1. SCR746 – Dynamic Rating Data to TSP Using ICCP Link Background for ERCOT Board February 21, 2006

2. 2 How are transmission ratings used by ERCOT communicated? Dynamic transmission line ratings are posted for TSPs via the Portal. TSPs have direct access to ERCOT’s current network model. (SCR723 - implemented summer 05). All market participants can access ERCOT’s network model converted to PTI/PSSE format from the public website. This SCR would ‘push’ dynamic transmission line ratings to the TSPs in a more usable form via ICCP.

3. 3 CBA Highlights Over 4 Year period Costs - $1.3 Million  $300K ERCOT cost to develop  $700K ERCOT ongoing cost (1.5 FTEs) 1 IT FTE for maintenance of additional 15,000 ICCP data points 0.5 Operations FTE (est.) for additional TSP communications  $300K TSPs’ cost to implement (5 @ $60K) Benefit - $900K  Avoiding $1 Million of unnecessary congestion costs once every four years (assumed in year 3)  Based on actual cost of only known incident of incorrect ratings causing unnecessary congestion management

4. 4 CBA Uncertainty Benefits are dependent upon TSPs:  Modifying their processes to receive rating data via ICCP  Implementing applications to review the rating data  Contacting ERCOT if inconsistencies are found Other Factors influencing Benefits:  If these new processes lead to more data inconsistencies being discovered than existing processes have found, benefits would increase  Assuming rigorous checking by TSPs, there would be an incremental increased confidence in ERCOT’s Network Model which would be a valuable, but intangible, benefit

5. Background Info

6. 6 Dynamic Ratings Application Overview Carlos Gonzalez-Perez / EMMS Production Support Manager

7. 7 Impact Analysis Highlights Cost: 5-L ($100k - $500k)  Development and testing ERCOT will exceed the licensed number of SCADA (Substation Control and Data Acquisition) points with this effort, therefore an additional cost will be incurred to change ERCOT’s licensed number of SCADA points with the software vendor. The cost of the additional licensing could not be explicitly determined at this time and is not included in the estimated budget impact above; however, it is not anticipated to push the overall cost into the next higher budget range. Staffing: 1.5 FTEs  1 FTE in EMMS Production Support for ongoing maintenance - querying and publishing SCADA points after each database load.  0.5 FTE in Operations Support for ongoing support in resolving perceived dynamic rating discrepancies with Transmission Providers. Business Function Impacts:  A significant effort of ongoing support to existing business functions, which affects staffing levels, will be added by this request.

8. 8 Staffing Impact SCR 746 will increase the modeling effort in the EMMS Production systems Current Total Real-Time Data exchange: approx 55,000 points today  Currently 3 individuals performing real-time data collections maintenance. New SCR represents is an increase in 29% the maintenance load of real time data collections About 1 additional FTE from EMMS Production Support This person will not be solely dedicated to the Dynamic Rating application, but to the maintenance of the SCADA/ICCP/Network Model Carlos Gonzalez-Perez / EMMS Production Support Manager

9. 9 Impact Analysis Highlights Time: 4-5 months  2 months for EMMS database development and documentation  4-5 weeks to model the new SCADA points  4-5 weeks for PI (Plant Interface) development work  4-5 weeks for ICCP (Inter-Control Center Protocol) development work and testing with Transmission Providers The PI and ICCP development work can be done in parallel and these steps can overlap partially with the modeling of the SCADA points.  2-3 weeks for EIS (Enterprise Information Services) development work that is required to mirror EMMS database changes The EIS development work can begin after the EMMS database changes are complete and can be done in parallel with all other work effort.

10. 10 Impact Analysis Highlights System Impacts:  SCADA points need to be added to the EMMS database for sending transmission line dynamic ratings to Transmission Providers.  Accompanying modeling changes and changes to ICCP and PI systems will also be necessary to complete the mapping of the SCADA points. All development and testing efforts can be done by ERCOT staff. Other Comments:  The system impact of the capability for Transmission Providers to receive and provide ongoing support for the proposed additional data points needs to be assessed.  Transmission Providers attempting to view all transmission SCADA points provided by ERCOT by ICCP may experience a bandwidth issue.  Transmission line dynamic ratings are currently published and will continue to be published on the ERCOT portal.

11. 11 EMMS Production Support Evaluation Assumptions The Static Table will not be sent via ICCP ERCOT will make available only the “current” ratings in the Dynamic Rating database. Values will be available to all the entities with credentials to pull this information (TDSPs only) This is a critical production system -- 7x24 support It will be maintained following the EMMS Database Load Maintenance Procedures. Carlos Gonzalez-Perez / EMMS Production Support Manager

12. 12 Dynamic Ratings SCR 746 CurrentlySCR 746 Total Dynamic Rating database (point) 7905 (2635x3)7905 (2635x3) ICCP INBOUND MVA ( points )00 ICCP INBOUND Amp. ( points ) 1586 (793x2)1586 (793x2) TEMPERATURE11 STATIC TABLE 6319 (1842x3+793) 6319 (1842x3+793) Potential Total for Dynamic Ratings (points) 15732 (5244x3)15732 (5244x3) ICCP Outbound (points)015732 Carlos Gonzalez-Perez / EMMS Production Support Manager

13. 13 Dynamic Ratings Additional Maintenance Over 15,000 dynamic rating points in the SCADA database (~30% increase) and in our data historian. Consistency/mapping of the dynamic ratings with ERCOT models:  The network model  The ICCP model  The SCADA model  1500 modeling change request in the ERCOT model in 2004  Over 500 SCADA verification requests with the current SCADA system  47 database loads in 2004 and 36 database loads in 2005 Carlos Gonzalez-Perez / EMMS Production Support Manager

14. 14 Tricorner – Watermill History March ’04 – Line modified to operate at 2000A. Rating changed to 1195MVA May ’04 – Line dynamically rated  August ’04 – dynamic ratings adjusted Fall ’04 – Outages taken to set/relocate towers and reconductor line March ’05 – short outages to replace terminal equipment and change out riser May 20, 2005 – Service Request submitted to revise dynamic ratings to nominal 1793MVA

15. 15 Tricorner – Watermill Congestion events – May 2005 Loss Of: Overloads Tricorner to Watermill 345kV Estimated cost May 18 Allen Switch – Royse Switch & Monticello 345kV108% of 1195 MVA$0.2 M May 19 Big Brown – Richland Chambers 345kV107% of 1195 MVA$1.2 M May 20 Watermill – Trinidad 345kV106% of 1280 MVA$0.05 M

16. 16 CBA Highlights Assumptions The information ERCOT provides to the portal and/or by ICCP will be reviewed by Transmission Service Providers (TSPs) and inconsistencies of this data will be reported to ERCOT using the current Service Request process. Both ERCOT and TSPs already have a functioning ICCP link with ERCOT.  The NDSWG determined that for some TSPs, the cost to implement data across the ICCP link is minimal. However, the cost to other TSPs is comparable to ERCOT's cost to implement this SCR. For such TSPs, using methods other than ICCP, such as flat file transfer, would be more cost effective. The cost differences among TSPs depends upon how many transmission circuit ratings are monitored and system architecture. Example: OOME payments on May 19, 2005 totaled ~ $1 million for the overload of Tricorner to Watermill. If only one day of incorrect OOME were avoided this SCR would pay for itself. Problem occurred for three days before being fixed. Total cost was ~$1.5 Million For purposes of this estimate, it is assumed that one high impact rating variance (similar to what was described above) will be discovered/corrected every 4 years due to this enhanced data validation capability 5 TSPs will choose to implement ICCP in order to participate in this data exchange (there are currently 15 TSP ICCP links in operation). Estimated cost = $60k per TSP Additional SCADA points required for this process require a proportional increase in ongoing operational support by ERCOT staff. Multiple methods of delivering dynamic rating data are desired  Data file in CSV format is available on TML

17. 17 CBA Highlights Non-quantifiable Impacts This SCR aims to reduce network model errors. The economic benefits, in terms of unnecessary congestion costs incurred due to erroneous limitations, depend upon a number of factors including (1) how many errors exist; (2) how many errors would be eliminated by this SCR; and (3) the congestion costs caused by the errors. Regarding item (2) above, using ICCP will be cost- prohibitive for some TSPs to apply to all elements, and will therefore reduce the benefits of this SCR. However, the same is true if some other mechanism were used, such as flat file transfer. Network model errors can cause congestion if transfer limits are set artificially low due to the errors. Conversely, network errors can cause reliability problems if transfer limits are set artificially high due to the errors. Therefore, in addition to reducing congestion costs, this SCR also improves reliability, which is difficult to quantify in terms of economic benefit. It is difficult to assess the total system benefit achieved by implementation of this SCR. The risk of a significant grid impact caused by an incorrect line rating would be lessened with the addition of this enhanced data validation process.

18. 18 Procedural History 6/29/05SCR746 was posted. 7/8/05Centerpoint & TXU ED comments were posted. 8/9/05ERCOT comments were posted. 8/11/05ROS / unanimously recommended approval 9/8/05ERCOT posted the Impact Analysis (IA). 9/15/05ROS / reviewed the IA and remanded SCR to the NDSWG to investigate data delivery alternatives. 10/11/05NDSWG discussed this SCR. 10/15/05ROS / endorsed prior approval and requested NDSWG look into additional enhancements to this SCR in the future 10/27/05PRS / reviewed CBA, assigned Priority and Rank. 11/3/05TAC / directed ERCOT to provide specific examples of the magnitude of the problems that the SCR is addressing 12/1/05TAC / instructed ERCOT to provide a more detailed CBA characterizing the full range of benefits and revisit the 1.5 FTE 1/12/06TAC / recommended approval

19. 19 Procedures Transmission & Security Desk 2.2.10Managing Line Rating Changes Step #Procedural Steps 1When notified by a Transmission Operator of a line rating that is different from the ratings currently in RTNET, obtain the following information from the Transmission Operator:  Equipment ID Name  MVA ratings (Continuous, Emergency, and 15 Minutes)  Name of Operator on duty  Name of Transmission Operator (Company)  Name of Transmission Operator’s authorizing engineer  Authorizing engineer’s contact phone number 2Continue to operate according to RTNET ratings.  Provide this information to the Shift Supervisor  Enter this information in the Transmission log under the “Line Rating Changes” log type

20. 20 Procedures Shift Supervisor 2.1.8 Coordinating Line Rating Changes Step #Procedural Steps 1When notified by the Transmission and Security Desk operator that a Transmission Operator has provided changes to a line’s ratings, NOTIFY the engineer on-call and provide the following information:  Equipment ID Name  MVA ratings (Continuous, Emergency and 15 Minute)  Name of Operator on duty  Name of Transmission Operator  Name of Transmission Operator’s authorizing Engineer  Authorizing Engineer’s contact phone number. 2Log this communication in the Shift Supervisor’s Log, using the “Line Rating Changes” log type 3Log the response of the ERCOT Operations Engineer in the Shift Supervisor’s Log, using the “Line Rating Changes” log type. NOTEIf the rating received is a dynamic rating, the Transmission Operator must send it by e-mail or fax. 4Forward related correspondence (email or fax) to Ricson Chai.