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EEA Workshop April 22, 2014

EEA Workshop April 22, 2014. Workshop Process Dan Woodfin. Workshop Process. Workshop 1 Background on EEA Identify Issues Workshop 2 Options to Resolve Issues Consensus Items Future Activities. Background on EEA Stephen Solis. NERC Standards.

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EEA Workshop April 22, 2014

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  1. EEA Workshop April 22, 2014

  2. Workshop Process Dan Woodfin

  3. Workshop Process • Workshop 1 • Background on EEA • Identify Issues • Workshop 2 • Options to Resolve Issues • Consensus Items • Future Activities

  4. Background on EEA Stephen Solis

  5. NERC Standards • Energy Emergency Alerts were first part of the NERC Operating Policies (Policy 5.C.) • NERC Operating Policy 5.C. was transferred to EOP-002 as part of version 0 standards related to FERC Order 693 in 2007. • Appendix 5C (Energy Emergency Alerts) of the NERC Operating Policy was also moved over as Attachment 1-EOP-002 as part of EOP-002.

  6. NERC Standards • Primary Applicable Standard in effect is EOP-002-3.1 Capacity and Energy Emergencies. • EOP-001-2.1b is applicable to ensure appropriate plans are in place. • EOP-003-2 is applicable related to load shed plans and actions for EEA3. • EOP-004-2 is applicable related to required reporting.

  7. Single vs Multiple BA Interconnection • EEA requirements are built around the concept of minimizing risk associated with a BA area “leaning” on another area in a multiple BA Interconnection. • CPS and DCS criteria are measures that are expected to be met even during emergencies to minimize the risk on the Interconnection.

  8. Multiple BA Interconnection • Area Control Error (ACE) has an Interchange component • Frequency is supported by remainder of Interconnection • Emergency status allows additional transmission capacity by modifying transmission service priority • Importance of reducing risk associated with “leaning” on other areas highlighted by requirement to shed load if CPS and DCS cannot be met.

  9. Single BA Interconnection • ACE does not have an interchange component, only frequency. • Frequency is only supported by the single BA area. • Transmission capacity is not reserved (ERCOT) • No “leaning” risk, frequency preservation is priority. • Frequency Responsive Reserves are more critical without additional BA’s support for disturbance.

  10. Single vs Multiple BA Interconnection • ERCOT is a single BA Interconnection. • Frequency preservation and frequency responsive reserves are focus during an EEA in a single BA area.

  11. Questions

  12. Physical Responsive Capability (PRC) Calculation Bill Blevins

  13. Physical Responsive Capability (PRC) A representation of the total amount of system wide On-Line capability that has a high probability of being able to quickly respond to system disturbances. • Control room operators monitor PRC for determining OCN, Advisory, Watch and EEA • Currently PRC includes available capability from Online Generation, Loads Resources and Hydro units on Synchronous Condenser mode • PRC uses a Reserve Discount Factor (RDF) to account for effect of temperature on Generator Capability • Conventional Generation Resources and Controllable Load Resources maximum contribution to PRC is limited to 20% of their HSL*RDF • Why 20%? The Generator with a governor droop setting of 5% will provide 20% of its HSL as Governor Response if Frequency drops to 59.40 Hz from 60.00 Hz. • Hydro Resources operating under synchronous condenser fast response mode can contribute their full HSL*RDF towards PRC • Non-Controllable Load Resources providing RRS is 100% counted towards PRC.

  14. Physical Responsive Capability (PRC) The ERCOT-wide Physical Responsive Capability (PRC) calculated as follows:

  15. Physical Responsive Capability (PRC)

  16. Changes to PRC in near Future • Once NPRR-573 is implemented, Wind Generation Resources that are Primary Frequency Response capable will be contributing to the PRC. Maximum contribution from WGRs will also be limited to 20% of their HSL. • Once NPRR-555 is implemented Controllable Load Resource (CLR) that are active in SCED will also be contributing to PRC. Maximum contribution from CLR will also be limited to 20% of their net telemetered consumption. • Once recently approved NPRR-598 is implemented, Generation Resources telemetering ONTEST, STARTUP or SHUTDOWN Resources Status will be excluded from PRC calculation.

  17. Questions?

  18. Current Procedures and Triggers Colleen Frosch

  19. Preliminary Actions

  20. EEA Steps EEA procedure in the ERCOT Protocols defined by levels 1 Maintain 2,300 MW of on-line reserves Maintain 1,750 MW of on-line reserves. Interrupt loads providing Responsive Reserve Service. Interrupt loads providing Emergency Response Service (ERS). 2 Maintain System frequency at or above 59.8 Hz and instruct TSPs and DSPs to shed firm load in rotating blocks. 3

  21. EEA Level 1 – Maintain a total of 2,300 MW of PRC ERCOT shall: • Notify the Southwest Power Pool Reliability Coordinator; • Request available Generation Resources that can perform within the expected timeframe of the emergency to come On-Line by initiating manual HRUC or through Dispatch Instruction; • Use available DC Tie import capacity not already being used; • Issue a Dispatch Instruction for Resources to remain On-Line which, before start of emergency, were scheduled to come Off- Line; and • At ERCOT’s discretion, deploy available contracted ERS-30. June – September weather-sensitive ERS is available.

  22. EEA Level 1 – Maintain a total of 2,300 MW of PRC QSEs shall: • Ensure COPs and telemetered HSLs are updated and reflect all Resource delays and limitations; and • Suspend any ongoing ERCOT required Resource performing testing.

  23. EEA Level 1 – Maintain a total of 2,300 MW of PRC • TO Load Management Program • Deploy all available capacity from their Load Management Programs • Only applies June through September • Currently 5 TOs participate

  24. EEA Level 2 – Maintain 60 Hz or 1,750 of PRC In addition to the measures associated with EEA Level 1, ERCOT shall take the following steps: • Instruct TSPs and DSPs or their agents to: • reduce Customers’ Load by using distribution voltage reduction measures, if deemed beneficial by the TSP, DSP, or their agents. • Instruct QSEs to deploy: • available contracted ERS-10 Resources • RRS supplied from Load Resources (controlled by high-set under-frequency relays). ERCOT may deploy ERS-10, ERS-30, or RRS simultaneously or separately, and in any order. June – September Weather-Sensitive ERS is available.

  25. EEA Level 3 – Maintain 59.8 Hz or greater • In addition to measures associated with EEA Levels 1 and 2, ERCOT will direct all TSPs and DSPs or their agents to shed firm Load, in 100 MW blocks, as documented in the Operating Guides in order to maintain a steady state system frequency of 59.8 Hz. • In addition to measures associated with EEA Levels 1 and 2, TSPs and DSPs or their agents will keep in mind the need to protect the safety and health of the community and the essential human needs of the citizens. Whenever possible, TSPs and DSPs or their agents shall not manually drop Load connected to under-frequency relays during the implementation of the EEA.

  26. Questions?

  27. History of EEA Bill Blevins

  28. Objectives • Summarize EEA historical information • Discuss recent weather challenges • Identify variables leading to EEAs

  29. History of Energy Emergencies Note EECP was converted to EEA in after 2008 EEA2A and EEA2B were combined into EEA 2 after 2011

  30. Sudden Unit Trip • Example • 2010 • 2011 • 2014

  31. EEA-1 May 15th 2010 Executive Summary At 16:13:49 on May 15th, 2010, Unit A tripped causing the loss of 815 MW. One minute and 18 seconds later, Unit B tripped causing the loss of 745 MW of generation, for a total of 1560 MW. ERCOT ISO frequency initially dropped to 59.71 Hz immediately after the Unit A trip at 16:13:49. System Frequency recovered to 59.76 Hz before Unit B tripped at 16:15:07. As a result of the trip of Unit B the frequency dropped to 59.69 Hz. This dip below 59.7 Hz caused a total of 1111.8 MW of Responsive Reserve, in the form of Load acting as Resource (LaaR), to be automatically deployed. In addition to the LaaRs, 1152 MW of Generation Responsive Reserve was deployed from the 3484 MW of Adjusted Responsive Reserve available at the beginning of the event. ERCOT ISO Operators recognized that this was not a NERC Disturbance Control Standard (DCS) event as the two trips occurred more than 1 minute apart and were considered separate contingencies. At 16:30 ERCOT implemented Level 1 of its Energy Emergency Alert (EEA). EEA Level 1 was declared due to the ERCOT Adjusted Responsive Reserve (ARR) dropping below 2300 MW. ERCOT deployed 1107 MW of Non-Spin Reserve Service (NSRS) at 16:45. EEA Level 1 was cancelled at 17:00. The following operations report discusses primary and contributing factors leading up to and during the EEA event and action items that ERCOT has taken in response to the event.

  32. EEA-1 June 23 2010 Executive Summary At 15:19:54 on June 23rd, 2010, Unit A at the 138 kV Station A tripped causing the loss of approximately 733 MW of generation due to the failure of the main power transformer high side ‘C’ phase disconnect switch. At the same time, Circuit breakers CB1 and CB2 tripped at the 345 kV Station A. This opened one end of the 345 kV line from Station A to Station B, isolating 482 MW of generation output of units B, C and D at Station B and these units tripped approximately nine seconds later. Also, Unit E tripped at Station C causing the loss of 38 MW, for a total of 1253 MW. Two 138 kV lines opened and automatically reclosed from Station A-Station D and Station A-Station E with no impact. ERCOT ISO PI Data shows the frequency dropped to 59.709 Hz immediately after the trip at 15:19:54. After the event, frequency recovered within 6 minutes and 32 seconds to its pre-disturbance value of 59.98 Hz at 15:26:26 and within 14 minutes and 22 seconds to 60 Hz at 15:34:16. ERCOT ISO Operators responded to this event as a NERC Disturbance Control Standard (DCS) event by instructing Load acting as Resource (LaaRs) providing Responsive Reserve Service to deploy. 1150 MW of Generation Responsive Reserve was deployed (from 3281 MW of Adjusted Responsive Reserve (ARR) available). These reserves were deployed at the beginning of the event, along with approximately 246 MW of LaaRs, which tripped on under-frequency relay action. An additional 571 MW of LaaRs were deployed with VDIs between 15:31 and 15:34. A total of 817 MW of LAARs were deployed. Frequency recovered to 60 Hz at 15:34:16. At 15:35 ERCOT implemented Level 1 of its Energy Emergency Alert (EEA). EEA Level 1 was declared because ERCOT’s ARR dropped below 2300 MW. ERCOT deployed 522 MW of Non-Spin Reserve Service (NSRS) at 15:45:09. By 15:48:12 ARR was above 2300 MW. At 16:00 all QSEs were instructed to restore all LAARs deployed. An additional 525 MW of NSRS was deployed at 16:00:07 for a total of 1047 MW. EEA Level 1 was cancelled at 16:03.

  33. EEA-1 August 20 2010 Executive Summary At approximately 15:25:48 on August 20th, 2010, unit A at the 345 kV Station A tripped causing the loss of approximately 1319 MW of generation in the Houston area due to an inadvertent turbine trip signal initiated during planned surveillance testing. Approximately eight seconds later, unit B at the 138 kV Station B tripped offline. At approximately 15:31:56 unit C tripped, and at approximately 15:32:36 unit D tripped. The total loss of generation from this west Texas plant was approximately 212 MW. ERCOT ISO Operations responded to this event as a NERC Disturbance Control Standard event; however it should be excluded from compliance evaluation for being larger than the single largest contingency event. ERCOT ISO historical (PI) data indicates that frequency dropped to approximately 59.749 Hz immediately after the first trip of unit A. The system frequency recovered to 60 Hz in approximately 4 minutes and 42 seconds (~15:30:30). ERCOT ISO recovered from the frequency deviation as required by the NERC Reliability Standard BAL-002-0. At 15:25:48, 1150 MW of Generation Responsive Reserve was deployed due to the low frequency. These reserves were deployed at the beginning of the event, along with approximately 20 MW of Load acting as Resources (LaaRs), which tripped on under-frequency relay action. At 15:28 ERCOT ISO requested all Qualified Schedule Entities (QSE) to deploy all remaining LaaRs scheduled to provide Responsive Reserve Service. A total of 1320 MW of LaaRs were deployed. At 15:41, all QSEs were instructed to restore LaaRs. Non-Spinning Reserve Service (NSRS) was deployed at 15:44 in the Houston zone for interval ending 16:15, and 15:45 in the South, North and West zones for interval ending 16:30. ERCOT ISO implemented Level 1 of its Energy Emergency Alert (EEA) at 15:48 due to Adjusted Responsive Reserve (ARR) dropping below 2300 MW. By 16:13:38, ARR was above 2300 MW and EEA Level 1 was cancelled at 16:35. The following operations report discusses primary and contributing factors leading up to and during the EEA event and action items that ERCOT has taken in response to the event.

  34. June 27th 2011 EEA - Frequency

  35. June 27th 2011 EEA – Physical Responsive Capability

  36. EEA-1 Jan 18 2014 Executive Summary The morning of January 18, 2014, ERCOT entered into emergency operations. This was the result of a Disturbance Control Standard (DCS) qualifying event which occurred at approximately 08:41. Nuke unit X tripped, resulting in approximately 1237 MW of energy being lost to the grid shortly after the morning peak. When the unit tripped, nearly 1000 MW of Physical Responsive Capability (PRC) was lost, as PRC dropped from approximately 3300 MW to 2300 MW in approximately 90 seconds. At approximately 08:47 ERCOT declared a Watch for PRC below 2500 MW, and then at approximately 09:02 ERCOT declared Emergency Energy Alert (EEA) Level 1 for PRC below 2300 MW. Off-Line Non-Spin was deployed between 08:44 and 10:18. Responsive Reserve Service (RRS) from generators was also deployed as a result of the unit trip. Given that system frequency reached approximately 59.699 Hz, approximately 850 MW of RRS from Load Resources was provided from under-frequency relays. PRC was below 2300 MW for approximately 30 minutes, below 2500 MW for approximately 38 minutes, and below 3000 MW for approximately 50 minutes. At approximately 09:47 ERCOT exited EEA level 1 due to improving conditions, and resumed normal operations. No firm load shed actions were taken.

  37. Large Cap Unavail due to Forced Outage and Derate • Example • 2011 • 2014

  38. A record-breaking arctic front was approaching prior to February 2, 2011 Extremely Cold Weather Grips Texas February 1, 2011 Major Winter Storm Expected to Develop Over Texas February 2, 2011 Winter Returns with Fury February 1, 2011 The Coldest Week for North Texas in 22 Years The arctic cold front that descended on the Southwest during the first week of February 2011 was unusually severe in terms of temperature, wind, and duration of the event. In many cities in the Southwest, temperatures remained below freezing for four days, and winds gusted in places to 30 mph or more. The geographic area hit was also extensive, complicating efforts to obtain power and natural gas from neighboring regions. The storm, however, was not without precedent. There were prior severe cold weather events in the Southwest in 1983, 1989, 2003, 2006, 2008, and 2010. The worst of these was in 1989, the prior event most comparable to 2011.

  39. More than 8,000 megawatts (MW) of generation unexpectedly dropped offline overnight

  40. The ERCOT System responded as expected Feb 2nd 2011

  41. A timeline of the emergency steps that were taken leading to rotating outages in ERCOT Feb 2nd 2011 • Issued EEA 3 • EILS deployed • Firm Load Shed 1,000 MW New winter Peak Record 56,480 MW 7:57am Restored 500 MW (3,500 MW out) 8:22am Restored 500 MW (3,000 MW out) 9:25am Restored 500 MW (2,500 MW out) Move to EEA 2B From EEA 3 1,804 MW Non-Spin deployed Restored 500 MW Restoration Complete Feb 2 Feb 3, 10 AM EEA 2A ends & EILS recalled 4:30am 5:43am 1:07pm 2:01pm 7:15pm 5:08am 5:20am 6:04am Firm load shed 1,000 MW (2,000 MW total) 6:05am Frequency 59.576Hz 6:23am Firm Load Shed 2,000 MW (4,000 MW total) 6:59am Media Appeal issued 11:39am Restored 500 MW (2,000 MW out) 12:04pm Restored 500 MW (1,500 MW out) 12:25pm Restored 500 MW (1,000 MW out) 12:49pm Restored 500 MW (500 MW out) 1:57pm 3:14pm • Issued EEA 2A • Reserves below 1,750 MW • Load Resources deployed Move to EEA 2A From EEA 2B Load Resources Recalled Issued Watch Reserves below 2,500 MW

  42. Event Summary – January 6, 2014 • At 6:52, ERCOT declared Level 1 of its Energy Emergency Alert (EEA) and declared EEA Level 2 at 7:01, primarily due to the loss of a number of generating units • Non-Spin Reserve Service (NSRS), Load Resources (LR) and Emergency Response Service (ERS) were deployed, but firm load shed was not required • ERCOT moved from EEA2 to EEA1 at 7:51 and resumed normal operations at 9:12 • Generation outages & derates peaked at 9355 MW just before 07:00, with 3541 MW due to weather • Hourly peak demand was 55,487 MW for HE08 and instantaneous peak demand was 56,478 MW at 07:08:24

  43. Timeline – January 6, 2014 EEA EEA Level 1 cancelled. Watch remains in effect. 07:51 AM ERCOT recalled EEA Level 2. EEA Level 1 remains in effect 07:56 AM ERCOT recalled 30 minute ERS 07:58 AM ERCOT recalled 10 minute ERS. ERCOT issued EEA Level 1 for PRC below 2300 MW ERCOT issued EEA Level 2 for PRC below 1750 MW Watch terminated as PRC was above 3000 MW Watch issued due to PRC below 2500 MW 09:12 AM 09:55 AM 06:42 AM 07:01 AM 06:52 AM 06:42 AM 06:57 AM 06:52 AM 06:37 AM 08:10 :36 AM ERCOT recalled all Non-Spin 08:10:48 AM ERCOT deployed RRS to Generators for frequency below 59.91 Hz 08:17 AM ERCOT recalled all RRS from Generators due to frequency above 59.91 Hz 07:02 AM ERCOT deployed 30 minute ERS for 111.68 MW 07:05 AM ERCOT deployed 10 minute ERS for 508.72 MW 07:13 AM ERCOT recalled all RRS from Generators due to frequency above 59.91 Hz ERCOT deployed Non-Spin for 187 MW ERCOT deployed Group 1 RRS for 546.36 MW 07:43 AM ERCOT recalled all Group 2 RRS 07:50 AM ERCOT recalled all Group 1 RRS ERCOT deployed RRS to Generators for frequency below 59.91 Hz ERCOT deployed Group 2 RRS for 536.24 MW

  44. Reserves

  45. High Summer Demand • Example • 2011

  46. 2011 High Load Summer Energy Emergency Alerts

  47. August 2011 Peak Loads 8/3: Record Peak

  48. ERCOT Load, Wind, and PRC 8/4/2011 12:00–24:00

  49. Wind Forecast/Ramp • Example • Feb 26, 2008

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