1. August 17, 2011 Reliability Deployments Task Force Meeting Updated Analysis of Non-Spin Deployments and RUC John Dumas Director Wholesale Market Operations

2. 2 Outline of Presentation July 13 & July 18 : Results of SCED Re-Run: LSL=0, LDL recalculated for different “floor” scenarios August 8, 2011: Non-Spin Deployment Summary of August 8 Non-Spin Deployment Discussion of Adjusting Non-Spin Deployment and Recall Discussion of Adjusting RUC Approach August 17, 2011Reliability Deployments Task Force Meeting

3. 3 July 13 & July 18 : Results of SCED Re-Run: LSL=0, LDL recalculated for different “floor” scenarios August 17, 2011 July 13: FIP=4.41July 18: FIP=4.445 System Lambda @14:35 Before Non- Spin Deployment System Lambda @14:55 - After Non-Spin Deployment System Lambda @15:20 Before Non- Spin Deployment System Lambda @15:55 - After Non-Spin Deployment Sum(HDL)-GTBD =459 MW (New) = -7 MW (Original) Sum(HDL)-GTBD =505 MW (New) =505 MW (Original) Sum(HDL)-GTBD =335 MW (New) =280 MW (Original) Sum(HDL)-GTBD =1149 MW (New) =1149 MW(Original) Original LSL OFFNS LSL=0 LDL recalc Original LSL OFFNS LSL=0, LDL recalc Original – No change $2999.99$76.79$76.80$267.75$63.35$64.61 Original – Only online HASL/HDL changed, NO floor $92.88$76.79$76.80$62.54$63.35$64.61 Low Floor$81.28$83.61$186.15$85.08$80.92$93.52 Med Floor-1 $500 $475.57$80.92$472.08 Med Floor-2 $1000 $968.96$80.92$967.59 High Floor $3000 $2968.95$80.93$2967.58 Reliability Deployments Task Force Meeting

4. 4 August 8, 2011: Non-Spin Deployment August 17, 2011 All Non-Spin deployed at 14:56 in the amount of 1540.70 MW Continued All Non-Spin deployment at 17:02 in the amount of 1626.74 MW All Non-Spin recalled at 18:41 @14:56, of the total 1540.7 MW of Non-Spin Responsibility, 1103 MW Non-Spin ALREADY available to SCED from Online QSGR. Between 14:52 and 15:56 - PRC went below 2500. Between 17:00 and 18:00 PRC went below 2500. Between 14:25 and 17:30 the Avail_CAP_30MIN went below 1000 MW (negative for some 5 minute intervals) and  HDL-GTBD went below 200 after 16:10 (29.11 MW @16:52) Load Forecast for HE 15 = 64464 MW Load Forecast for HE 16 = 66355 MW Load Forecast for HE 17 = 67195 MW Load Forecast for HE 18 = 66668 MW Reliability Deployments Task Force Meeting

5. 5 August 8, 2011: Non-Spin Deployment August 17, 2011 Telem Non-Spin Responsibility @14:55=1540 Telem Non-Spin Responsibility @15:25=1657 Telem Non-Spin Responsibility @17:00=1627 @14:55 System_Lambda=$725.83 @15:25 System_Lambda=$60.13 Load increase from 14:55 to 15:25 = 564.9 MW LSL injection from OFFNS resources from 14:55 to 15:25 = 0 (“OFFNS” QSGR) + 101 (“OFFNS” Non-QSGR) = 101 MW Reliability Deployments Task Force Meeting

6. 6 August 8, 2011: Non-Spin Deployment (continued) August 17, 2011 @14:55LSLNon-Spin Responsibility “ON” Non-QSGR990306.7 “OFFNS” Non-QSGR101131, HSL=277 “ON” QSGR2841103 (TelemMW=294.92, HSL=1104.8) “OFFNS” QSGR00 “OFF” Non-QSGR that came online by 15:25 850 (80 MW were ONRUC) “OFF” QSGR that came online by 15:25 00 Note 1: All are telemetry values at 14:55 (before Non-Spin Deployment) Note 2: The total HSL from “OFF” Generation Resources that came online = 206 MW Reliability Deployments Task Force Meeting

7. 7 August 8, 2011: Non-Spin Deployment (continued) August 17, 2011Reliability Deployments Task Force Meeting

8. 8 August 8, 2011: Non-Spin Deployment (continued) August 17, 2011 OFFNS Non-QSGR resources carrying Non-Spin: Aggregated EOC from LSL to HSL Reliability Deployments Task Force Meeting

9. 9 August 8, 2011: Non-Spin Deployment (continued) August 17, 2011 Online Non-QSGR resources carrying Non-Spin: Aggregated EOC from HASL to HASL+Non-Spin Reliability Deployments Task Force Meeting

10. 10 Summary of August 8 Non-Spin Deployment August 17, 2011 Price is $725.83 just before Non-Spin Deployment Note all QSGR are online. Price reduction 30 minutes after Non-Spin deployed is due to additional EOC available to SCED at low price. Reliability Deployments Task Force Meeting

11. 11 August 8: Results of SCED Re-Run for different “floor” scenarios August 17, 2011 August 8: FIP=$3.965/MMBtu System Lambda @14:55 Before Non-Spin Deployment System Lambda @15:25 - After Non-Spin Deployment Sum(HDL)-GTBD =843 MW (New) = 418.4 MW (Original) Sum(HDL)-GTBD =778.83 MW (New) =778.83 MW (Original) Original LSLOFFNS LSL=0 LDL recalc Original – No change$725.83$60.13$60.14 Original – Only online HASL/HDL changed, NO floor $136.40$60.13$60.43 Low Floor$136.27$72.09 Med Floor-1 $500 $113.24$202.68 Med Floor-2 $1000 $113.24$444.41 High Floor $3000 $113.24$444.41 Reliability Deployments Task Force Meeting

12. 12 Current Non-Spin Deployment based on “HDL-GTBD” 1)If  HDL – GTBD >>> deploy HALF of Non-Spin. (Partial deployment of Non-Spin) 2)If  HDL – GTBD >>> deploy ALL Non-Spin. (Full deployment of Non-Spin) Avail_Cap30Min =  HASL – GTBD – 30MinLoadRamp 30MinLoadRamp=( NextHourLoadForecast – CurrentHourLoadForecast)/2 August 17, 2011Reliability Deployments Task Force Meeting

13. 13 Illustrative Example of Revision to Deployment Based on “HDL-GTBD” (Section 3.4 of RT Desk Operating Procedure ) 1)If  HDL – GTBD <= 400 AND Avail_Cap30Min < 1000 MW; Then deploy all of On-Line Non-Spin [Starts earlier with On-Line only] 2)If  HDL – GTBD <= 200 AND Avail_Cap30Min < 1000 MW; Then deploy HALF of Off-Line Non-Spin. (Partial deployment of Off-Line Non- Spin) 3)If  HDL – GTBD <= 200 AND Avail_Cap30Min < 500 MW; Then deploy ALL Non-Spin. (Full deployment of Non-Spin) Avail_Cap30Min =  HASL – GTBD – 30MinLoadRamp 30MinLoadRamp=( NextHourLoadForecast – CurrentHourLoadForecast)/2 August 17, 2011Reliability Deployments Task Force Meeting

14. 14 Additionally Current Non-Spin Deployment based on “PRC” 1)If Physical Responsive Capability (PRC) < 2500 MW – deploy enough to recover PRC to 2500 (Partial deployment of Non-Spin) 2)If Physical Responsive Capability (PRC) < 2300 MW – deploy ALL Non- Spin. (Full deployment of Non-Spin) Physical Responsive Capability =  Min (Max ((HSL – TelemMW), 0.0), 0.2*HSL) for online units + RRS from Load Resources August 17, 2011Reliability Deployments Task Force Meeting

15. 15 Illustrative Example on Revision to Deployment Based on “PRC” (Section 5.2 of RT Desk Operating Procedure) 1)If Physical Responsive Capability (PRC) < 2700 MW; Then deploy all On-Line Non-Spin (Partial deployment of Non-Spin) 1)If Physical Responsive Capability (PRC) < 2500 MW; Then deploy enough Off-Line Non-Spin to recover PRC to 2500 (Partial deployment of Non-Spin) 3)If Physical Responsive Capability (PRC) < 2300 MW; Then deploy ALL Non-Spin. (Full deployment of Non-Spin) Physical Responsive Capability =  Min (Max ((HSL – TelemMW), 0.0), 0.2*HSL) for online units + RRS from Load Resources August 17, 2011Reliability Deployments Task Force Meeting

16. 16 Current Recall Procedure (No suggested changes at this time) If (HDL-GEN) ≥ 500 MW, Avail_CAP_30Min ≥ 1000, AND PRC is ≥ 3000 MW; Then recall half of Non-Spin. If (HDL-GEN) ≥ 1000 MW, Avail_CAP_30Min ≥ 1000, AND PRC is ≥ 3000 MW Then recall all Non-Spin. August 17, 2011Reliability Deployments Task Force Meeting

17. 17 Possible Revisions to Non-Spin Deployment and Recall Procedure August 17, 2011 Several possible revisions to the Non-Spin deployment and recall procedures have been discussed. For some revisions, in addition to procedure changes that need to be approved by TAC, there would need to be changes to the ERCOT systems in order to have deployments and recalls that discriminate between On-Line Non-Spin and Off-Line Non-Spin Resources. At least several months would be needed to implement the needed display changes and software changes. Reliability Deployments Task Force Meeting

18. 18 Adjustments to the RUC Process August 17, 2011 RUC is used to ensure ERCOT System reliability and to ensure that enough Resources Capacity, in addition to Ancillary Service capacity, is committed in the right locations to reliably serve the forecasted Load on the ERCOT system. Bias already subtracted from the Load Forecast. (Average 1259 MW across peak hours in August) Any adjustment would need to be studied and take into consideration the way the Quick Starts are represented in COP. Protocol changes are likely required. Reliability Deployments Task Force Meeting

19. 19 Last Slide August 17, 2011Reliability Deployments Task Force Meeting QUESTIONS