ERCOT Public 1

Future Ancillary Services Team (FAST) andTechnical Advisory Committee (TAC)Workshop

ERCOT Staff

July 25, 2014

ERCOT Public 2

Presentation Outline

1. Review the Drivers to Implement a New AS Framwork

2. Review the Scope of the FAST

3. Recap and Next Steps

4. Review the Proposed New Framework

5. Review each AS (definition, need, qualification, performance requirements)

6. Review How the AS Requirements are Determined

7. Review Proposed Procurement and Pricing Approach

8. Review Deployment Sequence Guidelines

9. Review Draft NPRR (review edits, deletes and additions)

10.Discussion/Questions

ERCOT Public 3

1. Drivers for New Ancillary Service Framework

• Current AS Framework has performed well but has issues• Resources could provide some services more efficiently if the

requirements were unbundled (Responsive Reserve Service unbundled into Primary Frequency Response, Fast Frequency Response and Contingency Reserve)

• An increase of emerging technologies that do not provide synchronous inertia and that displace conventional generation can reduce the ability of the grid to respond to contingencies. The current AS requirements may have to be increased to maintain reliability

• Inability to use some technologies (e.g. CCGTs with duct firing, storage resources and Load Resources) to provide the current AS. This reduces the pool of AS suppliers

ERCOT Public 4

Goal

Current AS Framework-Based on capabilities of conventional steam generating units-Unique services bundled together due to inherent capabilities of conventional units-Mix of compensated and uncompensated services-New technologies are cobbled on, with difficulty

Future AS Framework-Technology neutral-Market-based-Based on fundamental needs of the system, not resource characteristics-Unbundled services-Flexible for new technologies-Pay for performance, where practical

3+ YearsNow

Transition Plan TBD

ERCOT Public 5

2. Scope of Proposed AS Framework

• Ancillary Services (AS) framework intended to guide:– Requirements for changes to ERCOT systems (EMS,

MMS, S&B etc.)– Investment in new resources and new resource types

• Framework should include roadmap for transition from current AS to future framework– Prioritization of services to be transitioned– Inter-relationship of services that must transition

concurrently – High-level consideration of ERCOT systems and

market impacts

ERCOT Public 6

1) Original Concept Paper provided 9-27-132) Concept Paper version 1.1 provided 11-1-13

which incorporated written comments and info received at the October 2013 Workshop.

3) Weekly work sessions began in January 2014. (17 meetings so far in 2014)

4) 15 sets of comments from Market Participants on the “Consolidated Working Document” reviewed in June 2014

5) Draft NPRR (based on “Consolidated Working Document” and discussion) posted 6-26-14 to the “key documents” area on FAST meeting page at: http://www.ercot.com/committees/other/fast/index.html

3. Recap

ERCOT Public 7

1) Two FAST-TAC Workshops to review Draft NPRR: July 25, 2014 and one planned in August, 2014 (TBD)

2) Comments on Draft NPRR expected September 15, 2014

3) Revise the Draft NPRR and submit the numbered NPRR October 15, 2014.

4) Cost-Benefit Analysis is expected to be provided after the numbered NPRR is submitted.

3. Next Steps

ERCOT Public 8

Regulation Up

Fast-Responding Regulation Up

Current Proposed

Fast Frequency Response 1

Primary Frequency Response

Contingency Reserves 1

Synchronous Inertial Response

Supplemental Reserves 1

Mostly unchanged

59.8 Hz, Limited duration

59.7 Hz, Longer durationFast Frequency Response 2

Contingency Reserves 2

SCED-dispatched

Manually dispatched

Supplemental Reserves 2

SCED-dispatched

Manually dispatched

Ongoing development

Non-Spin

Responsive

4. Proposed Transition to Future Ancillary Services

Regulation Down

Fast-Responding Regulation Down

Regulation Up

Fast-Responding Regulation Up

Regulation Down

Fast-Responding Regulation Down

ERCOT Public 9

1. Fast Frequency Response Service (FFRS)

2. Primary Frequency Response Service (PFRS)

3. Regulation-Up Service

4. Regulation-Down Service

5. Contingency reserve Service (CRS)

6. Supplemental reserve Service (SRS)

5. Review each Ancillary Service

ERCOT Public 10

FAST FREQUENCY RESPONSE SERVICE (FFRS)

ERCOT Public 11

Fast Frequency Response Service (FFRS) - Need

Provide quick (within 30 cycles) automatic response at specified frequency threshold to arrest frequency decay following a generation trip event;

To provide sufficient time for PFRS to respond and arrest frequency excursion in the event of sudden large power imbalance

ERCOT Public 12

Fast Frequency Response Service (FFRS)

Sub-Groups FFRS1: Group FFRS1 includes Resources capable of

sustaining a full response for at least 10 minutes and, once recalled, restoring their full FFRS Ancillary Service Supply Responsibility within 15 minutes.

FFRS2: Group FFRS2 includes Resources capable of sustaining a full response until receiving an ERCOT recall instruction or until the Resource’s FFRS Ancillary Service Resource Responsibility expires, whichever occurs first, and, once recalled, restoring their full FFRS Ancillary Service Supply Responsibility within 180 minutes

ERCOT Public 13

Fast Frequency Response Service (FFRS)- Discussion

Presently there is no separate FFRS in ERCOT, however up to 1400 MW of Responsive Reserve Service (RRS) procured from Load Resources (LR) satisfy FFRS characteristics

In the proposed AS framework FFRS and PFRS are highly interdependent and the required quantity of each service can vary based on the system conditions

There is an equivalency ratio (R) between FFRS and PFRS that equates 1 MW of FFRS to R MW of PFRS. This ratio (R) is greater than or equal to 1 and depends on system conditions

FFRS and PFRS work together to meet the desired reliability goals

PFRS provides a continuous frequency support. FFRS cannot completely replace the PFRS

ERCOT Public 14

FFRS – Performance Self deployment (automatically detect frequency threshold

and respond) Provide full response within 30 cycles (0.5 secs.) at a

specified frequency thresholds and sustained FFRS1 Resources must be able to sustain for up to 10 minutes FFRS2 Resources must be able to sustain until ERCOT issues recall

instruction or Resource’s FFRS Responsibility expires

Must be able to fully respond within 10 minutes of an ERCOT manual dispatch instruction

ERCOT Public 15

PRIMARY FREQUENCY RESPONSE SERVICE (PFRS)

ERCOT Public 16

Definition of PFRS

Primary Frequency Response Service (PFRS) is defined as the immediate proportional increase or decrease in real power output provided by a Resource in response to system frequency deviations.

This response is in the direction that stabilizes frequency. PFRS is attained due to Governor or Governor-like action PFRS is an immediate response relative to the frequency deviation, PFRS is fully deployed within 12 to 16 seconds.

ERCOT Public 17

PFRS - Need

ERCOT as a single Balancing Authority Interconnection with only limited interconnection to the other Interconnects is solely responsible for maintaining frequency to maintain reliability and meet NERC standard requirements.

All of ERCOT’s frequency response can only come from Resources within the ERCOT Interconnection.

BAL-003 NERC Frequency Response Standard sets a Frequency Response Obligation (FRO) for ERCOT based on loss of two largest single units.

The minimum FRO for ERCOT is 413 MW/0.1 HzERCOT must develop methodologies for the regular

assessment of the needed concurrent amounts of both FFRS and PFRS.

ERCOT Public 18

PFRS - Performance and Resource Limit

ERCOT will use events measured by BAL-TRE-001 Regional Standard to calculate the droop performance The quantity of PFRS that can be provided by a specific Resource, will be based on the median of actual measured “Initial” and “Sustained” performance of the Resource in last six measurable events.

ERCOT Public 19

PFRS - Performance and Resource Limit

Capacity that can be deployed by a Resource’s Governor for 1% change in Frequency outside Governor Dead-band

ERCOT Public 20

REGULATION-UP & REGULATION-DOWN SERVICE

ERCOT Public 21

Regulation Service – Up & Down

ERCOT generation is dispatched through Security Constrained Economic Dispatch (SCED) every five minutes to balance the generation and demand. The power imbalance between each SCED interval will cause frequency deviation that requires Resources providing Regulation to compensate

ERCOT Public 22

Regulation Service – Up & Down

Regulation is made up of “Conventional” Regulation and Fast Responding Regulation ---- similar to today. Future method to deliver instructions will remain similar to today’s approach (with QSE instructions and participation factors).

Need for tighter performance metric A single Generation Resource shall not be allowed to carry more

than 25% of total ERCOT wide regulation requirement for that particular hour

Resources shall be limited to provide Regulation Service up to the amount successfully tested during the qualification test

Criteria for determining maximum allowed FRRS participation, shall be included in the AS Methodology document.

ERCOT Public 23

Regulation Service - Sub-GroupsFast Responding Regulation Down Service (FRRS-Down) A subset of Reg-Down in which the participating Resource provides Reg-Down capacity to ERCOT within 1 second of either its receipt of an ERCOT Dispatch Instruction or its detection of a trigger frequency independent of an ERCOT Dispatch Instruction. Except where otherwise specified, all requirements that apply to Reg-Down also apply to FRRS-Down.Fast Responding Regulation Up Service (FRRS-Up)A subset of Reg-Up in which the participating Resource provides Reg-Up capacity to ERCOT within 1 second of either its receipt of an ERCOT Dispatch Instruction or its detection of a trigger frequency independent of an ERCOT Dispatch Instruction. Except where otherwise specified, all requirements that apply to Reg-Up also apply to FRRS-Up.

ERCOT Public 24

CONTINGENCY RESERVE SERVICE (CRS)

ERCOT Public 25

Contingency Reserve Service (CRS)

An Ancillary Service provided by Generation Resources that can be synchronized and ramped to a specified output level within 10 minutes and Load Resources that can provide demand response within 10 minutes.

CRS is needed to restore frequency within defined limits following a large generator trip event and restore the FFRS and PFRSTo ensure ERCOT can meet the NERC standard, the CRS must be fully deliverable within 10 minutes so that frequency is restored to the pre-disturbance level within 15 minutes to achieve compliance with NERC BAL-002 StandardERCOT’s CRS is not to be confused with the NERC Contingency Reserve

ERCOT Public 26

Contingency Reserve Service (CRS) - Sub-Groups

CRS may be provided by two CRS sub groupsGroup CRS1 includes Resources that are capable of responding to SCED Base Point Dispatch InstructionsGroup CRS2 includes Resources that are not SCED dispatchable.

Once recalled, Resources providing CRS2 should be capable of restoring its CRS2 responsibility, within 180 minutes for it to be qualified as CRS2.

ERCOT Public 27

Qualification Resources providing CRS should be qualified up to the MW value to

which they are able to ramp within 10 minutes from the time of deployment.

Deployment ERCOT will deploy CRS for a sizable generation trip. Resources providing CRS1 must telemeter their ramp-rates such

that SCED can dispatch the full Resource CRS responsibility within 10 minutes.

Performance Resources providing CRS must be able to deliver and sustain the

reserve deployments for the entire duration it is carrying that responsibility.

Contingency Reserve Service (CRS)

ERCOT Public 28

SUPPLEMENTAL RESERVE SERVICE (SRS)

ERCOT Public 29

Supplemental Reserve Service (SRS)

An Ancillary Service provided by Generation Resources capable of ramping to a specified output level within 30 minutes and Load Resources capable of providing Demand response within 30 minutes.

1)SRS is the reserve that will be used to compensate for net load forecast error, abnormal number of unit unavailability and/or net load ramps.

2)ERCOT may also procure additional SRS capacity in anticipation of severe weather conditions.

ERCOT Public 30

Supplemental Reserve Service (SRS) - Sub-Groups

SRS may be provided by two SRS groupsGroup SRS1 includes Resources that are capable of responding to SCED Base Point Dispatch InstructionsGroup SRS2 includes Resources that are not SCED dispatchable

Once recalled, Resource providing SRS2 should be capable of restoring its SRS2 responsibility, within 180 minutes for it to be qualified as SRS2

ERCOT Public 31

6. OVERVIEW OF METHODOLOGY TO DETERMINE MINIMUM

QUANTITIES OF ANCILLARY SERVICE

ERCOT Public 32

6. Overview of Methodology

When to publish the monthly minimum AS Procurement quantity (by 20th of each month)

The minimum AS requirement by each hour or by block of hours

The methodology to analyze sufficiency of AS in day-ahead time-frame (normal and severe weather conditions)

The maximum limit on how much FFRS can be procured The maximum limit on how much FRRS can provide

Regulation The methodology will also include minimum requirement

for CRS1 and SRS1 Equivalency ratio between PFRS and FFRS

ERCOT Public 33

PFRS and FFRS

Frequency nadir shall be equal to or above 59.4 Hz when losing two largest units. (0.1 Hz margin for the first stage of UFLS at 59.3 Hz)

Frequency overshoot does not result in generation trip

No angular and voltage instability

ERCOT Public 34

Regulation Service 5 minute Net load variability—98.8

percentile of previous month and the same month in the previous year

Short Term Load Forecast (STLF) Error- 98.8 percentile of previous month and the same month in the previous year

CPS1-Metric (if CPS1 Less than 100% for more than 10 times for a given hour, add 10% to the base requirement for that hour) of the previous month?

ERCOT Public 35

Contingency Reserve Service (CRS) Recovery from settled frequency to 60 Hz Back-up Regulation Build in a margin based on the amount of CRS a

single Resource can provide BAL-002 Disturbance Control Standard

ERCOT Public 36

Supplemental Reserve Service

95 Percentile 6-Hour-ahead net-load forecast error

95 Percentile of hourly net-load rampsFor extreme weather condition, SRS

requirement to be based on unit forced outage rate

ERCOT Public 37

7. OVERVIEW OF PROCUREMENT AND PRICING OF ANCILLARY

SERVICES

ERCOT Public 38

General Philosophy

The current scope of the procurement and pricing for Ancillary Services is for the following future Ancillary Services: Regulation Up Service [Reg-Up and FRRS-Up] Regulation Down Service [Reg-Down and FRRS-Down] Primary Frequency Response Service (PFRS) Fast Frequency Response Service (FFRS) [FFRS1 and

FFRS2] Contingency Reserve Service (CRS) [CRS1 and CRS2] Supplemental Reserve Service (SRS) [SRS1 and

SRS2]

Synchronous Inertial Response Service is to be considered at a later time.

ERCOT Public 39

General Philosophy - continued

The Day-Ahead Market (DAM) Procurement of Ancillary Services will be performed under the energy and Ancillary Service co-optimization framework. This results in DAM optimizing such that the capacity offered from a Resource is divvied up between energy and AS such thatTotal System Cost to procure energy and AS is

minimizedFor the given prices, each Resource is

guaranteed the maximum revenue from the sale of energy and AS in the DAM

ERCOT Public 40

General Philosophy - continued

Procurement of Ancillary Service from the offered Resource capacity, as per the above energy and AS co-optimization framework, requires a capacity reservation for the procured amounts This capacity reservation on the Resource is mutually exclusive;

i.e. a given capacity cannot be reserved for more than one type of Ancillary Service. i.e. a given MW cannot be paid for providing more than one Ancillary Service

Unless instructed by ERCOT, the capacity reserved for a given Ancillary Service, a Generation Resource cannot use that same capacity for energy production and a Load Resource cannot curtail energy consumption to a level below this capacity reservation level for AS

ERCOT Public 41

General Philosophy - continued

Following current DAM practice, the procurement of AS will be setup in a manner such that the MCPC for AS that will be paid to Load Resource AS awards will incorporate opportunity costs for energy and other applicable AS in a manner similar to Generation Resource AS awards Load Resources, unlike Generation Resources cannot submit Resource

specific Energy Bids (to buy energy at their location) and hence, if cleared on a separate stack from the Generation Resource AS Offers, are not afforded the opportunity costs of energy (and other AS) in the resulting Load Resource specific Market Clearing Price Capacity (MCPC) for AS

ERCOT Public 42

Constraints & AS MCPCs

Generally, the constraints for the procurement of AS will be setup similar to the current DAM where the AS offers are stacked from lowest price to highest price and are cleared to meet the AS Plan requirement (minus AS Self arrangement)

Regulation procurement constraint and MCPC is generally the same as in the current DAM implementation Reg-Up and FRRS-Up have the same MCPC which is the

shadow price of the Regulation Up requirement constraint Reg-Down and FRRS-Down have the same MCPC which is the

shadow price of the Regulation Down requirement constraint

ERCOT Public 43

Constraints & AS MCPCs - continued

CRS offers from Load Resources and Generation Resources are cleared together with an additional constraint to ensure that a minimum amount of CRS is procured from SCED dispatchable Resources (CRS1). The MCPC for CRS is the sum of the shadow prices of the CRS

procurement constraint and the shadow price of the constraint that ensures a minimum amount of CRS is procured from SCED dispatchable Resources. i.e. the MCPC for CRS1 and CRS2 are the same.

ERCOT Public 44

Constraints & AS MCPCs - continued

SRS offers from Load Resources and Generation Resources are cleared together with an additional constraint to ensure that a minimum amount of SRS is procured from SCED dispatchable Resources (SRS1). The MCPC for SRS is the sum of the shadow prices of the SRS

procurement constraint and the shadow price of the constraint that ensures a minimum amount of SRS is procured from SCED dispatchable Resources. i.e. the MCPC for SRS1 and SRS2 are the same.

ERCOT Public 45

Constraints & AS MCPCs - continued

PFRS and FFRS procurement is combined into one constraint as the amounts of each to be procured are interdependent. Studies have shown that during certain scenarios (low load, high wind),

when there is lower amounts of synchronous inertia, the value of FFRS is higher than PFRS. This ratio that defines how many MW of PFRS capacity is needed to replace 1 MW of FFRS capacity is incorporated into the clearing process and has an impact on the MCPC of FFRS.

The MCPC for PFRS will be the shadow price of the combined PFRS and FFRS procurement constraint

The MCPC for FFRS is the product of the MCPC for PFRS and the ratio (R) that equivalences 1 MW of FFRS with R MW of PFRS. Both FFRS1 and FFRS2 are given the same MCPC

There is another constraint that limits the maximum amount of FFRS procured – this is equivalent to stating that there is a minimum amount of PFRS to be procured

There is another constraint that limits the maximum amount of FFRS1 procured

ERCOT Public 46

URLs for more details on procurement and pricing of AS

Consolidated Working Documents as of 5-6-14 (last section)

http://www.ercot.com/content/committees/other/fast/keydocs/2014/Consolidated_Working_Document_as_of_5-6-14.doc

FAST Redline Documents 5-6-14

http://www.ercot.com/content/meetings/fast/keydocs/2014/0606/FAST%20Redline%20Documents%205-6-14.zip

In this zip file the redline version of the following documents: Procurement and Pricing Working Document.docx Results of Example procurement and Pricing 05022014.docx - examples ExampleDAM_FutureAS-05062014.xlsx – spreadsheet tool to create your own

scenarios

ERCOT Public 47

8. Deployment Sequence Guidelines

Capacity Insufficiency (Manual)

SRS1

CRS1

SRS2

CRS2

PFRS (Manual release of HASLs to SCED)ERS-30 (EEA must be in effect)

ERS-10 (EEA2 must be in effect)

FFRS2 (Manual)

FFRS1 (Manual)

Firm Load Shed

Firm Load Restoration

PFRS

FFRS1

FFRS2

CRS1

CRS2

ERS-10

ERS-30

SRS1

SRS2

RECALL SEQUENCE

ERCOT Public 48

8. Deployment Sequence Guidelines

Slow Frequency Recovery (potential DCS Event with frequency at or below 59.7 Hz)

PFRS (Automatic) CRS1 (Automatic release to SCED at 59.91 Hz)FFRS1 (Relay action at 59.80 Hz)FFRS2 (Relay action at 59.70 Hz)CRS2 (Manual)

SRS1 (Release to SCED) and SRS2 (Manual)

PFRS (restored automatically)FFRS1

FFRS2

CRS1

CRS2

SRS1

SRS2

RECALL SEQUENCE

ERCOT Public 49

9. Review Draft NPRR

See the spreadsheet showing the Protocol sections edited, deleted or added

ERCOT Public

Appendix

ERCOT Public

Synchronous Inertial Response (SIR)

ERCOT Public 52

SIR is stored kinetic energy that is extracted from the rotating mass of synchronous machines following a disturbance in a power system

SIR is not included in the proposed future AS framework and the draft NPRR.

Synchronous Inertial Response

ERCOT Public 53

SIR can be provided by synchronous machines, whenever in operation.

Quantity of inertia contribution is determined as kinetic energy that can be provided by a synchronous machine during system imbalance:

H·MVA

where H is machine inertia constant in seconds, MVA is machine’s rated power

SIR is based on actual physical characteristics of a machine SIR is independent of machine’s operating point.

Synchronous Inertial Response

ERCOT Public 54

Maintain minimum Rate of Change of Frequency (RoCoF) Provide sufficient time from Point A to Point C, for the Ancillary

Services to respond. With increasing use of non-synchronous generation, changing load

characteristics, increase in Combined Cycle units (lower inertia), the system SIR is reduced.

As a result, RoCoF increases, leaving less time for primary frequency response to deploy and arrest the system frequency excursion.

SIR Need

ERCOT Public 55

SIR, Current Conditions

Case TimeGeneration

(MW)Load (MW)

WIND (MW)

Wind Penetration

RatioKinetic Energy

(MW-Second)

A3/31/2014

2:00 24,822 24,534 9,514 0.39 133,232

B3/26/2014

20:00 36,423 35,827 10,120 0.28 177,638

C4/19/2014

2:00 24,313 24,822 6,822 0.27 129,630

Case A: Highest Wind Penetration CaseCase B: Highest Wind MW CaseCase C: Lowest Kinetic Energy Case

ERCOT Public 56

To date, RoCoF at HWLL conditions during frequency events is around 0.2 Hz/s and the average time to reach frequency nadir is 4-6 seconds.

SIR available under current operating conditions is still sufficient. SIR will not be introduced as a new AS yet. Analysis based on Jan-May 2014 system conditions indicated

RoCoF as high as 0.65 Hz/s for two largest unit trip (2750 MW as per NERC BAL-003 standard).

From July 2014, ERCOT will start monitoring SIR in real-time. Further analysis of SIR real-time data and determination of

minimum SIR needs. EPRI will investigate capability and value of synthetic inertial

response from wind resources in ERCOT system.

SIR, Summary and Future Work

Reg depl. over 5min

CR depl.over 10min

Deployment of the reserves during an event

A

C

B

t=0, Gen trip

FFR trig.

Inertial Resp.

1st PFR trig.

PFR depl.

Effect of FFR on freq. decay

PFR DB

CR trig.

Time, seconds

FFR depl.

1st AGC run ACE=-10B(fa-60)

Deployment of the reserves after the event (showing FFR1)

CRS starts depl.

CRS sust.

FFR1 sust.

PFR sust.

Time, seconds

PFR undepl. FFR1 undepl.

Reg sust.

Deployment of the reserves after the event (showing FFR1&2)

CRS starts depl.

CRS sust.

FFR1&2 sust.

PFR sust.

Time, seconds

PFR undepl. FFR undepl.

Reg sust.