David PenneySr. Principal Engineer, Reliability Services

Performance Indicatorsand

Texas RE 2018 Assessment of Reliability Performance

ROS May 2, 2019

2

Objectives

Review Performance Indicators

Outline Observations

• North American Electric Reliability Corporation (NERC) State of Reliability report

Overview Activities and Emerging Issues

Data Sources

• Transmission Availability Data Systems (TADS)• Generation Availability Data Systems (GADS)• Misoperation Information Data Analysis System (MIDAS)• Electric Reliability Council of Texas (ERCOT) PI System• ERCOT Market Information System (MIS) historical data

ROS May 2, 2019

3

Focus Areas

Resource Adequacy and Performance

System Resilience

Changing Resource Mix

Human Performance

Bulk Power System Planning

Loss of Situational Awareness

Protection and Control Systems

Physical and Cyber Security

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4

NERC’s Inherent Risk Mapping 2018-19

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5

Key Performance Trends for 2014 through 2018

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Key Performance Indicator Negative Trend * Stable Trend * Positive Trend *

Resource Adequacy

Planning reserve marginNatural gascurtailments

Sufficient operating reserves maintained during summer and winter peaks

Transmission Performance

Outage rates per circuit & per 100 miles0 IROL exceedances

Resource Performance

Inverter generation low voltage ride-through

EFOR ratesNo Balancing Contingency event failures

Primary frequency response

System Inertia

Negative inertia trend during minimum load hours Stable trend during other hours

Misoperation RateIncreased rate in 2018 5-year overall stable trend

Human PerformanceStable trend in generation HP errors

Improving trend in transmission and misoperation HP errors

Situational Awareness7 Loss of EMS events in 2018 State Estimator convergence rate

6

Resource Adequacy

ROS May 2, 2019

Average recovery time from generation lossevents was 6.2 minutes in 2018 versus 5.4minutes for calendar year 2017. The averageevent recovery time is showing a long-termgradual increase since 2012, but is still wellwithin NERC requirements.

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Event Recovery Time (Minutes) - Reportable Balancing Contingency Events

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NERC Primary Frequency Response Per BAL-003 (MW per 0.1 Hz)

Primary frequency response metrics continue to be maintained at high levels.

7

Resource Adequacy

ROS May 2, 2019

• The impact of a generator loss is becoming more predictable based on system conditions.

• The relationships between inertia, rate-of-change of frequency, and the MW loss during frequency events are well understood.

R² = 0.6706

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TI UFLS Margin vs. MW Loss % of RLPCUFLS Margin

MW Loss as a Percentage of RLPCR² = 0.7172

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TI RoCoF (3 sec) vs. MW Loss (MW) divided by Inertia (MW-sec)

MW Loss/Inertia

RoCoF (3 sec)

8

Resource Adequacy

ROS May 2, 2019

0%

5%

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30%

Total Coal, Lignite,Fluidized Bed

GG - Gas Nuclear Gas Turbine/JetEngine (Simple

Cycle Operation)

Combined CycleBlock

CC GT units CC steam units

2014 2015 2016 2017 2018MW Weighted EFOR Fossil Performance Metrics

In 2018, 2,026 immediate forced outage events, totaling 120,037 hours, were reported in GADS.

The majority of the immediate forced outage events were due to boiler control or other control system issues, blade path temperature spreads, fuel piping, human error, and vibration issues.

2018 Fossil Unit Forced Outages

Major System

Number of Forced Outage Events

Total Duration (hours)

Total Capacity

(MW)

Median Duration per Event (hours)

Median Capacity per Event (MW)

Average Duration per Event (hours)

Average Capacity per Event (MW)

Boiler System 199 9,941.8 72,873.2 8.8 300.0 49.9 366.2Balance of Plant 399 12,481.1 84,564.3 4.9 170.0 31.3 211.9Steam Turbine/Generator 1,091 35,929.3 178,597.3 3.6 157.5 32.9 163.7Heat Recovery Steam Generator 92 5,647.6 18,962.9 21.8 185.0 61.4 206.1Pollution Control Equipment 31 938.0 4,431.0 5.3 57.0 30.3 142.9External 114 54,371.7 18,432.9 15.3 102.7 476.9 161.7Regulatory, Safety, Environmental 14 182.8 1,471.6 13.9 85.0 13.1 105.1Personnel/Procedure Errors 78 376.6 19,627.7 2.3 182.0 4.8 251.6Other 8 168.0 247.0 1.8 46.8 21.0 30.9

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Resource Adequacy

ROS May 2, 2019

0%

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All Summer Winter Shoulder

Wind GenerationResource Equiv Forced Outage Rate Resource Equiv Scheduled Outage Rate

Wind Capacity Factor, Jun-Aug 2018, HE1500-1900

• 2018 was the first full year of mandatory reporting for wind generators > 200 MW in WindGADS

• In 2018, 81 ERCOT wind facilities submitted a total of 795 unit-months of data

• WindGADS provides similar metrics to GADS (EFOR, EAF, NCF, etc.)

• In 2019, mandatory reporting begins for wind units > 100 MW

10

Resource Adequacy

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0

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Winter Spring Summer Fall

Sum of Unavailable MW due to Gas Curtailments

2012 2013 2014 2015 2016 2017 2018

• Significant increase in the unavailable generation capacity due to natural gas fuel curtailments in 2018.

• Most curtailments occurred in January 2018 during two extreme cold events that month.

11

System Resilience

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EventsTotal Events Cat 4 & 5 Cat 3 Cat 2 Cat 1 Cat 0 Generator Trips >450MW

• There were no Category 2 or higher events in 2018.• During one system event, the voltage collapsed in a local area following a transmission line

fault, resulting in the loss of fourteen 138 kV and 69 kV lines and 140 MW of load.

12

System Resilience

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2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018

ERCOT 345kV Outages / circuit ERCOT 345kV Outages/100 mi-yearERCOT 138kV Sustained Outages / circuit ERCOT 138kV Sustained Outages/100 mi-year

• 345kV and 138kV transmission outage rates remained stable.

13

System Resilience

ROS May 2, 2019

345 kV circuits111 sustained outages3,447 outage hours

345 kV transformers28 sustained outages19,172 outage hours

138 kV circuits429 sustained outages7,514 outage hours

For 345 kV transmission circuits, failed transmission circuit equipment accounted for 8% of cause and 76% of duration.

For 138 kV transmission circuits, failed substation and transmission circuit equipment accounted for 33% of cause and 85% of duration.

14%

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2018 345 kV Sustained Outage CauseWeather, ExcludingLightningLightning

Environmental

Contamination

Foreign Interference

Fire

Failed AC SubstationEquipmentFailed Protection SystemEquipmentFailed AC CircuitEquipmentPower System Condition

Human Error

Unknown

3% 0…0% 1%1%

2%5%

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76%

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1% 4%

2018 345 kV Sustained Outage DurationWeather, ExcludingLightningLightning

Environmental

Contamination

Foreign Interference

Fire

Failed AC SubstationEquipmentFailed ProtectionSystem EquipmentFailed AC CircuitEquipmentPower SystemConditionHuman Error

Unknown

Other

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2018 138 kV Sustained Outage DurationWeather, ExcludingLightningLightning

Environmental

Contamination

Foreign Interference

Vandalism, Terrorism, orMalicious ActsFire

Failed AC SubstationEquipmentFailed AC/DC TerminalEquipmentFailed Protection SystemEquipmentFailed AC CircuitEquipmentVegetation

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2018 138 kV Sustained Outage Cause Weather, ExcludingLightningLightning

Environmental

Contamination

Foreign Interference

Vandalism, Terrorism, orMalicious ActsFire

Failed AC SubstationEquipmentFailed AC/DC TerminalEquipmentFailed Protection SystemEquipmentFailed AC CircuitEquipmentVegetation

14

Changing Resource Mix

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Fuel Type as % of Total Energy

Gas Coal Nuclear Renewable12 per. Mov. Avg. (Gas) 12 per. Mov. Avg. (Coal) 12 per. Mov. Avg. (Nuclear) 12 per. Mov. Avg. (Renewable)

• The portion of total energy supplied by natural gas increased in 2018, up from 38% in 2017 to 44% in 2018 due to retirement of multiple coal units.

• Coal’s portion of total energy decreased from 32% in 2017 to 25% in 2018.

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Changing Resource Mix

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MW of ERCOT Units Reporting GADS by Age

Coal/Lignite Nuclear Gas Waste Heat Other

• There is an age bubble around 35–39 years which is driven by coal and some gas units.• Another age bubble around occurs at 12–17 years comprised almost exclusively of

combined cycle units.

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Changing Resource Mix

ROS May 2, 2019

Year Minimum Inertia (GW-s) Load (MW) Net Load (MW) IRR %2015 130.3 27,798 20,569 26.1%2016 138.4 26,839 14,797 44.9%2017 130.0 28,443 13,178 53.7%2018 128.8 28,412 13,452 52.7%

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IRR % vs Inertia (MW-sec)

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Changing Resource Mix

ROS May 2, 2019

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Inertia Duration Curve

2015 2016 2017 2018

Iner

tia(M

W-s

ec)

Number of Hours

• Average inertia increased across most operating hours in 2018, but decreased during minimum net load conditions.

18

Human Error Performance

ROS May 2, 2019

Operator error58%

Maintenance personnel error

19%

Contractor error12%

Operating procedure error

5%

Maintenance procdure error

5%

Contractor procedure error

1%

Generator Human Error - by Cause

• 138 kV circuit outage rates caused by human error are showing an improving trend. Generator outage rates caused by human error remain stable.

• Since 2014, there have been 498 generator immediate forced outages caused by human error.

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AC Circuit300-399 kV

AC Circuit100-199 kV

Transformer300-399 kV

GeneratorForced Outages

ProtectionSystem

Misoperations

Outages Rates Initiated by Human Error

2015 2016 2017 2018

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Human Error Performance

ROS May 2, 2019

• Cause coding for system events continues to yield outstanding data.

• 47% of root cause and contributing causes for system events are related to potential human performance issues.

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50Event Analysis Cause Codes

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Bulk Power System Planning

ROS May 2, 2019

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Annual Energy Peak DemandGWH

• Load zones with the largest percentage energy increases are the West load zone followed by the North load zone.

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LZ_AEN LZ_CPS LZ_HOUSTON LZ_LCRA LZ_NORTH LZ_RAYBN LZ_SOUTH LZ_WEST

2011 2012 2013 2014 2015 2016 2017 2018Total Energy by Load Zone (GWH)

• Total annual energy usage was 376.8 GWH, an increase of 5.4% over 2017.

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Bulk Power System Planning

ROS May 2, 2019

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2019 2020 2021 2022 2023

Summer Reserve Margin EstimatesERCOT December 2018 CDR NERC December 2018 LTRA

• Reference planning reserve margin is 13.75%, based on a 1 event in 10 year loss of load probability.

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Loss of Situational Awareness

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2013 2014 2015 2016 2017 2018

Loss of EMS and SCADA Events Reported by YearCategory 1 events include:• Loss of operator ability to

remotely monitor, control BES elements,

• Loss of communications from SCADA Remote Terminal Units (RTU),

• Unavailability of Inter-Control Center Communications Protocol (ICCP) links,

• Loss of the ability to remotely monitor and control generating units via Automatic Generation Control (AGC), and

• Unacceptable State Estimator or Contingency Analysis solutions for more than 30 minutes.

EMS/SCADA events are a focus point at NERC and federal levels.

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Loss of Situational Awareness

ROS May 2, 2019

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% System Availability Total Telemetry Points

• ERCOT telemetry performance criteria states that 92% of all telemetry provided to ERCOT must achieve a quarterly availability of 80%. For 2018, the average number of telemetry points failing this metric was approximately 4,011 each month, or 3.8% of the total system telemetry points.

24

Protection and Control System Performance

ROS May 2, 2019

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Overall 345kV 138kV 4 per. Mov. Avg. (Overall)% Misoperation Rate

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Protection and Control System Performance

ROS May 2, 2019

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Questions?

ROS May 2, 2019