WESM

Trading Operations in the Philippine WESM

Philippine Electricity Market Corporation

Objectives Familiarize the participant with the WESM operations. Describe the responsibilities of the different entities involved,

specifically the Trading Participants, the Market Operator, and the System Operator.

Provide an overview of the scheduling and dispatch in WESM Establish the WESM Timetable Show an illustration of the dispatch implementation

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Introduction A clear definition and delineation of responsibilities are necessary to

ensure the reliable operation of the grid, especially with the Market Operator (MO) and the System Operator (SO) being two separate entities – Dispatch Protocol Issue 6.0

As a result, the WESM Manual on the Dispatch Protocol was formulated after rigorous discussions between MO and SO

The Dispatch Protocol Clearly establishes the WESM Timetable for the execution of

specific processes (WESM Rules 3.4.2 and 10.4.8.1) Establish scheduling and dispatch procedures to be followed in Normal Conditions Emergency Conditions that should be consistent with the WESM Timetable and features of the MMS

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Scheduling and Dispatch Procedures Prior to WESM Operations

Scheduling and dispatch of generating facilities were the sole responsibility of SO

SO was also responsible in demand forecasting Generating facilities were required to submit daily nominations of

capacities they want to be scheduled for dispatch on the following day

Regardless of contractual commitments of generating units, the SO shall prepare a day-ahead generating schedule using the nominations considering system conditions and requirements such as (1) load forecasts, (2) weather forecasts, (3) reliability and security standards, and (4) scheduled outages

Week-ahead nominations were also required by SO

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Scheduling and Dispatch Procedures Prior to WESM Operations

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System Operator

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3

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Nomination of available capacities

Forecast of demand Scheduling - forecast (load and weather) - security and reliability - scheduled outages

Day –Ahead Schedules

The Day-Ahead schedules shall be implemented by SO subject to changes at real-time (forecast error, tripping, etc.)

Energy and Reserve

Scheduling and Dispatch upon Establishment of WESM Operations

WESM was established as the trading platform of energy transactions in grids with WESM operations (Luzon and Visayas)

WESM was also established as the central platform for the scheduling and dispatch of generating facilities with WESM operations

SO is still responsible in the dispatch of generating units at real-time

MO has the responsibility of forecasting demand, and prepares a Security Constrained Economic Dispatch (SCED) schedule of generators and loads based on the hourly demand bids and generation offers. MO also maintains a Market Network Model (MNM) which shall

be used by the Market Dispatch Optimization Model (MDOM), which shall be able to consider transmission constraints and losses

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Responsibilities in WESM’s Scheduling and Dispatch

The Market Operator (MO), System Operator (SO), and Trading Participants (TPs) are the three entities involved in the scheduling and dispatch of generating facilities in WESM

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MO Responsibilities in Scheduling and Dispatch

Maintenance of the Market Network Model (MNM) in coordination with the SO

Generation of dispatch schedules using the MDOM Transmittal of dispatch schedules to the SO for implementation

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SO Responsibilities in Scheduling and Dispatch

Submission of overriding constraints to ensure the reliable operation of the grid Outage Schedule - List of Equipment (e.g. generators, lines,

transformers, breakers, etc.) that will be out of service for a certain defined period.

Contingency List - List of Equipment enlisted for contingency analysis (As Per Grid Code: N-1 Contingency Requirement).

Security Limits - List of Generators and Branch Groups that will have its limits overridden for security purposes (e.g. MRU/testing/commissioning).

Transmission Limits - list of transmission capacities of lines and transformers to be consider in the scheduling process

Implementation of the dispatch schedules provided by MO Issuance of deviation report to MO (actual vs. schedule)

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TP Responsibilities in Scheduling and Dispatch

Submission of bids and offers to WESM consistent with the WESM Timetable

Comply to the dispatch instructions of SO

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Scheduling and Dispatch upon Establishment of WESM Operations

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WESM Timetable Trading activities in WESM operate at different time frames Week Ahead Projection (WAP) Day Ahead Projection (DAP) Hour-Ahead or Real-Time Dispatch (RTD) Real-Time Ex-post (RTX)

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WESM Timetable: WAP The Week-Ahead Projection (WAP) gives indicative hourly dispatch

schedules and spot prices for the next seven days Its results serve as a guide to the following entities Participants when bidding transactions in the market for the next

seven days SO in the determination of the cost impact of planned outages

It considers the following information, which shall be used by the Market Management System (MMS) to generate schedules Demand bids and energy offers from Trading Participants Demand forecasts Outage Schedules Security Limits Latest available system snapshot

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WESM Timetable: WAP WAP is executed every day to produce results for the next seven

days

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D-1 D D+1 D+2 D+3 D+4 D+5 D+6 D+7 D+8 D+9

TRADING DAYS

Execution of WAP at Day D

Study Period of WAP at Day D (From D+1 to D+7)

WESM Timetable: WAP WAP is executed at 0900H of each trading day

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TRADING HOURS

… 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 …

WAP Results and Analysis Coordination with SO

WAP Execution

Prior to 0900H, the following activities are made for D+1 to D+7 Gathering of weather

forecasts Preparation of

demand forecasts Submission or

revision of bids and offers

The latest information provided by SO prior to 0900H shall be used System Snapshot Outage Schedule Security Limit Transmission Limit Contingency List

Publish WAP Results in WEB

WESM Timetable: DAP The Day-Ahead Projection (DAP) gives indicative hourly dispatch

schedules and spot prices covering the succeeding hours of the day up to the end of the following day

It allows the SO to prepare a more accurate contingency plan for the relevant intervals

It considers the following information, which shall be used by the Market Management System (MMS) to generate schedules Demand bids and energy offers from Trading Participants Revisions of bids and offers for consideration in the DAP run can

be done until a cut-off time (four hours prior to the trading hour) Demand forecasts Outage Schedules Security Limits Latest available system snapshot

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WESM Timetable: DAP DAP is executed every four hours to produce results for the

succeeding hours until the end of the following day

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TRADING HOURS

… 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 …

0400H DAP 0800H DAP 1200H DAP 1600H DAP

The latest information provided by SO prior to each DAP run shall be used The latest bids and offers shall be used. Submission or revision of bids and offers

relevant to the succeeding hours can be made prior to the execution of the DAP run. Demand forecasts for each of the succeeding hours evaluated by the DAP run should be

provided prior to its execution. Revisions may still be implemented prior to the DAP run

DAP Results Analysis Coordination with SO

DAP Results Analysis Coordination with SO is done up until 1 hour after the DAP execution

WESM Timetable: DAP DAP Study Period

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DAP Run at Current Day “D”

Study Horizon From To

0400H 0500H of D 2400H of D 0800H 0900H of D 2400H of D 1200H 1300H of D 2400H of D+1 1600H 1700H of D 2400H of D+1 2000H 2100H of D 2400H of D+1 2400H 0100H of D+1 2400H of D+1

WESM Timetable: RTD The Hour-Ahead or Real-Time Dispatch publishes schedules that

shall be implemented by SO, and spot prices that shall be used in the settlement of market transactions

The RTD schedules are subject to the final screening of SO before a dispatch instruction is issued to a Trading Participant

The dispatch schedule is the target MW loading of all Trading Participants at the end of a trading interval

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WESM Timetable: RTD RTD is executed every 55th minute of the hour

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40 50 00 10 20 30 40 50 0 0 10 20 30 40 50 00 10 20 30 40

HH-2 HH-1 HH HH+1

RTD Execution for Trading Hour HH

The latest information provided by SO prior to each DAP run shall be used

Gate Closure for bids and offers

Target Interval HH

Trading Interval HH

Transmit RTD Schedules and MOT to SO

Publish results in WEB Dispatch Implementation

for HH to meet Target Schedule

WESM Timetable: RTX The Real-Time Ex-Post (RTX) represents the duration of the trading

interval It is not used by the SO in the dispatch implementation since it is

merely used for “price discovery”, in which its results represent the actual events that transpired for the duration of the trading interval

Its results are used to settle imbalances in the market (schedule vs. actual)

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WESM Timetable: RTX RTX is executed every 1st minute of the hour

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40 50 00 10 20 30 40 50 0 0 10 20 30 40 50 00 10 20 30 40

HH-2 HH-1 HH HH+1

RTX Execution for Trading Hour HH

The latest information provided by SO prior to each DAP run shall be used

Trading Interval HH

During Normal Conditions Majority of the day-to-day activities in the market fall under the

category of normal conditions

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WESM Tasks during Normal System Condition

Activities Procedure in the Dispatch Protocol

Responsible Group

MO SO

Bids and Offers Appendix A.1 X

Demand Forecasting Appendix A.2 X

Outage Scheduling Appendix A.3 X

Contingency Planning Appendix A.4 X

Pre-Dispatch Market Projections Appendix A.5 X

Real-Time Dispatch Schedule Appendix A.6 X

Dispatch Implementation Appendix A.7 X

System Status Report Appendix A.8 X

Post Dispatch Report Appendix A.9 X

Market Information Publication Appendix A.10 X

Daily Operational Report Appendix A.11 X X

During Emergency Conditions WESM Rules 6.3.1.1 states that an emergency condition is a

situation which has an adverse effect on electricity supply or which poses a significant threat to system security

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Classification of Emergency Events

Market Operations System Operations

Market Failure MMS Failure System Failure EMS Failure

Medium-term supply deficiency

Communication network Breakdown

Total system Collapse

Communication network Breakdown

Effects of force majeure events

Computer systems failure

Grid Islanding or Isolation

Computer systems failure

Site-related Emergencies

Multiple forced Outages

Site-related Emergencies

Threat to system Security

During Emergency Conditions WESM Rules 6.3.1.1 states that an emergency condition is a

situation which has an adverse effect on electricity supply or which poses a significant threat to system security

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WESM Tasks during Normal System Condition

Activities Procedure in the Dispatch Protocol

Responsible Group MO SO

System Emergency and Restoration -- X X Market Suspension and Intervention Appendix B.2 X EMS Disaster Recovery Procedures -- X MMS Disaster Recovery Procedures -- X Report and Documentation of Events -- X X

Sample Normal Dispatch Process

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FOR THE 0900H TARGET TRADING INTERVAL (08:01 AM UNTIL 09:00 AM)

SUBMISSION OF ENERGY OFFERS

7:00 AM 8:00 AM 9:00 AM

SUBMISSION OF SO OVERRIDING CONSTRAINTS

RTD WORKFLOW RUN FOR 0900H

Sample Normal Dispatch Process

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FOR THE 0900H TARGET TRADING INTERVAL (08:01 AM UNTIL 09:00 AM)

RTD SCHEDULES

MERIT ORDER TABLE

SYSTEM OPERATOR

TRADING PARTICIPANTS

A

B

C

D

FOR INFORMATION

FOR IMPLEMENTATION

FINAL DISPATCH INSTRUCTIONS WILL COME FROM SO

DEVIATIONS ARE REPORTED TO MO IN CONSIDERATION OF

NON-COMPLIANCE AND MUST-RUN UNITS

End of Presentation