Intra Hour Tagging/Oasis During System Contingencies The transmission tagging process was initially developed
to solve an after the fact accounting issue which manifested from an explosion of energy transactions and the number of entities trading the same blocks of energy across the interconnected system.
Over time the tagging process has evolved into a system which is utilized to determine transmission path availability, track transmission access rights, schedule hourly capacity and energy, and provide a tool to help Balancing Authorities (BA) with their hourly balancing requirements.
Intra Hour Tagging/Oasis During System Contingencies There is a direct relationship between Tags and the
transmission reservation process through OASIS. If there is not a transmission reservation number on a
tag the tag will not implement. linking both processes, especially during system
contingencies when scheduling processes are time constrained, a schedule re-direct, or energy acquisition
process is quite complex.
Intra Hour Tagging/Oasis During System ContingenciesFor an hourly transaction, tagging and OASIS guidelines
are as follows:
For a tag adjustment, adjustments are required to be submitted by half past the hour.
For submittal of a new tag, a tag is considered late 20 minutes prior to the beginning of the next hour. There are penalties imposed on the Balancing Authority if they approve an excessive amount of late tags. This penalty has resulted in an inconsistent approach to the approval of late tags by individual BA’s.
Intra Hour Tagging/Oasis During System Contingencies Emergency tags may be issued after the time limit. It’s
up to the sink BA to determine if an emergency exists. There is no controlling definition as to what an emergency is.
Request for transmission is limited to 30 minutes prior to the start of the next hour. There are very few entities who allow mid-hour purchase of transmission (one?) and this is subject to monitoring and approval time lags.
Intra Hour Tagging/Oasis During System Contingencies Transmission and generation curtailments or outages
are not restricted to tagging and OASIS scheduling restrictions.
Power will flow to load utilizing the path of less resistance with or without a tag or OASIS reservation unless alternative action is taken, the transmission system is interrupted by automatic protection devices, or load is intentionally dropped.
Tagging and OASIS procedures have limited our ability to respond to less than normal conditions.
Intra Hour Tagging/Oasis During System Contingencies Accounting and scheduling tools
(Tagging/OASIS) have evolved into a limiting factor on the power system during certain conditions making it difficult for load serving entities to manage their load serving and system reliability obligations during system contingencies and therefore contribute to the degradation of system reliability.
Intra Hour Tagging/Oasis During System Contingencies Tagging and transmission reservation timelines and/or
requirements do not relax during system contingencies. Existing tagging and OASIS timelines make it
burdensome to redirect schedules within the hour even when alternative firm transmission rights exist. It forces load serving entities to incur EI or transmission penalties due to denied tags or complex tagging obligations.
Emergency tagging provisions are enacted inconsistently making it difficult to determine proper processes and procedures during system events.
Intra Hour Tagging/Oasis During System Contingencies Tags have been denied as late while the LSE is
attempting to make necessary tag adjustments during a USF mitigation process.
Load has been dropped during a system contingency due to the complexities of the tagging and OASIS process and the inability to obtain generation resources to serve load in a timely fashion.
Intra Hour Tagging/Oasis During System Contingencies
In the PACE February 14th Disturbance Report, Recommendation #21a states:
“The WECC MIC shall initiate an investigation into how it might be able to allow more flexibility in the tagging process, including specifically addressing initiation of tags at times other than the top of the hour.
Intra Hour Tagging/Oasis During System Contingencies The MIC is asking for committee participants
from both the marketing and transmission scheduling segments to explore ways to address conflicts between energy and transmission scheduling and existing tagging and OASIS transmission reservation procedures which occur outside existing timelines, specifically during system events which require timely schedule re-directs and/or resource acquisition.
Intra Hour Tagging/Oasis During System Contingencies It will be the objective of this group to
develop solutions to the problem, frame the solutions into a white paper to post for comment and develop necessary changes to industry processes and procedures and/or standards.
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