1. Oncor Electric Delivery Company LLC Smart Grid Demonstration Project – Dynamic Line Rating (DLR) June 25, 2010 Justin Johnson ERCOT Reliability Operations Subcommittee Meeting

2. Oncor Electric Delivery Company LLC Tension Based Dynamic Rating Technology

3. 2 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 Dynamic Line Rating Transmission Line Ratings are governed by:  Current flowing in the conductor  Conductor size and resistance  Ambient weather conditions: –Temperature –Wind speed and direction –Solar radiation

4. 3 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 Ambient Temperature: – 2 o C fluctuation  +/- 2% capacity, – 10 o C drop in ambient  + 11% capacity Solar Radiation: – Cloud shadowing  +/- a few percent, – Total eclipse  + 18% capacity Wind increase 1 m/sec: – 45° angle  ~ 18% capacity – 90° angle  ~ 23%capacity How Weather Conditions Affect Ratings (Illustrative Only)

5. 4 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 What to Monitor? Dead-end Suspension Tension increases in spans cooled by wind, and decreases in spans not cooled by wind…..

6. 5 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 Tension Monitoring - Dynamic Line Rating Tension Equalizes Suspension insulator strings swing to equalize horizontal conductor tension Monitoring the conductor’s tension solves the problem of varying winds and exposure along the transmission line. A conductor’s tension is directly related to the average temperature of all the spans in the line section. That temperature is directly correlated to the conductor sag and clearances. Dead-end Suspension

7. 6 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 Know true line capacity in real time Improve system reliability Optimize grid utilization Dynamic Line Rating Concepts (Illustrative Only) Dynamic Line Rating Design Isotherm

8. 7 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 Line was operating within limits in accordance with operating standards Without DLR, this event must be reported as a violation The operator would have been forced to move the grid off its optimum dispatch Dynamic Rating Actual Load Static Rating Impact On Transmission Grid Operations Example Of Safely Managed Contingency

9. 8 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 LOCATION OF INSTRUMENTED CIRCUITS Study Area in Critical Congestion Zone  45 Loadcell Tension Monitoring Units  8 Master Locations Feeding into SCADA

10. 9 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 DLR Smart Grid Demonstration Project Goal : Increase available capacity on a known congested and constrained transmission path and remove existing commercial constraints to implementing DLR technology Existing Commercial Constraints Include: Clear Demonstration that DLR Technology is Reliable Utility Planners Understand the Cost Structure and Benefits Interoperability with Utility Transmission Management Systems

11. 10 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 PROJECT OBJECTIVES Operational Objectives  Relieve congestion and transmission constraints  Gain operational knowledge of DLRs for wide scale deployment  Ensure that safety code clearances are not impacted  Demonstrate that multiple monitoring units can be integrated into operations  Identify/quantify other operational limits that may impact ability to raise ratings

12. 11 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 PROJECT OBJECTIVES Demonstration Objectives  Extrapolate the impact of DLRs on the study’s transfer path to entire ERCOT region  Determine a methodology to release day-ahead ratings  Develop user friendly tools for the operator to manage improved WASA

13. 12 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 PROJECT OBJECTIVES Economic Objectives  Quantify economic value of released transmission capacity to market  Estimate the savings associated with deferral of rebuilding, reconductoring, or building new circuits  Quantify the total costs of implementing this type of DLR

14. 13 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 Integrated Dynamic Line Rating Systems Tension-based Dynamic Line Rating System for overhead transmission lines Tension resolves all environmental factors for accurate results Best way to capture spatial variability of wind, sun, air temperature Captures as built, as aged condition of line Communicates with utility’s Energy Management System

15. 14 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 Solid stainless steel construction. Sized to match maximum tension Real Time Rating - Loadcell Monitors Tension

16. 15 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 Real Time Rating – Communications Package Reads conductor tension, net radiation temperature, ambient temperature Communicates with substation via spread spectrum radio Solar powered

17. 16 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 Integrated Dynamic Line Rating Systems SCADA/EMS Master Existing SCADA protocol over substation RTU channel (RS232/485) License free Spread Spectrum Radio IntelliCAT TM for Windows ICCP or MODBUS protocol CAT-1 ™ and line load data from EMS Substation Control Center Transmission Line Operator’s Console’ CAT-1 TM Remote Monitors CATMaster TM Base Station Line capacity and temperature to EMS

18. 17 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 MAJOR PARTICIPANTS Oncor  Purchase DLR equipment and manage project The Valley Group, a Nexans company  Provide DLR equipment Siemens Energy, Inc.  Integrate DLR technology into Oncor’s TMS system Chapman Construction Company  Install equipment on designated circuits Southwest Research Institute  Perform independent analysis

19. 18 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 Initial Device Installation PROJECT TIMELINE 2010 Qtr 1 20112012 2013 Qtr 2Qtr 3Qtr 4Qtr 1Qtr 2Qtr 3Qtr 4Qtr 1Qtr 2Qtr 3Qtr 4Qtr 1Qtr 2Qtr 3Qtr 4 Design/Initial Procurement Fine-tune Initial Device Output Terminal Upgrades Remaining Device Installation Final Report Submitted to DOE Project Studies Reporting (Quarterly to DOE)

20. 19 Oncor Electric Delivery Company LLC Justin Johnson ERCOT ROS Presentation 06/25/2010 Summary Target Completion is 2 nd Quarter 2013 Provides two years of summer peak data Will provide a “roadmap” for other utilities to follow - study will be public Success Factors include increasing transmission capacity and removing existing commercial constraints to DLR technology All eight circuits should be instrumented by end of this year