SPP Priority Projects Nebraska Area FCITC Sensitivity Analysis

1. SPP Priority ProjectsNebraska Area FCITC Sensitivity Analysis

2. Study Scope Evaluate FCITC impacts of SPP Priority Projects on existing NPPD flowgates and known constraints to regional transfer capability. Document incremental FCITC impacts due to SPP Priority Projects. Evaluate competing alternatives to Cooper-Maryville-Sibley 345 kV to mitigate COOPER_S and known constraints in area.

3. Model Development Base: 2009 Series MRO models 2015 Summer Peak, 2015 Summer Off-Peak, 2015 Winter Peak Case 2: Base Models + Balanced Portfolio Projects Case 3: Case 2 Models + Priority Projects Case 4: Case 3 Models (Priority Projects) + Replace Cooper-Maryville-Sibley 345 kV with Nebraska City-Maryville-Sibley 345 kV Case 5: Case 3 Models (Priority Projects) + Replace Cooper-Maryville-Sibley 345 kV with Nebraska City-Stranger Creek 345 kV

4. MRO vs. SPP Models SPP staff had initially raised concerns with NPPD’s utilization of MRO vs. SPP models for this study. A sensitivity analysis was performed to compare FCITC results using 2015 SUPK MRO and 2014 SUPK SPP models. No significant differences were discovered.

5. FCITC Analysis Source Areas Northern MAPP/MRO Western NE Sink Areas Southern SPP Monitored Elements & Contingencies NPPD Flowgates Known constraints to regional transfer capability PSS/E Activity TLTG

6. GGS GRIS_LNC WNE_WKS COOPER_S

7. Priority Project FCITC Impacts Beneficial Impacts COOPER_S flowgate & underlying constraints Cooper-Maryville-Sibley 345 kV provides parallel 345 kV path Significant increase in FCITC Parallel 161 kV paths are still most limiting GRIS_LNC flowgate Axtell-Wolf-Spearville 345 kV benefits this flowgate Priority Projects more tightly network the Spearville terminal to eastern Kansas which further benefits this flowgate.

8. Priority Project FCITC Impacts Adverse Impacts WNE_WKS flowgate & underlying constraints Lower impedance west-to-east paths south of this flowgate Slightly decreases FCITC on this flowgate Cooper-Nebraska City 345 kV FLO Cooper-Moore 345 kV Most limiting 345 kV path with Priority Projects Potential new Flowgate in future

9. Competing Alternatives Evaluated two competing alternatives to Cooper-Maryville-Sibley 345 kV line Re-terminate new line at Nebraska City instead of Cooper (Case 4) Replace Cooper – Sibley 345 kV line with Nebraska City – Stranger Creek 345 kV (Case 5)

10. Case 4 Alternative Priority Project Case 5 Alternative

11. Competing Alternatives Results Existing Cooper – Maryville – Sibley 345 kV Priority Project greatly improves COOPER_S flowgate FCITC, but may result in new flowgate in future (Cooper-Nebraska City 345 kV). Re-termination of Sibley line to Nebraska City would address potential Cooper-Nebraska City issue and provide even more FCITC benefits on COOPER_S and underlying 161 kV constraints.

12. Supporting FCITC Data

13. Competing Alternatives Cost Implications Cooper – Maryville – Sibley 345 kV ~152 Miles of new 345 kV Nebraska City – Maryville – Sibley 345 kV (Case 4) ~177 Miles of new 345 kV Nebraska City – Stranger Creek 345 kV (Case 5) ~131 Miles of new 345 kV

14. Summary Overall, the Priority Projects significantly improved the COOPER_S and GRIS_LNC flowgates. WNE_WKS was slightly adversely impacted due to the lower impedance west-to-east paths in Kansas. Two competing alternatives demonstrated better FCITC performance than the proposed Cooper-Maryville-Sibley 345 kV project. Neb City-Stranger 345 kV alternative was best performing option, but this option would not provide access to wind resource zones in NW Missouri.

15. Summary Cooper – Maryville – Sibley 345 kV Priority Project greatly improves COOPER_S Nebraska City – Maryville – Sibley 345 kV alternative would be the preferred Priority Project Costs are expected to be similar to existing Cooper – Maryville – Sibley 345 kV priority project Provides transmission access to wind resource zones in NW Missouri Provides superior regional transfer capability characteristics in the COOPER_S corridor