UFMP methodology changes in the updated webSAS February 2015 A video presentation reviewing the webSAS UFMP methodology changes going into effect March 4th 2015 Craig Williams – WECC Market Interface Manager

Why Did We Update the UFMP? The previous UFMP relief requirement calculation methodology did not take into account the transmission priority on tags when determining relief requirement allocations. This is not in line with the pro forma OATT. – Order 888 – Order 890 – Order 713-A and 713-B

UFAS Recommendation After a long period of development the Unscheduled Flow Administrative Subcommittee in March 2012 recommended to the OC and WECC Board that the Relief Requirement calculation methodology be updated and modified to utilize a combination of Transmission Priority and Transfer Distribution Factor to determine Relief Requirement allocations for unscheduled flow events.

Three Main Changes to the UFMP 1.There are now 16 groups of tags based on transmission priority and On or Off-Path status.

Three Main Changes to the UFMP Group 1 – Priority 0 (0-NX) off-path Group 2 – Priority 0 on-path Group 3 – Priority 1 (1-NS) off-path Group 4 – Priority 1 on-path Group 5 – Priority 2 (2-NH) off-path Group 6 – Priority 2 on-path Group 7 – Priority 3 (3-ND) off-path Group 8 – Priority 3 on-path

Three Main Changes to the UFMP Group 9 – Priority 4 (4-NW) off-path Group 10 – Priority 4 on-path Group 11 – Priority 5 (5-NM) off-path Group 12 – Priority 5 on-path Group 13 – Priority 6 (6-NN, 6-CF) off-path Group 14 – Priority 6 on-path Group 15 – Priority 7 (7-F, 7-FN) off-path Group 16 – Priority 7 on-path

Three Main Changes to the UFMP 2.Only e-tag schedules with Transfer Distribution Factors (TDF) greater than or equal to 10 Percent are utilized for curtailment. 3.The effective transmission priority is determined by: – The lowest priority on any leg for Off-Path Tags. – The priority of the On-Path Transmission segment for On-Path Tags.

Comparison of Methodology The USF Task Force evaluated several different USF events to compare the impact of these changes. To ensure comparability, the MW relief required under the previous methodology was used as the target relief required for new methodology. The number of tags curtailed and the total amount of MWs curtailed were compared.

Event 5637 Action 5640 Path 66 Previous Method Tags Impacted = 94 MW Impact = 1091 Firm Tags = 39 Firm MWs = 518 Relief Required = MWs Relief Provided = 331.2MWs New Method Tags Impacted = 43 MW Impact = 615 Firm Tags = 0 Firm MWs = 0 Relief Provided = MWs

Event 5751 Action 5752 Path 66 Previous Method Tags Impacted = 91 MW Impact = 948 Firm Tags = 31 Firm MWs = 564 Relief Required = MWs Relief Provided = 357.4MWs New Method Tags Impacted = 40 MW Impact = 426 Firm Tags = 0 Firm MWs = 0 Relief Provided = MWs

Event 5779 Action 5801 Path 66 Previous Method Tags Impacted = 88 MW Impact = 849 Firm Tags = 33 Firm MWs = 358 Relief Required = MWs Relief Provided = MWs New Method Tags Impacted = 43 MW Impact = 523 Firm Tags = 0 Firm MWs = 0 Relief Provided = MWs

Event 5779 Action 5802 Path 66 Previous Method Tags Impacted = 94 MW Impact = 1091 Firm Tags = 39 Firm MWs = 518 Relief Required = MWs Relief Provided = MWs New Method Tags Impacted = 43 MW Impact = 615 Firm Tags = 0 Firm MWs = 0 Relief Provided = MWs

Event 5779 Action 5803 Path 66 Previous Method Tags Impacted = 64 MW Impact = 449 Firm Tags = 19 Firm MWs = 150 Relief Required = MWs Relief Provided = MWs New Method Tags Impacted = 36 MW Impact = 310 Firm Tags = 0 Firm MWs = 0 Relief Provided = MWs

Event 5779 Action 5804 Path 66 Previous Method Tags Impacted = 79 MW Impact = 608 Firm Tags = 23 Firm MWs = 197 Relief Required = MWs Relief Provided = MWs New Method Tags Impacted = 43 MW Impact = 376 Firm Tags = 0 Firm MWs = 0 Relief Provided = MWs

Event 5779 Action 5805 Path 66 Previous Method Tags Impacted = 90 MW Impact = 864 Firm Tags = 30 Firm MWs = 353 Relief Required = MWs Relief Provided = MWs New Method Tags Impacted = 46 MW Impact = 501 Firm Tags = 0 Firm MWs = 0 Relief Provided = MWs

Event 6378 Action 6381 Path 66 Previous Method Tags Impacted = 54 MW Impact = 459 Firm Tags = 16 Firm MWs = 220 Relief Required = MWs Relief Provided = MWs New Method Tags Impacted = 27 MW Impact = 216 Firm Tags = 0 Firm MWs = 0 Relief Provided = MWs

Event 6503 Action 6514 Path 31 Previous Method Tags Impacted = 51 MW Impact = 323 Firm Tags = 38 Firm MWs = 239 Relief Required = 39.1 MWs Relief Provided = 50.6 MWs New Method Tags Impacted = 5 MW Impact = 203 Firm Tags = 0 Firm MWs = 0 Relief Provided = 39.2 MWs

Event 7000 Action 7013 Path 23 Previous Method Tags Impacted = 64 MW Impact = 605 Firm Tags = 58 Firm MWs = 597 Relief Required = 56.6 MWs Relief Provided = MWs New Method Tags Impacted = 44 MW Impact = 301 Firm Tags = 37 Firm MWs = 196 Relief Provided = 56.9 MWs

Event 7000 Action 7014 Path 23 Existing Method Tags Impacted = 64 MW Impact = 609 Firm Tags = 58 Firm MWs = 601 Relief Required = 69.7 MWs Relief Provided = MWs Proposed Method Tags Impacted = 46 MW Impact = 366 Firm Tags = 38 Firm MWs = 216 Relief Provided = 68.7 MWs

Event 7000 Action 7015 Path 23 Previous Method Tags Impacted = 59 MW Impact = 619 Firm Tags = 53 Firm MWs = 586 Relief Required = 83.2 MWs Relief Provided = MWs New Method Tags Impacted = 43 MW Impact = 391 Firm Tags = 38 Firm MWs = 194 Relief Provided = 83.3 MWs

Event 7000 Action 7016 Path 23 Previous Method Tags Impacted = 43 MW Impact = 351 Firm Tags = 42 Firm MWs = 333 Relief Required = 35.7 MWs Relief Provided = 85.0 MWs New Method Tags Impacted = 4 MW Impact = 146 Firm Tags = 0 Firm MWs = 0 Relief Provided = 35.0 MWs

Event 7120 Action 7127 Path 30 Previous Method Tags Impacted = 49 MW Impact = 443 Firm Tags = 44 Firm MWs = 418 Relief Required = 87.3 MWs Relief Provided = 86.3 MWs New Method Tags Impacted = 24 MW Impact = 242 Firm Tags = 14 Firm MWs = 39 Relief Provided = 87.2 MWs

Event 5615 Action 5616 Path 36 Previous Method Tags Impacted = 39 MW Impact = 408 Firm Tags = 36 Firm MWs = 395 Relief Required = 94.2 MWs Relief Provided = 98.1 MWs New Method Tags Impacted = 24 MW Impact = 242 Firm Tags = 14 Firm MWs = 39 Relief Provided = 94.8 MWs

Additional Benefits Under the previous program, we moved from Step 1 to Step 9 depending on the severity of the event. The new methodology has four steps: – Step 1Path Operator advises the RC of the situation. – Step 2 Path Operator uses available devices to mitigate flows. – Step 3 Coordinated Operation of Phase Shifters. – Step 4 Path Operator requests a specific amount of relief and e-tag curtailments are calculated.

Example Previous Process – Step 7 Relief Available 100 MWs – Step 8 Relief Available 100 MWs – Step 9 Relief Available 300 MWs – Needed relief is 150 MWs. – QTPO requests Step 9 New Method QTPO requests 150 MW relief

Additional Methodology Changes Once an Event is called, Restricted Transactions will be curtailed to zero after approval. - Approval allows them to be reloaded if required and follows transmission priority requirements. Restricted Transactions may bump schedules with lower priority transmission when they are approved.

Additional Methodology Changes Each hour will be a distinct Event – If a Restricted Transaction is for multiple hours, then all hours after the first hour may be able to flow, dependent upon its transmission priority and TDF. The mathematics have changed to a TDF squared methodology to reduce the amount of tags curtailed in an event.

Go live is scheduled for March 4, 2015 Please direct your questions to: Craig Williams Questions?