SCED Re-Runs: Before And After Non-Spin Deployment on July 13 & July 18

1. SCED Re-Runs: Before And After Non-Spin Deployment on July 13 & July 18 John Dumas Director Wholesale Market Operations Reliability Deployments Task Force Meeting

2. Outline of Presentation • Additional Data from July 13 & 18 Non-Spin Deployment. • Results of SCED Re-Run for different “floor” scenarios. • Limitations of the SCED Re-Run • QSE actions to submit EOC with floor for Non-Spin • Summary of the SCED Re-Run • Observations

3. Additional Data from July 13 Non-Spin Deployment. • Note 1: All are telemetry values at 14:35 (before Non-Spin Deployment) • Note 2: Load increase from 14:35 to 14:55 = 540 MW • Note 3: LSL injection from OFFNS resources from 14:35 to 14:55 = • 219 (“OFFNS” QSGR) + 104 (“OFFNS” Non-QSGR) = 323 MW • Note 4: The total HSL from “OFF” Generation Resources that came online = 248 MW

4. Additional Data from July 18 Non-Spin Deployment. • Note 1: All are telemetry values at 15:20 (before Non-Spin Deployment) • Note 2: Load increase from 15:20 to 15:55 = 507 MW • Note 3: LSL injection from OFFNS resources from 15:20 to 15:55 = • 288 (“OFFNS” QSGR) + 116 (“OFFNS” Non-QSGR) = 404 MW

5. Scenarios for SCED Re-Run with different “floors” • For “ON” Generation Resources (QSGR and Non-QSGR), change HASL/HDL calculation to give SCED ability to ALWAYS use capacity reserved for Non-Spin. • Re-Run SCED with modified EOC for Generation Resources having Non-Spin Responsibility as per the following:

6. Results of SCED Re-Run for different “floor” scenarios

7. Results of SCED Re-Run for different “floor” scenarios • July 13 : 13:00 – 20:00 @14:55 GTBD=62801 MW lorig=$76.79 lHASL=$76.79 llow=$83.61 lmed-1=$500 lmed-2=$1000 lhigh=$3000 @14:35 GTBD=62261 MW lorig=$2999.99 lHASL=$92.88 llow=$81.28 lmed-1=$500 lmed-2=$1000 lhigh=$3000

8. Results of SCED Re-Run for different “floor” scenarios • July 18 : 13:00 – 20:00 @15:55 GTBD=61677 MW lorig=$63.35 lHASL=$63.35 llow=$80.92 lmed-1=$80.92 lmed-2=$80.92 lhigh=$80.93

9. Limitations of the SCED Re-Run • In Production, the additional EOC available to SCED after Non-spin deployment pushed down the output of other Generation Resources not carrying any Non-Spin Responsibility. • The SCED re-runs used the Production telemetered MW. The telemetered MW would have been different if the floor were applied ALL of the time.

10. QSE actions to submit EOC with floor for Non-Spin • No change to QSE process of submitting EOC and AS offers to DAM • No change to QSE process of submitting AS offers to SASM • QSE will update EOC to incorporate floor before the end of the Adjustment Period. • With the ability provided by NPRR 321 “Allow Change to Energy Offer Curve MW Amounts in the Adjustment Period”,

11. Summary of the SCED Re-Run • After Non-Spin deployment, if the “floored” EOC segments are marginal, then the LMPs will be at the floor – i.e. LMPs are administered - by the value of the floor. • After Non-Spin deployment, if none of the “floored” EOC segments are awarded, then the Generation Resources providing Non-Spin will be at risk of being price-takers at their LDL. • Floors over or under compensate relative to prices without Non-Spin deployment.

12. Observations • ERCOT did not over deploy Non-Spin on July 13 and July 18. • Sum(HDL)-GTBD <200 • Load growth exceeded the remaining Non-Spin deployed • Is the impact to the Day-Ahead and Real-Time energy price convergence because of permanently allowing SCED to use Non-Spin capacity mitigated by the floor on the Non-Spin segment of the EOC? • ERCOT procedure to deploy Non-Spin will need to be reviewed if the Non-Spin capacity is permanently made available to SCED.