ERCOT Monthly Operational

Overview (August 2013)

ERCOT Public

September 15, 2013

2

Grid Operations & Planning

ERCOT Public 3

• Operations

– The peak demand of 67,180 MW on August 7th was less than the mid-term

forecast peak of 67,225 MW but greater than the August 2012 actual peak

demand of 66,509 MW. The instantaneous load on August 7th was 67,314 MW.

– Day-ahead load forecast error for August was 2.07%

– ERCOT issued two Advisories. • Two separate advisories for extreme hot weather expected in the North Central and South Central

weather zones (8/7,8/8).

– No Watches were issued

– ERCOT issued an Emergency Notice due to SCED failure (8/16 03:10)

– No Energy Emergency Alert (EEA) events

• Planning Activities

– 162 active generation interconnection requests totaling over 41,400 MW,

including 20,900 MW of wind generation as of August 31, 2013. One less

request and 1,400 less total MW from July 31, 2013

– 10,570 MW wind capacity in commercial operation August 31, 2013; no change

from July 31, 2013

Summary – August 2013

ERCOT Public 4

Daily Peak Demand: Hourly Average Actual vs.

Forecast, Wind Day-Ahead COPs & On-line Capacity at Peak – August 2013

ERCOT Public 5

0

500

1000

1500

2000

2500

3000

3500

4000

4500

8/1

8/2

8/3

8/4

8/5

8/6

8/7

8/8

8/9

8/10

8/11

8/12

8/13

8/14

8/15

8/16

8/17

8/18

8/19

8/20

8/21

8/22

8/23

8/24

8/25

8/26

8/27

8/28

8/29

8/30

8/31

MW

Daily Averaged Aggregated Wind Output Estimated Wind Curtailment Daily Averaged Day-Ahead COP HSL

Actual Wind Output plus Curtailments vs. Wind Day-Ahead COPs for All

Hours – August 2013

Note: QSEs must use the AWST 50% probability of exceedance forecast as the HSL in their COPs

% of Hours when Estimated Uncurtailed Wind Output

>= COP HSLs (Target = 50%)

44%

ERCOT Public 6

ERCOT’s CPS1 Monthly Performance – August 2013

CPS1 12 Month Rolling Average = 166.86%

ERCOT Public 7

Monthly Peak Actual Demand – August 2013

ERCOT Public 8

Monthly Minimum Actual Demand – August 2013

ERCOT Public 9

Day-Ahead Load Forecast Performance – August 2013

Mean Absolute Percent Error (MAPE) for ERCOT Mid-Term Load Forecast (MTLF)

Run at 14:00 Day Ahead

2010

MAPE

2011

MAPE

2012

MAPE

2013

MAPE

Aug 2013

MAPE

Average

Annual

MAPE 2.83 2.83 3.02 2.78

2.07

Lowest

Monthly

MAPE 2.24 1.63 2.51 2.07

Lowest

Daily

MAPE

0.55 August - 7

Highest

Monthly

MAPE 3.79 3.55 3.49 3.50

Highest

Daily

MAPE

4.16 August – 24

ERCOT Public 10

Reliability Unit Commitment (RUC) Capacity by Weather Zone – August

2013

ERCOT Public 11

Generic Transmission Limits (GTLs) – August 2013

GTL: A transmission flow limit more constraining than a Transmission Element’s normal limit

established to constrain flow between geographic areas of the ERCOT Transmission System that is

used to enforce stability and voltage constraints that cannot be modeled directly in ERCOT’s

transmission security analysis applications.

Note: This table lists how many times a constraint has been activated to avoid exceeding a GTL limit, it does

not imply an exceedance of the GTL occurred.

GTLs Aug 12

Days GTLs

Jun 13

Days GTLs

Jul 13

Days GTLs

Aug 13

Days GTLs

Last 12

Months

Total Days (Aug12 – Aug13)

North – Houston 0 0 0 0 0

West – North 3 4 0 0 81

Valley Import 0 0 0

0

0

ERCOT Public 12

• Advisories issued for Physical Responsive Capability (PRC) below 3000 MW. – None

• Advisories issued for extreme hot weather expected in the North Central and South Central weather zones

– Issued two days (08/07; 08/07)

• Advisories issued for geomagnetic disturbance storm of K-7 or higher. – None

• Watches issued for Physical Responsive Capability (PRC) below 2500 MW. – None

• Transmission Watches – None

• Emergency Notice – ERCOT issued an emergency notice due to SCED execution failure 8/16 03:10

• Energy Emergency Alerts – None

Advisories and Watches – August 2013

ERCOT Public 13

Significant Events – August 2013

• No significant events to report

ERCOT Public 14

Lake Levels Update – September 1, 2013

Surface Water & (MW)

*Level @ Full

Conservation

Pool

*Level on

Jan 1, 2011

*Level on

Oct 7, 2011

*Level on

Sep 1, 2013

Lake Texana (56) 44.50 41.00 32.81 40.22

Bardwell Lake (312) 421.00 420.71 416.23 416.38

Lake Colorado City (407) 2,070.20 2057.33 2052.4 2050.64

Lake Ray Hubbard (916) 435.50 432.37 429.22 429.80

Lake Granbury (983) 693.00 691.90 686.27 685.33

Lake Houston (1016) 41.73 42.10 36.76 41.40

Twin Oaks Reservoir (1616) 400 398.87 398.27 400.12

Lake Limestone (1689) 363 359.03 354 356.14

Martin Lake (2425) 306 300.48 295.06 301.70

* In Feet above Mean Sea Level

ERCOT Public 15

• ERCOT is currently tracking 162 active generation interconnection requests

totaling over 41,400 MW. This includes over 20,900 MW of wind generation.

• ERCOT is currently reviewing proposed transmission improvements with a

total cost of $750 Million

• Transmission Projects endorsed in 2013 total $349.8 Million

• All projects (in engineering, routing, licensing and construction) total

approximately $8.82 Billion.

• Transmission Projects energized in 2013 total about $1.29 Billion.

Planning Summary – August 2013

ERCOT Public 16

County Location of Installed Generation with Interconnection Requests (all

fuels) – August 2013

ERCOT Public 17

County Location of Wind Generation – August 2013

ERCOT Public 18

Wind Generation – August 2013

ERCOT Public 19

Generation Interconnection Activity by Fuel – August 2013

ERCOT Public 20

Generation Interconnection Activity by Project Phase – August 2013

21

Market Operations

ERCOT Public 22

Day-Ahead Schedule (Hourly Average) – August 2013

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

MW

Scheduled Energy Only Offer

Scheduled Three-part Offer

DAM Energy Purchase

RT System Load

DAM Net Flow

Liquidity and activity is normal in Day-Ahead Market

DAM_Net_Flow = Combined market transmission flow of Energy purchased/sold in

Day-Ahead Market plus Point-to-Point Obligations and

NOIE CRR Options carried forward to real-time.

ERCOT Public 23

Day-Ahead Electricity And Ancillary Service Hourly Average Prices –

August 2013

0

10

20

30

40

50

60

70

80

90

100

110

120

Pri

ce

($

/MW

h)

Regulation Up

Regulation Down

Responsive Reserve

Non Spinning Reserve

Ancillary Service price reflect the opportunity cost of energy

High prices for Regulation Up, Responsive Reserve, and

Non-Spinning Reserve during hours 16 to 18 were due to the

co-optimization of higher Energy/Ancillary Service

offers and higher Energy bids for those hours.

ERCOT Public 24

Day-Ahead Vs Real-Time Load Zone SPP (Hourly Average) – August 2013

0

20

40

60

80

100

120

140

160

180P

ric

e (

$/M

Wh

)

RTSPP - LZ West

RTSPP - LZ North

RTSPP - LZ South

RTSPP - LZ Houston

DASPP - LZ West

DASPP - LZ North

DASPP - LZ South

DASPP - LZ Houston

Prices reflect relative transmission congestion and system scarcity

Higher Real-Time prices in Load Zone West were mainly due to

outages and low wind in the west area

Higher Day-Ahead prices in late afternoon and evening reflect

hedging activities against exposure to Real-Time prices

ERCOT Public 25

Day-Ahead Vs Real-Time Hub Average SPP (Hourly Average) – August 2013

0

20

40

60

80

100

120P

ric

e (

$/M

Wh

)

RTSPP - Hub Average

DASPP - Hub AverageEnergy prices reflect the risk premium between Day-Ahead & Real-Time

ERCOT Public 26

DRUC Monthly Summary (Hourly Average) – August 2013

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000M

Wh

Self Scheduled Capacity

Self Scheduled Ancillary Service Limit

Load Forecast

DRUC Recommended Capacity

31 executions (none missed)

None published after 1600

8 minutes average execution time

No Resource Commitments

ERCOT Public 27

HRUC Monthly Summary – August 2013

0

0

0

1

1

1

1M

Wh

744 executions (none missed)

8 minute average execution time

No Resource commitments

Colors Indicate Individual Resources

ERCOT Public 28

Non-Spinning Reserve Service Deployment – August 2013

Deployment Start Time Deployment End

Time

Deployment

Duration (Hours)

Max Deployment

(MW) Reason

None

ERCOT Public 29

CRR Price Convergence – August 2013

0

10

20

30

40

50

60

70

80M

illio

ns

$

Cost

Value

Congestion Revenue Right cost in auction convergence with

payment in Day-Ahead Market and Real Time Market

Congestion Revenue Right cost in auction convergence with

payment in Day-Ahead Market and Real Time Market

ERCOT Public 30

ERS Procurement for June 2013 – September 2013

10-Minute ERS

BH1 BH2 BH3 NBH

MW Procured 472.125 351.550 345.500 384.875

Average Price Per MW per Hour1 $10.21 $12.07 $12.60 $10.13

Note: Four Generators procured with an average of 11.7 MW across all 4 time periods 30-Minute ERS Pilot

MW Procured 126.970 87.645 76.190 100.940

Clearing Price2 $11.00 $12.00 $14.00 $11.00

BH1 - Business Hours 1 HE 0900 through 1300, Monday thru Friday except ERCOT Holidays BH2 - Business Hours 2 HE 1400 through 1600, Monday thru Friday except ERCOT Holidays BH3 - Business Hours 3 HE 1700 through 2000, Monday thru Friday except ERCOT Holidays NBH - Non-Business Hours All other hours

Weather Sensitive ERS Pilot

BH2 BH3 WEH

MW Procured 2.60 2.60 2.60

Clearing Price2 $50.00 $50.00 $50.00

BH2 - Business Hours 2 HE 1400 through 1600, Monday thru Friday except ERCOT Holidays BH3 - Business Hours 3 HE 1700 through 2000, Monday thru Friday except ERCOT Holidays WEH- WeekEnd & Holidays HE 1400-2000, Saturday, Sundays & Holidays

1 Procured on a Pay-As-Offer basis 2 Procured using a Clearing Price Mechanism

ERCOT Public 31

Market Enhancements to Address IMM Recommendations –

August 2013

Enhancement Further Information

Adequate scarcity pricing in

SCED using Operating

Reserve Demand Curve:

Hogan solution

• ERCOT is scheduled to provide a draft NPRR and corresponding Other Binding

Document (OBD) that would implement Hogan B+ as described in the white

paper

• The target date for the submittal to the PUC is 9/19/2013 (3 weeks from

the 8/29/2013 Open Meeting)

• Key parameters will be left as variables

Potential solutions to prevent

price reversals due to

deployment of existing load

resources

• NPRR 508 – Setting of Real-Time LMPs during EEA ERS/Load Resource

Deployment

• At the 6-6-13 TAC meeting, the NPRR failed to get sufficient votes for approval

(14 yes/13 no/2 abstain)

• NPRR 508 has a status of “rejected”

• TAC produced a report for July Board of Director meeting on pricing during

Reserve Deployments

“Over-mitigation” in SCED

• NPRR 520 – Real-Time Mitigation Rules and Creation of a Real-Time Constraint

Competitiveness was approved by BOD on 3-19-13

• The NPRR was partially (MMS functionality) implemented on 6-12-13

• The last remaining part of the NPRR which provides additional informational

telemetry to QSEs was implemented on 7-31-13

ERCOT Public 32

Reliability Services – August 2013

Reliability Unit Commitment (RUC) $ in Millions

RUC Make-Whole Payments ($0.00)

RUC Clawback Charges $0.00

RUC Commitment Settlement ($0.00)

RUC Capacity Short Charges $0.00

RUC Make-Whole Uplift $0.00

RUC Commitment Cost Allocation $0.00

RUC Decommitment Payments $0.00

RUC Cost continues to trend low.

There were no RUC Costs in August 2013, compared to:

• A charge of $0.02 in July 2013

• A charge of $0.00 in August 2012

ERCOT Public 33

Ancillary Services – August 2013

Capacity Services $ in Millions

Regulation Up Service $3.65

Regulation Down Service $0.81

Responsive Reserve Service $19.7

Non-Spinning Reserve Service $5.56

Black Start Service $0.52

Voltage Services - Reactive Power $0.0

Voltage Services - Lost Opportunity $0.0

Total Capacity Service $30.20

Capacity Services costs were up from last month and are less than

August 2012.

August 2013 cost was $30.20M, compared to:

• A charge of $20.13M in July 2013

• A charge of $47.33M in August 2012

ERCOT Public 34

Energy Settlement – August 2013

Day-Ahead and Real-Time energy settlement

increased from last month.

Day-Ahead Market settlements are less than

August 2012 and Real-Time Market

settlements are higher.

Day-Ahead Market Energy Settlement $ in Millions

Energy Purchases $710.26

Point to Point Obligation Purchases $45.86

RMR Day-Ahead Revenue $0.00

Energy Sales ($697.72)

Day-Ahead Congestion Rent $58.40

Day-Ahead Market Make-Whole Payments ($0.05)

Real-Time Market Energy Settlement $ in Millions

Energy Imbalance at a Resource Node ($696.59)

Energy Imbalance at a Load Zone $1,005.51

Energy Imbalance at a Hub ($264.27)

Real Time Congestion from Self Schedules $0.37

Block Load Transfers and DC Ties ($12.61)

Impact to Revenue Neutrality $32.41

Emergency Energy Payments ($0.27)

Base Point Deviation Charges $0.38

Real-Time Metered Generation (MWh in millions) 35.27

ERCOT Public 35

Congestion Revenue Rights (CRR) – August 2013

Auction Disbursements $ in Millions

Annual Auction ($32.43)

Monthly Auction ($10.25)

Total Auction Revenue ($42.69)

Day-Ahead CRR Settlement ($54.02)

Day-Ahead CRR Short-Charges $1.07

Day-Ahead CRR Short-Charges Refunded ($1.07)

Real-Time CRR Settlement ($0.00)

Real-Time CRR Short-Charges $0.00

Real-Time CRR Short-Charges Refunded ($0.00)

Total CRR Proceeds ($54.02)

Day-Ahead Point to Point Obligations

Settlement $45.86

Real-Time Point to Point Obligation

Settlement ($36.24)

Net Point to Point Obligation Settlement $9.61

Congestion Revenue Rights were fully funded

and excess funds were available for

distribution to load.

Distribution of Balancing Account funds to load

for August 2013 was $4.42 M, compared to:

• $3.24M in July 2013

• $24.13M in August 2012

Point to Point Obligations settled with a net

charge of $9.61M compared to a net gain of

$8.56M last month.

ERCOT Public 36

Revenue Neutrality – August 2013

Revenue Neutrality Settlement $ in Millions

Real-Time Point to Point Obligation Settlement ($36.24)

Real-Time Point to Point Options and Options with Refund Settlement ($0.00)

Real-Time Energy Imbalance Settlement $44.66

Real-Time Congestion from Self-Schedules Settlement $0.37

DC Tie & Block Load Transfer Settlement ($12.61)

Charge to Load $3.82

Revenue Neutrality charges to load decreased

compared to last month and to August 2012.

August 2013 was a charge of $3.82M,

compared to:

• $ 5.00M charge in July 2013

• $10.11M charge in August 2012

ERCOT Public 37

Net Uplift to Load – August 2013

Net uplift to Load increased significantly from last

month and decreased from August of 2012

August 2013 was a charge of $1.67M, compared

to:

• A credit of $ 8.33M in July 2013

• A charge of $18.55M in August 2012

Market-Based Uplifts $ in Millions

CRR Auction Revenue Disbursement Settlement ($42.69)

Balancing Account Proceeds Settlement ($4.42)

Net Reliability Unit Commitment Settlement $0.00

Ancillary Services Settlement $30.20

Reliability Must Run Services Settlement $0.0

Reliability Must Run for Capacity $0.0

Real-Time Revenue Neutrality Settlement $3.82

Emergency Energy Settlement $0.27

Base Point Deviation Settlement ($0.38)

Total ($13.21)

Fee Uplifts

ERCOT Administrative Fee Settlement $14.89

Net Uplift Charge to Load $1.67

ERCOT Public 38

Advanced Meter Settlement Impacts – August 2013

August 2013: At month

end, settling 6.4M ESIIDs

using Advanced Meter

data.

August 2013: 97.2% of the

load in ERCOT is settled with

15-min interval data (AMS,

Competitive IDR, and NOIE

IDR).

ERCOT Public 39

ERCOT Wide Load Volumes by Meter Type – INITIAL Settlement –

August 2013

ERCOT Public 40

Retail Transaction Volumes – Summary – August 2013

Year-To-Date Transactions Completed

Transaction Type August 2013 August 2012 August 2013 August 2012

Switches 637,432 677,807 91,240 89,052

Acquisition 134 0 0 0

Move - Ins 1,602,271 1,523,022 259,489 232,716

Move - Outs 778,222 750,930 119,193 114,124

Continuous Service Agreements (CSA) 346,514 504,027 46,558 188,159

Mass Transitions 0 5,518 0 0

Total 3,364,573 3,461,304 516,480 624,051

Total since June 1, 2001 53,256,099

ERCOT Public 41

Retail Transaction Volumes – Summary – August 2013 Switches/Acquisitions

Move-Ins

Move-Outs Mass Transition

0

1,000

2,000

3,000

4,000

5,000

6,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

2013 2012

ERCOT Public 42

Retail Performance Measures – Switch – August 2013 1st Quarter 2nd Quarter

3rd Quarter 4th Quarter

ERCOT Public 43

1st Quarter 2nd Quarter

3rd Quarter 4th Quarter

Retail Performance Measures (Same Day Move-In) – August 2013

ERCOT Public 44

1st Quarter 2nd Quarter

3rd Quarter 4th Quarter

Retail Performance Measures (Standard Move-In) – August 2013

45

Projects Report

ERCOT Public 46

ERCOT Portfolio Stoplight Report (as of 9/12/2013)

ERCOT Public 47

ERCOT Portfolio Stoplight Report (as of 9/12/2013)

ERCOT Public 48

ERCOT Portfolio Stoplight Report (as of 9/12/2013)

ERCOT Public 49

ERCOT Portfolio Stoplight Report (as of 9/12/2013)