Module 2: Day-Ahead OperationsModule 2: Day Ahead Operations
Module Objectives
Upon completion of this module, you will be able to:
• Identify the components of Day-Ahead Operations
• Explain the timeline and purpose of Day-Ahead Operations• Explain the timeline and purpose of Day-Ahead Operations– Day-Ahead Market (DAM)
– Day-Ahead Reliability unit Commitment (DRUC)y y ( )
• Describe the inputs and outputs of DAM / DRUC
• Describe the functions within DRUCesc be e u c o s UC– Transmission Security Analysis (TSA)
– Reliability Unit Commitment (RUC)
Slide 2
• Identify impacts of Day-Ahead Operations on Real-Time
Module Overview
Course Modules:
Nodal Market Overview
Day-Ahead Operations
Module 1
Module 2 Day Ahead Operations
Adjustment Period
Module 2
Module 3
Operating Period
Emergency Operation Conditions
Module 4
Module 5
Performance MonitoringModule 6
Slide 3
Day-Ahead Operations
Day-Ahead Operations
Slide 4
Day-Ahead Market
Day-Ahead Market (DAM)
Slide 5
Day-Ahead Reliability Unit Commitment
Day-Ahead Reliability Unit Commitment (DRUC)
Slide 6
Day-Ahead Market Overview
1 Day-Ahead Market Basics1 Day Ahead Market Basics
2 Pre-Market Activities2 Pre-Market Activities
3 DAM Clearing & Post-Market Activities
Slide 7
3 DAM Clearing & Post-Market Activities
Day-Ahead Market Overview
1 Day-Ahead Market Basics1 Day Ahead Market Basics
2 Pre-Market Activities2 Pre-Market Activities
3 DAM Clearing & Post-Market Activities
Slide 8
3 DAM Clearing & Post-Market Activities
Day-Ahead Market Timeline
• Day-Ahead Market TimelineDAM i t d b t 1000 d 1330 h• DAM is executed between 1000 and 1330 hrs.
• Information relevant to DAM must be posted by 0600 hrs.
DRUCDAM
10000600 1330
Slide 9
10000600 1330
Day-Ahead Market Features
•Participation in Day-Ahead is:V l t• Voluntary
RMR Units may be required to participate
• Financially Binding
Ancillary Services also carry physical commitmentAncillary Services also carry physical commitment
Slide 10
What Occurs in the Day-Ahead Market?
Energy AwardsEnergy AwardsEnergy Bids & Offers
Energy Bids & Offers
Ancillary Service
Ancillary ServiceAncillary Ancillary Service AwardsService AwardsService OffersService Offers
CCPTP Obligation
AwardsPTP Obligation
AwardsPTP Obligation
BidsPTP Obligation
Bids
Co-Optimization
Engine
Co-Optimization
Engine
Slide 11
What Occurs in the Day-Ahead Market?
Energy Bids & Offers
Energy Bids & Offers Energy AwardsEnergy Awards
Ancillary Ancillary Ancillary Service
Ancillary ServiceService OffersService Offers Service AwardsService Awards
CCPTP Obligation
BidsPTP Obligation
BidsPTP Obligation
AwardsPTP Obligation
Awards
Co-Optimization
Engine
Co-Optimization
Engine
Slide 12
Energy Bids and Offers
QSE
DAM DRUC
Q10000600 1330 1430
Options for Day-AheadOptions for Day Ahead Energy Bids and Offers:
E Bid• Energy Bids
• Energy-Only Offers
AllQSEs
• Three-Part Supply Offers QSEs w/
Slide 13
Three Part Supply Offers QSEs w/Generation
The Energy Bid
QSE
DAM DRUC
Bid to buy energy at a DAM Settlement Point
Q10000600 1330 1430
Bid to buy energy at a DAM Settlement Point• Available to all QSEs• Helps lock in price certainty
FORFORSALE
Slide 14
The Energy-Only Offer
QSE
DAM DRUC
Offer to sell energy at a DAM Settlement Point
Q10000600 1330 1430
Offer to sell energy at a DAM Settlement Point• Virtual transaction• Available to all QSEs
H l l k i i t i t FOR• Helps lock in price certainty FORSALE
Slide 15
The Three-Part Supply Offer
QSE
DAM DRUC
Offer to sell energy at a DAM Settlement Point
Q10000600 1330 1430
Offer to sell energy at a DAM Settlement Point• Linked to a specific resource• Available only from QSEs with Generation
QSE ti i ti i D Ah d h l FOR• QSE participation in Day-Ahead helps ERCOT plan Real-Time commitments
FORSALE
Slide 16
Submission Options
QSE
DAM DRUC
Q10000600 1330 1430
OROTh P t S l Off E Off C
Slide 17
Three-Part Supply Offer Energy Offer Curve
What Occurs in the Day-Ahead Market?
Energy Bids & Offers
Energy Bids & Offers Energy AwardsEnergy Awards
Ancillary Service
Ancillary ServiceAncillary Ancillary Service AwardsService AwardsService OffersService Offers
CCPTP Obligation
BidsPTP Obligation
BidsPTP Obligation
AwardsPTP Obligation
Awards
Co-Optimization
Engine
Co-Optimization
Engine
Slide 18
The Ancillary Service Plan
ERCOT
DAM DRUC
The Ancillary Service Plan identifies obligations for each
1330 143010000600
The Ancillary Service Plan identifies obligations for each hour of the next Operating Day, assigned to each QSE with load on a load-ratio share basis.
Slide 19
Ancillary Service Obligation
QSE
DAM DRUC
Q10000600 1330 1430
Self-ArrangedgQuantity
AND/OR
AncillaryService
Obligation
PurchaseFromERCOT
Slide 20
Obligation ERCOT
Self-Arranged Ancillary Services
QSE
DAM DRUC
Q10000600 1330 1430
Self-SupplySupply
AND/OR
BilateralPurchases
Self-ArrangedQuantity
Slide 21
Quantity
What Occurs in the Day-Ahead Market?
Energy Bids & Offers
Energy Bids & Offers Energy AwardsEnergy Awards
Ancillary Ancillary Ancillary Service
Ancillary ServiceService OffersService Offers Service AwardsService Awards
CCPTP Obligation
BidsPTP Obligation
BidsPTP Obligation
AwardsPTP Obligation
Awards
Co-Optimization
Engine
Co-Optimization
Engine
Slide 22
Locational Market Pricing
Day-Ahead Market LMPs
An LMP is the offer-based,
marginal cost of serving the g
next increment of Load at an
electrical buselectrical bus
Slide 23
Congestion
LMPs may reflect impact of congestion caused by:
• Supply & Demand
– Offers and Bids
• Transmission Constraints
• OutagesOutages
– Transmission
Resources– Resources
Slide 24
Settlement Points
LMPs are used to calculate Settlement Point Prices
• Settlement Points may be:
• Resource Nodes• Resource Nodes
• Load Zones
• Hubs
Slide 25
Resource Node
R N dResource Node• An electrical bus where a
Generation Resource’s measured output is settled.
• Settlement Point Prices - Based on the LMP at the Resource Nodethe LMP at the Resource Node.
+
Slide 26
Load Zone
Load Zone
Three types of Load Zones:• Competitive• NOIE• DC Tie
Settlement Point Prices - Load-weighted average of the LMPs at all the load buses in the zone.
Slide 27
Trading Hub
• Settlement Point Prices at
Hub
Hubs are calculated using the simple average of LMPs for all hub-buses in the d fi d h bdefined hub.
Slide 28
DAM vs. Real-Time
LMPs are generated in both Day-Ahead and Real-time • Calculated separately• Calculated separately• Typically different• Creates financial impact on QSEsC ea es a c a pac o QS s
$15$10 $12$15
≠$5
$25 $10
$10
$35 $2≠
Slide 29
$5 $10
Pre-Market Activities
1 Day-Ahead Market Basics1 Day Ahead Market Basics
2 Pre-Market Activities2 Pre-Market Activities
3 DAM Clearing & Post-Market Activities
Slide 30
3 DAM Clearing & Post-Market Activities
Update RMR COPs
QSE
DAM DRUC
Q10000600 1330 1430
QSEs with RMR Agreements must submit their updatedQSEs with RMR Agreements must submit their updated Current Operating Plans.
RMR
Slide 31
Publish System Conditions
ERCOT
DAM DRUC
1330 143010000600
ERCOT must publish:ERCOT must publish:• Operations model topology
• Weather assumptions• Weather assumptions
• Load forecasts & distribution factors
S ttl t P i t li t d• Settlement Point lists and maps
• Transmission constraints
Slide 32
DAM Clearing and Post-Market Activities
1 Day-Ahead Market Basics1 Day Ahead Market Basics
2 Pre-Market Activities2 Pre-Market Activities
3 DAM Clearing & Post-Market Activities
Slide 33
3 DAM Clearing & Post-Market Activities
DAM Clearing
Energy Bids & Offers
Energy Bids & Offers Energy AwardsEnergy Awards
Ancillary Ancillary Ancillary Service
Ancillary Service
CC
Service OffersService Offers Service AwardsService Awards
PTP Obligation Bids
PTP Obligation Bids
Co-Optimization
Engine
Co-Optimization
EnginePTP Obligation
AwardsPTP Obligation
Awards
Slide 34
Publish Market Results
ERCOT
DAM DRUC
ERCOT must publish:
1330 143010000600
ERCOT must publish:• Awarded Ancillary Service Offers• Awarded Energy Bids & Offersgy• Awarded PTP Obligation Bids • DAM LMPS and Shadow Prices• DAM Settlement Point Prices
Slide 36
Updating Current Operating Plans
QSE
DAM DRUC
Q1330 143010000600
Slide 37
Updating Current Operating Plans
QSE
DAM DRUC
QSE is responsible for updating COP due to:
Q1330 143010000600
QSE is responsible for updating COP due to:• Changes in Market conditions• DAM awards
RUC• RUC• SASMs• Outages*
Th COP b d t d tig
• Deratings* The COP may be updated any time before end of Adjustment Period
Slide 38
* Must also update Outage Scheduler – to be covered later
COP Contents
QSE
DAM DRUC
Q1330 143010000600
The COP reflects anticipated operating conditionsThe COP reflects anticipated operating conditions, including:
• Expected Status, by hourC it• Capacity
• Ancillary Service commitments
Each QSE has one and only one COP of each Resource
Slide 39
COP of each Resource
Integrity
QSE
DAM DRUC
ERCOT monitors COPs for validity
Q1330 143010000600
ERCOT monitors COPs for validity• If invalid, QSE must update ASAP within applicable
timeframes
Slide 40
Reasons for updating Current Operating Plans
QSE
DAM DRUC
Q1330 143010000600
By 1430 COPs must be updated toBy 1430 COPs must be updated to reflect:
• Assignment of AS Resource R ibilitResponsibility
• Commitments due to award of resource-specific offers.
• Self-Commitments in response to DAM results.
Slide 41
Life-Span
QSE
DAM DRUC
COP ceases to be in effect at Real Time
Q1330 143010000600
COP ceases to be in effect at Real-Time.
COP TelemetryAdjustment Period Real-Time Operations
COP Telemetry
Slide 42
DAM Awards
QSE
DAM DRUC
Q10000600 1330 1430
Update COPUpdate COP
AwardedAwarded
Update COPUpdate COP
OR
3PSO3PSO DAM DRUCOR
Not Awarded
Not Awarded OR
Slide 43
Self-CommitSelf-Commit
Ancillary Service Supply Responsibility
QSE
DAM DRUC
AS Supply Responsibility is the total amount of
Q1330 143010000600
AS Supply Responsibility is the total amount of each Ancillary Service commitment expected to be delivered in Real-Time
P QSE• Per QSE• For each Ancillary Service
AS Supply = +
Self-ArrangedQ
AncillaryService +
AncillaryService
Slide 44
Responsibility Quantity Trades Awards(Sale – Purchase)
Ancillary Service Resource Responsibility
QSE
DAM DRUC
Q1330 143010000600
AS ResourceResponsibility
AS ResourceResponsibility A
Bp y
AS ResourceResponsibility
AS Supply C
Slide 45
ResponsibilityResponsibility
Making Bilateral Trades
QSE
DAM DRUC
Q1330 143010000600
QSEs may wish to make Bilateral Trades based upon theQSEs may wish to make Bilateral Trades based upon the results of the Day-Ahead Market.
• QSE-to-QSE trades:E• Energy
• Capacity• Ancillary Service
Trades and corresponding COP updates should be reported
Slide 46
Trades and corresponding COP updates should be reported to ERCOT by 1430 to be recognized in the DRUC process
Energy Trades
QSE
DAM DRUC
Q1330 143010000600
Transfers responsibility to supply energy at Real-TimeTransfers responsibility to supply energy at Real Time.
Slide 47
Capacity Trades
QSE
DAM DRUC
Q1330 143010000600
Transfers responsibility to supply capacity at Real-TimeTransfers responsibility to supply capacity at Real Time
Slide 48
Ancillary Service Trades
QSE
DAM DRUC
Q1330 143010000600
Transfers responsibility to supply Ancillary Services atTransfers responsibility to supply Ancillary Services at Real-Time
Slide 49
DC Tie Schedules
QSE
DAM DRUC
Q1330 143010000600
DC Ties connect the ERCOT transmission grid to outsideDC Ties connect the ERCOT transmission grid to outside transmission elements
• QSEs may leverage to buy / sell energy
• Transactions subject to NERC and ERCOT scheduling restrictions
Slide 50
Impacts on QSE
QSE
DAM DRUC
Q1330 143010000600
ERCOT considers DC Tie transactions when examiningERCOT considers DC Tie transactions when examining grid reliability:
• Energy entering the grid is treated as a ResourceE l i th id i t t d L d• Energy leaving the grid is treated as a Load
These transactions can impact the pQSE during RUC
Slide 51
Timing
QSE
DAM DRUC
Q1330 143010000600
DAM Results may prompt a QSE to submit a DC TieDAM Results may prompt a QSE to submit a DC Tie Schedule.
1430 hrs
DRUC HRUCDRUC HRUCSubmitted after…Submitted prior to…
Slide 52
Day-Ahead Reliability Unit Commitment (DRUC)
1 DRUC Basics1 DRUC Basics
2 Transmission Security Analysis2 Transmission Security Analysis
3 Reliability Unit Commitment
Slide 53
3 Reliability Unit Commitment
DRUC Overview
1 DRUC Basics1 DRUC Basics
2 Transmission Security Analysis2 Transmission Security Analysis
3 Reliability Unit Commitment
Slide 54
3 Reliability Unit Commitment
Introduction
This module covers Day-Ahead Reliability Unit Commitment
Slide 55
Why DRUC?
Why look at reliability at the end of the DAM?B Th D Ah d M k t ll th k t l tBecause The Day-Ahead Market allows the marketplace to:• Buy / Sell energy• Meet Ancillary Service obligations• Meet Ancillary Service obligations• Commit enough Resources
Slide 56
Why DRUC?, cont’d
Errors and uncertainty may occur in:W th f t• Weather forecasts
• Demand forecasts• Time of day forecasts are taken• Time of day forecasts are taken• Resource shortages
Slide 57
DRUC Sequence
DRUC Comprised of 2 Sub-Processes:T i i S it A l i (TSA)• Transmission Security Analysis (TSA)
• Reliability Unit Commitment (RUC)
1430
1600
TSA RUCDRUC
Slide 58
Transmission Security Analysis
1 DRUC Basics1 DRUC Basics
2 Transmission Security Analysis2 Transmission Security Analysis
3 Reliability Unit Commitment
Slide 59
3 Reliability Unit Commitment
TSA Overview
TSA Inputs• Forecast potential problems on grid• Forecast potential problems on grid• Screen contingencies• Generate inputs for RUCGenerate inputs for RUC• Make adjustments in Load and weather data
Slide 60
TSA Summary
DRUC TSA Sub-Process
Inputs Processes Outputs
Ne
Base Case Network Model
Normal Breaker & Switch Status
Load ForecastValid Network Model
Known Contingency List
ERC
OT O
p
etwork Secu
Updated N
e
Load Forecast
Load Distribution Factors
Weather ForecastList
Self Committed Resource Set
perator Rev
urity Analysi
etwork M
ode
Violations to resolve
iew
isel
Generic Constraints
Slide 61
Screened Contingency ListContingency List
TSA Summary
DRUC TSA Sub-Process
Inputs Processes Outputs
Ne
Valid Network Model
Known Contingency List
ERC
OT O
p
etwork Secu
Updated N
eList
Self Committed Resource Set
perator Rev
urity Analysi
etwork M
ode
Equipment Ratings
Unplanned Transmission Outages
Violations to resolve
iew
isel
Slide 62
Screened Contingency List
TSA Summary
DRUC TSA Sub-Process
Inputs Processes Outputs
Ne
Valid Network Model
Known Contingency List
ERC
OT O
p
etwork Secu
Updated N
eList
Self Committed Resource Set
perator Rev
urity Analysi
etwork M
ode
Violations to resolve
iew
iselUnplanned Resource Outages / Deratings
Other COP Input
Slide 63
Screened Contingency List
Contingency List
DRUC TSA Sub-Process
Inputs Processes Outputs
Ne
Valid Network Model
Known Contingency List
ERC
OT O
p
etwork Secu
Updated N
eList
Self Committed Resource Set
perator Rev
urity Analysi
etwork M
ode
Violations to resolve
iew
isel
Slide 64
Screened Contingency ListContingency List
Network Security Analysis
DRUC TSA Sub-Process
Inputs Processes Outputs
Ne
Valid Network Model
Known Contingency List
ERC
OT O
p
Updated N
e
etwork Secu
List
Self Committed Resource Set
perator Rev
etwork M
ode
urity Analysi
Violations to resolve
iew
el is
Slide 65
Screened Contingency List
ERCOT Review
DRUC TSA Sub-Process
Inputs Processes Outputs
Ne
Valid Network Model
Known Contingency List
ERC
OT O
p
Updated N
e
etwork Secu
List
Self Committed Resource Set
perator Rev
etwork M
ode
urity Analysi
Violations to resolve
iew
el is
Slide 66
Screened Contingency List
Outputs
Processes Outputs
DRUC TSA Sub-Process
Inputs
Ne
ERC
OT O
p
Updated N
e
etwork Secu
Valid Network Model
Known Contingency Listperator R
ev
etwork M
ode
urity Analysi
List
Self Committed Resource Set
iew
el is
Violations to resolve
Slide 67
Screened Contingency ListScreened Contingency List
Reliability Unit Commitment
1 DRUC Basics1 DRUC Basics
2 Transmission Security Analysis2 Transmission Security Analysis
3 Reliability Unit Commitment
Slide 68
3 Reliability Unit Commitment
RUC Overview
RUC’s goal is to maintain grid reliability while observing transmission
constraints and minimizing costs.
Slide 69
RUC Overview
Day-Ahead RUC Sub-Process Inputs Processes Outputs
Resource Standing Data
RUC Time StampER
CO
T
RU
C It
RUResource Cost and Fuel Data
RUC Time Stamp
Cleared Commitments
Cleared De-
T Operator R
teration Res
UC
Function
Self-Arranged AS & Previous RUCs
Mitigated Offer-Cap Curve
commitments
Procured AS capacity for DAM insufficiency
Review
sultsRMR 3-Part Supply Offers
Previous DRUC, SASM, & HRUC Results
Hourly TSA ResultsInfeasible ResourceAS Capacity
Hourly TSA Results
DC Tie Schedules
3-Part Supply Offers
Slide 70
IterationsCurrent Operating Plan
RUC Inputs - ERCOT
Day-Ahead RUC Sub-Process Inputs Processes Outputs
RUC Time StampER
CO
T
RU
C It
RU
Resource Standing Data
Resource Cost and Fuel DataRUC Time Stamp
Cleared Commitments
Cleared De-
T Operator R
teration Res
UC
Function
Self-Arranged AS & Previous RUCs
Mitigated Offer-Cap Curve
commitments
Procured AS capacity for DAM insufficiency
Review
sultsRMR 3-Part Supply Offers
Infeasible ResourceAS Capacity
Slide 71
Iterations
RUC Inputs - TSA
ProcessesDay-Ahead RUC Sub-Process
Inputs Outputs
RUC Time StampER
CO
T
RU
C It
RU
RUC Time Stamp
Cleared Commitments
Cleared De-
T Operator R
teration Res
UC
Functioncommitments
Procured AS capacity for DAM insufficiency
Review
sults
Previous DRUC, SASM, & HRUC Results
Hourly TSA ResultsInfeasible ResourceAS Capacity
Hourly TSA Results
Slide 72
Iterations
RUC Inputs - QSE
ProcessesDay-Ahead RUC Sub-Process
Inputs Outputs
RUC Time StampER
CO
T
RU
C It
RU
RUC Time Stamp
Cleared Commitments
Cleared De-
T Operator R
teration Res
UC
Functioncommitments
Procured AS capacity for DAM insufficiency
Review
sults
Infeasible ResourceAS Capacity
DC Tie Schedules
3-Part Supply Offers
Slide 73
IterationsCurrent Operating Plan
RUC Outputs
ProcessesDay-Ahead RUC Sub-Process
Inputs Outputs
ERC
OT
RU
C It
RU
RUC Time StampT Operator R
teration Res
UC
Function
RUC Time Stamp
Cleared Commitments
Cleared De-Review
sults commitments
Procured AS capacity for DAM insufficiency
Infeasible ResourceAS Capacity
Slide 74
Iterations
RUC Outputs
ProcessesDay-Ahead RUC Sub-Process
Inputs Outputs
ERC
OT
RU
C It
RU
RUC Time StampT Operator R
teration Res
UC
Function
RUC Time Stamp
Cleared Commitments
Cleared De-Review
sults commitments
Procured AS capacity for DAM insufficiency
Infeasible ResourceAS Capacity
Slide 75
Iterations
Summary
You’ve learned about…
• Components of Day-Ahead Operations
• Purpose of Day Ahead Operations• Purpose of Day-Ahead Operations
– Day-Ahead Market (DAM)
– Day-Ahead Reliability unit Commitment (DRUC)Day Ahead Reliability unit Commitment (DRUC)
• Inputs and outputs of DAM / DRUC
• Functions within DRUCFunctions within DRUC
– Transmission Security Analysis (TSA)
– Reliability Unit Commitment (RUC)
Slide 76
y ( )
• Impacts of Day-Ahead Operations on Real-Time
Module ConclusionModule Conclusion