Profiling Working Group 1 PWG Update Report By Ernie Podraza of Direct Energy ERCOT PWG Chair Ed Echols Of Oncor ERCOT PWG Vice Chair for COPS Meeting August 10, 2010

Profiling Working Group 2

3 Annual Validation 2010

4 Round 2 Sample PWG Discussions (Goal 8) Previous PWG Discussions Preliminary slides of sample vs. current profiles shown at the 3/24 PWG Mtg. Comparison of round 2 sample vs. current profiles shown at 5/26 PWG Mtg. Comparison of round 2 sample vs. current profiles shown at 6/24 PWG Mtg. The PWG via polled the members for feedback; full report and latest evaluation at 7/28 PWG Mtg. PWG shall review in September the latest evaluation pending discussion at the August 10 COPS Mtg. At the May 26, 2010 PWG meeting the Market Participants ruled out changing the Load Profile Model Structure.

Polling Question (Round 2 Sample cont.) Do you wish to: (A) Leave Current Models (as is) (B) Refresh current model coefficients or (C) Other with your explanation? Reference; from Ernie Podraza to PWG and COPS on 6/29/2010 Subject: PWG Poll Action Item - Load Profile Round 2 Refresh 5

Poll Results (Round 2 Sample cont.) Seven (7) responses (from 5 companies) for Option A – Leave current models as is. Two (2) responses for Option B – Refresh model coefficients. One (1) Option C – Neutral. 6

As IS vs. Refresh Coefficients (Round 2 Sample cont.) Leave Current Models As Is because: –resources needed for NODAL go live, – overall improvement of new coefficients appears marginal, –advanced metering is replacing NIDR Load Profile settlement, and –do not wish to allocate resources on a transition plan. –ERCOT after Nodal Go Live would not need to budget a project above the line for ERCOT system changes for transition plan. –Market Participants would not need to recalibrate pricing models, forecast models, and balancing market hedge positions. –Review again after Nodal Gray box implementation, Stabilization period and post go live system issues. 7

As IS vs. Refresh Coefficients (Round 2 Sample cont.) Refresh Model Coefficients because: –ERCOT’s Round 2 Load Study provides an improved sample of CNP meter points over the Round 1 Load Study (half sample). –ERCOT PWG analysis indicates significant MAPE reduction and the potential for greater UFE reduction. –CNP’s Round 2 Load Study data appears to yield improved UFE results for CNP based on internal CNP customized application of Houston area weather data. –Updating model coefficients with Round 2 Load Study data allows the market to apply revised load shapes during market settlement when AMS data is unavailable or insufficient. 8

CNP Comments (Round 2 Sample cont.) CNP considers option A (As IS) as a short-term and partial solution until Nodal implementation and market-wide AMS deployments are completed in Conditions for CNP’s acceptance of option (A) is dependent on the following additional analysis: a. ERCOT review of impacts of Round 2 Load Study data on estimation of coincident peak demand (4CP) values for market settlement, and b. ERCOT review of selection and weighting of weather station inputs for CNP service area to gain UFE improvements. 9

As IS vs. Refresh Coefficients (Round 2 Sample cont.) How well do the Round 1 (current) models estimate the Round 2 means? –The average MAPE overall for all days is 8.5% –The average MAPE for the CP days is 6.7% –The average MAPE for the high UFE days is 9.3% MAPE = ABS(backcast-LRS_Mean)/LRS_Mean *

Summary for All Intervals Summary for All Intervals (Round 2 Sample cont.) 11 RESHIWR, RESLOWR, BUSHILF and BUSMEDLF profiles for NCENT, COAST and SOUTH weather zones are at or below total mean of 8.5% where load is most concentrated except for 2 of the 12 cells.

Summary for 4CP and High UFE Days Summary for 4CP and High UFE Days (Round 2 Sample cont.) 12

Provisioned AMS Meters after 2 nd Quarter 2011 Provisioned AMS Meters after 2 nd Quarter 2011 (Round 2 Sample cont.) 13 TDSP Estimates 2,043,000 Oncor 1,132,241 CNP 285,000 AEP/TCC 107,000 AEP/TNC 57% AMS of total ERCOT 6 Million meters

Best Case Revised Timeline Best Case Revised Timeline (Round 2 Sample cont.) 14 Based on September COPS Motion to proceed with Refresh Place Holder Slide Pending ERCOT Staff Estimates

15 1)Draft LPGRR language per NPRR208, Registration and Settlement of Distributed Generation (DG) Less Than One MW (Goal 6). NPRR208 approved 7/20/2010. Discussion on LPGRR Draft began at the PWG July meeting and to continue. 2)Draft LPGRR on valid profile id assignment not in settlement to improve settlement system processing time. 3)Draft LPGRR to clarify IDR and AMS weather sensitive type code assignment. 4)Draft LPGRR that takes the LRS TDSP CSV Operations Guide and makes it Appendix A of the Load Profiling Guide (LPG). PWG to review draft LPGRR language in August. 5)LPGRR038 Revisions for Texas Nodal Market Implementation and Synchronization with PRR821, Update of Section 21, Process for Protocol Revision. The COPS voting slide to follow. 6)LPGRR039 Revisions for Texas Nodal Market Implementation Part Two. The COPS voting slide to follow. 7)Draft PRR on Weather Sensitivity the COPS voting slide to follow. 8)NPRR250 Suspension of Annual Profile ID Validation With Advanced Meter Deployment (Goal 3) at PRS. LPGRR and NPRR / PRR Status

16 LPGRR Vote LPGRR038 Revisions for Texas Nodal Market Implementation and Synchronization with PRR821, Update of Section 21, Process for Protocol Revision LPGRR039 Revisions for Texas Nodal Market Implementation Part Two VOTE PWG requests the following motion: That COPS recommend to the TAC approval of this Nodal Synchronization change with Normal Status

17 PRR Vote Draft PRR Weather Responsiveness Determination for Interval Data Recorders VOTE PWG requests the following motion: That COPS sponsor the draft PRR to the PRS with Urgent Status

18 To: Subject: M-B ERCOT to adjust Coast Weather Zone Load Profiles NOTICE DATE: September 26, 2008 LONG DESCRIPTION: In accordance with PUC Project No (Issues Relating to the Disaster Resulting from Hurricane Ike), ERCOT will be adjusting all Load Profiles for the Coast Weather Zone used for aggregating load starting with Operating Day September 13, 2008 and continuing forward until further notice. These adjusted Load Profiles will first be reflected on the Initial Settlement of Operating Day September 18, Adjustments for Operating Days September , 2008 will be reflected in the Final Settlement for these Operating Days. Would ERCOT know ahead of the storm if such an adjustment would occur again? PUCT Project No – Active or Not?

Profiling Working Group 19 PWG 2010 meeting dates - 4th Wednesday of the month The August meeting shall be a full day with the large UFE Annual Presentation and new LPGRR drafts to discuss.