Market Participant Data Access Jan 22 2008 Stephen Kerr

1. Market Participant Data AccessJan 22 2008Stephen Kerr 1

2. Agenda • Market Participant Data Access • External Interface Specification • MIS External Interface Specification 2

3. Market Participant Data Access Overview • MP’s have multiple methods to access ERCOT data • External web services for machine to machine interactions • MIS for user interaction • The MP Data Access booklet has been updated (from April 07) • Substantially complete Nodal Data Services Master List • Substantially completed External Interface Specification • Substantially complete MIS External Interface Specification 3

4. There are three ways for machines to access ERCOT’s data • The External Interface Specification describes all of the data services available through web services • The second method is to retrieve extracts that are also available on the MIS through a single “getReport” web service • The MIS External Interface Specification • Originally intended to support MIS dashboards only • The web services are also useful for MPs and will be exposed in exactly the same way as the External Interface Specification i.e. web services. 4

5. There are three ways for users to access ERCOT’s data • The MIS provides users with a view of reports and extracts as well as a method for downloading the reports and extracts • Each application displays its user interface through the MIS • Some applications allow for upload and download of data 5

6. Reviewing and changing the data services lists • Nodal Data Services Master List • References all interactions outside of user interfaces, including the External Interface Specification and MIS External Interface Specification • Contain extracts, downloads, web services, real-time reports • Updated weekly and loaded to http://nodal.ercot.com/readiness/reports/index.html • Should be reviewed for completeness and access methods • External Interface Specification • Published for review and approval every 2 months approximately • Changes communicated through monthly TPTF reviews • http://nodal.ercot.com/docs/pd/eip/index.html#oth • MIS External Interface Specification • Never been published for review and approval • Will be treated as the External Interface Specification • http://nodal.ercot.com/docs/pd/eip/index.html#oth 6

7. External Interface Specification • Outage interfaces are the biggest new element in the external interface specification • Version 1.07 in review, all received comments will be incorporated in 1.08 • Key string composition for Outage mRIDs • PriceCurve multi-hour block • Explanations for OutageIdent, OutageWarning, LastModifiedby, LastModified, versionID, groupID, OutageNotes • Difference between newSchedule and Schedule • Currently all machine interfaces use the web. ERCOT will test machine interfaces on the WAN this year but there is no published plan yet • We are adding an enhancement called chunking that will allow multi-day submissions • SCED active contingency information  will be: • the contingencies that have created initial constraint violations as calculated by EMS and as passed to the MMS.  MMS already provides us with capability (staging tables/reports) to capture these contingencies.  • the contingencies that have been de-selected at the EMS side 7

8. MIS External Interface Specification • Version 0.35 in review, all received comments will be included in 1.0 • Frequency of update of WGRPP and frequency of access • WGRPP resource name • MIS services are additional to existing External Interfaces (sortBy, Role, Category) with different URLs • Ancillary Service types will be made consistent between the two specifications • Complete set of new services • Weather Data • List of Zones, Hubs, or Buses • System Control Error • Frequency • Responsive Reserve Capacity • Non-Spinning Reserve • Undeployed Reg-Up and Reg-Down • Available Capacity • Wind-Powered Generation Resource Production Potential • Short-Term Wind Power Forecast • Dynamic ratings deviation adjusted for the current temperature • Average monthly Dynamic deviation • Total ERCOT Load • Total ERCOT Generation • Total ERCOT Generation Operating Reserve • MID-MIR Get Report List • RRS Deployment Instruction for non-controllable load resources 8

9. Three Part Offer Incremental/Decremental Offers Current Operating Plan Output Schedule Bid Set Acceptance Bid Set Errors Get mRID System Status Self Arranged Ancillary Services (AS) Ancillary Services Offer Ancillary Services Trade DAM Energy Bid DAM Energy Only Offer Forecasted Load Real-Time System Load Market LMPs and SPPs Mitigated Curves Outage Creation Congestion Revenue Rights PTP Obligation Bid Self Schedule Total Regulation Load Ratio Share Unit Availability Startup and Shutdown Instructions Proxy Curves Notices and Alerts CRR Awards Outage Notifications Capacity Trade DC Tie Schedule Energy Trade Get AwardSet Market MCPCs Ancillary Service Schedule Obligations Load Distribution Factors Customer Load Profile Energy Offer Awards PTP Obligation Awards Market Totals Binding Constraints Active Contingencies in SCED -SCEDViolatedConstraints Voltage Profiles Competitive Constraints Shift Factors Ancillary Service System Plan Pending Trade Energy Only Offer Awards Energy Bid Award Ancillary Service Awards Dynamic Ratings Aggregated Ancillary Service Offer Curves Total Ancillary Service Offers Total DAM Energy/ total Energy Derated CRRs Alert Acknowledgement Outage Query Outage Cancellation Services defined in the External Interface Specification 9