ERCOT Operating Guides Revision Request

OGRR Number / 116-OGRR / OGRR Title / Day Ahead Schedule Changes due to PRR 268, 319 & PIP144
Status / Posted
Operating Guide Section Requiring Revision / 2.5.1 Day Ahead Scheduling
2.6.1 ERCOT Responsibilities (2.6 Ancillary Services)
3.2.2.1 Day Ahead Scheduling
Protocol Section Requiring Revision, if any. /

None

Requested Resolution /

Normal

Revision Description / Revise the Operating Guides as follows:
Section 2.6.1 reflects that the Load Ratio Share used to determine AS Obligation will be for the same hour and day of the week and from the initial settlement data that is available. [PRR 319, approved by the Board 3/19/2002; effective 3/20/2002]. Also, to reflect the implementation of PIP 144, assignment of AS Obligations by LSE, aggregated to the QSE level.
Sections 2.5.1, 3.1.3.2, and 3.2.2.1 reflect changes made to the Day Ahead Scheduling Time Line. [PRR 268, approved by the Board 10/16/2001; effective 11/01/2001]. In addition, revise Section 2.5.1 to reflect the implementation of PIP 144, Assignment of AS Obligations by LSE, aggregated to the QSE level.
Reason for Revision / Update the Operating Guides to mirror revisions made to the Protocols.

Sponsor

Name / Jack Thormahlen
E-mail Address /
Company / Lower Colorado River Authority
Company Address / P.O. Box 220, Austin, Texas 78767-0220
Phone Number / 512-473-3200 ext. 2635
Fax Number / 512-469-6856

Timeline

Date Received / 07/25/2002
Date Posted / 07/26/2002
ROS Review Date
ROS Recommendation
Other Subcommittee Consideration
TAC Consideration
Proposed Operating Guide Language Revision

2.5.1 Day Ahead Scheduling

The Control Area Authority is required to perform specific analysis of the ERCOT System and provide information to QSEs and others within the ERCOT System during specific periods of the day prior to the Operating Day, as follows:

TIME PERIOD / ERCOT ACTION /
Prior to 0600 / For each hour of the Operating Day, ERCOT shall post:
Reference: Protocol, Section 4.4.2, January 5, 2001
No later than 0600 in the Day Ahead ERCOT shall post the following information for each hour of the Operating Day:
(1)  A forecast of conditions on the ERCOT System, including known transmission line and other Transmission Facility Outages;
[PIP156: System is not calculating or posting item #2. When the system supports, add the following item:]
(2) A forecast of Total Transfer Capability including any relevant information describing forecasted transfers for each CSC.
(3)  Weather assumptions used by ERCOT to forecast ERCOT System conditions.
0600 / Publish updated transmission system information:
Ø 
Reference: Protocol, Section 4.4.4, January 5, 2001
[PIP 144: Ref. paragraph below, current design assigns AS obligation at the QSE level, not the LSE leve per 6.3.1(1)l. When the system support LSE assignment, replace the paragraph below with the following:
ERCOT will notify QSEs by 0600 of the Day Ahead of the QSE’s Day Ahead Ancillary Service Obligations. The Day Ahead Ancillary Service Obligation will be assigned by LSE and will be aggregated to the QSE level.
ERCOT will notify QSEs by 0600 of the Day Ahead of the QSE’s Day Ahead Ancillary Service Obligations. The Day Ahead Ancillary Service Obligation will be assigned to the QSE level.
ERCOT will notify QSEs by 0600 of the Day Ahead of the QSE’s Day Ahead Ancillary Service Obligations. The Day Ahead Ancillary Service Obligation will be assigned to each QSE by multiplying the ERCOT Obligation by the sum of the load ratio shares, rounded to no fewer than six (6) decimal places, for the LSEs that a QSE represents.
Reference: Protocol, Section 4.4.5, January 5, 2001
[PIP 145 Ref. paragraph below, current design does not provide a notification to QSEs of Mandatory BES Down bid percentage requirements. When functionality added, add the following section:]
ERCOT will notify QSEs by 0600 of the Day Ahead of the QSE’s percentage requirement for Balancing Energy Service Down bids by Congestion Zone for each hour of the Operating Day. The percentage requirement will be the same for all QSEs.
1100 / Validate Schedules and notify affected Qualified Scheduling Entities (QSEs) of any invalid or mismatched schedules.
1115 / Ø  Review Schedules using the Commercial Model
Ø  Evaluate CSC Congestion
Ø  Notify QSEs of Congested CSCs
Ø  Post schedule impact on CSCs
Ø  Notify QSEs of any difference in ERCOT’s zonal Load forecast and the aggregate of QSE schedules in a zone.
1300 / Validate Schedules and notify affected QSEs of any invalid or mismatched schedules
1315 / Validate resubmitted schedules and adjust as necessary.
1330 / Ø  Purchase AS through ERCOT AS Market in order to complete ERCOT’s Day Ahead AS plan.
Ø  Review Day Ahead Market Clearing Prices for Capacity (MCPC) for each Day Ahead AS market operated by ERCOT.
14001500 / Review and validate AS schedules as necessary.
14301600 / Verify that Resource Plans are sufficient to meet the QSE schedule. If not, ERCOT will notify the QSE.
No later than 16301800 / Ø  Evaluate Resource Plans to determine system security
Ø  Evaluate RPRS needed to correct CSC, and Operational Congestion – Operational Model, and capacity insufficiency.
Ø  Create Merit Order of RPRS by Zone or operational constraint as applicable
Ø  Determine MCPC for RPRS by Zone as applicable and save RPRS energy bids for applicable balancing markets.
Ø  Close and clear Day Ahead RPRS market

2.6 Ancillary Services

2.6.1 ERCOT Responsibilities

Reference Protocols, Section 6.3.1, January 5, 2001

(1)  ERCOT through its Ancillary Service functions shall develop the Operating Day Ancillary Service Plan for the ERCOT System and allocate Ancillary Service obligations to individual QSEsthe Day Ahead Ancillary Service Obligation will be assigned based on load ratio share data, by LSE, aggregated to the QSE level. Unless otherwise provided in these Protocols, a QSE’s allocation for Ancillary Services obligation will be determined for each hour according to that QLSE’s Load Ratio Share computation by ERCOT. The QLSE Ancillary Service allocation shall be the hourly Load Ratio Share of the Load from the availableinitial settlement data, as defined in Section 9.2, Settlement ChargesStatements, for the same hour and day of the prior week multiplied by the quantity of the service in the Operating Day AS Plan.

PIP144: When system is assigned to LSE and then aggregating to the QSE Level, amend item #1 above with the following:

(1) ERCOT through its Ancillary Service function shall develop the Operating Day Ancillary Service Plan for the ERCOT System and allocate Ancillary Service Obligations to individual LSEs, aggregated to the QSE level. Unless otherwise provide in these Protocols, a QSEs allocation for Ancillary Services obligation will be determined for each hour according to that LSE’s Load Ratio Share computation by ERCOT. The LSE Ancillary Service allocation shall be the hourly Load Ratio Share of the Load from the available settlement data, as defined in Section 9.2, Settlement Charges, for the same hour and day of the prior week multiplied by the quantity of the service in the Operating Day AS Plan

3.1.3.2 Daily Resource Plan

Reference Protocols Section 4.4.15 January 5, 2001

Each QSE that represents a Resource will present a Resource Plan to ERCOT at 14301600[Protocols state 1600]. These Resources may be specific generating units and/or Load acting as a Resource. The Resource Plan capacity should be sufficient to accommodate the combined quantity of energy and Ancillary Services scheduled by that QSE from the Resources that the QSE represents. The Resource Plan shall indicate the availability of the Resources represented by the QSE and the planned operating level of each Resource, for each hour of the Operating Day. The Resource Plan shall indicate the High Operating Limit and Low Operating Limit by Resource. A Resource may be listed as unavailable to ERCOT if the Resource’s capacity has been committed to markets in regions outside of ERCOT.

Reference Protocols, Section 5.5.1, Changes in Resource Status January 5, 2001

Changes in Resource Status

The QSE will notify ERCOT of an unplanned change in Resource status as soon as practicable following the change. The QSE representing the Resource will report any changes in Resource status to ERCOT in the Resource Plan by the beginning of the next hour following the change in status.

Each QSE that represents a Resource, either Load or Generation, shall submit to the ERCOT Control Area Authority by 1430 1600 hours each day their Resource Plan for the next day.

The capacity of all Resources shown as available in the Resource Plan should be sufficient to accommodate the combined quantity of energy and Ancillary Services scheduled by that QSE from the Resources which the QSE represents.

The Resource Plan shall indicate the availability of all Resources represented by the QSE and the planned operating level of each Resource, for each hour of the Operating Day.

The Resource Plan shall indicate the High Operating Limit and Low Operating Limit of each Resource.

A Resource may be listed as unavailable to ERCOT if the Resource’s capacity has been committed to markets in regions outside of ERCOT.

The QSE representing the Resource will report to ERCOT any changes in Resource status by updating its Resource Plan before the beginning of the next hour following the change in status

3.2.2.1 Day Ahead Scheduling

Extracted from Protocols, Section 4.1.1 January 5, 2001

DAY AHEAD TIME PERIOD / QUALIFIED SCHEDULING ENTITY (QSE) SUBMISSION: /
1100 / Ø  Balanced Energy Schedule of Obligations and Resources
Ø  Self-Arranged AS Schedule
1115 / Ø  Resubmit corrected schedules
1300 / Ø  Update Balanced Energy Schedule of Obligations and Resources
Ø  Update Self-Arranged AS schedule
Ø  AS bids to supply AS to ERCOT AS Market
1315 / Ø  Resubmit corrected updated schedules.
14001500 / Ø  Submit updated AS schedule that includes Self-Arranged and AS bids selected by ERCOT.
14301600 / Ø  Submit Resource Plans with non-binding unit-specific information
Ø  Submit Replacement Reserve Service (RPRS) Bids and associated Balancing Energy bids.
After 16301800 / Ø  Modify RPRS bids

Other TAC Subcommittee Review

PRS Review Date
PRS Protocols Impact Decision
WMS Review Date
RMS Review Date

TAC Action

TAC Vote Date
TAC Proposed Implementation Date
TAC Vote Results

File: 116OGRR Day Ahead Schedule Update - PIP144 PRRs 268 294.doc Page: 1