Presented to ERCOT Retail Market Subcommittee January 9, 2002

1. Load Profiling Operating Guides(LPOG) Profiling Working Group Darryl Nelson, Chair Presented to ERCOT Retail Market Subcommittee January 9, 2002

2. Summary of Approved Sections • Sections of LPOG Approved by RMS: • Change Control Process for LPOG (3) • Validation of Load Profile IDs (10) • Requests for Changes to Profile Segment Definitions (11) • Requests for Changes to Weather Zone Definitions (12) • Load Profile Dispute Resolution Process (13)

3. Goal for Today • Approval of Approach for 6 sections: • Purpose of Load Profiling (1) • Guidelines for Load Profile Development (4) • Request for Changes to Load Profile Methodology (6) • Request for Changes to Load Profile Models (7) • kVa to kW Conversion (9) • Access to Load Profiling Materials (17)

4. Purpose of Load Profiling Brief Overview • Part of Settlements • 15-minute intervals • Non-IDR customers • Created in fair and equitable manner

5. Goal for Today • Approval of Approach for 6 sections: • Purpose of Load Profiling (1) • Guidelines for Load Profile Development (4) • Request for Changes to Load Profile Methodology (6) • Request for Changes to Load Profile Models (7) • kVa to kW Conversion (9) • Access to Load Profiling Materials (17)

6. Guidelines for Load Profile Development Background • More detail for principles listed in Protocols 18.2.1 • Part of Load Profiling Methodology document, v1.04 • Approved by PWG in May 2000

7. Guidelines for Load Profile Development Guidelines • Minimize total number of load profiles by leveraging existing load research data • Incorporate generation cost data into analysis to determine appropriate number of load profiles • Suggested issues to be addressed when assigning load profiles to areas that do not currently have load research data • (cont’d)

8. Guidelines for Load Profile Development Guidelines (cont’d) • Use readily identifiable parameters to assign load profiles • Use most accurate load research data available • Possible methods to accommodate Time-of-Use, controlled loads and other similar demand-side management programs. • (cont’d)

9. Guidelines for Load Profile Development Guidelines (cont’d) • Load profile information shall be consistent, clear, easy to understand, and readily available. • Load profile methodology shall be fully and unambiguously defined.

10. Goal for Today • Approval of Approach for 6 sections: • Purpose of Load Profiling (1) • Guidelines for Load Profile Development (4) • Request for Changes to Load Profile Methodology (6) • Request for Changes to Load Profile Models (7) • kVa to kW Conversion (9) • Access to Load Profiling Materials (17)

11. Changes to Load Profile Methodology Introduction ERCOT Board approval is necessary for any change from one load profile methodology to another. (Protocols 18.2.9) This section does not address changes to profile segments or weather zones. A request for a load profile methodology change will not be accepted until 2 years after market open.

12. Changes to Load Profile Methodology Current Methodologies • Adjusted Static - Residential and Commercial • Engineering Estimates - street lighting and other constant loads • Proxy Day - estimating IDR loads • Lagged Dynamic Sampling - Direct Load Control

13. Changes to Load Profile Methodology Who May Submit Any market participant, Profiling WG, or ERCOT may submit a request to change a load profiling methodology.

14. Changes to Load Profile Methodology Timing • No requests accepted for 2 years • Submitter of a request will be notified within 2 business days by ERCOT of receipt of request and inform submitter of next PWG meeting dates. • Submitter will present request at next PWG meeting.

15. Changes to Load Profile Methodology Timing (cont’d) • After request has been presented, ERCOT will respond within 60 days to address these issues: • - Completeness of request • - Additional data, if needed • - Assessment criteria • - Estimate of time to evaluate request • - Estimate of time to implement request • A methodology change will only be implemented with Board approval and at least 12 months notice to market participants.

16. Changes to Load Profile Methodology Information Required with Request • State why a change is necessary, why the proposed methodology is superior to current, and how the benefits of change outweigh costs to implement. • Supporting data, such as: • - Analysis of data available in ERCOT systems • - Analysis of load research data not available to ERCOT • - Other data or supporting evidence

17. Changes to Load Profile Methodology Evaluation of Request • ERCOT will evaluate the request for change to methodology using these factors: • Quality of supporting data • Magnitude of differences • Size of affected load profile population • Effect on rest of market if change is accepted

18. Changes to Load Profile Methodology Approval of Request Ultimate approval by ERCOT Board after following proper approval sequence through appropriate TAC subcommittees and TAC.

19. Changes to Load Profile Methodology Costs for Methodology Changes The submitter of request will pay all costs associated with developing supporting data and documentation. Also, ERCOT may charge a processing fee for evaluating the request. Costs for implementing changes to ERCOT systems will be borne by ERCOT.

20. Changes to Load Profile Methodology Procedure for Submitting a Request • Submit request to ERCOT • (All materials in electronic format only) • Present request to PWG • PWG, ERCOT, and submitter will jointly review request • PWG and ERCOT will determine any additional supporting data needed from submitter to evaluate request.

21. Goal for Today • Approval of Approach for 6 sections: • Purpose of Load Profiling (1) • Guidelines for Load Profile Development (4) • Request for Changes to Load Profile Methodology (6) • Request for Changes to Load Profile Models (7) • kVa to kW Conversion (9) • Access to Load Profiling Materials (17)

22. Profile Models Types of Evaluations • Routine • ERCOT will perform annual evaluations • Interim • Request for model performance evaluation from marketparticipant, TAC subcommittee, or ERCOT.

23. Profile Models Implementation of Model Changes Any changes based on annual and interim evaluations will be implemented together as part of the annual implementation of changes (including changes to profile segments and/or weather zones), unless evaluation determines a need for a more immediate change.

24. Profile Models Types of Profile Models • Adjusted Static Model • Most profile segments are adjusted static • Regression • Based on load research, weather, and calendar • Engineering Estimates • Non-metered: lighting and flat • Assume same operating schedule and same load • Sunrise/sunset effect on lighting

25. Profile Models Evaluations of Adjusted Static • With Current Load Research Data • Best data for comparison/evaluation • Factors for Comparison • Load-weighted average price • On/Off Peak ratio • Load factor • Summary statistics on difference in series • Deadweight loss • Without Current Load Research Data • Old load research data • Monthly consumption data

26. Profile Models Evaluation of Engineering Estimates • Evaluate any new operating schedules • Evaluate any new load information • Compare monthly consumption data

27. Profile Models Routine Evaluations • Compare existing profile model with profile based on load research data • Consider any end-use saturation data • Consider any current data useful for engineering models • Review magnitude of load migration • Compare aggregate monthly consumption data with profile model • Evaluate weather zone definitions for adequacy of weather stations and weighting

28. Profile Models Interim Evaluations Same as Routine Evaluation except attention will be limited to those profile segment models and weather zones that are of concern.

29. Profile Models Assessing the Type of Change Needed • Possible Recommendations • Adjust coefficients for one or more profile segments • Re-estimate models • Begin to collect new load research data • Implement changes to weather zone(s) • Implement changes to profile segment(s) • No change

30. Profile Models Assessing the Type of Change Needed • Qualitative Criteria • Determine if serious bias is present • Determine degree of bias, e.g. modest, extensive • Implement necessary actions to rectify bias problem: • Adjustment factors • Change definition of weather zone(s) • Limited load research program • Adjust coefficients • Re-estimate models

31. Profile Models Criteria for Requiring a Change • No criteria at this time. • Criteria might be established after the first annual evaluation is complete.

32. Profile Models Procedures for Making a Change • Approval by the appropriate TAC subcommittee • Implement changes to Adjusted Static: • Adjustment factors • Model Re-estimation • New engineering estimates • Changes will occur annually unless required immediately

33. Profile Models Requesting a Change to Models • Procedures • General info • Model adjustment factors • Analysis of data in ERCOT systems • Analysis of load research data not available to ERCOT • Analysis of other supporting data • Engineering estimates • Re-estimation of Models

34. Goal for Today • Approval of Approach for 6 sections: • Purpose of Load Profiling (1) • Guidelines for Load Profile Development (4) • Request for Changes to Load Profile Methodology (6) • Request for Changes to Load Profile Models (7) • kVa to kW Conversion (9) • Access to Load Profiling Materials (17)

35. kVa to kW Conversion General Info ESI Ids with demand meters are assigned a Load Profile type based on average annual load factor. To calculate load factor, a demand in kW is needed. If kVa is metered instead of kW, then the TDSP must determine the appropriate power factor(s) that should be used for the conversion. This conversion from kVa to kW is used only for assigning the proper load profile type to each ESI ID.

36. kVa to kW Conversion Applicable Market Participants • This section applies to any market participant such as: • TDSP who currently meters kVa • TDSP who changes from kW to kVa metering • NOIE that decides to opt-in • New competitive metering market participant

37. kVa to kW Conversion Procedure • TDSP will conduct a case study to determine appropriate power factor(s) to be used in conversion. • TDSP will submit case study to ERCOT • PWG will meet within 30 days of submittal to review • If PWG approves, then sent to RMS, TAC and Board for approval as appropriate. • TDSP implements approved power factor(s) conversion for load profile ID assignments.

38. kVa to kW Conversion Power Factor Performance Review TDSP must periodically review the performance of the power factor(s) at the discretion of ERCOT or the PWG.

39. kVa to kW Conversion Other Issues ERCOT and the PWG will specify minimal reporting standards for power factor analysis to each requestor on a case-by-case basis. Without approval of the case study, a default power factor of 1.0 shall be imposed.

40. Goal for Today • Approval of Approach for 6 sections: • Purpose of Load Profiling (1) • Guidelines for Load Profile Development (4) • Request for Changes to Load Profile Methodology (6) • Request for Changes to Load Profile Models (7) • kVa to kW Conversion (9) • Access to Load Profiling Materials (17)

41. Access to Load Profiling Materials Daily Load Profiling Market Info • Backcasted (Actual) Load Profiles • Forecasted Load Profiles

42. Access to Load Profiling Materials Load Profiling Documents • Profile File Format • Profile Decision Tree • Profile Model Spreadsheets • Final Profile Model Report • Load Profile History • Historical Weather Data by Weather Zone • Profile Types and Weather Zones • Profile Data Evaluation Report

43. Access to Load Profiling Materials Other Materials Calendar of Events Provides information on the PWG meetings Profiling Working Group Meeting Info Will contain information similar to Calendar of Events, but in a more accessible form. Incomplete (gray boxed)