module 5: reliability unit commitment · slide 2 day 2 reliability unit 8:30 a commitment module...

Module 5: Reliability Unit

Commitment

Day 2

Reliability Unit

8:30 A

Commitment

Module Objectives: Reliability Unit Commitment

CRR Balancing

Account

11:30

Upon completion of this module,

learners will be able to:

• Describe the overall Reliability Unit

Commitment settlement process.

• Identify Market and ERCOT actions that

impact RUC Settlements.

• Explain the RUC Make-Whole process

– Calculate Make-Whole Payment

– Calculate RUC Capacity Short Charge

• Describe and calculate the RUC Clawback

payment and charge.

Reliability Unit Commitment

Purpose of Reliability Unit Commitment (RUC)

It ensures:

• Enough capacity is committed to serve

the forecasted load

• Committed capacity is in the right locations


The Reliability Unit Commitment Process


Committing Enough Capacity


Committing Capacity in the Right Locations


What if ERCOT must commit additional capacity?


Final Results of RUC Process: Resource Commitments

Resource Decommitments

Nothing


Day-Ahead Reliability Unit Commitment (DRUC)

• Occurs once a day

• Ensures enough capacity committed for next Operating Day

Day 1 Day 2

1430

DRUC runs

DRUC studies all hours of Day 2

DRUC Study Period


Hourly Reliability Unit Commitment (HRUC)

• Occurs hourly

• Reviews all hours already studied by DRUC

Day 1 Day 2

1430

DRUC runs

HRUC runs each hour

0000 0100

0200

1600 1700

1800

Reliability Unit Commitment - Combined Cycle Resources

Combined Cycle Train (CCT)

• A group of Combustion Turbines (CT) and Steam Turbines (ST)

• Operate in one or more configurations

Combined Cycle Generation Resource (CCGR)

• A registered configuration of a Combined Cycle Train

• Settled at a Logical Resource Node

CCGR is offered, committed,

dispatched and settled as a

single Resource.

Reliability Unit Commitment - Combined Cycle Resources

CCGR 1

CCGR 2

Combined Cycle Plant

Train 1 Train 2

ST1 CT1 CT2 CT3 ST2 CT4 CT5 CT6

RUC may start an entire

CCGR or transition from one

CCGR to another

Reliability Unit Commitment: Settlements

• Charges and Payments for CRRs

DAM Commitment

• Make-Whole

DAM

Participation in DAM

• Energy

• AS

• PTP Obligations

Settlement of CRRs

purchased in the

Auction

RUC

Commitment

• Make-Whole

• Clawback

Decommitment

CRR Auction

• Revenue

Distribution

RUC Make-Whole Payment

QSE’s Representing RUC committed

resources may receive a Make-Whole

payment

Outcome

#1

What: Payment when the Real-Time revenues are less

than actual costs for a RUC-Committed Resource

Why: To ensure that a QSE recovers its costs to run a

RUC-Committed Resource


Calculating RUC Make-Whole Payment

Incremental

Energy Costs

Minimum

Energy Costs

Revenues Received

$

Costs Incurred

Start-up Costs



Incremental

Energy Costs

Minimum

Energy Costs

Start-up Costs

Revenues Received

$

Costs Incurred

Real-Time

Revenues



Incremental

Energy Costs

Minimum

Energy Costs

Start-up Costs

Revenues Received

$

Costs Incurred

Real-Time

Revenues

Real-Time Revenues = RT SPP * Metered Generation


What if revenues are less than cost?

Real-Time

Revenues

Revenues Received

Incremental

Energy Costs

Minimum

Energy Costs

$

Costs Incurred

Start-up Costs



Real-Time

Revenues

Make-Whole Payment Incremental

Energy Costs

Minimum

Energy Costs

Revenues Received

$

Costs Incurred

Start-up Costs

Difference = Make-Whole Payment


Now we re-arrange the balance sheet slightly . . .

Subtract Incremental Energy Costs from both columns

Real-Time

Revenues

Make-Whole Payment

Minimum

Energy Costs

Start-up Costs

Revenues Received

$

Costs Incurred

Incremental

Energy Costs

Incremental

Energy Costs



Make-Whole Payment Minimum

Energy Costs

Start-up Costs

Revenues Received Costs Incurred

Real-Time

Revenues

Incremental

Energy Costs

Real-Time Revenues – Incremental Energy Costs

= RT SPP * Metered Generation – AIEC * Metered

Generation

Above LSL ( ) $



Make-Whole Payment Minimum

Energy Costs

Start-up Costs

Revenues Received

$

Costs Incurred

Real-Time

Revenues

Incremental

Energy Costs

RUC Guaranteed Amount


Trigger

#1

RUC Guaranteed

Amount ( ) ( ) < Resource

Revenues

A QSE is paid the Real-time Settlement Point Price for all

energy produced by its Resource

A QSE will also receive a Make-Whole Payment if its

Resource’s net revenues are less than its Startup and

Minimum Energy Costs


Trigger

#1 ( ) ( ) < RUC Guaranteed

Amount

Resource

Revenues


Calculate RUC Guaranteed Amount

RUC Guaranteed Amount = ( ) Startup costs

Minimum energy costs +

$ to Start Up

$/MWh at LSL

Startup Offer Minimum-Energy Offer

$/MWh Above LSL

Energy Offer Curve

Startup Price = Resource Category Generic

Startup Cost

Minimum Energy

Price =

Resource Category Generic

Minimum Energy Cost

Startup Price = Verifiable Startup Costs

Minimum Energy

Price =

Verifiable Minimum-

Energy Costs


Calculate RUC Guaranteed Amount

Calculate Startup Costs without a Three-Part Supply Offer

Verifiable Costs Generic Costs


Trigger

#1 ( ) ( ) <

Startup Price (SUPR) $ 5000

RUC Startup Flag (RUCSUFLAG) 1

Minimum Energy Price (MEPR) $10/MWh

Low Sustained Limit (LSL) 20MW

Real-Time Metered Generation (RTMG) 50MWh

RUC Guaranteed

Amount

Resource

Revenues

RUCG q,r,d = (SUPR q,r,s * RUCSUFLAG q,r,s)

+ (MEPR q,r,i * Min ((LSL q,r,i * (¼)), RTMG q,r,i))

QSE4’s

Resource is

committed

for 5 hours

𝑠

𝑖


Trigger


Amount

Resource

Revenues

RUCG = (SUPR * RUCSUFLAG) + ∑(MEPR * Min ((LSL * (¼)), RTMG ))

RUCG = ($5000 * 1) + ($10/MWh * Min(20MW * ¼h, 50MWh) * 4i/h * 5h)

= $5000 + ($10/MWh * (20MW * ¼h) * 4i/h * 5h)

= $5000 + ($10/MWh * 100MWh)

= $6000


Trigger


Amount

Resource

Revenues

• Per QSE

• Per Resource

• Per Operating Day with RUC

Commitment

RUC Guaranteed Amount

QSE1 $4,000

QSE4 $6,000

QSE6 $8,000


Trigger


Amount

Resource

Revenues

Resource Revenues = ( ) Minimum-Energy Revenue up to LSL

Revenue Less Cost above LSL

Revenue Less Cost during QSE-

Clawback intervals

+ +

Calculate Resource Revenues


Minimum-Energy revenue up to LSL

• Per QSE

• Per Resource

• Per Operating Day with RUC

Commitment $/MWh

MW

LSL

Minimum Energy Offer

SPP




Quantity = Minimum of:

Real-Time

Metered

Generation

¼ of LSL

RUC Minimum Energy Revenue

= (Price)* (Quantity)



RUC Minimum-Energy Revenue

Real-Time Settlement Point

Price

Low Sustained Limit

Real-Time Metered Generation


Determinants

RUCMEREVq,r,d = ∑ (RTSPP p,i * Min (RTMG q,r,i , (LSL q,r,i * (¼))))




RUCMEREV = ∑ (RTSPP * Min (RTMG, (LSL * (¼))))

RUCMEREV = $50/MWh * Min (50MWh, (20MW * ¼h)) * 4i/h * 5h

= $50/MWh * (20MW * ¼h) * 4i/h * 5h

= $50/MWh * 100MWh

= $5000


Trigger


Amount

Resource

Revenues

RUC

Guaranteed

Amount

Minimum-

Energy revenue

up to LSL

Revenue Less

Cost Above LSL

During RUC-

Committed Hours

Revenue Less Cost

During QSE-

Clawback Intervals

QSE1 $4,000 $2,000

QSE4 $6,000 $5,000

QSE6 $8,000 $4,000


• Per QSE

• Per Resource

• Per Operating Day with

RUC Commitment


$/MWh

MW

LSL

Costs

(AIEC)

SPP

RTMG * 4

Revenue Less Cost Above LSL During RUC-Committed Hours

Energy Offer Curves for

RUC-Committed Resources

must be priced at the

System-Wide Offer Cap

Energy Offer Curve

EOCPRCAP Revenues

SWCAP

HSL




Revenues Costs

Energy Revenue above LSL Average Incremental Energy

Cost above LSL Voltage Support Service

Emergency Power Increase



RUCEXRR q,r,d = Max {0, ∑ [RTSPPp,i * Max (0, RTMG q,r,i – (LSL q,r,i * (¼)))

+ (-1) * (VSSVARAMT q,r,i + VSSEAMT q,r,i)

+ (-1) * EMREAMT q,r,i

– RTAIEC q,r,i * Max (0, RTMG q,r,i – (LSL q,r,i * (¼)))]}


Additional Determinants

Revenue Less Cost Above LSL (RUCEXRR)

Voltage Support Service VAR Amount

Voltage Support Service Energy Amount

Emergency Energy Amount

Real-Time Average Incremental Energy Cost



RUCEXRR q,r,d = Max {0, ∑ [RTSPPp,i * Max (0, RTMG q,r,i – (LSL q,r,i * (¼)))






Average Incremental Energy Cost (RTAIEC) $20/MWh

RT Settlement Point Price (RTSPP) $50/MWh



RUCEXRR = Max {0, ∑ [RTSPP * Max (0, RTMG – (LSL * (¼)))

– RTAIEC * Max (0, RTMG – (LSL * (¼)))]}

RUCEXRR = Max {0, [$50/MWh * Max (0, 50MWh– (20MW* (¼)))

– $20/MWh* Max (0, 50MWh– (20MW* (¼)))] * 4i/h * 5h}

= Max {0, [$50/MWh * Max (0, 45MWh)

– $20/MWh * Max (0, 45MWh)] * 4i/h * 5h}

= Max {0, 45MWh * ($50/MWh – $20/MWh )] * 4i/h * 5h}

= $1350 * 4i/h * 5h

= $27,000



Trigger


Amount

Resource

Revenues

RUC

Guaranteed

Amount

Minimum-

Energy revenue

up to LSL

Revenue Less

Cost Above LSL

During RUC-

Committed Hours

Revenue Less Cost

During QSE-

Clawback Intervals

QSE1 $4,000 $2,000 $1,000

QSE4 $6,000 $5,000 $27,000

QSE6 $8,000 $4,000 $4,000


• QSE-Committed Interval

• Contiguous block with one RUC-Committed hour

• QSE-Committed AFTER RUC-Commitment

Revenue Less Cost During QSE Clawback Intervals


Hour 5 10 15 20

QSE-Committed

RUC-Committed



Revenues Costs

Energy Revenue Minimum Energy Costs

Voltage Support Service Average Incremental Energy

Cost above LSL Emergency Power Increase





Additional Determinants

Revenue Less Cost (RUCEXRQC)

RUCEXRQCq,r,d = Max {0, ∑ [(RTSPPp,i * RTMG q,r,i)



– [MEPR q,r,i * Min (RTMG q,r,i , (LSL q,r,i * (¼)))]






Average Incremental Energy Cost (RTAIEC) $20/MWh

RT Settlement Point Price (RTSPP) $50/MWh

RUCEXRQCq,r,d = Max {0, ∑ [(RTSPPp,i * RTMG q,r,i)



– [MEPR q,r,i * Min (RTMG q,r,i , (LSL q,r,i * (¼)))]




RUCEXRQC = Max {0, ∑ [(RTSPP * RTMG)

– [MEPR * Min (RTMG, (LSL * (¼)))]

– RTAIEC * Max (0, RTMG – (LSL * (¼)))]}

RUCEXRQC = Max {0, [($50/MWh * 50MWh)

– [$10/MWh * Min (50MWh, (20MW * (¼)))]

– $20/MWh * Max (0, 50MWh – (20MW * (¼)))] * 4i/h * 2h}

= Max {0, [($50/MWh * 50MWh) – [$10/MWh * 5MWh]

– ($20/MWh * 45MWh)] * 4i/h * 2h}

= Max {0, [$2500 – $50 – $900] * 4i/h * 2h}

= $1550 * 4i/h * 2h = $12,400



Trigger


Amount

Resource

Revenues

RUC

Guaranteed

Amount

Minimum-

Energy revenue

up to LSL

Revenue Less

Cost Above LSL

During RUC-

Committed Hours

Revenue Less Cost

During QSE-

Clawback Intervals

QSE1 $4,000 $2,000 $1,000 $0

QSE4 $6,000 $5,000 $27,000 $12,400

QSE6 $8,000 $4,000 $4,000 $8,000


Trigger


Amount

Resource

Revenues

RUC

Guaranteed

Amount

Resource Revenues

QSE1 $4,000 $2,000 + $1,000 + $0 = $3,000

QSE4 $6,000 $5,000 + $27,000 + $12,400 = $44,400

QSE6 $8,000 $4,000 + $4,000 + $8,000 = $16,000


( ) ( ) < RUC Guaranteed

Amount

Resource

Revenues

RUC Guaranteed

Amount

Resource

Revenues

Eligible for Make-

Whole Payment?

QSE1 $4,000 $3,000 Yes

QSE4 $6,000 $44,400 No

QSE6 $8,000 $16,000 No

?

? ?

Outcome

#1

Trigger

#1


• QSE1 Resource is RUC-

Committed

• QSE1 is eligible for a Make-

Whole Payment

RUCMWAMT = (-1) * Max (0, RUCG – RUCMEREV

– RUCEXRR – RUCEXRQC) / ∑ RUCHR

Outcome

#1

Trigger

#1

RUCHR will be set to 1 for

each RUC-Committed hour

of the day.


• QSE1 is RUC-Committed

• QSE1 is eligible for a Make-

Whole Payment

Outcome

#1

Trigger

#1

RUCMWAMT = (-1) * Max (0, RUCG – RUCMEREV

– RUCEXRR – RUCEXRQC) / ∑ RUCHR

RUCMWAMT = (-1) * Max(0, $4000–$2000–$1000– 0) / 5

= - $200 per hour

RUC Make-Whole Payment for CCGR Transitions

DAM to RUC • RUC is contiguous to DAM commitment,

• RUC committed in different configuration,

• Train is online and generating in the RUC

committed configuration for at least 1 minute

RUC to RUC

• RUC is contiguous to previous RUC,




SELF to RUC • RUC is contiguous to previous SELF commitment,




1

2

3

CCGR 1

CCGR 2

Combined Cycle Plant

Train 1 Train 2

ST1 CT1 CT2 CT3 ST2 CT4 CT5 CT6

Transition cost is the

difference between Start-up

costs of the two CCGRs.


Trigger

#1 ( ) ( ) <

Startup Price (SUPR)

RUC Startup Flag (RUCSUFLAG)

Minimum Energy Price (MEPR)

Low Sustained Limit (LSL)

Real-Time Metered Generation (RTMG)

RUC Guaranteed

Amount

Resource

Revenues

RUCG q,r,d = ∑(SUPR q,r,s * RUCSUFLAG q,r,s)

+ ∑(Transition costs)

+ ∑(MEPR q,r,i * Min ((LSL q,r,i * (¼)), RTMG q,r,i))

Max(0, SUPR afterCCGR – SUPR beforeCCGR)

--and--

Max(0, SUPR beforeCCGR – SUPR afterCCGR) RUC-to-QSE Transition

Transition to RUC


Transition costs:

DAM Commitment

• Make-Whole

DAM


• Energy

• AS

• PTP Obligations

Settlement of CRRs

purchased in the

Auction


RUC

RUC Commitment

• Make-Whole

• Clawback

Decommitment


CRR Auction

• Revenue

Distribution


To remain revenue neutral, ERCOT will first try to directly

assign all costs incurred for Make-Whole Payments.

Costs are distributed based on QSE’s

shortfalls in each 15-minute interval.

RUC Commitment Period

RUC Capacity-Short Charge

Charge to a QSE that was capacity-

short in a RUC

Outcome

#1

What: Charge to QSEs that are capacity short

Why: Collect funds to pay the Make-Whole Payments to

eligible QSEs

RUC Capacity Short Charge

When a QSE does not provide enough capacity to meet its

obligations, it may be assessed a Capacity Short Charge

Capacity

Required to meet

QSE Obligations

QSE Shortfall

Capacity

arranged by

QSE



What is included in the total QSE obligation?

• Adjusted Metered Load

• Capacity Trades where the QSE is a seller

• Energy Trades where the QSE is a seller

• Cleared DAM Energy Offers

Capacity

Required to meet

QSE Obligations



How can a QSE arrange to meet these obligations?

• Show capacity from its Resources in its COP

• Capacity Trades where the QSE is a buyer

• Energy Trades where the QSE is a buyer

• Cleared DAM Energy bids

Capacity

arranged by

QSE



When does ERCOT compare QSE capacity versus obligation?

• Execution of RUC

• Real-time Operations

Capacity

Required to meet

QSE Obligations

QSE Shortfall

Capacity

arranged by

QSE



The larger QSE capacity shortfall is used for

capacity short calculations

Capacity

required to

meet QSE

Obligations

QSE Shortfall

Capacity

arranged by

QSE

QSE Shortfall

RUC (DRUC / HRUC) Real-Time

Capacity

required to

meet QSE

Obligations

Capacity

arranged by

QSE



All QSEs who were capacity short in each RUC will pay a

portion of the RUC Make Whole Payments for that particular

RUC:

RUC Make Whole Total ( ) RUC Capacity

Shortfall

Ratio Share *

RUC Capacity

Short Charge

by 15-Minute Settlement Interval

=


Short Charge Cap

The charge to each QSE is capped at

RUC Make Whole Total

RUC Capacity Total RUC Capacity Shortfall 2 * *

Price / MW

of RUC Procurement RUC Capacity Shortfall 2 * * ( )

. . . which is the same as



A QSE with a capacity shortfall will pay the lesser of

RUC Make Whole Total ( ) RUC Capacity

Shortfall

Ratio Share *

Price / MW

of RUC Procurement RUC Capacity Shortfall 2 * * ( )

or their cap


RUCCSAMT = (-1) * Max [(RUCSFRS * RUCMWAMTRUCTOT),

(2 * RUCSF * (RUCMWAMTRUCTOT / RUCCAPTOT))] / 4

RUCCSAMT ruc, i, q RUC Capacity Shortfall Amount

RUCSFRS ruc, i, q RUC Shortfall Ratio Share

RUCMWAMTRUCTOT ruc, h RUC Make Whole Amount Total per RUC

RUCSF ruc, i, q RUC Shortfall

RUCCAPTOT ruc, h RUC Capacity Total



RUC Shortfall Ratio Share

• Per RUC process

• Per QSE

• Per 15-minute Interval


RUCSFRS ruc,i,q = RUCSF ruc,i,q / RUCSFTOT ruc,i

Determinants


RUC Shortfall

RUC Shortfall Total


Determining a QSE’s RUC Shortfall

ERCOT takes Snapshots:

• QSE’s market position

each time RUC is

executed

• QSE’s market position

at end of each

Adjustment Period

DAM DRUC

RUC Snapshot (DRUC)

Looks at QSE’s market

position for each hour

during the RUC Study

Period


17 18 19 20 21 22 23 24

9 10 11 12 13 14 15 16

1 2 3 4 5 6 7 8


Adjustment Period Snapshot

Looks at QSE’s market

position at the end of

each Adjustment Period

17 18 19 20 21 22 23 24

9 10 11 12 13 14 15 16

1 2 3 4 5 6 7 8

ADJ

1

ADJ

2

ADJ

3 . . .

ADJ

6 . . .

ADJ

12

ADJ

22

. . .

. . .


Determine QSE’s RUC Shortfall

For each hour:

• ERCOT compares the

Adjustment Snapshot

with the corresponding

hour in the RUC

Snapshot

• The QSE’s RUC

shortfall is based on

the snapshot that is

the most short

17 18 19 20 21 22 23 24

9 10 11 12 13 14 15 16

1 2 3 4 5 6 7 8

ADJ

1

ADJ

2

ADJ

3

ADJ

4

ADJ

5

ADJ

6

ADJ

7

ADJ

8

ADJ

9

ADJ

10

ADJ

11

ADJ

12

ADJ

13

ADJ

14

ADJ

15

ADJ

16

ADJ

17

ADJ

18

ADJ

19

ADJ

20

ADJ

21

ADJ

22

ADJ

23

ADJ

24


RUC Shortfall

RUCSFruc,i,q = Max (0, Max (RUCSFSNAPruc,q,i, RUCSFADJruc,q,i)

– ∑ RUCCAPCREDITq,i,z)

RUC Shortfall

RUC Short Fall at Snapshot

RUC Short Fall at Adjustment

Period

RUC Capacity Credit

RUCSFSNAP

• Snapshot of the QSEs market position

each time a RUC is executed

• Different RUCSNAP for each RUC

Determinants

Prior

RUCs

RUC Shortfall


Capacity at snapshot:

High Ancillary Service Limits + DC Tie Imports

Capacity Purchase – Capacity Sales (Capacity Trades)

Day-Ahead Energy Purchases – Day-Ahead Energy Sales

QSE-to-QSE Energy Purchases – QSE-to-QSE Energy Sales

(Energy Trades)

RUCSFSNAPruc,q,i = Max (0, ((∑ RTAMLq,p,i * 4) + ∑ RTDCEXPq,p,i

– RUCCAPSNAPruc,q,i ))

RUC Shortfall

RUCCAPSNAPruc,q,i = ∑ HASLSNAPq,r,h

+ (RUCCPSNAPq,h – RUCCSSNAPq,h)

+ (∑ DAEPq,p,h – ∑ DAESq,p,h)

+ (∑ RTQQEPSNAPq,p,i – ∑ RTQQESSNAPq,p,i)

+ ∑ DCIMPSNAPq,p,i


RUC Capacity Snapshot at time

of RUC High Ancillary Service Limit at

Snapshot

RUC Capacity Purchase

Day-Ahead Energy Purchase

Day-Ahead Energy Sale

QSE-to-QSE Energy Purchase

QSE-to-QSE Energy Sale

Determinants

RUC Capacity Sale

RUCSFSNAPruc,q,i = Max (0, ((∑ RTAMLq,p,i * 4) + ∑ RTDCEXPq,p,i

– RUCCAPSNAPruc,q,i ))

DC Import at Snapshot

Real-Time DC Tie Export

(Oklaunion Exemption)

RUC Shortfall


RUCSFADJ

• Snapshot of the QSEs market position at the

end of the Adjustment period

• Built over time

• Complete at the end of the last Adjustment

period of the day


– ∑ RUCCAPCREDITq,i,z) Prior

RUCs

RUC Shortfall



Period

RUC Capacity Credit

Determinants

RUC Shortfall


Capacity at Adjustment Period:

High Ancillary Service Limits + DC Tie Imports

Capacity Purchase – Capacity Sales (Capacity Trades)

Day-Ahead Energy Purchases – Day-Ahead Energy Sales

QSE-to-QSE Energy Purchases – QSE-to-QSE Energy Sales

(Energy Trades)

RUCSFADJruc,q,i = Max (0, ((∑ RTAMLq,p,i * 4) + ∑ RTDCEXPq,p,i

– ∑ HASLSNAPruc,q,r,h – RUCCAPADJq,i ))

WGR

RUC Shortfall

RUCCAPADJ q,i = ∑ HASLADJ q,r,h

+ (RUCCPADJ q,h – RUCCSADJ q,h)

+ (∑ DAEP q,p,h – ∑ DAES q,p,h)

+ (∑ RTQQEPADJ q,p,i– ∑ RTQQESADJ q,p,i)

+ ∑ DCIMPADJq,p,i


RUCSFADJruc,q,i = Max (0, ((∑ RTAMLq,p,i * 4) + ∑ RTDCEXPq,p,i

– ∑ HASLSNAPruc,q,r,h – RUCCAPADJq,i ))

RUC Capacity Snapshot at

Adjustment Period High Ancillary Service Limit at

Adjustment Period

RUC Capacity Purchase

Day-Ahead Energy Purchase

Day-Ahead Energy Sale

QSE-to-QSE Energy Purchase

QSE-to-QSE Energy Sale

Determinants

RUC Capacity Sale

DC Import at Adjust. Period

Real-Time DC Tie Export

(Oklaunion Exemption)

WGR

Activity: Now it’s your turn!

Refer to your Settlements Workbook

In a small group, respond to the questions

that relate to Scenario #RUC1

You have 10 minutes to complete your questions.

If you can not complete all questions, don’t worry

– all questions will be reviewed as a class.

RUC Shortfall


Capacity Credit

• Credit to QSEs to ensure not charged twice

for the same capacity shortage


– ∑ RUCCAPCREDITq,i,z) Prior

RUCs

RUC Shortfall



Period

RUC Capacity Credit

Determinants

RUC Shortfall


RUC Capacity Credit

RUC Capacity Total

RUC Shortfall


RUCSF

RUCCAPTOT * RUCSFRS Determinants

RUCCAPCREDIT ruc,i,q

= Min [RUCSF ruc,i,q, (RUCCAPTOT ruc,h * RUCSFRS ruc,i,q)]

Activity: Now it’s your turn!

Refer to your Settlements Workbook

In a small group, respond to the questions

that relate to Scenario #RUC2.

You have 5 minutes to complete your questions.

If you can not complete all questions, don’t worry

– all questions will be reviewed as a class.


• QSE3 is capacity-short for a RUC

process

• 20 MW

• Total short is

• 100 MW

RUCSFRS = RUCSF / RUCSFTOT

= 20 MW / 100 MW

= 0.20


Outcome

#1

Trigger

#1


• QSE3:

– RUC Shortfall: 20 MW

– RUC Shortfall Ratio Share of: 20 %

• ERCOT-wide Values

– Total RUC Make-Whole Payments: -$800

– RUC Capacity Total: 400 MW

Trigger

#1

RUCCSAMT = (-1) * Max [(RUCSFRS * RUCMWAMTRUCTOT),

(2 * RUCSF * (RUCMWAMTRUCTOT / RUCCAPTOT))] / 4

RUCCSAMT = (-1) * Max [(.20 * $-800), (2 * 20 MW * ($-800/400 MW))] / 4

= (-1) * Max [(-$160), (-$80)] / 4

= $20


RUC Capacity Short Charge is limited to $20

by the Short Charge Cap.

Without cap, charge would have been $40.

Outcome

#1

Trigger

#1

• QSE3:

– RUC Shortfall: 20 MW

– RUC Shortfall Ratio Share of: 20 %



– RUC Capacity Total: 400 MW

Reliability Unit Commitment Settlements

Total RUC Make-

Whole Payments

Total Capacity-

Short Charges

... then ERCOT needs to procure additional

funds to pay the Make-Whole Payments.

If after all the Capacity-Short charges have been

collected and...

RUC Make-Whole Uplift Charge

Charge to all QSEs to collect enough

funds to pay the RUC Make-Whole

Payments

Outcome

#1

What:

If the revenues from the Capacity-Short Charge

don’t cover all RUC Make-Whole Payments then

additional funds will be uplifted to QSEs on a Load

Ratio Share basis

Why: Keep ERCOT revenue neutral


LARUCAMTq,i = (-1) * ( RUCMWAMTTOTh / 4 + RUCCSAMTTOTi ) * LRSq,i


RUC Make-Whole Amount Total

RUC Capacity Amount Total

Load Ratio Share

Total RUC Make-

Whole Payments / 4

Total Capacity-

Short Charges

for the interval

Uplifted at

Load Ratio Share

Determinants


• QSE5 represents Load

– Load Ratio Share = .25



– RUC Capacity-Short Charge Total: $100

• ERCOT needs additional funds to pay

Make-whole Payments

Trigger

#1

LARUCAMT = (-1) * ( RUCMWAMTTOT / 4

+ RUCCSAMTTOT ) * LRS

Outcome

#1

LARUCAMT = (-1) * (- $800 / 4 + $ 100) * .25

= (-1) * ( - $100 ) * .25

= $25



DAM Commitment

• Make-Whole

DAM


• Energy

• AS

• PTP Obligations

Settlement of CRRs

purchased in the

Auction

RUC

RUC Commitment

• Make-Whole

• Clawback

Decommitment

CRR Auction

• Revenue

Distribution

RUC Clawback Charge

Charge to all QSEs whose revenues

exceed the RUC Guarantee

Outcome

#1

What: Collects a portion of revenue above costs

Why: Resource was committed for reliability. Excess

revenue should be returned to Load


What if revenues are greater than cost?

Minimum

Energy Costs

Start-up Costs

Revenues Received Costs Incurred

Real-Time

Revenues

Incremental

Energy Costs

$


What if revenues are greater than cost?

Minimum

Energy Costs

Start-up Costs

Revenues Received

$

Costs Incurred

Clawback Charge

Real-Time

Revenues

Incremental

Energy Costs

But how does ERCOT

determine how much to

clawback?

RUC Clawback Charge

Clawback Factors

Three-Part Supply

Offer in DAM

No Three-Part

Supply Offer in DAM

RUC Clawback

Factor for RUC hours 50% 100%

RUC Clawback

Factor for QSE hours 0% 50%

RUC Clawback Charge

Trigger

#1

RUC Guaranteed

Amount

Resource

Revenues

Receive a RUC

Clawback Charge?

QSE1 $4,000 $3,000 No

QSE4 $6,000 $44,400 Yes

QSE6 $8,000 $16,000 It depends . . .

? ?

Outcome

#1

RUC Guaranteed

Amount ( ) ( ) > Resource

Revenues

?

RUC Clawback Charge

RUCCBAMT = [(RUCMEREV + RUCEXRR – RUCG) * RUCCBFR

+ (RUCEXRQC * RUCCBFC)] / ∑ RUCHR

RUCCBAMT q, r, h RUC Clawback Charge Amount

RUCMEREVq, r, d RUC Minimum-Energy Revenue

RUCEXRR q, r, d Revenue Less Cost Above LSL from RUC Hours

RUCG q, r, d RUC Guarantee

RUCEXRQC q, r, d Revenue Less Cost from QSE Clawback Intervals

RUCCBFR q, r, d RUC Clawback Factor for RUC-Committed Hours

RUCCBFC q, r, d RUC Clawback Factor for QSE Clawback Intervals

RUCHR RUC Hour

Calculate Clawback Amount

RUC Clawback Charge

RUCCBAMT = [(RUCMEREV + RUCEXRR – RUCG) * RUCCBFR

+ (RUCEXRQC * RUCCBFC)] / ∑ RUCHR

= [($5,000 + $27,000 – $6000) * 0.5

+ ($12,400 * 0)] / 5

= [$26,000 * 0.5] / 5

= $2600 per hour

Trigger

#1

• QSE4’s Resource Revenues are

greater than its RUC Guaranteed

Amount

• QSE4’s Resource was committed with

a Three-Part Supply Offer

RUC Clawback Payment

Payment to all QSEs that represent

Load

Outcome

#1

What: Revenue collected above costs through Clawback charge



• ERCOT receives funds from

Clawback charges


• Load Ratio Share (LRS) of 30%

Outcome

#1

Trigger

#1

LARUCCBAMT = (-1) * (RUCCBAMTTOT * (¼) * LRS)

= (-1) * ($2600 * (¼) * 0.30)

= (-1) * ($650 * 0.30)

= -$195


= (-1) * (Hourly RUC Clawback * (¼) * QSE’s LRS)

DAM Commitment

• Make-Whole

DAM


• Energy

• AS

• PTP Obligations

Settlement of CRRs

purchased in the

Auction


RUC

RUC Commitment

• Make-Whole

• Clawback

Decommitment


CRR Auction

• Revenue

Distribution

RUC Payment for Decommitment

Payment to QSE for a QSE-committed

Resource that the RUC process

decommitted

Outcome

#1

If all criteria met:

• ERCOT pays QSE for

decommittment

• Payment occurs only for

Operating Day of

decommitment

• QSE gets RUC Capacity

Credit

Decommitment of a QSE-Committed Resource


Three-Part

Supply Offer Verifiable Costs Generic Costs

SUPR Startup Offer Verifiable Startup

Costs


Startup Cost

MEPR Minimum

Energy Offer

Verifiable Minimum-

Energy Costs


Minimum Energy Cost

RUC Decommitment Payment

• Start-up Price (SUPR)

• Less cost savings (MEPR – RTSPP), if any

• Distributed across Decommitted Hours (NCDCHR)

• ERCOT decommits QSE1 Unit 1

• QSE-Committed Resource

• Resource is NOT scheduled to

shutdown within the Operating

Day


Trigger

#1

RUCDCAMT

= (-1) * Max {0, [SUPR - (Max (0, MEPR – RTSPP)

* (LSL * (¼)))]} / NCDCHR

Outcome

#1

RUCDCAMT

= (-1) * Max {0, [$1200 - (Max (0, $30 – $40)

* (10MW * (¼)))]} / 6

= (-1) * $1200 / 6 = -$200

• ERCOT decommits QSE1 Unit 1

• QSE-Committed Resource

• Resource is scheduled to

shutdown within the Operating

Day


Trigger

#2

Outcome

#2

QSE will not receive

payment for decommitment

RUC Decommitment Charge

Charge to QSEs that represent Load Outcome

#1

What: Charge to fund Decommitment Payments


Outcome

• Resource are decommitted by the

RUC process and are eligible to

receive a decommitment payment


• Load Ratio Share of 30%


Trigger

#1


= (-1) * [(RUC Decommitment Payments / 4 ) * LRS]

LARUCDCAMTq,i = (-1) * [(RUCDCAMTTOTh / 4 ) *LRS q,i ]

= (-1) * [(-$200 / 4 ) * 0.30]

= (-1) * [ -$50 * 0.30 ]

= $15

Module Summary

$ Describe the overall Reliability

Unit Commitment Settlement

process

$ Identify Market and ERCOT

actions that impact RUC

Settlements.

$ Calculate various charges and

payments associated with

RUC Commitments and

Decommitments

Day 2

Reliability Unit

8:30 A

Commitment

CRR Balancing

Account

11:30

module 5: reliability unit commitment · slide 2 day 2 reliability unit 8:30 a commitment module...

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