Lead from the front Texas Nodal 1 External Web Services Update Nodal Implementation Team Presentation July 7, 2009

Lead from the frontTexas Nodalhttp://nodal.ercot.com 1

External Web Services Update

Nodal Implementation Team Presentation

July 7, 2009

Lead from the frontTexas Nodal

Agenda

• External Interface Specification– Additional v1.19 comments received since last meeting

• EIS Market Information Services Update– Further discussion of removal of certain interfaces

• Q&A


Overview

• EIS 1.19 was released for comment on 6/5/09

• Comments closed on 6/19/09– Received several comments Friday afternoon 6/19/09, too late for

detailed discussion at the last meeting

• Sandbox– 1.19 is being released to the Sandbox today, 7/7/09


Comments / Questions Received

Review Comments / Questions Received


EIS Market Information Services Update: Interface Review

• Total of 19 items from the Market Information section of the document (read-only interfaces) initially targeted for removal from EIS/EWS implementation

• 9 items called out for additional review– Limited Review: we extended the deadline for receiving

comments and questions for the 19 interfaces, which were due 7/2/09

– 8 items on this list already identified for further ERCOT evaluation by the NIT, 1 was added as a result from comments received

• These are items that are not suitable to be provided via web services for various reasons– All are available through other means except the four items that

lack protocol traceability



1) EIS Section 4.3.35, Responsive Reserve Capacity

2) EIS Section 4.3.36, Non-Spinning Reserve

3) EIS Section 4.3.37, Undeployed Reg-Up and Reg-Down

4) EIS Section 4.3.38, Available Capacity

5) EIS Section 4.3.45, Total ERCOT Generation Operating Reserve

Resolution:• These 5 sections will be combined into one interface called System Parameters • This information is also provided in one MIS display (System Parameters)• EIP will create a new web service that offers similar functionality as the System

Parameters display. • EIP implementation will cache the last good reading from MIS and will feed that

to all incoming web service requests for SystemParameters noun• Only returns current information. No history will be provided. • This data is also provided via ICCP





1) EIS Section 4.3.35, Responsive Reserve Capacity

2) EIS Section 4.3.36, Non-Spinning Reserve

3) EIS Section 4.3.37, Undeployed Reg-Up and Reg-Down

4) EIS Section 4.3.38, Available Capacity

5) EIS Section 4.3.45, Total ERCOT Generation Operating Reserve

Resolution (cont’d):• A decision was made at March 31, 2008 TPTF regarding the AS Capacity

Monitor Data (the title of the Protocol Section 6.5.7.5, Ancillary Services Capacity Monitor, that describes the provision of this data to the market)

• “Ancillary Service (AS) Capacity Monitor Data

Ms. Flores discussed issues for meeting the required ten-second posting frequency for AS Capacity Monitor data, noting that testing indicated the data could not be generated more frequently than once per minute. However, if the data was provided via web service, it could be refreshed per the ten-second requirement. The web-service option would not allow the data to be captured historically. No one objected to this approach. Ms. Flores noted that she could withdraw NPRR121, System Parameters Posting Frequency, in favor of the web service option"



6) EIS Section 4.3.16, Dynamic Ratings

Status:• The current MIS report posting for dynamic ratings contains hourly data for the

real-time + next 7 days, and uses current + forecasted weather assumptions

• No MIS report or requirement for real-time dynamic ratings adjusted to the actual temperature, refreshed every 5 minutes.

• This data will not be provided via ICCP as there is no requirement

• ERCOT needs more time to evaluate what is needed beyond the current implementation



6)EIS Section 4.3.16, Dynamic Ratings

Relevant Protocols and planning postings to satisfy:

3.10(4): For each model, ERCOT shall post ratings and the ambient temperatures used to calculate the ratings on the MIS Secure Area when the model is published.

– This will be posted with the model

3.10.8(3): Each Operating Hour, ERCOT shall post on the MIS Secure Area updated Dynamic Ratings adjusted for the current temperature.

– This is the CDR report referenced previously (posted hourly with 7 days of data)

4.2.3(b) Weather assumptions used by ERCOT to forecast ERCOT System conditions and used in the Dynamic Rating Processor

– This is a different CDR report posting daily at 0600

6.5.7.1.7(1): ERCOT shall post summaries of dynamically adjusted Transmission Element limits on the MIS Secure Area in a form that allows Market Participants to directly upload Real-Time data into the Common Information Model (CIM)

– This is under evaluation

3.10.8.4(1): ERCOT shall provide a system to accept and implement Dynamic Ratings or temperatures to be applied to rating tables for each hour in the Day-Ahead and in the Operating Hour

– ERCOT receives this information via ICCP



7) EIS Section 4.3.32, List of Zones, Hubs or Buses

Resolution:• Current implementation is to get this via the Network Model posting on the MIS• This is still under evaluation to satisfy business and technical needs

8) EIS Section 4.3.30, Derated CRRs

Resolution:• For shadow settlements, data is available in the DAM extracts• No protocol traceability for posting this information in a report on the MIS• A NPRR would need to be submitted

10) EIS Section 4.3.26, Unit Availability

Resolution:• No protocol traceability for this posting this information• A NPRR would need to be submitted



Summary

Of the 19 items from the Market Information section initially targeted for removal from EIS/EWS implementation:– 5 will be developed as a new single interface– 2 are still under evaluation– 12 will be removed from the EIS specification document

4 not in protocols

51 Market Info interfaces

19 interfaces under review

7 provided other

mechanism

2 still under evaluation

5 will be newinterface



Summary (cont’d)

Targeted for removal from document:

4.3.17 Voltage Profiles

4.3.18 Total Regulation

4.3.21 Load Distribution Factors

4.3.22 Shift Factor

4.3.23 Customer Load Profile

4.3.26 Unit Availability

4.3.30 Derated CRRs

4.3.33 Area Control Error

4.3.34 Frequency

4.3.41 Dynamic ratings deviation adjusted

4.3.42 Average monthly Dynamic deviation

4.3.44 Total ERCOT Generation

Still under evaluation:

4.3.16 Dynamic ratings

4.3.32 List of Zones, Hubs, or Buses

Documents

Lead from the front Texas Nodal 1 External Web Services Update Nodal Implementation Team Presentation July 7, 2009