Intermittent Renewable Resources...Resource that can only produce energy from variable, uncontrollable Resources, such as wind, solar, or run-of-the-river hydroelectricity. Currently,

ERCOT Market Education

Intermittent Renewable Resources

2

This presentation provides a general overview of the Texas Nodal Market and is not intended to be a substitute for the ERCOT Protocols, as amended from time to time. If any conflict exists between this presentation and the ERCOT Protocols, the ERCOT Protocols shall control in all respects.

For more information, please visit:

http://www.ercot.com/mktrules/nprotocols/

Protocol Disclaimer

Housekeeping


3

• Restrooms

• Refreshments

• Attendance sheet

• Questions

Housekeeping

Please silence smart phones & other electronics

Course Introduction

5

This course is intended for personnel responsible for registering, operating and marketing Intermittent Renewable Resources (IRRs) in ERCOT

Includes:

• Resource Entities

• Qualified Scheduling Entities

• ERCOT staff

Course Audience

6

• Differentiate between IRRs and other generation technologies in ERCOT

• Identify the unique telemetry requirements of IRRs

• Describe the operational requirements for IRRs

• Summarize how IRR capabilities are forecast

• Summarize how IRRs are dispatched

• Describe a few Settlement impacts for IRRs

Upon completion of this course, you should be able to:

Course Objectives

7

Course Modules

Resource Landscape in ERCOT1

2 Market Provisions and Requirements for IRRs

3 IRR Forecasting

4 IRRs in Market and System Operations

5 Financial Settlements of IRRs

Modules in this course include:

6 MIS Reports for IRRs

Module 1

Resource Landscape in ERCOT

9

• Installed capacity and energy produced by fuel type

• Landscaping trends

• A few definitions

Topics in this module ...

Module Topics

10

The Generation Resource Landscape

Natural Gas53.3%

Coal20.5%

Wind19.6%

Nuclear5.0%

Other1.6%

2017 Installed Capacity

Natural Gas38.9%

Coal32.2%

Wind17.4%

Nuclear10.8%

Other0.8%

2017 Energy Produced

Total 78,251 MW

Total 357 million

MWh

Peak Demand Record: 73,308 MW on July 19, 2018

11

Landscape Trends

Natural Gas56%

Coal23%

Wind13%

Nuclear7%

Other1%

2011 Installed Capacity

Natural Gas39%

Coal39%

Wind9%

Nuclear12%

Other1%

2011 Energy Produced

Total72,349 MW

Total 334 million

MWh

Peak Demand in 2011: 68,305 MW on August 3, 2011

12

ERCOT Wind Generation (as of January 2018)

13

ERCOT Utility-Scale Solar Generation (as of January 2018)

14

Intermittent Renewable Resource (IRR) – A Generation Resource that can only produce energy from variable, uncontrollable Resources, such as wind, solar, or run-of-the-river hydroelectricity.

Currently, two types:

• Wind-Powered Generation Resource (WGR)

• PhotoVoltaic Generation Resource (PVGR)

A Few Definitions

Typically, WGRs and PVGRs are aggregations of Wind Turbines or Photovoltaic equipment

15

A Resource Entity may aggregate Intermittent Renewable Resource generation equipment together to form a single IRR.

General Rules:• Same Electrical Bus

• Generally, same model and size1

• Does not reduce ERCOT’s ability to model

Aggregation to form IRRs

1 See Protocol 3.10.7.2 (11) for exceptions

16

IRR Group – A group of two or more IRRs whose performance in responding to Security-Constrained Economic Dispatch (SCED) Dispatch Instructions will be assessed as an aggregate

• All IRRs must have the same Resource Node

• No Split Generation Resources

One More Definition

IRR1

IRR2

ERCOT

ERCOT-Polled Settlement (EPS) Meter

Resource Node

IRR Group

17

A Resource Entity wants to build a single generation site with both wind generation and photovoltaic systems

Class Discussion

IRR Definitions Test Drive

1. Can they create a single IRR?

2. Can they create an IRR Group?

No – Equipment is too dissimilar. Must be two IRRs

Yes – Assuming that the two IRRs can be set up with the same Resource Node.

Module 2

Market Provisions and Requirements for IRRs

19

• What makes IRRs unique?

• Impacts to ERCOT

• General IRR operating requirements


Module Topics

20

What Makes IRRs Unique?

Variability Location Technology

Intermittent Energy Supply

Large and Sudden Ramps

Capacity Uncertainty

Transmission Constraints

Subsynchronous Resonance

Not Synchronous Generators

Limited Governor Control

21


Variability




Challenges

• Dispatching to a Base Point

• Managing Variances

22

IRR Dispatch

Intermittent Energy Supply Wind and Solar Energy – Use it or Lose it

• Non-IRRs chase their Base Points

• IRRs chase their energy supply

• Run at max capability (unless curtailed)

• Base Point is permissive

23

Managing Variances


ERCOT responds to variability with Regulation Service

Regulation matches generation with demand by responding to changes in system frequency

But how much Regulation does ERCOT need?

Is the amount impacted by IRRs?

24

Net Load

Load

Net Load

Non-Coastal Wind

Coastal WindSolar

Regulation manages risk of changes in Net Load


IRR outputs are subtracted from System Load to derive Net Load

25

• Hourly need based on two years’ history for the same month

Max

• Incremental MWs for additional Wind Generation 1

Regulation Impact

95th percentile of Regulation deployed 95th percentile Net Load changes


Continued IRR growth may impact Regulation requirements

1 Details in Methodology for Determining Minimum Ancillary Service Requirements

26


Variability




Challenges

• Energy supply may change dramatically at times

• IRRs have nearly instantaneous ramp rates

27

Energy Supply Ramp

Large and Sudden Ramps Dramatic changes in Energy Supply

Wind Output 12/19/2017

28

Impact of Energy Supply Ramp


• Regulation manages Net Load changes

• Non-Spin manages under-forecast Net Load ramp

May impact ERCOT procurement of Regulation and Non-Spin Reserves

Load

Wind

MW

Hour

Periods of increasing load with decreasing wind may put system

at ramping risk

29

IRR Ramp Rates

Time (seconds)0 +100 +200 +300

60.000

60.050

59.950

60.025

59.975

Time (seconds)0 +100 +200 +300

60.000

60.050

59.950

60.025

59.975

Large and Sudden Ramps With nearly instantaneous ramp rates …

Frequency could dip when IRRs curtailed

Frequency could spike when curtailment released

30

IRR Ramp Rate Limits


IRRs ramp rates limited to 20% of Nameplate Rating per minute

FullOutput

5 minutes

ZeroOutput

When curtailed by ERCOT

When released from curtailment by ERCOT

FullOutput

5 minutes

ZeroOutput

31


Variability




Challenges

• Difficult to predict available capacity for future hours

• Peak capacity may not coincide with peak demand

32

Predictability

Centralized IRR Forecasting

• ERCOT is responsible for IRR forecasting

• Consistent methodology for all IRRs


More details on forecasting later in the course

33

Telemetry to Enhance Predictability

More telemetry data for IRRs means better forecasting

• Meteorological Tower Data from each site

• Detailed equipment status

• Wind turbines in service

• Inverters in service


In-Service Out Unknown

Turbines 42 2 1

Inverters 28 1 1

34

Peak Capacity and Peak Demand

IRR capacity may not peak when most beneficial to the system


Load

Net Load

Non-Coastal Wind

Coastal WindSolar

35

Wholesale Storage Loads

Wholesale Storage Load

Generation(May be IRR)

OtherLoad Metered

separately

EPSMeter

Wholesale Storage Loads may help Capacity Uncertainty

Basic Idea:1. Store energy when not needed2. Release later when needed

36


Challenges

• Interconnection in remote areas

• Interconnection in weak areas

Location



37

Potential Constraints

Potential constraints highlighted in Full Interconnection Study (FIS)


FIS Study Report includes:

• Nature of constraints• Stability• Overload

• Base Case• Contingency Case

• Severity of constraints

38


Challenges

• Series compensated lines increase likelihood of resonance at frequencies below 60Hz

• Resonance may damage generators

Location



Generator(May be IRR)

Line Impedance

Series Capacitor

System Load

39

Initial Assessment

New Interconnecting Generation Resources

• Initial SSR1 screening by ERCOT

• Vulnerability Assessment by TSP if needed


1Subsynchronous Resonance

If countermeasures are required,

• Interconnecting Entity responsible

• Must be implemented prior to Initial Synchronization

40

Annual Re-Assessment

Resources in the Planning Model

• Annual SSR1 Review by ERCOT

• Vulnerability Assessment by TSP if needed


If countermeasures are required,

• TSP responsible

• Must be implemented by latter of1. Completion of transmission project 2. Initial Synchronization

1Subsynchronous Resonance

41


Challenges

• All Generation Resources must provide Reactive Power

• Induction generators and photovoltaic panels don’t produce reactive power

Technology



MVAR

MW

42

Voltage Support

IRRs must provide Reactive Power

Operating at or above 10% Nameplate Rating• Support voltage set point at POI1

• Up to Unit Reactive Limit (URL)


If output is below 10% of Nameplate, ERCOT may

request shutdown Leading

LaggingMW

MVAR

Typical Generator

Max MW at .95 PF

URL

URL

1 Point of Interconnect

43


Challenges

• All Resources must provide Primary Frequency Response

• IRRs don’t have traditional governors (if any)

Technology



44

A Governor by any other name . . .

IRRs must provide equivalent governor response to stabilize frequency


0 +50 +100 +150 +200 +250 +300

60.000

60.017

59.983

Time (seconds)

Syst

em F

requ

ency

(Hz) Governor

Deadband

Governor Deadband

Resources provide proportional response

Resources provide proportional response

Module 3

IRR Forecasting

46

• IRR Hourly Forecasting

• Wind Generation

• Photovoltaic Generation

• IRR Ramp Forecasting


Module Topics

IRR Hourly Forecasting

48

Combination of QSE, Vendor, and ERCOT processes

Wind Generation Forecasting

Resource Site Data

Vendor Forecasting

Process(Proprietary)

Wind Generation Forecasts

49

QSE must provide site data for each WGR

Resource Site Data

Resource Site Data

Met Tower Data

Resource Telemetry

Outages

ICCP HandbookReported through

ICCP Telemetry

Details in ERCOT ICCP Handbook

Reported through Outage Scheduler

http://www.ercot.com/services/mdt/userguides

50


Meteorological Tower Data

Resource Site Data

Resource Telemetry

Outages

Met Tower Data

Site meteorological data

• Wind Speed

• Wind Direction

• Temperature

• Barometric Pressure

. . . updated every 10 seconds

51


Resource Telemetry

Resource Site Data

Resource Telemetry

Outages

Met Tower Data

Resource operational data• Resource Status

• Power Output (MW & MVAR)

• High Sustained Limit (HSL)

• Number of Turbines Online

• Number of Turbines Offline

• Number of Turbines Unknown

. . . updated every 2-10 seconds

52


Outages

Resource Site Data

Resource Telemetry

Outages

Met Tower Data

Resource availability data• Outage – A Resource that has

been removed from service

• Forced Derate – A portion of a Resource that has been removed from service

• 10 MW or 5% of rating*

• Must be reported if expected to last more than 48 hours

*Seasonal Net Max Sustainable Rating

53

Vendor process uses multiple forecasting models

Vendor Forecasting Process

ResourceSite Data

Forecasting Process

Plant Output Model

Statistical Models

Atmospheric Physics Models

Met Tower Data

Resource Telemetry

Outages

54



Forecasting Process

Plant Output Models

Statistical Models


Forecasting Process

Plant Output Models

Statistical Models


Suite of physical weather models

• Consume regional weather data from National Weather Service and other sources

• Produce an ensemble of weather forecasts for each region

55


Statistical Models

Forecasting Process

Plant Output Models

Statistical Models


Statistical Models

Suite of statistical models

• Incorporate QSE Met Tower Data

• Refine regional forecasts

• Accommodate local topography and conditions

• Incorporate initial conditions

• Produce an ensemble of wind speed forecasts around each Wind Generation Resource

56


Plant Output Models

Forecasting Process

Plant Output Models

Statistical Models


Plant Output Models

A model for each WGR

• Translates wind speed forecasts into wind power forecasts

• Uses manufacturer’s power curves for new plants

• Builds plant-specific power curve over time

• Met Tower Data

• Resource Telemetry Data

57

Where are we now?

From Models to Forecast

Forecasting Process

Plant Output Models

Statistical Models


At this point:

• We have an ensemble of forecasts for each WGR

• We need hourly forecasts:• For each WGR• For each ERCOT Region• For ERCOT system

. . . and all these forecasts must be consistent

58

Ensemble of hourly forecasts

Total ERCOT Wind Power Forecast

0

2000

4000

6000

8000

10000

12000

14000

1 3 5 7 9 11 13 15 17 19 21 23

MW

Hour

Summed from individual WGR forecasts

59

Protocols specify two statistical values

Using the Total ERCOT Wind Power Forecast

0

2000

4000

6000

8000

10000

12000

14000

1 3 5 7 9 11 13 15 17 19 21 23

MW

Hour

0

2000

4000

6000

8000

10000

12000

14000

1 3 5 7 9 11 13 15 17 19 21 23

MW

Hour

50% Probability of Exceedance (POE)80% Probability of Exceedance (POE)

60

Created from Total ERCOT Wind Power Forecast

Hourly Individual WGR Forecasts

Short-Term Wind Power Forecast• Allocated proportionally from 50% POE

• Rolling 168 hour forecast for each WGR

• Used in reliability studies

WGR Production Potential• Allocated proportionally from 80% POE

• Rolling 168 hour forecast for each WGR

• Used in financial settlements

61

WGR Forecasting Summary

Wind Generation Forecasting

Resource Site Data

Forecasting Process

Wind Forecasts

Plant Output Models

Statistical Models


Met Tower Data

Resource Telemetry

Outages

62

PVGR Forecasting is very similar

Solar Generation Forecasting

Resource Site Data

Forecasting Process

PhotoVoltaic Forecasts

Plant Output Models

Statistical Models


Met Tower Data

Resource Telemetry

Outages

63

QSE must provide site data for each PVGR

Meteorological Tower Data

Resource Site Data

Resource Telemetry

Outages

Met Tower Data

Site meteorological data• Wind Speed

• Wind Direction

• Temperature

• Barometric Pressure

• Back Panel Temperature

• Plane of Array Irradiance

. . . updated every 10 seconds

64

QSE must provide site data for each PVGR

Resource Telemetry

Resource Site Data

Resource Telemetry

Outages

Met Tower Data

Resource operational data• Resource Status

• Power Output (MW & MVAR)


• Number of Inverters Online

• Number of Inverters Offline

• Number of Inverters Unknown

. . . updated every 2-10 seconds

65

Ensemble of hourly forecasts

Total ERCOT PhotoVoltaic Power Forecast

0

2000

4000

6000

8000

10000

12000

14000

1 3 5 7 9 11 13 15 17 19 21 23

MW

Hour

0

2000

4000

6000

8000

10000

12000

14000

1 3 5 7 9 11 13 15 17 19 21 23

MW

Hour

50% Probability of Exceedance (POE)80% Probability of Exceedance (POE)

66

Created from Total ERCOT PhotoVoltaic Power Forecast

Hourly Individual PVGR Forecasts

Short-Term PhotoVoltaic Power Forecast• Allocated proportionally from 50% POE

• Rolling 168 Hour forecast for each PVGR

• Used in reliability studies

PVGR Production Potential• Allocated proportionally from 80% POE

• Rolling 168 Hour forecast for each PVGR

• Used in financial settlements

67

WGR Dusty Mesa has just entered commercial operation

Class Discussion

IRR Hourly Forecasting Process

Resource Site Data

Met Tower Data

Resource Telemetry

Outages

1. What are the impacts if the telemetered MW Power Output is consistently low?

2. What are the impacts if the telemetered output is accurate, but the wind speed data is consistently low?

68

Posted on MIS Hourly

Publishing of Forecast Data

• Total WGR Forecasts• Regional WGR Forecasts• Total PVGR Forecasts• Regional PVGR Forecasts

• Individual WGR Forecasts• Individual PVGR Forecasts

IRR Ramp Forecasting

70

• Assesses risk of large increase in Net Load

• Estimates adequacy of scheduled Generation and Reserves to manage risk

Capacity Available Tool (CAT)

IRR Ramp Forecasting

Load

Wind

MW

Hour

CAT study window is six hours

71

• Retrieves expected Generation schedules from COPs

• Considers historical forecast uncertainties

• Wind

• Load

ERCOT Operators run CAT on demand

Capacity Available Tool (CAT) Functionality

72

• Deploying Non-Spin Reserve

• Procuring additional Non-Spin Reserve

• Committing additional Resources through RUC

ERCOT may take action to mitigate ramping risk

Capacity Available Tool (CAT) Results

30 MinReliability

UnitCommitment

Current Operating Plans

Load Forecast

Three-Part Supply Offers

Module 4

IRRs in Market and System Operations

74

• Preparing for Real-Time Operations

• IRRs during Real-Time Operations

• Dispatch Scenarios


Module Topics

Preparing for Real-Time Operations

76


ReportTrades

Submit Energy Offer Curves

Update Current Operating Plan

77

• Should span operational range of the Resource

• Priced between -$250/MWh and SWCAP

• May be submitted or updated until the end of the Adjustment Period

Energy Offer Curves for IRRs


Energy Offer Curve

$ / M

Wh

MW0

78


ReportTrades



79

QSEs may have Trades involving IRRs

Report Trades

Bilateral Trades

• Financial transactions between QSEs

• Transfer financial responsibility

Types

• Capacity• Energy• Ancillary Service

80

Trade Submittal Criteria

Information Needed Energy Trade Capacity Trade

Buying QSE

Selling QSE

Settlement Point:

MW quantity for each Settlement Interval 15 minute Hourly

Deadline for Submission

1430, Day after Operating Day

End of Adjustment Period

81

Trades do not “exist” until both QSEs agree

• One QSE reports the trade

• The other QSE confirms the trade

Once confirmed, either QSE may reject a Trade if the deadline for doing so has not passed.

Buyer and Seller must confirm Trades

Trade Confirmation

82

Energy Trade

• Energy supply/obligation in Real-Time

• Capacity supply/obligation in subsequent RUC

Capacity Trade

• No Energy supply/obligation in Real-Time

• Capacity supply/obligation in subsequent RUC

Energy and Capacity Trades have only Financial Impacts

Trade Impacts

83


ReportTrades



84

• COP reflects expected status and capabilities for each hour

• May be updated until the end of the Adjustment Period

• Must be updated within 60 minutes ofany event that impacts status or capabilities

QSE must maintain a Current Operating Plan (COP) for each Resource


85

• Which Resources are planned to run

• How much capacity each Resource contributes

Reliability Unit Commitment (RUC) Process

Where is the Current Operating Plan Used?

ReliabilityUnit

Commitment

Current Operating Plans

Load Forecast

Resource Commitments

Resource DecommitmentsThree-Part

Supply Offers

86

• ON: QSE has committed to run the Resource

• OFF: Resource is offline but available for RUC commitment

• OUT: Resource is not available

Typical COP Statuses for IRRs

Current Operating Plan Status

87

• ERCOT updates COP HSL to the Short-Term Wind Power Forecast (STWPPF) for first 168 hours

• QSE may override to a lesser value

Photovoltaic Generation Resource (PVGR):

• ERCOT updates COP HSL to the Short-Term Photovoltaic Power Forecast (STPPF) for first 168 hours

• QSE may override to a lesser value

Wind-Powered Generation Resource (WGR):

Current Operating Plan Capabilities

IRRs During Real-Time Operations

89

• Manage reliability

• Resolve Transmission Constraints

• Match generation with demand

• Operate the system at least cost

Goals of SCED

Security Constrained Economic Dispatch (SCED)

SCED dispatches all available Resources in a way that

achieves these goalsSCED

90

SCED requires multiple inputs

Real-Time Dispatch

Security-ConstrainedEconomic Dispatch

Telemetry

Offers

NetworkOperations

Model

Contingencies

Real-Time Network Security Analysis

Pricing

Dispatch Instructions

91

Security Analysis provides Transmission Constraints

Real-Time Dispatch



Telemetry

Offers

Pricing


NetworkOperations

Model

ContingenciesReal-Time Dispatch


Constraints & Shift Factors

92

Generation-to-be-Dispatched is the projected demand

Real-Time Dispatch


Telemetry

Offers

Pricing


NetworkOperations

Model

Contingencies

Generation to be Dispatched


93

Resource Limit Calculator determines Dispatch Limits

Real-Time Dispatch


Telemetry

Offers

Pricing


NetworkOperations

Model

Contingencies


Resource Limit Calculator


94

QSE Telemetry


• Low Sustained Limit (LSL)

• Power Output

• Ramp Rates


• High Dispatch Limit (HDL)

• Low Dispatch Limit (LDL)

Resource Dispatch Limits

PowerOutput

Base PointRegion

HDL

LDL

LSL

HSL

PowerOutput

5 minutes

Resource Capacity

95

• Nameplate rating

• Max output under ideal conditions

High Sustained Limit is …

• Current net output capability

• Based on current conditions

• Wind / Irradiance

• Turbines / Inverters online

High Sustained Limit is not …

HSL Expectations for IRRs

96

Resource Offers provide cost information to SCED

Real-Time Dispatch


Telemetry

Offers

Pricing


NetworkOperations

Model

Contingencies




97

Pricing and Dispatch Instructions

Telemetry

NetworkOperations

Model

ContingenciesReal-Time Dispatch


Offers

Pricing



Locational MarginalPrices

Resource Base Points

98

1. Dispatch to manage reliability

2. Operate the system at the least cost

Goals of IRRs

1. Dispatch to follow energy supply

2. Operate at max capability

Goals of SCED

Competing Goals?

Are IRR’s goals competing with SCED’s goals?

99

Fitting a square peg into a round hole?Class Discussion

Reconciling the Goals of SCED and IRRs

High Sustained Limit should reflect current net output capability

Give the IRR a really low price

1. How does a QSE tell SCED how much the IRR has to offer?

2. How can a QSE make SCED take everything the IRR has to offer?

Dispatch Scenarios

101

Real Time Dispatch of IRRsScenarios

Dispatch Scenarios

1. IRR with Energy Offer Curve

2. Curtailed IRR with Energy Offer Curve

3. IRR is released from curtailment

102

IRR is available for dispatch and not impacted by any binding constraints

Scenario 1

IRR with Energy Offer Curve

Energy Offer Curve

$ / MWh

MW0

• IRR runs at HSL

• IRR is a “Price-Taker”

• Base Point follows HSL

HSL

BP

103

IRR has positive shift factor on a binding constraint and must be curtailed

Scenario 2

Curtailed IRR with Energy Offer Curve

Energy Offer Curve

$ / MWh

MW0

• Base Point is less than HSL

• IRR Energy Offer Curve sets LMP

• IRR must comply with Base Point

HSL

BPBP

104

IRR has positive shift factor on a binding constraint and must be curtailed

Scenario 2

Dispatch Limits when IRR is curtailed

• SCED can move IRR from full output to any lower output in five minutes

• IRR must limit ramping to 20% of nameplate per minute

While curtailed, HSL should still represent current net output capability of the IRR

PowerOutput

LDL(LSL)

HSL

5 minutes

105

IRR has been curtailed because of a constraint. Curtailment is now lifted.

Scenario 3

IRR is Released From Curtailment

Energy Offer Curve

$ / MWh

MW0

• IRR becomes a “Price Taker” once again

• SCED will set Base Point to HSL again

BP

HSL

BP

106

IRR has been curtailed because of a constraint. Curtailment is now lifted.

Scenario 3

Dispatch Limits when IRR is Released From Curtailment

• SCED can move IRR from curtailed output to full output in five minutes

• IRR must limit ramping to 20% of nameplate per minute

LSL

HDL(HSL)

5 minutes

PowerOutput

Module 5

Financial Settlements of IRRs

108

• Real-Time Energy Imbalance

• RUC Capacity Short Charge

• Base Point Deviation Charge


Module Topics

Real-Time Energy Imbalance

110

Real-Time Energy Imbalance at a Resource Node:


+

DAM Energy Purchases+

Trade Energy Purchases

DAM Energy Sales+

Trade Energy SalesRTSPP*

RTRMPR*

(-1)

(-1)

–

Metered Generation

111

At a Resource Node,

Real-Time Settlement Point Price

Time-Weighted Average LMPs

RTSPP Real-Time Settlement Point PriceRTRSVPOR Real-Time Reserve Price for On-Line ReservesRTRDP Real-Time On-Line Reliability Deployment Price

RTSPP = RTRSVPOR + RTRDP +

RTSPP is used to settle financial transactions

112

At a Resource Node,

Real-Time Resource Meter Price

(Base-Point * Time)Weighted Average LMPs

RTRMPR Real-Time Resource Meter PriceRTRSVPOR Real-Time Reserve Price for On-Line ReservesRTRDP Real-Time On-Line Reliability Deployment Price

RTRMPR = RTRSVPOR + RTRDP +

RTRMPR is used to settle physical energy production

113

Real Time Energy ImbalanceScenarios

Financial Settlement Scenarios

1. QSE with IRR in Real-Time2. QSE with IRR and Energy Trades

114

QSE has an IRR, Solaris VentumScenario 1

Scenario Data

• 100 MW nameplate rating• On-line continuously in Real-Time• During Interval 1515

• Produces 10 MWh• RTSPP = $30.00• RTRMPR = $30.02

115

Real-Time Energy Imbalance for Interval 1515:

Scenario 1

Simplifying the equation

+

DAM Energy Purchases+

Trade Energy Purchases

DAM Energy Sales+

Trade Energy SalesRTSPP*

RTRMPR*

(-1)

(-1)

–

Metered Generation

DAM Energy Sales+

Trade Energy SalesRTSPP*(-1) RTRMPR*Metered

Generation –*

Which simplifies and re-arranges to . . .

116


Scenario 1

Calculation

$30.02/MWh10 MWh(-1) –* = –$300.20

DAM Energy Sales+


Generation –*

* $30/MWh0 MWh *

117

QSE Schedules Energy Trades on their IRR, Solaris Ventum

Scenario 2

Scenario Data

• 100 MW nameplate rating• On-line continuously in Real-Time• Trade Energy Sale of 40MW during

Hour 1600• During Interval 1515

• Produces 10 MWh• RTSPP = $30.00• RTRMPR = $30.02

118

• Energy Trades are reported as hourly MWs

• Real-Time is settled as 15-minute MWhs

Trades in Real-Time Energy Settlements

Trade Conversions

Trades must be multiplied by ¼ hour

0715073007450800

0815083008450900

Hour 0800 Hour 0900

119


Scenario 2

Calculation

$30.02/MWh10 MWh(-1) –* = –$0.20

DAM Energy Sales+


Generation –*

* $30/MWh10 MWh *

RUC Capacity Short Charge

121

If ERCOT commits a Resource through RUC

• ERCOT provides QSE with a payment guarantee

• May provide “Make-Whole Payment”

Cost recovery

• QSEs are responsible for capacity

• QSEs with capacity shortfalls paythe RUC Capacity Short Charge

Reliability Unit Commitment (RUC) Costs

122

• Adjusted Metered Load

• Capacity Trades where QSE is the seller

• Energy Trades where QSE is the seller

• Cleared DAM Energy Offers

Transactions that create a capacity obligation

Capacity Obligations

Capacity required to meet QSE

Obligations

123

• Commitment of the QSE’s Resources

• Capacity Trades where the QSE is the buyer

• Energy Trades where the QSE is the buyer

• Cleared DAM Energy Bids

Transactions that create a capacity supply

Capacity Supplies

Capacity arranged by

QSE

124


QSE

Capacity required to meet QSE ObligationsCapacity

arranged by QSE

Capacity required to meet QSE Obligations

Capacity Shortfalls captured through snapshots


QSE Shortfall

RUC (DRUC / HRUC) Adjustment Period

QSE Shortfall

• Execution of RUC• Close of Adjustment Period

Charge based on largest shortfall

125

Real Time Energy Imbalance with RUC Capacity Shortfall in Interval 1615

Scenarios

Financial Settlement Scenarios

3. QSE with WGR and Trade before RUC4. QSE with WGR and Trades before RUC

and after Operating Hour

For both Scenarios:• WGRPP = 36 MW• STWPF = 44 MW• ERCOT has RUC Make Whole

costs to recover

126

QSE Schedules Energy Trades on their WGR, Dusty Mesa

Scenario 3

Scenario Data

• Trade Energy Sale of 40 MW reported prior to any RUC commitments

• During Interval 1615• Produces 10 MWh• RTSPP = $40.03• RTRMPR = $40.00

127


Scenario 3

Real-Time Energy Imbalance Calculation

$40/MWh10 MWh(-1) –* = $0.30

DAM Energy Sales+


Generation –*

* $40.03/MWh10 MWh *

128

QSE’s Energy Imbalance Volume is zero!Scenario 3


Energy required to meet QSE

Obligations

Energy provided by

QSETradeEnergy

Sale

Metered Generation

129

However, QSE has a Capacity ShortfallScenario 3


Capacity required to meet QSE

Obligations

ShortfallCapacity

arranged by QSE

TradeEnergy

Sale(40MW)

WGRPP(36MW)

QSE must pay share of RUC Make Whole costs!

130

QSE Schedules Energy Trades on their WGR, Dusty Mesa

Scenario 4

Scenario Data

• Trade Energy Sale of 36 MW reported prior to any RUC commitments

• Additional Trade Energy Sale of 4 MW reported after the Operating Hour

• During Interval 1615• Produces 10 MWh• RTSPP = $40.03• RTRMPR = $40.00

131


Scenario 4

Real-Time Energy Imbalance Calculation

$40/MWh10 MWh(-1) –* = $0.30

DAM Energy Sales+


Generation –*

* $40.03/MWh10 MWh *

132

QSE has no Capacity ShortfallScenario 4


Capacity Required to meet QSE

Obligations


QSE

TradeEnergy

Saleprior to RUC

(36MW)

WGRPP(36MW)

Base Point Deviation Charge

134

IRR must be Curtailed

• Curtailment Flag

IRR must be Over-Generating

• Telemetered generation

• Instructed Base Point

Wider tolerances for deviation from Base Point

Key Differences between Intermittent Renewable Resources (IRRs) & other Resources

Base Point Deviation Charge – IRRs

135

When are IRRs exposed to deviation charges?

Conditions for Base Point Deviation

IRR output within10% acceptable range

IRR output exceeds10% acceptable range

Curtailment Flag is not set No Charge No Charge

Curtailment Flag is set No Charge Charge

IRR Groups are assessed as an aggregate

136

IRR Solaris Ventum is curtailed. How is the QSE settled?

Scenario 5

Financial Settlement Scenario

Energy Produced

IntermittentRenewableResource

AverageBasePoint

AverageOutput

10%ToleranceCharged in Base Point DeviationPrice: Max ($20, RTSPP)

Paid in Real-Time Energy ImbalancePrice: RTRMPR??

Module 6

MIS Reports for IRRs

138

• Available IRR Reports on MIS

• Details of IRR Reports

• Where to find IRR Reports


Module Topics

139

Available IRR Reports on MIS

MIS IRR Reports

140

Wind Power Forecasts

System and Regional Totals

STWPF

WGRPP

COP HSLs

Posted every hour

Includes• Previous 48 hrs• Future 168 hrs

141

Wind Power Actuals


5 Minute

Hourly summary posted every 5 min

Hourly

48 hour summary posted every hour

142

Wind Integration Report

Daily Values

Record Values

Wind vs. Load Comparisons

Output vs. Installed Capacity

Posted daily for previous day

143

Daily Values

Current Daily Values:

Peak Load 40,830 MWPeak Load Hour (HE) 20Wind at Peak Load Hour 3,195 MW

Max Wind 14,569 MWMax Wind Time 00:00Penetration at Max Wind Time 45.83%

Max Wind Penetration 46.53%Max Wind Penetration Time 00:30Wind Generation at Max Wind Penetration Time 14,333 MW

ERCOT Grid OperationsWind Integration Report : 03/05/2018

144

Record Values

All Time Record Values:

Record Wind Generation 17,542 MWRecord Wind Generation Time 02/19/2018 22:05Penetration at Record Wind Generation Time 46.86%

Record Wind Penetration 54.22%Record Wind Penetration Time 10/27/2017 04:00Wind Generation at Record Wind Penetration 15,408 MW

ERCOT Grid OperationsWind Integration Report : 03/05/2018

145

Wind vs. Load Comparisons

Actual Wind Output as a Percentage of the ERCOT Load03/05/2018

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 00

(Win

d O

utpu

t/Lo

ad)%

Time

Actual Integrated Wind Output Actual Load

146

Output vs. Installed Capacity

Actual Wind Output as a Percentage of the Total Installed Wind Capacity03/05/2018

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 00

(Win

d O

utpu

t/In

stal

led

Win

d Ca

paci

ty)%

Time

Actual Integrated Wind Output Total WGR Installed Capacity

147

Available IRR Reports on MIS

MIS IRR Reports

148

Solar Power Forecasts


STPPF

PVGRPP

COP HSLs

Posted every hour

Includes• Previous 48 hrs• Future 168 hrs

149

Solar Power Actuals


5 Minute

Hourly summary posted every 5 min

Hourly

48 hour summary posted every hour

150

IRR Forecast Reports on MIS Public

151

IRR Actual Output Reports on MIS Public

152

• Differentiate between IRRs and other generation technologies in ERCOT

• Identify the unique telemetry requirements of IRRs

• Describe the operational requirements for IRRs

• Summarize the IRR forecasting process

• Summarize the dispatch process for IRRs

• Describe a few Settlement impacts for IRRs

You should now be able to …

Course Summary

153

ERCOT Protocolshttp://www.ercot.com/mktrules/nprotocols/

ERCOT Traininghttp://www.ercot.com/services/training/

ERCOT Account Management [email protected]

ERCOT Market Education [email protected]

Accessing additional information


http://www.ercot.com/services/training/

http://www.ercot.com/services/training/

mailto:[email protected]

154

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Intermittent Renewable Resources...Resource that can only produce energy from variable, uncontrollable Resources, such as wind, solar, or run-of-the-river hydroelectricity. Currently,