donner Summit Metering Station. Available transmission capacity for this path is posted on the OASIS under the path name GON.PAV / SUMMIT120.
• Los Angeles Department of Water and Power (LADWP) and the Intermountain Power Project: A TTC of 200MW is provided from Sierra's interconnection with PacifiCorp's Utah division on the Gonder-Pavant transmission line to Sierra's interconnection with LADWP and other Intermountain Power Project Parties on the Gonder-IPP transmission line. Available transmission capacity for this path is posted on the OASIS under the path name GON.PAV / GON.IPP.
• Southern California Edison (SCE)" A TTC of 17MW is provided from Sierra's interconnection with PacifiCorp's Utah division on the Gonder-Pavant transmission line to Sierra's interconnection with SCE at the Control substation. Available transmission capacity for this path is posted on the OASIS under the path name GON.PAV / SILVERPEAK55..
  

From Los Angeles Department of Water and Power (LADWP) and the Intermountain Power Project Parties to:

• Sierra Pacific Network: A TTC of 200MW is provided from Sierra's interconnection with IPP Parties on the Gonder-IPP line to the Sierra Pacific Network. Available transmission capacity for this path is posted on the OASIS under the path name GON.IPP / SPPC.
• Bonneville Power Administration: A TTC of 200MW is provided from Sierra's interconnection with LADWP and the IPP Parties on the Gonder-IPP line to Sierra's interconnection with Bonneville Power Administration at the Hilltop substation. Available transmission capacity for this path is posted on the OASIS under the path name GON.IPP / HILLTOP345.
• Idaho Power Company: A TTC of 200MW is provided from Sierra's interconnection with LADWP and the IPP Parties on the Gonder-IPP transmission line to Sierra's interconnection with the Idaho Power Company at the Midpoint substation. Available transmission capacity for this path is posted on the OASIS under the path name GON.IPP / M345..
• Pacific Gas & Electric: A TTC of 105MW is provided from Sierra's interconnection with LADWP and the IPP Parties on the Gonder-IPP line to Sierra's interconnection PG&E at the Donner Summit Metering Station. Available transmission capacity for this path is posted on the OASIS under the path name GON.IPP / SUMMIT120..
• PacifiCorp's Utah Division: A TTC of 200MW is provided from Sierra's interconnection with LADWP and the IPP Parties on the Gonder-IPP transmission line to Sierra's interconnection with PacifiCorp's Utah division on the Gonder-Pavant transmission line. Available transmission capacity for this path is posted on the OASIS under the path name GON.IPP / GON.PAV.
• Southern California Edison (SCE): A TTC of 17MW is provided from Sierra's interconnection with LADWP and the IPP Parties on the Gonder-IPP line to Sierra's interconnection with SCE at the Control substation. Available transmission capacity for this path is posted on the OASIS under the path GON.IPP / SILVERPEAK55.
  

From Southern California Edison (SCE) to:

• Sierra Pacific Network: A TTC of 17MW is provided from Sierra's interconnection with SCE at the Control substation to the Sierra Pacific Network. Available transmission capacity for this path is posted on the OASIS under the path name SILVERPEAK55 / SPPC.
• Bonneville Power Administration: A TTC 17MW is provided from Sierra's interconnection with SCE at the Control substation to Sierra's interconnection with Bonneville Power Administration at the Hilltop substation. Available transmission capacity for this path is posted on the OASIS under the path name SILVERPEAK55 / HILLTOP345.
• Idaho Power Company: A TTC 17MW is provided from Sierra's interconnection with SCE at the Control substation to Sierra's interconnection with the Idaho Power Company at Midpoint substation. Available transmission capacity for this path is posted on the OASIS under the path name SILVERPEAK55 / M345.
• Pacific Gas & Electric: A TTC 17MW is provided from Sierra's interconnection with SCE at the Control substation to Sierra's interconnection PG&E at the Donner Summit Metering Station. Available transmission capacity for this path is posted on the OASIS under the path name SILVERPEAK55 / SUMMIT120.
• PacifiCorp's Utah Division: A TTC 17MW is be provided from Sierra's interconnection with SCE at the Control substation to Sierra's interconnection with PacifiCorp's Utah division on the Gonder-Pavant transmission line. Available transmission capacity for this path is posted on the OASIS under the path name SILVERPEAK55 / GON.PAV.
• Los Angeles Department of Water & Power and the Intermountain Power Project Parties: A TTC 17MW is provided from Sierra's interconnection with SCE at the Control substation to Sierra's interconnection with LADWP and other Intermountain Power Project Parties on the Gonder-IPP transmission line. Available transmission capacity for this path is posted on the OASIS under the path name SILVERPEAK55 / GON.IPP.