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

2. 2 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) Summary of Approved Sections

3. 3 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) Goal for Today

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

5. 5 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) Goal for Today

6. 6 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 Guidelines for Load Profile Development

7. 7 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) Guidelines for Load Profile Development

8. 8 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) Guidelines for Load Profile Development

9. 9 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. Guidelines for Load Profile Development

10. 10 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) Goal for Today

11. 11 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. Changes to Load Profile Methodology

12. 12 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 Changes to Load Profile Methodology

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

14. 14 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. Changes to Load Profile Methodology

15. 15 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. Changes to Load Profile Methodology

16. 16 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 Changes to Load Profile Methodology

17. 17 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 Changes to Load Profile Methodology

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

19. 19 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. Changes to Load Profile Methodology

20. 20 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. Changes to Load Profile Methodology

21. 21 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) Goal for Today

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

23. 23 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. Profile Models

24. 24 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 Profile Models

25. 25 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 Profile Models

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

27. 27 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 Profile Models

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

29. 29 Assessing the Type of Change Needed Profile Models 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. 30 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 Profile Models

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

32. 32 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 Profile Models

33. 33 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 Profile Models

34. 34 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) Goal for Today

35. 35 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. kVa to kW Conversion

36. 36 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 kVa to kW Conversion

37. 37 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. kVa to kW Conversion

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

39. 39 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. kVa to kW Conversion

40. 40 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) Goal for Today

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

42. 42 Load Profiling Documents Access to Load Profiling Materials 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. 43 Other Materials Access to Load Profiling 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)