Market Trials DAM/RUC/SASM

Market TrialsDAM/RUC/SASM Weekly Update April 30, 2010 http://nodal.ercot.com 1

Antitrust Admonition ANTITRUST ADMONITION ERCOT strictly prohibits Market Participants and their employees who are participating in ERCOT activities from using their participation in ERCOT activities as a forum for engaging in practices or communications that violate the antitrust laws. The ERCOT Board has approved guidelines for members of ERCOT Committees, Subcommittees and Working Groups to be reviewed and followed by each Market Participant attending ERCOT meetings. If you have not received a copy of these Guidelines, copies are available at the Client Relations desk. Please remember your ongoing obligation to comply with all applicable laws, including the antitrust laws. DISCLAIMER All presentations and materials submitted by Market Participants or any other Entity to ERCOT staff for this meeting are received and posted with the acknowledgement that the information will be considered public in accordance with the ERCOT Websites Content Management Operating Procedure. http://nodal.ercot.com 2

Agenda • DAM/ RUC summary • QSE Activities for Next Week • General Reminders/Updates • Environment Report • Outages • Known Issues • Special Topic: External Interfaces Specification • Settlements/COMS • Question and Answers / General Discussion • Appendix ERCOT asks that Market Participants log into the WebEx session using their company name and then their name. This will allow ERCOT to take roll-call offline. http://nodal.ercot.com 3

Market Trials 2010 Roadmap http://nodal.ercot.com 4

Submission Overview for Apr 27 Submission overview • 214 QSEs participated for Op Day 4/28 • Cleared 18,462 - 23,838 MW per hour • Load Zone prices ranged from $3.95 to $31.76. http://nodal.ercot.com 5

Submission Overview for Apr 27 http://nodal.ercot.com 6

Submission Overview for Apr 27 http://nodal.ercot.com 9 • MCPCs were over $1,000 for hour 4 and 9. Ran low on AS Offers in these hours • Hour 4: AS Offer was submitted with this high price that was the marginal offer needed to meet the AS requirement for RRS • Hour 9: • AS Offer was submitted with this high price that was the marginal offer needed to meet the AS requirement for two of the three online reserves (RegUp and RRS) • RegDn – High price AS Offer not submitted for RegDn. The high RegDn price was due to the offer price plus lost opportunity for the marginal AS Offer that could have otherwise received the high RRS/RegUp price. • In general, we are not seeing very many AS Offers from Load Resources • Can affect RRS prices • Some QSE with Load Resources are consistently submitting RRS offers, but many are not

Submission Overview for Apr 27 Submission overview • Energy Bids from QSEs – 80% of Load was requested. http://nodal.ercot.com 10

Submission Overview for Apr 27 Submission overview • AS Offers • 31 QSEs submitted • No AS insufficiency • AS Self-Arrangement from QSEs • No guardrails • 37 QSEs sent in AS Self-Arrangement • Energy Only Offers – 95 QSEs submitted EOOs • PTP Obligation Bids • 63 QSEs submitted PTP Bids • Averaged 4,849 MW hourly bid, 2,228 hourly award http://nodal.ercot.com 11

Submission Overview for Apr 27 NOTE: • AS Plan did not match zonal AS Plan at 6 am, so different AS Obligations were sent out than with previous DAM • This occurred because ERCOT reduced the AS Plan for last Thursday’s DAM, as reported on last week’s market call, to avoid an AS insufficiency. • The DAM operators did not adjust it back when the DAM completed, so the reduced value was carried over each day (the previous value for AS Plan is automatically carried over daily unless changed by an operator since the AS Plan only changes once a month). • This was corrected in time for this Thursday’s DAM http://nodal.ercot.com 12

DRUC Overview for Apr 27 DRUC overview • ERCOT ran DRUC on Apr 27 and published 4 Resource commitments. • Many resources with zero startup/ minimum energy were selected by the software to resolve constraints – the operator then deselected them due to operational experience showing that they had a small impact on the constraint • Operators chose to wait on three recommended resources until HRUC because the startup time did not require a day-ahead commitment decision • Input data to RUC still under review (e.g., modeling data such as line ratings, normal breaker status, etc.) http://nodal.ercot.com 13

HRUC Overview for Apr 28 HRUC overview • ERCOT ran HRUC on Apr 28 at 10 am and made one Resource commitment. • This commitment represented one of the Resources recommended by DRUC that operators chose to wait on. • The other 2 resources recommended by the software were deselected by the operator based on operator experience http://nodal.ercot.com 14

SASM Overview for Apr 28 SASM overview • SASM ran as scheduled on Apr 28 • SASM market was opened at 9:16AM and closed at 9:46AM. The study period is from Hour 13 to Hour 24. AS Plan for NSRS was increased by 200 MW for Hour 16 • Zero MW was self-arranged • The SASM price was $3.02. • Nine Resources received SASM AS Awards http://nodal.ercot.com 15

Submission Overview for Apr 29 Submission overview • 191 QSEs participated for Op Day 4/30 • Cleared 22,341 - 30,978 MW per hour • Load Zone prices ranged from $20.03 to $41.10. http://nodal.ercot.com 16

Submission Overview for Apr 29 Submission overview • Energy Bids from QSEs – 120% of Load was requested. http://nodal.ercot.com 20

Submission Overview for Apr 29 Submission overview • AS Offers • 29 QSEs submitted • Potential for AS insufficiency given the inputs received, so DAM Operators reduced the AS Plan by 10% across the hours and AS types prior to DAM clearing • AS Self-Arrangement from QSEs • No guardrails on self-arrangement • 32 QSEs sent in AS Self-Arrangement • Energy Only Offers – 71 QSEs submitted EOOs • PTP Obligation Bids • 39 QSEs submitted PTP Bids • Averaged 2,199 MW hourly bid, 1,570 hourly award http://nodal.ercot.com 21

DAM Execution Overview for Apr 29 DAM execution overview: • There were issues with completing by 1330 deadline: • Correcting Market Bid/Offer IDs with special characters (discussed above) • Reminder asked to not submit special characters. Long-term fix of validation rule added, short-term fix is screening prior to run • MMS subroutines having issues with certain combinations of decimals in clearing process • This issue was reported last week – at the time, the suspected root cause was that the QSE and sub-QSE had identical bids. The same QSE and sub-QSE were involved with today’s issue • Will be fixed in emergency patch in coming days • Identifying and employing manual workarounds resulted in completing at 1333, rather than 1330 • Solution looks reasonable, still being validated • Technical issue stopped creation of AS Awards • AS MCPC report not generated, which is used by internal integration to create the AS Awards report. • Issue fixed and AS Awards were generated at around 2:30 pm • Manually retriggered AS Awards notifications – pushed out at 6 pm • Root cause under investigation http://nodal.ercot.com 22

DAM Execution Overview for Apr 29 DRUC execution overview: • Number of issues created solution for RUC that was not operationally approved • ERCOT did not publish AS Awards from DAM in time for RUC • Resulted in dramatically less COP updates for RUC • High Load Forecast with deficient Online COPs created large issue (up to 3,000 MW capacity short for some hours) • Some other possible issues observed • Known issue of handling outages that close breakers (discussed in known issues slide later in this call) • Other potential issues still under investigation such as possible modeling issues • Results were published to exercise market and ERCOT downstream systems (as described last week) • 115 resources committed • RUC clearing engine software was consistent with input data ERCOT is proceeding with SASM and HRUC today as scheduled for Op Day 4/30 – results will be discussed on next week’s call. http://nodal.ercot.com 23

Next Week’s Activities Next week – Op Days are 5/5 and 5/7 DAM executing on 5/4 and 5/6 • No changes to DAM from this week’s activities. • We will continue to evaluate for potential AS insufficiency and reduce the AS Plan prior to clearing if necessary to avoid an AS insufficiency DRUC executing on 5/4 and 5/6 after DAM HRUC and SASM executing on 5/5 and 5/7 • HRUC and SASM • HRUC will be executed on Wednesday and Friday at 10 am (target Operating Hours will be the balance of the Op Day) • SASM will be opened for target Operating Hours 15-18 for reason ‘AS undeliverable’ for RRS (200 MW), RegUp (100 MW) and RegDn (100 MW) on Wednesday and Friday at 9 am http://nodal.ercot.com 24

Next Week’s Activities Next week • Reminder that we transfer zonal outages to nodal every week on Monday • This transfer represents approximately 85% of the actual zonal outages • Again, next week ERCOT may do workarounds outside the normal business process to sidestep any issues that arise. Furthermore, we may approve the results of the RUC software even if the result is operationally unreasonable. The purpose of this is to exercise settlement and billing determinants related to RUC. http://nodal.ercot.com 25

General Reminders/Updates • Network Model Update • Next scheduled load is 5/3 • An updated settlement points and MP short name list will be posted 5/3 at http://nodal.ercot.com/readiness/markettrials/index.html • Phase 5 Kick Off WebEx was yesterday, April 29, 2010 • Materials posted on the calendar page at http://www.ercot.com/calendar/2010/04/20100429-MT • Phase 5 Handbook for DAM/RUC/SASM was posted on 3/31 • http://nodal.ercot.com/readiness/markettrials/dam/index.html • As mentioned on the kick off, please review the scripted operational scenarios in June described in the DAM Handbook. Send any suggested operational scenarios to markettrials@ercot.com by May 17thfor consideration to be added to the schedule. http://nodal.ercot.com 26

General Reminders/Updates • Reminder that ERCOT has ran/is running DAM (and sometimes DRUC) on non-supported days (4/28, 4/30 – 5/3). • The purpose is to provide internal ERCOT settlements & billing with 7 consecutive days of data – no settlements data will be published for non-supported operating days • ERCOT is manually entering test data for market participants. No market participation requested. • The exception is TPOs and COPs. ERCOT did not and will not make any changes to market participant TPOs or COPs being submitted to support real-time market trials • Please ignore any extraneous notifications/awards you may receive from this testing http://nodal.ercot.com 27

General Reminders/Updates • ERCOT will run a DRUC on Wednesday, May 5 (for Operating Day May 6) • Please note that we may send instructions to online Resources since we are manually overriding the RUC process to ensure every QSE gets an instruction • ERCOT also plans to test these manual RUC commitments as part of the Operational Scenarios in June (Market Trials Phase 5) • The purpose of this is as a technical test only so QSEs can receive the Startup/Shutdown Instructions xml message in order to test their systems • There was a defect that caused the reportDate field to be missing from the instructions. This was fixed yesterday, prior to this test. http://nodal.ercot.com 28

General Reminders/Updates • Request on last week’s call regarding information about SPS in DAM • DAM accounts for the action of SPS/RAP http://nodal.ercot.com 29

Support Metrics Market Participant Inbound Questions Last Week This Week * This week, 15 out of 285 questions were responded to outside of the 24 hour time frame. http://nodal.ercot.com 30

Day-to-day operations summary: Planned / Unplanned Outages Outages • Planned Outages • 04/27/10 06:00 P.M. – 04/27/2010 07:00 P.M. • Market Manager application availability may have been briefly interrupted as a result of a site fail over test conducted during this time period • 04/28/10 06:00 P.M. – 04/28/2010 07:00 P.M. • Market Manager application availability may have been briefly interrupted as a result of a site fail over test conducted during this time period • Unplanned Outages • 04/29/10 01:30 P.M. – 04/29/2010 02:30 P.M. • AS Awards for operating day 04/30/10 were unavailable for download via EWS and Market Manager applications. Issue was identified to a report posting error and was corrected at 2:30 P.M. • 04/29/10 05:00 P.M. – 04/29/2010 05:30 P.M. • EWS system was patched to address defect associated with RUC Startup/Shutdown instruction report. Interruption with submission & query services may have been noticed during this period. http://nodal.ercot.com 31

Environment Report-Known Issues Full DAM/RUC/SASM known issues list will post every Friday night at http://nodal.ercot.com/readiness/markettrials/dam/index.html Issue this week that is already resolved: • Software migration over the weekend set the energy offer floor to $-50 instead of $-250. Because of this, some offers were canceled during Phase 2 validation. The issue was resolved Monday afternoon. New DAM/RUC/SASM known issues • When querying Resource Parameters for Generation Resources, Hot Time is returned in place of Hot to Intermediate Time. Similarly, when querying Resource Parameters for Non Controllable Load Resources, Max Weekly Energy is returned incorrectly. Both of these values are stored correctly in the database, and will be stored correctly if updated, but it is not returned in the query. • If an energy only offer has a curve type but has one price/quantity pair and the price is zero, the offer would be ignored by DAM. http://nodal.ercot.com 32

Environment Report-Known Issues New DAM/RUC/SASM known issues (cont’d) • AS Offer, Energy Only Offer, Energy Bid, PTP Obligation, CRR Offer query issue: when transactions exist in the system that do not cover all 24 hours but have identical values for every hour that is part of the transaction, the system is filling in the interior hours for the whole time period when querying. The system is checking that all the data is the same, but it is not checking that the hours are continuous. Example - an identical bid exists for hour 1 and hour 24, and a query for hours 1-24 returns as though transactions exist for hours 2-23 as well as hours 1 and 24. Only the query operation is affected. DAM and SASM will still use the correct data. • DAM is not properly handing outages that close a breaker. If an outage opens some breakers while closing others, DAM is not closing the breaker but is opening the others. This can cause the network to split and can cause high prices in certain areas • EMS defects reported last week regarding the table that counts offline and online hours to send to the market system for purposes of respecting minimum online time and offline time – reported that after database loads the table is not properly counting the data in the table that keeps track of how long the unit has been online or offline past the last data load. Reporting this week that this issue also occurs during a software migration, like that over the 4/23 weekend. http://nodal.ercot.com 33

Environment Report-Known Issues Closed Issues: • The web service for the Load Ratio Share (LRS) report is temporarily disabled. There is a defect in the values in the report created related to significant digits. • Market Manager - When using the Market Manager, if an attempt is made to cancel with hour 3 selected for either Start Hour or End Hour, the request fails and yields an error message, ‘Invalid Start (End) Hour 3 due to Daylight Savings Transition’. • Notifications referencing a report are supposed to push the report to the QSE via its listener. In certain situations, the retrieval of the report is failing and the report is not being pushed out. The report may still be retrieved via invocation of the appropriate web service. • MMS is creating the MCPC correctly, but publishing from the wrong table, resulting in incorrect SASM MCPCs displayed to the market participants. • Market Manager- When buyer and seller both = submitting QSE, the details screen should show a column for each hour for the user to enter P or S. Buyer and seller are initially set to submitting QSE upon page load, so these columns should appear. Currently, the columns only show if the user selects a different QSE and then selects their own QSE again. http://nodal.ercot.com 34

Environment Report-Known Issues Closed Issues (cont’d): • There is an issue with the DAM when AS Offers are submitted for two Load Resources that are mapped to the same load point (PTID) in the network model. This is a valid modeling scenario and the DAM software will be updated to deal with this scenario. In the interim, DAM Operators will need to cancel one of the two AS Offers submitted until the defect is fixed. • When a MultiHourBlock tag is not given in an xml submission for Energy Bids/Offers, the default is supposed to be ‘false’. Currently it is defaulted to ‘true’. • The following reports were delivered with known defects:NP4-34-CD, QSE Load Ratio Share (Hour Ending 0100 missing from all QSE Load Ratio Share reports. So, instead of having 24 hours for the day, it only shows 23 hours)NP7-464-CD, Day Ahead Point-to-Point Option Price Report (contains data for the next Op day + seven days back; instead of having data for one day, report has data for multiple days)" • The trade confirmation notification that follows the cancellation of a confirmed trade is currently returning a verb of ‘created’ instead of ‘canceled’ http://nodal.ercot.com 35

Environment Report-Known Issues Status update of recurring DAM/RUC software issues: • Issue caused by special scenario created with outage data – split network/islanding of resources • Manual workaround is in place for ERCOT Operators • Emergency patch to fix issue is targeted for week of 5/10 • Decimal combination issue within DAM subroutines • Manual workaround has delayed DAM results • Emergency patch to fix issue is targeted for week of 5/10 • Outage issue with regard to closed breakers • Potential fix identified, delivery date TBD • We are still evaluating possible workarounds http://nodal.ercot.com 36

Special Topic – External Interfaces Specification External Interfaces Specification v1.19K migrated 4/24. High level summary of changes in v1.19K • New - Get Notifications API • This will be a new API available to the market but not required for consumption. It will provide a market participant with the ability to query for Bid, Resource Parameter, and VDI acceptance and rejection notifications. • Supports such features as querying by MRID, by time range, and by status (acceptance / rejection). • Change - Startup / Shutdown Instructions Schema – hour ending definition changed from integer to string to allow the API to better represent DST (repeating hours using the * convention found elsewhere in the API for DST). • Change - Dynamic Ratings API deliveryTime to deliveryDate • Change- Ancillary Service values from “Float” to “Decimal” values to avoid scientific notation (eg, 1.6E01) http://nodal.ercot.com 37

Special Topic – External Interfaces Specification External Interfaces Specification v1.19L will post to the Readiness Center this evening at http://nodal.ercot.com/readiness/sandbox/index.html Will be migrated to the production environment on 5/28 High level summary of changes coming in v1.19L • Change: Schema for Bid ID – must be at least two characters with no leading or trailing white spaces, must be alphanumeric, dash, or underscore (no special characters) • Note that when this Bid ID schema change is made to restrict to alphanumeric, dashes and underscores, MPs will not be able to retrieve already submitted bids if they do not meet the new schema restrictions • Change: Notification of cancellation of confirmed trade will provide verb of ‘canceled’ rather than ‘created’ • Change: EMS alert texts to reflect those being returned from EMS http://nodal.ercot.com 38

DAM Settlement Overview for Apr 23 Statement and Invoice Overview • 225 Statements/Invoices posted to QSEs • 38 Statements/Invoices posted to CRRAHs • 45 QSEs received Statements/Invoices for $0 CRR Overview • There were CRR Derations • CRR Owners were fully funded (i.e. there were no Short Fall Charges) General Reminders • ERCOT will assume all invoices have been paid in full (no need to ‘submit payments’) • Submit any questions/issues about statements, invoices, extracts or calculations to markettrials@ercot.com http://nodal.ercot.com 39

DAM Settlement Overview for Apr 28 Statement and Invoice Overview • 221 Statements/Invoices posted to QSEs • 38 Statements/Invoices posted to CRRAHs • 21 QSEs received Statements/Invoices for $0 CRR Overview • There were CRR Derations • CRR Owners were fully funded (i.e. there were no Short Fall Charges) General Reminders • ERCOT will assume all invoices have been paid in full (no need to ‘submit payments’) • Submit any questions/issues about statements, invoices, extracts or calculations to markettrials@ercot.com http://nodal.ercot.com 40

Week in Review • RMR and Blackstart For 4-21 and 4-23 • One RMR resource was not set up in Lodestar, and another was incorrectly set up as an RMR resource • Two Blackstart resources where entered with the incorrect unit name • Extract XML Updates • The Public Reference Data Extract (PRDE) XSD and XML files have been updated and reposted as of Tuesday 04/27/2010. • The Day Ahead Market Market Operating Day Extract (DAM MODE), Day Ahead Market Consolidated Operating Day Extract (DAM CODE) and Settlement Inputs Data (SID) extracts that posted yesterday, 04/29/2010 contain the XML files fixes for date format and element configurations. • In order to prevent duplicate postings, ERCOT has removed all DAM MODE and DAM CODE files posted to the MIS on Sunday 04/25/2010 for the 04/21/2010 operating day. These files will be rerun and posted to the MIS on Friday 04/30/2010 based on changes implemented. http://nodal.ercot.com 41

Next Week’s Activities • 5/5 Op Day • DAM Statements and Invoices posted on 5/7 • RTM Initial Statement posted on 5/17 • 5/7 Op Day • DAM Statements and Invoices posted on 5/11 • RTM Initial Statement posted on 5/17 • RTM Initial Statements for Operating Dates 4/21 and 4/23 will be posted on 5/3 • DAM Statements and Invoices for 4/30 will be posted on 5/4 • COMS Extracts (DAMMODE, DAMCODE, RTMMODE, RTMCODE) • For 4/28 DAM Settlement will be posted on Sunday 5/2 • For 4/30 DAM Settlement will be posted on Thursday 5/6 • For 4/21 and 4/23 RTM Initial Settlement will be posted on Wednesday 5/5 http://nodal.ercot.com 42

Environment Report-Known Issues COMS New Known Issues • CSI Logic needs to be updated for the CRRSFTVIOL Bill Determinant. The logic needs to be updated to include TO_STATION, FROM_STATION, TO_STA_KV and FROM_STA_KV. It also should only create the BD when the same constraint is binding for the same hour in both SFT and DAM. This is currently only an issue if the same constraint and contingency is binding in both SFT and DAM, but To-From direction is different in both processes • Lodestar metadata for the Market Constraint table needs to be updated to include the new columns TO_STATION, FROM_STATION, TO_STA_KV and FROM_STA_KV • In order for TWOS (Time Weighted Output Schedule) to be considered ‘valid’ it must have a value greater than the LSL and less than the HSL. Currently, if the TWOS is equal to the LSL or HSL it is considered valid. This affects the calculation of RTAIEC for resources on output schedules. • FQDEVFLAG is not calculating correctly for the first interval of the operating date. In certain circumstances, the value for interval ending one is 3 instead of 1. This only affects the first interval of the Base Point Deviation Charge. http://nodal.ercot.com 43

Environment Report-Known Issues COMS Closed Issues • The Base Point Deviation calculation does not use AEBP as the base point in the calculation when Emergency Base Points have been issued, and it should. Also, Lodestar currently incorrectly exempts all QSEs from the Base Point Deviation Calculation when AEBP exists. • Currently, when doing look back logic to the prior day to evaluate RUC Starts and RUC Transitions, Lodestar will not calculate correctly when a Resource to QSE relationship has changed. The new logic should look only at the Resource name, not the QSE & Resource name. • Combined Cycle transitions that happen in the first hour of the operating day are not being captured. • In certain circumstances, the AEBP (Aggregated Emergency Base Point) logic is incorrect • When Emergency starts in prior day and ends in current Operating Day, AEBP is being incorrectly calculated in the Current Operating Day • After an Emergency stops, null values should be populated for Settlement Intervals following the end of the emergency. Currently, zeros are being populated • In certain circumstances, the BP logic is not correct • Need to look at the prior day's final SCED base point when an Operating Day starts under an Emergency • BP not being calculated correctly when Emergency Basepoints start and stop twice in the same settlement interval • When calculating AABP during a settlements interval change, the look back in the calculation (BP y -1) is not correct. http://nodal.ercot.com 44

Q&A Q&A / Open Forum http://nodal.ercot.com 45

Appendix Appendix • DAM Kickoff slides • Pre- and post-DAM reports • Special Topics http://nodal.ercot.com 46

Objectives Objectives of Phase 4.0 DAM/RUC Market Trials: • Execute DAM, RUC, and SASM in the Market Trials environment twice a week • Generate awards, notifications, and reports http://nodal.ercot.com 47

Entry Criteria ERCOT Entry Criteria for Phase 4.0: • ERCOT has completed required integration testing for Phase 4.0 functionality • ERCOT has published all known, market-relevant defects to Market Participants via the Readiness Center Market Participant Entry Criteria for Phase 4.0: • QSEs have met the system requirements (digital certificate with ‘MMS Trader’ role assigned, etc.) • QSEs have completed the qualification testing and have confirmed their ability to use Web Services or the Market Manager to submit transactions necessary to support Day-Ahead Market Trials http://nodal.ercot.com 48

Summary of QSE Activities • QSEs with Resources: • Maintain SCED offers and ensure Start-Up and Minimum Generation Offers are available prior to the Day Ahead 10:00 a.m. (Central) deadline • Submit AS Offers • Update COP after DAM, DRUC, HRUC starting 4/13 • QSEs with Load: • Self-Arrange requested amount of AS Obligations • Bid a portion of their Load in the DAM (see example on next slide). In general, this should take the form of an Energy Bid but during the last week of April, can also be in the form of a PTP Obligation Bid. • Tuesday- 80% of QSE’s forecasted Load • Thursday- 120% of QSE’s forecasted Load http://nodal.ercot.com 49

Summary of QSE Activities • QSEs with Load (cont’d): Example for load bids • All QSEs: • May submit a limited amount of DAM Energy Only Offers and DAM Energy Bids that do not represent actual Resources or Loads (virtual bids and offers) – limit is up to a MW quantity total contained within a certain number of transactions per hour. • PTP Obligation Bids will be limited as well Details with dates on next slide http://nodal.ercot.com 50

Market Trials DAM/RUC/SASM