American Electric Power ERCOT Boundary Metering

1. American Electric PowerERCOT Boundary Metering ERCOT UFE Task Force April 21, 2006 Kirk Schneider American Electric Power Tulsa, Oklahoma

2. Introduction • What is boundary metering? • Why does AEP need boundary metering? • How did we implement boundary metering • Problems to overcome • What does this have to do with UFE?

3. The American Electric Power System

4. What is Boundary Metering? • Measure Power Flow at Interconnect Points • Goal – to calculate total power consumption on system • Can directly measure load, but not losses

5. Power Consumption in North American Grid • Simplest Case • Power is consumed at the instant it is generated • Power Consumed = Power Generated • Power Consumed = Power used + power “lost”

6. ERCOT System Load • Connected to grid with 3 DC ties • System Load = generation + power imported over DC ties – power exported over DC ties • SYSTEM LOAD = GENERATION – NET INTERCHANGE • EPS Meters on Generation and DC Ties

7. AEP-ERCOT System Load • Texas North Co. (West TX) • Texas Central Co. (South TX) • TNC ~ 40 Interconnects • TCC ~ 40 Interconnects

8. Texas Central Trans. System

9. Texas North Trans. System

10. Why Does AEP Need Boundary Metering? • Loss Studies • Validate / Increase Accuracy of Load Research • Transmission Settlements • System Planning and Forecasting • Unbilled Energy Analysis • Checks and Balances

11. How Did AEP Implement Boundary Metering? • About 12 complete installations – meter and CT / PTs • About 24 installations of meter only using existing CT / PTs • Accuracy of Meters • Leveraging Existing Metering In South Texas

12. How Is AEP Collecting and Analyzing the Data? • Collecting Data Using MV-90 System • Analyzing Data Using SAS • Data Validation • Sent to CEAS System

13. Data Validation • Use SCADA Data to Validate MV90 • SCADA Strengths Complement MV90 • Use SCADA Data to Fill MV90 Gaps • Examples

14. MV90 vs. SCADA • MV-90 Strengths • True integrated values • Distributed data collection • Lower cost than SCADA • SCADA Strengths • Time synch extremely accurate • Data available real-time • Multiple backup measurements

15. MV90 vs. SCADA • CONCLUSION: • SCADA and MV-90 Strengths Complementary • Combination of 2 systems provides very accurate and reliable data source.

16. Results – July 2005

17. Results – December 2005

18. What Does All This Have To Do With UFE??? • Much more accurate loss studies • Validate / Increase Accuracy of Load Research • Assess value of multiple UFE zones • Learn lessons about loss calculations and load profiling

19. “Top Down” vs. “Bottom Up” Results

20. Summary • Boundary Metering In Place for TCC and TNC • Have successfully used data to calculate TNC load for 2005 to current • Challenge getting NOIE Data • We need support from other TDSPs that own some of the meters

21. American Electric PowerDistribution Loss Factor Calculation ERCOT UFE Task Force April 21, 2006 Kirk Schneider American Electric Power Tulsa, Oklahoma

22. Distribution Loss Factor Calculation • ERCOT Protocols, Sec. 13.3.1.1 • SILFi = ADLF * [ K+(1-K)*( SIELi/AAL)] • TDSPs to file distribution loss factors each year by October 30.

23. ERCOT Protocol Equation

24. ERCOT Protocol Equation

25. Proposed Equation

26. What Next? • Investigate Further • Estimate potential benefit • Will it work for all TDSPs