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

Module 5: Reliability Unit

Commitment

Reliability Unit

8:30 A

Commitment

Module Objectives: Reliability Unit Commitment

CRR Balancing

Account

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

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

DRUC runs

HRUC runs each hour

0000 0100

1600 1700

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

Participation in DAM

• Energy

• AS

• PTP Obligations

Settlement of CRRs

purchased in the

Auction

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

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

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

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

Minimum Energy Offer

Quantity = Minimum of:

Real-Time

Metered

Generation

¼ of LSL

RUC Minimum Energy Revenue

= (Price)* (Quantity)

RUC Minimum-Energy Revenue

Real-Time Settlement Point

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

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

(AIEC)

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

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

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

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

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

Trigger

• QSE1 Resource is RUC-

Committed

• QSE1 is eligible for a Make-

Whole Payment

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

– RUCEXRR – RUCEXRQC) / ∑ RUCHR

Outcome

Trigger

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

Trigger

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,

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

• Energy

• AS

• PTP Obligations

Settlement of CRRs

purchased in the

Auction

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

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

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

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

The larger QSE capacity shortfall is used for

capacity short calculations

Capacity

required to

meet QSE

Obligations

QSE Shortfall

Capacity

arranged by

QSE Shortfall

RUC (DRUC / HRUC) Real-Time

Capacity

required to

meet QSE

Obligations

Capacity

arranged by

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

portion of the RUC Make Whole Payments for that particular

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

3 . . .

6 . . .

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

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

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

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 ))

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)

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

RUC Shortfall

Period

RUC Capacity Credit

Determinants

RUC Shortfall

RUC Capacity Credit

RUC Capacity Total

RUC Shortfall

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

Trigger

• 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

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

RUC Capacity Short Charge is limited to $20

by the Short Charge Cap.

Without cap, charge would have been $40.

Outcome

Trigger

• 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

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

LARUCAMT = (-1) * ( RUCMWAMTTOT / 4

+ RUCCSAMTTOT ) * LRS

Outcome

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

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

DAM Commitment

• Make-Whole

• Energy

• AS

• PTP Obligations

Settlement of CRRs

purchased in the

Auction

RUC Commitment

• Make-Whole

• Clawback

Decommitment

CRR Auction

• Revenue

Distribution

RUC Clawback Charge

Charge to all QSEs whose revenues

exceed the RUC Guarantee

Outcome

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

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

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

• 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

Outcome

What: Revenue collected above costs through Clawback charge

• ERCOT receives funds from

Clawback charges

• Load Ratio Share (LRS) of 30%

Outcome

Trigger

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

• Energy

• AS

• PTP Obligations

Settlement of CRRs

purchased in the

Auction

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

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

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

Trigger

RUCDCAMT

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

* (LSL * (¼)))]} / NCDCHR

Outcome

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

Trigger

Outcome

QSE will not receive

payment for decommitment

RUC Decommitment Charge

Charge to QSEs that represent Load Outcome

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) * [(RUC Decommitment Payments / 4 ) * LRS]

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

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

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

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

Reliability Unit

8:30 A

Commitment

CRR Balancing

Account

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

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