ERCOT MARKET EDUCATION · Calculator . Constraints & Shift Factors . Real-Time Dispatch . Slide 38 . Resource Limit Calculator . ... Locational Marginal Prices (LMPs) • Offer-based

ERCOT MARKET EDUCATION

Basic Training Program

Module 6: Real-Time Operations

Slide 3

Module 6: Objectives

Upon completion of this module, you will be able to:

• Identify the timeline and processes of the Operating Period.

• Describe the inputs, process, and outputs relating to Real-Time Energy Dispatch

• Real-Time Network Security Analysis

• Security Constrained Economic Dispatch (SCED)

• Describe the Load Frequency Control process.

• Illustrate the primary financial impacts associated with the Operating Period.

Slide 4

Course Agenda

Slide 5

Real-Time Operations

The Operating Period Activity Timeline

Slide 6


Goals of Real-Time Operations

• Manage reliability • Match generation with demand • Operate transmission system

within established limits • Operate the system at least cost

ERCOT finds the balance between Reliability

and Economics.

Slide 7


Constraints • Power Balance (Generation = Demand) • Transmission constraints • Resource constraints

Contributing Factors • Weather conditions • Planned and unplanned

Outages

Slide 8


Real Time Processes • Energy Dispatch

• Achieve Power Balance • Manage Congestion • Least Cost Dispatch

• Load Frequency Control

• Maintain Power Balance

Slide 9


Energy Dispatch Overview

Offers

Telemetry

Network Operations

Model

Contingencies

Real-Time Network Security Analysis

Security-Constrained Economic Dispatch

Pricing

Dispatch Instructions

Real-Time Dispatch

Slide 10

Offers

Telemetry

Network Operations

Model

Contingencies



Pricing


Real-Time Dispatch

Energy Dispatch Process

Gather Real-Time System Data

Slide 11

QSE Data to ERCOT Telemetered Data includes:

• Resource Status • Generation Resource

• Power output (MW and MVAR) • High and Low Sustained Limits

• Load Resource • Real power consumption • Low and maximum power consumption limits

Real-Time System Data

Slide 12

QSE Data to ERCOT Telemetered Data (continued):

• Resource breaker & switch status • Resource Ramp Rates • Ancillary Service Resource

Responsibility • Ancillary Service Schedule • Current configuration of

combined-cycle Resources


Slide 13

TSP Data to ERCOT Telemetered Data:

• Breaker and Switch Status • Bus Voltage • Line Flows (MW and MVAR) • Transformer Flows (MW and MVAR) • Dynamic Ratings


Slide 14


Resource Decommitments in the Operating Period

A QSE may decommit a Resource for intervals that were not RUC-Committed

• A QSE may decommit a Quick Start Generation Resource (QSGR) without request

• For all other Resources, the QSE must verbally request permission from ERCOT

Slide 15

Communicating Forced Outages In the event of an outage, the telemetered status of the Resource automatically notifies ERCOT of a Forced Outage. Additionally, the QSE provides ERCOT with:

• Nature of Forced Outage • Actual Start time of the Forced Outage or De-rating • Planned End time of the Forced Outage or De-rating • Revised HSL and/or LSL


Slide 16

Offers

Telemetry

Network Operations

Model

Contingencies



Pricing




Real-Time Dispatch

Slide 17

Offers

Telemetry

Network Operations

Model

Contingencies



Pricing





State Estimator

Real-Time Dispatch

Slide 18

Offers

Telemetry

Network Operations

Model

Contingencies



Pricing




State Estimator

Contingency Analysis

Real-Time Dispatch

Slide 19

Offers

Telemetry

Network Operations

Model

Contingencies



Pricing




State Estimator

Contingency Analysis

Constraint Management

Real-Time Dispatch

Slide 20

Offers

Telemetry

Network Operations

Model

Contingencies



Pricing




Constraints & Shift Factors

Real-Time Dispatch

Slide 21

Offers

Telemetry

Network Operations

Model

Contingencies



Pricing



Security Constrained Economic Dispatch

Real-Time Dispatch

Slide 22

SCED

Balancing Reliability and Economics

SCED

Energy Offer

Curves

Network Security Analysis

Slide 23

SCED


SCED

Energy Offer

Curves Network Security Analysis

Slide 24

SCED


SCED

Energy Offer

Curves


Slide 25

SCED


SCED

Energy Offer

Curves


Slide 26

SCED

Energy Offer

Curves


SCED

Balancing Reliability and Economics Security Constrained Economic Dispatch (SCED) evaluates Energy Offer Curves to produce a least cost dispatch of On-Line Resources while respecting transmission and generation constraints.

Slide 27

The Texas Two Step

SCED

SCED

SCED executes twice each cycle

• Ensures competition

• Reduces Market Power

• Allows high prices under “the right circumstances”

Slide 28

The Texas Two Step

SCED

SCED

Circumstances for high prices

• All generation is expensive

• Expensive generation needed to resolve constraints

• Scarcity

Slide 29

SCED

The Texas Two Step

Constraints are classified as: • Competitive • Non-Competitive

SCED

Slide 30

SCED

The Texas Two Step Step One • Uses Energy Offer Curves

for all On-Line Generation Resources

• Observes the limits of Competitive Constraints only

• Determines “Reference LMPs”

SCED

Energy Offer Curve

$ / MWh

Reference LMP

MW

Slide 31

SCED

Energy Offer Curve

The Texas Two Step Step Two • Observes limits of all Constraints

$ / MWh

Reference LMP

MW SCED

Slide 32

SCED

Mitigated Offer cap

The Texas Two Step Step Two • Observes limits of all Constraints

• Energy Offer Curve for on-line Resource capped at Reference LMP or Mitigated Offer Cap (whichever is greater)

Energy Offer Curve

$ / MWh

Reference LMP

MW SCED

Slide 33

SCED Scenarios

Texas Two Step

Slide 34

Energy Offer Curve

$ / MWh

MW

Reference LMP

Mitigated Offer cap

SCED has completed Step 1 and determined Reference LMPs.

How will this Energy Offer Curve look in STEP 2?

SCED

Energy Offer Curve

$ / MWh

MW

Reference LMP

Mitigated Offer cap

Slide 35

Energy Offer Curve

$ / MWh

MW

Reference LMP

Mitigated Offer cap

SCED

SCED has completed Step 1 and determined Reference LMPs.

1. How will this Energy Offer Curve look in STEP 2?

2. What will it take for this scenario to occur?

Energy Offer Curve

$ / MWh

MW

Reference LMP

Mitigated Offer cap

Slide 36

Offers

Telemetry

Network Operations

Model

Contingencies


Pricing



The SCED Process



Real-Time Dispatch

Slide 37

Offers

Telemetry

Network Operations

Model

Contingencies


Pricing



The SCED Process

Resource Limit Calculator


Real-Time Dispatch

Slide 38


Telemetered by the QSE every few seconds

HSL

LSL

Operating Point

High Sustained Limit

Low Sustained Limit

Slide 39


HSL

HASL

LASL

LSL

Reg-Up, RRS & Non-Spin

Reg-Down

Operating Point

Also telemetered by QSE • AS Schedule (RRS & Non-Spin) • AS Resource Responsibility (Reg)

High Ancillary Service Limit

Low Ancillary Service Limit

Slide 40


Base Point Region

HASL

LASL

HDL

LDL

Reg-Up, RRS & Non-Spin

Reg-Down

LSL

Operating Point

HDL ≤ HASL

LDL ≥ LASL

High Dispatch Limit

Low Dispatch Limit

HSL

Slide 41

Offers

Telemetry

Network Operations

Model

Contingencies


Pricing



The SCED Process


Generation to be dispatched


Real-Time Dispatch

Slide 42

The SCED Process

Offers

Telemetry

Network Operations

Model

Contingencies


Pricing






Real-Time Dispatch

Slide 43

Avenues to Real-Time: • Awarded offer in DAM • Committed through RUC • Committed by QSE

Resource with no Offer Curve:

• Is a price taker at current output • Is last to be moved

Energy Offer Curves for Generation Resources:

Offers

Energy Offer Curve

LSL HSL

Slide 44

RTM Energy Bid for Load Resources:

Offers

Loads in SCED:

• Controllable Load Resources may qualify

• Bid represents price tolerance

• Load curtailed at the right price

RTM Energy Bid

LSL HSL (LPC) (MPC)

May be an Aggregate Load Resource

Slide 45

SCED Timeline SCED is executed:

• Every five minutes (at a minimum)

• More often as needed by ERCOT operators or other ERCOT systems.

Energy Dispatch Process Timing

SCED executed by schedule



Operator Initiated

Slide 46

Offers

Telemetry

Network Operations

Model

Contingencies


Pricing



The SCED Process




Real-Time Dispatch

Slide 47

Energy Dispatch Outputs

Locational Marginal Prices (LMPs)

• Offer-based marginal cost of serving the next increment of Load at an Electrical Bus

• Used to calculate Settlement Point Prices • Resource Nodes • Load Zones • Hubs

Resource Nodes

Load Zones

Hubs

Slide 48

Determining Locational Marginal Price

-- Warning --

Greek Letters Ahead!

Χ = Σ (Α + Ω)


∑−=c

ccbusbus SPSFLMP ,, *λ

Shadow Price for Transmission Constraint “c”

Shift Factor of the bus on Transmission Constraint “c”

System Lambda (Price for Power Balance)

Slide 49

Resource-Specific Base Points When SCED issues Base Point Dispatch instructions to QSEs, the information will include:

• Resource Identifier • Desired MW output level • Time of the Dispatch Instruction


Slide 50

Communication of Dispatch Instructions • ERCOT sends dispatch instructions to QSEs

• QSEs are responsible for communicating the instructions to the appropriate Resources


Slide 51

Communication of Dispatch Instructions When they receive dispatch instructions from ERCOT, QSEs must verify receipt.


Electronic Dispatch Instructions (ICCP) Receiving systems acknowledge receipt

to ERCOT within one minute.

For Verbal Dispatch Instructions Recipient orally repeats the instructions back to ERCOT.

Slide 52


Exceptions for Non-Compliance

If recipient recognizes that dispatch instructions…

Then…

• May create an undue threat to safety, undue risk of bodily harm or undue damage to equipment.

• Are not in compliance with the Nodal Protocols.

• Conflict with other valid Instructions.

• Recipient immediately notifies ERCOT

• ERCOT issues another Dispatch Instruction

• ERCOT decides final Dispatch Instructions

Slide 53


Non-Compliance Liability after Final Dispatch Instructions:

QSEs • Liable for failure as indicated in the Protocols • May be charged for the non-compliance

TSPs • Liable for failure as indicated in the Protocols and

the TSP’s Agreement with ERCOT

Slide 54


MIS Hourly Postings

At the beginning of each hour, ERCOT will post: • Changes in ERCOT system conditions • Updated system load forecasts and distribution factors • Total ERCOT System Demand for each Settlement Interval

Slide 55


MIS Postings After SCED

Upon completion of an execution of SCED, ERCOT posts: • LMPs for each Electrical Bus • SCED Shadow Prices • Settlement Point Prices for each Settlement Point

immediately following the end of each Settlement Interval • Active Binding Transmission Constraint and Contingency

pairs

Slide 56


Energy Dispatch Summary

Offers

Telemetry

Network Operations

Model

Contingencies



Pricing


Real-Time Dispatch

Slide 57

Load Frequency Control

Load Frequency Control Overview

SCED is scheduled to execute every 5 minutes.




Slide 58



SCED is scheduled to execute every 5 minutes.

In that same 5-minute interval, LFC runs 75 times.


LFC SCED executed by schedule


Slide 59



The purpose of Load Frequency Control (LFC) is to maintain system frequency.

• Responds to frequency deviations

• Control signal to QSEs

http://ep.ercot.com/npt/ERCOT Nodal Graphics/LFC_badge.png

Slide 60


Load Frequency Control Outputs

Load Frequency Control produces several critical outputs.

• MW correction to restore system frequency

• Deployment of Resources providing:

• Up Regulation (Reg-Up)

• Down Regulation (Reg-Down)

• Responsive Reserve

• Updated Desired Base Point


Slide 61

Load Frequency Control Outputs

Posted on MIS Secure Area:.

• Total amount of deployed Reg-Up and Reg-Down energy in each Settlement Interval from the previous day.

Settlement:

• Net energy for a 15-min. settlement interval is captured in the Resource’s metered generation

• QSE paid at the Real-Time Settlement Point Price.


Slide 62

Regulation Service Deployment

Regulation Service • An Ancillary Service that provides capacity that can

respond to control signals from ERCOT within three to five seconds to respond to changes in system frequency.

Two Types of Regulation Service • Regulation Up (Reg Up)

• Regulation Down (Reg Down)

Slide 63


Deployment of Generation Resource Regulation Service

Service Generation Resource Load Resource

Reg-Up

• Amount available above any Base Point, and below the High Sustained Limit (HSL)

• Above the Low Power Consumption limit

Reg-Down

• Amount available below any Base Point , and above the Low Sustained Limit (LSL)

• Below the Load Resource’s Maximum Power Consumption limit

Slide 64


Deployment of Load Resource Regulation Service

Service Generation Resource Load Resource

Reg-Up

• Amount available above any Base Point, and below the High Sustained Limit (HSL)

• Above the Low Power Consumption limit

Reg-Down

• Amount available below any Base Point , and above the Low Sustained Limit (LSL)

• Below the Load Resource’s Maximum Power Consumption limit

Slide 65


Regulation Service Communications

QSEs to ERCOT: • AS Resource Responsibility • Status indicators for Regulation • Participation Factors

ERCOT to QSEs providing Regulation: • Control Signals • Every 4 seconds • ICCP data link

Slide 66

Responsive Reserve Service Deployment

Responsive Reserve Overview Responsive Reserve is an Ancillary Service that provides operating reserves intended to:

• Help restore system frequency within the first few seconds of a significant frequency deviation.

• Provide energy or Load interruption during the implementation of the Energy Emergency Alert (EEA)


Slide 67

Responsive Reserve Service Deployment

Responsive Reserve Overview ERCOT may also deploy Responsive Reserve when:

• Power requirement to restore frequency within 10 minutes exceeds the Reg-Up ramping capability.

• Responding to system disturbances if SCED does not have sufficient capacity available to dispatch

ERCOT will use Non-Spin to alleviate Responsive Reserve as soon as possible.


Slide 68

Responsive Reserve Deployment

Responsive Reserve Communications

QSEs to ERCOT: • AS Resource Responsibility • AS Schedule by Resource

ERCOT to QSEs with Responsive Reserve: • Control Signals (4 seconds) • ICCP data link • XML for non-Controllable Load Resources

For Responsive Reserve: AS Schedule = AS Resource Responsibility – AS Deployment

Slide 69

Responsive Reserve Deployment

Responsive Reserve Deployment ERCOT allocates deployment proportionally among QSEs providing Responsive Reserve.

QSE adjusts each Resource’s AS Schedule to reflect the Responsive Reserve deployment.

SCED is triggered and energy from Resource is dispatched by SCED.

Slide 70

Non-Spinning Reserve


Non-Spinning Reserve is another ancillary service that provides reserve capacity, but with a longer response time than Responsive Reserve.

• Generally 30 minute response • Actual requirements vary by Resource type • May be used for system-wide or local needs

Slide 71

Resource Deployment Requirements Notes

Off-Line Generation Resource

Operator Dispatch

Instruction

Capable of reaching Non-Spin Resource Responsibility within 30 minutes of Dispatch Instruction.

Energy is dispatched by SCED

On-Line Generation Resource

Standing Deployment

QSE Reduces Non-Spin Schedule to zero at top of the hour


Controllable Load

Resource

Operator Dispatch

Instruction

Provide the requested deployment energy within 30 minutes of Dispatch Instruction



Non-Spinning Reserve Deployment

Slide 72


Load Frequency Control Inputs

Input Location

Actual System Frequency Real-Time Telemetry

Scheduled System Frequency Operator Input in EMS

ERCOT System Frequency Bias Calculation in EMS

Resource Limits Resource Limit Calculator

Resource Output QSE Real-Time Telemetry

Participation Factor (Reg-up & Reg-Down) QSE Real-Time Telemetry

Raise Block Status and Lower Block Status indicators QSE Real-Time Telemetry

Slide 73


Load Frequency Control Inputs

Input Location

Actual System Frequency Real-Time Telemetry

Scheduled System Frequency Operator Input in EMS

ERCOT System Frequency Bias Calculation in EMS

Resource Limits Resource Limit Calculator

Resource Output QSE Real-Time Telemetry

Participation Factor (Reg-up & Reg-Down) QSE Real-Time Telemetry

Raise Block Status and Lower Block Status indicators QSE Real-Time Telemetry

Slide 74


The ACE Algorithm ERCOT ACE (Area Control Error) is the MW-equivalent correction needed to control the actual system frequency to the scheduled system frequency value.

The Equation

ERCOT ACE = 10ß (FS – FA)

Legend

F Frequency

Sub A Actual

Sub S Scheduled

Beta (ß)

System Frequency bias

Slide 75

ACE Algorithm inputs: • Scheduled frequency is 60 Hz

• Actual frequency is 59.8 Hz

• System frequency bias of -100


Legend F Frequency

Sub A Actual 59.8 Hz

Sub S Scheduled 60 Hz

Beta (ß)

System Frequency

bias

-100

ERCOT ACE Algorithm:


ERCOT ACE = 10(-100) * (60 - 59.8)

ERCOT ACE = -1000 * (0.2)

ERCOT ACE = -200

Slide 76


Calculation informs ERCOT: • Short 200 MW

• Need to deploy 200 MW of Reg Up to restore system frequency to 60 Hz

Legend F Frequency

Sub A Actual 59.8 Hz

Sub S Scheduled 60 Hz

Beta (ß)

System Frequency

bias

-100

ERCOT ACE Algorithm:


ERCOT ACE = 10(-100) * (60 - 59.8)

ERCOT ACE = -1000 * (0.2)

ERCOT ACE = -200

Slide 77


Normal ACE Algorithm

14:00 14:05 14:10 14:15 14:20 14:25 14:30 14:35 14:40

200

150

100

50

0

-50

-100

-150

-200

ACE normally hovers around zero

Slide 78


Normal ACE Algorithm

14:00 14:05 14:10 14:15 14:20 14:25 14:30 14:35 14:40

200

150

100

50

0

-50

-100

-150

-200

When system frequency drifts away from 60 Hz, ERCOT deploys Regulation to correct it

Slide 79


Trend over time

14:00

200

150

100

50

0

-50

-100

-150

-200

14:01 14:02 14:03 14:04 14:05

What happens if system demand is increasing so quickly that ERCOT exhausts all Up-Regulation reserves before the next scheduled SCED run?

Slide 80


Scenario Details: • At 0900, SCED runs & issues

Base Points

• Demand rises rapidly in next few minutes

• By 0905, Reg-Up will be exhausted

What options does the ERCOT Operator have for managing this situation?

Slide 81


How does ERCOT know what Real-time reserves are available? Ancillary Services Capacity Monitor

• Calculates available levels of Resource capacity as per Real-time telemetry

• Calculated every 10 seconds

• Posted on MIS

• Streamed over ICCP

http://www.ercot.com/content/cdr/html/as_capacity_monitor.html

Slide 82


Scenario Details: • At 0900, SCED runs and issues a

set of Base Points • Large Generation Resource trips • ERCOT System Frequency drops • Loss is detected through Real-

Time telemetry • ERCOT operators notified by alarm

What happens next?

Slide 83


Real-Time Operations Timeline

Real-Time Financial Impacts

Slide 85


Real-Time Energy Imbalance

Real-Time Ancillary Service Imbalance

Real-Time Pricing 1

2

3

4 Base Point Deviation

Slide 86




Real-Time Pricing 1

2

3


Slide 87

Real-Time Pricing Methodology

Locational Marginal Prices (LMPs)

• Produced by SCED

• Combined with Reserve Price Adders to form Real-Time Settlement Point Prices

LMPs are location-specific. Reserve Price Adders represent the value of

reserves ERCOT-wide.

Resource Nodes

Load Zones

Hubs

Slide 88


Time

Pric

e of

Ene

rgy

($ M

Wh)

SWCAP

SCED can set Scarcity Pricing

under the right conditions

Slide 89


But there is additional value for Real-time Reserves

• Sufficient real-time reserves help avoid load-shedding events

• There is value in avoiding load-shedding events

Value of real-time reserves = Value of avoiding load-shed

Therefore, we may deduce . . .

Slide 90


ERCOT implemented an Operating Reserve Demand Curve on June 1, 2014

• Created a Real-time Price Adder to reflect the value of available reserves

• Reflects Value of Lost Load (VOLL)

• Based on Loss of Load Probability

Value of Lost Load (VOLL) is administratively set to $9000.

Slide 91

Operating Reserve Demand Curve

0 2000 4000 6000 8000

Pric

e of

Res

erve

s ($

/MW

h)

Available Reserves (MWs)

VOLL

Slide 92

Calculating Reserve Price Adders from ORDC

Overall goal is to improve scarcity pricing • SCED itself may produce scarcity pricing • Outside of any congestion impacts, energy pricing

should not exceed VOLL

Reserve Price Adders calculated based on

(VOLL – System Lambda) * Loss of Load Probability

Price of Power Balance in SCED

Slide 93


Time

Pric

e of

Ene

rgy

($ M

Wh)

SWCAP

VOLL

SCED can set Scarcity Pricing

under the right conditions

Reserve Price Adder improves Scarcity

Pricing

Slide 94


But not all reserves are created equal . . .

• Some are available to SCED immediately

• Some can be made available to SCED in 30 minutes

What are some examples of each?

Slide 95


Real-Time Reserve Price Adders

RTORPA – Available during the next 30 minutes

RTOFFPA – Available during the next 60 minutes ERCOT System

RTORPA Real-Time On-Line Reserve Price Adder RTOFFPA Real-Time Off-Line Reserve Price Adder

… calculated each SCED interval

Slide 96


Real-Time Reserve Price Adders

RTRSVPOR =

RTRSVPOFF =

ERCOT System

RTRSVPOR Real-Time Reserve Price for On-Line Reserves RTRSVPOFF Real-Time Reserve Price for Off-Line Reserves

Time-Weighted Average RTORPAs

Time-Weighted Average RTOFFPAs

… for each 15-minute interval

Slide 97

Resource Nodes

Load Zones

Hubs


Settlement Point Prices

= RTRSVPOR + Ave (LMPs)

… for each 15-minute interval

The way the LMPs are averaged varies by Settlement Point

Slide 98




Real-Time Pricing 1

2

3


Slide 99

Real-Time Energy Settlement In Real-time, energy sales and purchases are settled at each of the three Settlement Points:

• Resource Node • Load Zone • Hub

The Real-time Energy Imbalance Charge Type is used for this purpose.


Slide 100


The Basic Idea at any Settlement Point:

SUPPLIES ( ) OBLIGATIONS

( ) _ x RTSPP ($/MWh) Real-Time Settlement

Point Price

Now, we simply fill in the appropriate elements for each Settlement Point

Slide 101


Real-Time Energy Imbalance at a Load Zone Looking at a Load Zone, the calculation looks like this:

Notice that adjusted metered load is part of the equation.

Energy Bids Cleared in the DAM

+ Energy trades where

QSE is the buyer ( ) x RTSPP ($/MWh) Real-Time Settlement Point Price

Energy Offers Cleared

in the DAM +

Energy trades where QSE is the seller

+ Adjusted Metered

Load

( ) (-1) _

Slide 102

_


Real-Time Energy Imbalance at a Resource Node Looking at a Resource Node, the calculation looks like this:

For Resource Nodes, metered generation is included in the equation.

Metered Generation +



QSE is the buyer ( ) x

RTSPP ($/MWh) Real-Time Settlement Point Price

( ) (-1) Energy Offers Cleared

in the DAM +


Slide 103


Real-Time Energy Imbalance at a Hub At a Hub, the calculation looks even simpler.

x RTSPP ($/MWh) Real-Time Settlement Point Price

( ) (-1) _ Energy Bids Cleared in the DAM


QSE is the buyer ( ) Energy Offers Cleared in the DAM


QSE is the seller

Slide 104


Converting DAM Transactions & Trades

• DAM transactions & Trades are conducted hourly

• Real-Time is settled in 15 minute intervals

• For Real-Time Settlements, DAM transactions and Trades must be converted to 15 minute intervals

Slide 105

The Real Time Energy Imbalance – Scenario One

Real Time Energy Imbalance Scenarios 1. QSE with Load but no Generation

2. QSE with Load and Generation

3. QSE with only Generation

Slide 106

Real-Time Energy Imbalance – Scenario One

Scenario One: QSE with Load

Three ways QSE can choose to fulfill

it’s obligations:

No DAM Purchase, No Trades

DAM Purchase

Trade

2

3

1

Slide 107


Scenario One (Example 1):

• QSE does not participate in DAM

• No trades

• Load is 5 MWh for interval 0900



QSE is the buyer ( ) x RTSPP ($/MWh) Real-Time Settlement Point Price

( ) (-1) _

Energy Offers Cleared in the DAM


QSE is the seller +

Adjusted Metered Load

Slide 108



• Load is exposed to Real-Time Prices

• Settlement Point Prices

• North Load Zone: $40

• North Hub: $35

_

( ) ( ) X (-1)$40.00/MWh = $200.00 Real-Time Settlement

Point Price 0 5

Slide 109


( ) x RTSPP ($/MWh) Real-Time Settlement Point Price

( ) (-1)

Scenario One (Example 2): • QSE bought Day-Ahead Market

• No Trades


_ Energy Bids Cleared in the DAM


QSE is the buyer


in the DAM +


+ Adjusted Metered

Load

Slide 110



• QSE bought 28 MW in Day-Ahead Market for Hour Ending 0900

• QSE gets credit for 28 MW in Real-Time (7 MWh per 15 minute interval)

_

( ) ( ) X (-1)$40.00/MWh = -$80.00 Real-Time Settlement

Point Price 7 5

Slide 111



• QSE bought 28 MW for Hour Ending 0900 through a trade at the North Hub.


Slide 112


Real-Time Energy Imbalance at Hub

Real-Time Energy Imbalance at Load Zone

Scenario One (Example 3): • Imbalance calculated at both

Settlement Points (Hub & Load Zone)

Slide 113


_ ( ) ( ) X (-1)$35.00/MWh = -$245.00 Real-Time Settlement

Point Price 7 0

Energy Imbalance at Hub

• QSE gets credit for 7 MWh in Real-Time (28 MW Trade = 7 MWh in RT)

Energy Bids Cleared

in the DAM +

Energy trades where QSE is the buyer ( ) _ ( ) RTSPP

($/MWh) Real-Time Settlement Point Price

(-1) Energy Offers Cleared

in the DAM +


x

Slide 114

Energy Imbalance at Load Zone

• QSE Load is still 5 MWh



Point Price 0 5

( ) RTSPP ($/MWh) Real-Time Settlement Point Price

( ) (-1)

_

x _



QSE is the seller +

Adjusted Metered Load



QSE is the buyer

Slide 115


QSE’s net settlement in Real-Time

• Paid $245 at the North Hub

• Charged $200 at the North Load Zone

• QSE is paid $45

Net = -$245 + 200 = -$45

Slide 116

The Real Time Energy Imbalance – Scenario Two




Slide 117

Real-Time Energy Imbalance – Scenario Two

Scenario Two: QSE with Load & Generation

• Load is still 5 MWh • QSE is dispatched to 20 MW • Settlement Point Prices

• North Load Zone: $40 • Old North Tap (ONTap)

Resource Node: $30

Slide 118

Scenario Two: • Imbalance calculated at Settlement

Points (Resource Node & Load Zone)


Real-Time Energy Imbalance at Resource Node

Real-Time Energy Imbalance at Load Zone

Slide 119


( ) ( ) X (-1)$30.00/MWh = -$150.00 Real-Time Settlement

Point Price

5 0

Energy Imbalance at Resource Node




QSE is the buyer ( ) ( ) (-1) x _

_

RTSPP ($/MWh) Real-Time Settlement Point Price



QSE is the seller

Slide 120


Energy Imbalance at Load Zone

• QSE Load is still 5 MWh



QSE is the buyer ( ) RTSPP ($/MWh) Real-Time Settlement Point Price


in the DAM +


+ Adjusted Metered

Load

( )


Point Price

0 5 _

(-1) x _

Slide 121


What is the QSE’s net settlement in Real-Time?

• Paid $150 at the ONTap Resource Node

• Charged $200 at the North Load Zone

• QSE must pay $50

Net= -$150 + 200 = $50

Slide 122

The Real Time Energy Imbalance – Scenario Three




Slide 123

Real-Time Energy Imbalance – Scenario Three

Scenario One: QSE with Generation

Two Examples

QSE sells energy in DAM and produces it in Real-Time.

QSE sells energy in DAM and produces part of it in Real-Time.

2

1

Slide 124


Relevant Facts: • QSE is dispatched to 20 MW during

interval Ending 0900 • Settlement Point Prices

• ONTap Resource Node: $30 • North Hub: $35

Slide 125


Scenario Three (Example One): • QSE sells energy in DAM and

produces it in Real-Time.

• QSE’s metered generation is 5 MWh • QSE sold 12 MW in Day-Ahead

Market for Hour Ending 0900. • 12 MW in DAM = 3 MWh in Real-

Time

Slide 126


( ) X (-1)$30.00/MWh = -$60.00 Real-Time Settlement

Point Price

5 3


• QSE is paid $60

_


( ) (-1)

_

x

( )




QSE is the buyer



QSE is the seller

Slide 127


Scenario Three (Example Two): • QSE sells energy in the DAM and

produces part of it in Real-Time. • Sold 28 MW in DAM for 0900 • Obligation to provide 7 MWh in Real-

Time (28 MW in DAM = 7 MWh in RT) • QSE’s metered generation is 5 MWh

Slide 128



• QSE is charged $60

( ) Real-Time Settlement Point Price

5 7 _ ( ) X (-1)$30.00/MWh = $60.00

_


( ) (-1) x Metered Generation

+ Energy Bids Cleared

in the DAM +

Energy trades where QSE is the buyer



QSE is the seller

Slide 129


What is the QSE’s net settlement in Real-Time?

• Paid $150 at the ONTap Resource Node.

• Charged $175 at the North Hub.

• QSE must pay $25

Net= -$150 + 175 = $25

Slide 130




Real-Time Pricing 1

2

3


Slide 131

AS Capacity


Base Point

Base Point

$30.00 $34.50 $46.25 $67.80 $93.96 $131.16 $174.87 $227.12 $255.67

Base Point

Base Point

Gen 1 Gen 2

What if . . .

• we could keep on producing Energy from Gen 1?

• we could shift the AS from Gen 1 to Gen 2?

Slide 132


What would Real-Time Co-optimization Look Like?

AS Capacity

Available for

Energy Dispatch

DAM Co-opt.

Gen 1

Energy Produced

RT Co-opt.

QSE Real-Time Settlement:

• Paid RTSPP for energy produced in Real-Time

• Buy back AS Capacity at Real-Time AS Price

Slide 133



AS Capacity

Available for

Energy Dispatch

DAM Co-opt.

Gen 2

Energy Produced

RT Co-opt.



• Paid for AS Capacity at Real-Time AS Price

Slide 134



AS Capacity

Available for

Energy Dispatch

DAM Co-opt.

Gen 2

Energy Produced

RT Co-opt.



• Paid for AS Capacity at Real-Time AS Price

Currently, • No Real-Time Co-optimization • No Real-Time AS Prices

But we do have

Real-Time Reserve Prices

Slide 135


Real-Time Ancillary Service Imbalance Ancillary service reserves are settled at one of the Real-Time Reserve Prices.

• Approximates settlement impacts of Real-Time Co-optimization

• Provides payment for all capacity reserves

AS Capacity

System Capacity

Slide 136


The Basic Idea:

( ) On-line Reserve

Price * (-1) – On-Line Reserve SUPPLIES

On-Line Reserve OBLIGATIONS

( ) Off-line Reserve

Price * – Off-Line Reserve SUPPLIES

Off-Line Reserve OBLIGATIONS +

Calculated ERCOT-wide per QSE

Slide 137


Reserve Supplies and Obligations

Name some examples:

• On-Line Reserve Supplies

• On-Line Reserve Obligations

• Off-Line Reserve Supplies

• Off-Line Reserve Obligations

Slide 138


How’s it settled?

Energy Produced

Real-Time Generator

Paid in Real-Time Energy Imbalance Price: RTSPP

?

HSL

Slide 139


How’s it settled?

Energy Produced

Real-Time Generator

Paid in Real-Time Energy Imbalance Price: RTSPP

?

HSL Paid in Real-Time AS Imbalance Price: On-line Reserve Price ?

Slide 140

AS Capacity


How’s it settled?

Energy Produced

Real-Time Generator

Paid in Real-Time Energy Imbalance Price: RTSPP ?

HSL Paid in DAM or SASM Price: MCPC ?

Slide 141

AS Capacity

AS Deployed


How’s it settled?

Energy Produced

Real-Time Generator

Paid in Real-Time Energy Imbalance Price: RTSPP ?

HSL Charged in Real-Time AS Imbalance Price: On-line Reserve Price ?

Slide 142


How’s it settled?

Capacity Off-line

Real-Time Generator

If available in 30 minutes, Paid in Real-Time AS Imbalance Price: Off-line Reserve Price

It depends . . . ?

HSL

Slide 143


How’s it settled?

Energy Consumed

Real-Time Load

Resource

Charged in Real-Time Energy

Imbalance

Price: RTSPP

?

HSL

LSL

Paid in Real-Time AS Imbalance

Price: On-line Reserve Price

Slide 144


How’s it settled?

Energy Consumed

AS Capacity

Real-Time Load

Resource

Charged in Real-Time Energy

Imbalance

Price: RTSPP

?

HSL

LSL

Paid in Real-Time AS Imbalance

Price: On-line Reserve Price

?

Paid in DAM or SASM Price: MCPC ?

Slide 145




Real-Time Pricing 1

2

3


Slide 146

Base Point Deviation

Real Time Energy Settlement QSE is paid for energy supplies and charged for energy obligations at a settlement point.

But what if a QSE with a Resource: • Generates more than instructed? • Generates less than instructed?

In other words, what happens if a QSE operates a Resource off of its Base Point?

Slide 147


Base Point Deviation Charges Overview A QSE for a Generation Resource shall pay a base point deviation charge if the Resource did not follow Dispatch Instructions and Ancillary Services deployments within defined tolerances.

Slide 148


Base Point Deviation Charges Overview A QSE for a Generation Resource shall pay a base point deviation charge if the Resource did not follow Dispatch Instructions and Ancillary Services deployments within defined tolerances. The NODAL Protocols define the tolerances as:

• ± 5% or ± 5MW, whichever is greater • + 10% for Intermittent Renewable Resources (IRR’s)

Slide 149


Base Point Deviation Charge Exclusions • No charge during a frequency deviation greater than 0.05

Hz if the QSE’s deviation contributes to frequency correction

• No charge for intervals during which Responsive Reserve is deployed

Slide 150


Base Point Deviation Charge Exemptions • RMR units • Qualifying Facilities (as defined by PURA) that do not

submit energy offer curves • Quick Start Generation Resources exempt for 15 minutes

Slide 151


Base Point Deviation Charges

Scenarios are as follows:

1. QSE has a single generator in ERCOT system.

2. Resource is not a QSGR

3. QSE does not provide Ancillary Services.

4. QSE receives base point dispatches from ERCOT to operate at 40 MW during Interval Ending 0900.

Slide 152


Base Point Deviation Charge • Resource output exceeds Dispatch

Instructions by 8MW

• System Frequency at Max Deviation is 59.9400.

Frequency at max deviation during interval

5 9. 9 4 0 0 40 MW

48 MW

Slide 153

Does the QSE pay the base point deviation charge? No. System Frequency at Max Deviation exceeds the .05 threshold identified in the Protocols.



5 9. 9 4 0 0

-.06

40 MW

48 MW

Slide 154


Base Point Deviation Charge • Resource output exceeds Dispatch

Instructions by 8MW



6 0. 0 1 2 5 40 MW

48 MW

Slide 155


Does the QSE pay the base point deviation charge? Yes. Resource output exceeds Dispatch Instructions beyond tolerances, and Frequency at Max Deviation is within Protocol allowances.


6 0. 0 1 2 5

.0125

40 MW

48 MW

Slide 156


Base Point Deviation Charge • Resource output falls short of

Dispatch Instructions by 6MW



6 0. 0 1 2 5 40 MW

34 MW

Slide 157


Does the QSE pay the base point deviation charge? Yes. Resource output exceeds Dispatch Instructions beyond tolerances, and Frequency at Max Deviation is within Protocol allowances.


6 0. 0 1 2 5

.0125

40 MW

34 MW

Slide 158


Base Point Deviation Charge • Resource output falls short of

Dispatch Instructions by 6MW



6 0. 0 5 2 5 40 MW

34 MW

Slide 159


Does the QSE pay the base point deviation charge? No. Resource output exceeds Dispatch Instructions tolerances, but Frequency Deviation is greater than .05 Hertz.


6 0. 0 5 2 5

.0525

40 MW

34 MW

Slide 160

Determining Base Point Deviation Charges

ERCOT compares Adjusted Aggregated Base Points to the Time-Weighted Telemetered Generation.

Adjusted Aggregated Base Point

Time-Weighted Telemetered Generation


Slide 161


Calculating Adjusted Aggregated Base Point

Average Base Point

Adjusted Aggregated Base Point

Average Regulation = +

Considers Ramping

15 Minute Value

Slide 162


Base Point Deviation for QSE with Regulation

• QSE receives Base Point dispatches during Interval Ending 0900

• QSE also receives Regulation deployments


6 0. 0 7 8 6

Slide 163


Base Point Deviation for QSE with Regulation

• Not following Reg-down instructions looks like over-generating.

• Not following Reg-up instructions looks like under-generating.


6 0. 0 7 8 6

Slide 164

Module 6: Summary

You have learned: • Activities of ERCOT, TSPs, and QSEs in


• Impact of ERCOT, TSPs and QSEs on the processes that occur in Real-Time Operations

• Purpose of the Real-Time processes

• The financial impact of the activities in Real-Time Operations

Module Conclusion

ERCOT MARKET EDUCATION · Calculator . Constraints & Shift Factors . Real-Time Dispatch . Slide 38 . Resource Limit Calculator . ... Locational Marginal Prices (LMPs) • Offer-based

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