1. 1 Welcome to Load Participation Orientation Elev MenWomen Phones Info Presentation and other Load Participation information will be posted at: www.ERCOT.com Market Participants & Stakeholders Load Participation

2. 2 LaaRs & BULs Loads acting as Resource Balancing Up Loads Understanding &

3. 3

4. 4 Market Overview

5. 5 Control Area Old World - Before Retail Deregulation Utilities Customers Customer Service Control Area Regulated Function

6. 6 New World - After Deregulation Transmission Customers & maybe Resources Generators Load Serving Entity QSE Distribution Transmission Operator Regulated Function TDSP

7. 7 Bilateral Market - Coordination of Resources Customers & maybe Resources Generators Load Serving Entity QSE Regulated Function Contracts are confidential Prices are not visible Load About 90%- 95% of Texas Energy Transfer Arranged this way.

8. 8 What about the other 5% - 10%? Supported through Ancillary Services

9. 9 Pre-arranged operating reserves — the ability to call for additional energy to be made available on the system, on varying levels of short notice. Insurance in case a generating unit goes down, load is higher than anticipated, or other problem emerges. Ancillary Services (“AS”)

10. 10 1200 Adjustmen 060018000000 Day AheadAdjustment Operating Period 2300 Adjustment Period 0000 Adjustment Period 0100 Adjustment Period 0300 Adjustment Period 0200 Adjustment Period 0400 Adjustment Period 0500 Adjustment Period 0600 Adjustment Period 0700 Adjustment Period 0800 Adjustment Perio 0900 Adjustment Per 1000 Adjustment P 1100 Adjustment 1300 Adjustm Provide Forecasts Receive Balanced Schedules Receive Bids for Ancillary Services Evaluate Submittals Resolve Clear OP March 24, 3002 March 25, 2003

11. 11 Operating Hour O p e r a t i n g P e r i o d Hour Ahead 4 Settlement Intervals per Operating Hour

12. 12 Time  Power in Megawatts (MW)  1 23 4 56789 10 1112131415161718192021222324 ERCOT Forecast Load Scheduled Generation Actual Load Load vs Generation The need for Balance

13. 13 1 23 4 56789 10 11121314151617181920212223 Load vs Generation The need for Balance 1112 ERCOT Forecast Load Scheduled Generation Actual Load Power in Kilowatts (KW)  Time 

14. 14 Time  11 12 Power in Kilowatts (KW)  8 RESULT: curtail load increase generation change system frequency Up Regulation Service Up Balancing Service Down Balancing Service Down Regulation Service ERCOT Forecast Load Scheduled Generation Actual Load Load vs Generation The need for Balance

15. 15 Ancillary Services (“AS”) Response time is critical in determining which AS a resource can qualify for.  30 minutes  10 minutes Immediate Non-SpinReplacement Balancing Responsive

16. 16 QSE Most AS can be self-arranged. QSE has an obligation for AS supply based on “Load Ratio Share”

17. 17 If not self-arranged, AS will be purchased by ERCOT Ancillary Services (“AS”) In the AS markets, a QSE can bid in any resources (generation or loads) that aren't already committed. This creates an Ancillary Services Market.

18. 18 Is there money to be made by users of Electricity? User of electricity = load $$ Money may be paid $$ for a Load reduction on the system – pending contract & qualification conditions

19. 19 What is a Resource? A resource is a $upplier of electricity In the past this was considered an Electric Generating Unit such as: Coal Fired Power Plant Gas (Combustion) Turbine Generator Nuclear Power Plant Hydro Power, etc….

20. 20 What is a Resource? Electric Generating units create electricity, apply that energy to the Electric Grid, on demand, and are paid $

21. 21 What is a Load acting as a Resource? A resource is a $upplier of electricity - Generator or Load Loads (users of electricity) may reduce or stop their draw of power (curtail), and thus apply unused energy, to the Electric Grid, on demand, for a price $ In this a Load acts as a Resource (LaaR)

22. 22 Terminology Capacity Energy Telemetry Protocols Resource Plan Operating Guides The ability to make energy available on demand Electricity available for use Real-time system information used for grid operations, not settlements Rules that govern the Electric Market and System Operations Specific guidelines grid operations QSE submittal to ERCOT on available resources for planning and operations

23. 23 Payment Information Power in Megawatts (MW)  Time  1 23 4 56789 10 1112131415161718192021222324 Load Profiling ESIID Settlements QSEs

24. 24 Loads acting as Resource (LaaRs) Balancing Up Loads (BULs) LaaRs & BULs

25. 25 Loads acting as Resource (LaaRs) LaaRs are scheduled in the resource plan similar to generators LaaRs are telemetered to ERCOT and a component of the QSE’s frequency management program LaaRs are bid in and are awarded in the day ahead capacity market (capacity payment)

26. 26 Loads acting as Resource (LaaRs) LaaRs are deployed during the operating day as needed (energy payment) Presently 35% of ERCOT Responsive Reserve can be met with Loads qualified for RRS ~570MW of Loads qualified for RRS ~91 MW of Loads qualified for NSRS

27. 27 Ancillary Services (“AS”) Response time determines category of Ancillary Service provided  30 minutes  10 minutes Immediate Non-Spin Replacement Balancing Responsive

28. 28 LaaR Qualification Categories Responsive Reserve Service Loads – Loads on underfrequency relay (UFR): can be interrupted instantaneously and can be manually interrupted within 10 minutes Balancing Energy Service Loads – Loads that can be interrupted within 10 minutes Non-Spin Reserve Service Loads – Loads that can be interrupted within 30 minutes

29. 29 Loads Qualified for RRS Responsive Reserve Service, Non-Spinning Reserve Service, Replacement Reserve Service, and Balancing Energy Service LaaR Services that may be Provided

30. 30 Loads Qualified for BES Up Balancing Energy Service, Non-Spinning Reserve Service, and Replacement Reserve Service LaaR Services that may be Provided

31. 31 Loads Qualified for NSRS Non-Spinning Reserve Service LaaR Services that may be Provided

32. 32 LaaR - BUL LaaRs may participate in the AS Capacity market, BULs do not LaaRs are contracted for reliability - subject to OOM BULs, though taken from the Balancing bid stack, participate for economic reasons - not subject to OOM

33. 33 LaaR - BUL will be paid a capacity payment if struck in the capacity market, and receive an energy payment if they are deployed and respond LaaRs BULs BULs will not be considered in the capacity market, but if responsive to BES award will receive a capacity & energy payment

34. 34 Markets Loads May Play in if Qualified Reg Up/Dn Responsive Non-Spn Replacemnt Up Bal Down Bal OOM Gen AGC RRS BESNSRBUL L a a R s SERVICE RespMKT X X X X X X X X X X X XX X Imediat Cap X X X X 10 min 30 min 10 min ASAP Cap Ener X 10 min

35. 35 Balancing Up Loads (BULs) BUL service will require new Qualification, Annual Capacity Testing and QSE Control, and Performance Measurements Separate Bid curves than LaaRs & Gens

36. 36 Timeline for BULs: Deployment May 31, 2003 Balancing Up Loads (BULs) Block size limited to 50 MW or less BULs are not telemetered to ERCOT

37. 37 Load Options Load TypeResource or Service that can be Provided Requirements Load Acting as a Resource (LaaR) Various ERCOT Ancillary Services (AS) Telemetry IDR meter (minimum) EPS meter (optional) Qualification Qualified Balancing Up Load (BUL) Balancing-Up Load (associated with the Balancing Energy Market only) IDR meter (minimum) EPS meter (optional) Qualification Voluntary Load Response Curtailment or reduction in response to Market Price or other factors Metering and/or curtailment technology defined in REP contract

39. 39 Qualified Scheduling Entity (QSE) E R C O T Transmission/Distribution Service Providers (TDSPs) Consumer/Customer Resource Power Marketer (Optional) Aggregator (Optional) Load Serving Entity (LSE) Public Utility Commission of Texas (PUCT) Non-Opt In Entities (NOIEs) Regulated Organizations Non-Regulated Organizations Power Flow Key Information Flow