1. ERCOT PUBLIC 10/21/2014 1 2015 RTP Scope and Process Review October 21, 2014

2. ERCOT PUBLIC 10/21/2014 2 Outline  2015 RTP: What’s New  2015 RTP Process  2015 RTP Timeline

3. ERCOT PUBLIC 10/21/2014 3 2015 RTP: What’s New  New TPL Standard TPL-001-4 will be in effect for 2015 RTP  Scope of contingency definitions considered for the RTP will be broadened to include all categories applicable to TPL-001-4  Additional sensitivity cases and analysis will be performed

4. ERCOT PUBLIC 10/21/2014 4 2015 RTP: Impact of new TPL standards  New Off-peak (minimum load case) will be studied as a base case along with the summer peak cases  New contingency categories, P0-P7 and extreme events instead of A, B, C and D will be studied  Shunt devices to be considered as single element contingencies  Open Line (one-end of the line) without a fault  Definition of second level contingency in G-1+N-1 expanded to include Generators and Shunt devices

5. ERCOT PUBLIC 10/21/2014 5 2015 RTP: Impact of new TPL standards  Non-consequential load shedding shall no longer be an acceptable mitigation plan for the following contingencies  P2-2-Bus Section Fault (345-kV)  P2-3 Internal failure of non-bus tie breaker (345-kV)  P3-1 G-1+G-1  P4 – Stuck breaker of non-bus-tie breaker (345-kV)  P5 – Failure of non-redundant relay (345-kV)  Req. 3.3.1 of TPL-001-4 requires automatic tripping of elements where relay loadability limits are exceeded post-contingency  Until such ratings are added to the models a default limit of 115% will be used for 345-kV elements and 100% will be used for elements below 345- kV

6. ERCOT PUBLIC 10/21/2014 6 2015 RTP: Impact of new TPL standards  New sensitivity cases will be studied for each of the base cases  The sensitivity case for 2015 RTP will be prepared to study the effect of reduced reactive resource capability  Short Circuit Analysis will be conducted on year 3 and 5 summer peak cases with all projects modeled.

7. ERCOT PUBLIC 10/21/2014 7 2015 RTP: Other updates  Reserve margin of 2800 MW (instead of 1375 MW) will be used in the reliability cases to address G-1+G-1 conditions  Dynamic ratings will be applied in reliability analysis (in addition to the economic analysis)  TPs will be requested to identify generic equipment type which may take longer to replace; these will be studied as a first level contingency in N-1+N-1 test

8. ERCOT PUBLIC 10/21/2014 8 2015 RTP Process Case Conditioning Future projects review and update Future generation review and update (addition and retirement) Load comparison and adjustment Transmission outages, DC tie dispatch, and SOL updates Base Case Reliability Analysis N-1 SCOPF (P0; P1; and P7) G-1+N-1 and X-1+N-1 SCOPF (P3, P6)-ERCOT planning guide categories Contingency analysis (CA) (P2-1, 2 (>300kV), 3 (>300kV); P4-1,5 (>300kV); P5(>300kV)) Add or improve existing transmission projects to mitigate overloads Additional Reliability Analysis CA with multiple contingencies P2-2(<300kV), 3(<300kV), 4; P4-1,5 (<300 kV), 6; P5(<300kV), P6 (not studied earlier) Sensitivity analysis for year 1 and 5 summer peak cases, and year 3 off-peak case Extreme event analysis and short circuit analysis Economic Analysis Run economic analysis Add or improve projects that meet the economic criteria

9. ERCOT PUBLIC 10/21/2014 9 2015 RTP: Timeline (tentative) DeliverableDate RTP Scope DevelopedOctober 2014 RTP Scope FinalizedDecember 2014 Data request to TSPs CompletedJanuary 2015 Initial Conditioned Cases PostedFebruary 2015 Reliability Analysis CompleteJuly 2015 Economic Analysis CompleteAugust 2015 Draft Report Sent Out for TP reviewSeptember 2015 Final Report PublishedNovember 2015

10. ERCOT PUBLIC 10/21/2014 10 Questions?

11. ERCOT PUBLIC 10/21/2014 11 Contingency Categories Category Initial Condition Event Load Shedding allowed? Category under Old TPL > 300 kV <= 300 kV P0System intactNoneNN Cat A P1-1 System intact G-1 (generator)NN Cat B1 P1-2T-1 (transmission)NN Cat B2 P1-3X-1 (transformer)NN Cat B3 P1-4S-1 (Shunt device including FACTS devices that are connected to ground)NN P1-5DCNN Cat B4 P2-1 System intact Open Line (one-end of the line) W/O FaultNN P2-2BS (Bus section fault)NY Cat C1 P2-3NBTB (Internal failure of non-bus tie breaker)NY Cat C2 P2-4BTB (Internal failure of bus tie breaker)YY Cat C2 P3-1 G-1 + System Adjustment G-1 (generator)NN Cat C3 P3-2T-1 (transmission)NN P3-3X-1 (transformer)NN P3-4S-1 (Shunt device including FACTS devices that are connected to ground)NN P3-5DCNN P4-1 System intact Stuck Breaker of non-bus-tie breaker (NBTB) for the fault associated with G-1NY Cat C6 P4-2T-1NY Cat C7 P4-3X-1NY Cat C8 P4-4S-1NY P4-5BSNY Cat C9 P4-6Stuck Breaker of bus-tie breaker (BTB) for the fault associated withBS Y Cat C9 P5-1 System intactFailure of non-redundant relay for the fault associated with G-1NY Cat C6 P5-2T-1NY Cat C7 P5-3X-1NY Cat C8 P5-4S-1NY P5-5BSNY Cat C9 P6-1 N-1 + Adjustment T-1 (transmission)YY Cat C3 P6-2X-1 (transformer)YY P6-3S-1 (Shunt device including FACTS devices that are connected to ground)YY P6-4DCYY P7-1 System intact Two adjacent circuits on common structure. (exclude if 1 mile or less)YY Cat C5 P7-2Loss of a bipolar DCYY Cat C4