Long-Term System Assessment Transmission Analysis Update

1. Long-Term System AssessmentTransmission Analysis Update Warren Lasher Regional Planning Group

2. Purpose • To Inform Near-Term Planning with Potential Solutions that Meet Long-Range System Needs • Intent is not to select new circuits to recommend • Rather, the intent is to provide a selection of alternatives through scenario analysis that can be considered when developing solutions for near-term congestion or reliability needs • To meet the NERC TPL Requirements for development of 10-year transmission plan Regional Planning Group

3. Specific Focus – LTSA Transmission Analysis • A network simplification tool has been implemented and is being used for the Long-Term System Assessment transmission requirements analysis • The focus of the LTSA is to identify: • Long-Lead-Time Projects – projects that may require 5 or more years to bring on-line • Large Projects – short-term analyses tend to focus on short-term solutions. A long-term perspective can indicate larger projects that both solve short-term issues but also meet long-term system needs more cost-effectively. • This network simplification tool will provide a starting point for larger DOE study Regional Planning Group

4. After Simplification • Bus count reduced 6,000  3,000 (approx) • Line count reduced 6,000  3,000 (approx) • Flows on 138-kV and 345-kV bulk transmission network mostly unchanged. • Simplified case has similar N-1 behavior (branch loading and voltages) as full case. Regional Planning Group

5. LTSA Reliability Analysis Overloads 345 kV 138 kV • Overloads after simplification and redispatch. Regional Planning Group

6. LTSA Reliability Analysis: Houston Overloads 345 kV 138 kV Regional Planning Group

7. LTSA Reliability Analysis: DFW Overloads 345 kV 138 kV Upgrades being evaluated near Roanoke and Hicks Regional Planning Group

8. LTSA Reliability Analysis: Valley Overloads 345 kV 138 kV 8255 HAMILTN4 138 8264 EP.H TP4 138 1 Regional Planning Group

9. LTSA Reliability Analysis: Voltage Analysis • Added 2,000 MVAr of switched capacitors to Houston area • At Zenith and Kind; others more internal to the city.  • 400 MVAr added in Dallas • 200 Mvar at Kendal. Locations for low voltage excursions shown in light green Regional Planning Group

10. Economic Analysis • Four scenarios are being considered as part of this LTSA: • Business as Usual: Regulatory and market conditions continue in the next ten years as they are today • Low natural gas price: future generation expansion is gas fired. • High natural gas price: Future generation consists of coal and wind generation • High renewables: New generation consists of wind, solar, geothermal and biomass • Generation in each scenario is being added in likely locations. No thermal generation is being added in non-attainment zones. Economic transmission projects are being identified. Regional Planning Group

11. Summary • LTSA reliability analysis is nearly complete. ERCOT is working with TSPs to review the results. • LTSA economic analysis is in progress, however no projects have yet been identified. • Stability implications of the reliability case is being reviewed. • Results will be included in the Constraints and Needs Report completed by the end of December. Regional Planning Group

12. Questions? Regional Planning Group