1 April 27, 2011 Southeast Tornado Event System Operator Conference September and September 25-27, 2012 Memphis, TN Rocky Williamson, SOS Chair Operations Training Manager Southern Company Services - Transmission

2012 System Operator Conference 2 Learning Objectives At the conclusion of this training session, you will be able to: Identify the RC’s four tools for implementing control actions in an emergency condition Evaluate the unique circumstances the April 2011 Tornado Event offered Recognize the importance of working with neighbors and planning for contingencies Describe the value of Blackstart plans and emergency drills

2012 System Operator Conference 3 Outline of Topics RC toolbox – control actions Magnitude of storms SOCO Storm Report SOCO Damage Report Impacts to interfaces, generation Restoration/ Restoration support Lessons learned from April Tornado Event

2012 System Operator Conference 4 PLAY: TVA VIDEO: STORM_4_27_2011

2012 System Operator Conference 5 RC Toolbox – Control Actions Redispatch generation Reconfigure transmission system Adjust interfaces Shed load

2012 System Operator Conference 6 Please stand if: You worked on April 27, 2011

2012 System Operator Conference 7 You worked on April 27, 2011 You worked on the Restoration Please stand if:

2012 System Operator Conference 8 You worked on April 27, 2011 You worked on the Restoration You were directly affected by storm damage Please stand if:

2012 System Operator Conference 9 You worked on April 27, 2011 You worked on the Restoration You were directly affected by storm damage You know someone who was affected by the storm Please stand if:

2012 System Operator Conference 10 Magnitude of Storm

2012 System Operator Conference 11 Tornadoes are Red

2012 System Operator Conference 12 SERC Southeastern Subregion

2012 System Operator Conference 13 If You Build It, “Mother Nature” Will Tear It Down Normal storm damage Magnitude of this storm system  Greatest number of tornadoes in a single event  More tornadoes hit Alabama on April 27, 2011 than any year recorded  Yes, I said any year recorded!

2012 System Operator Conference 14 SOCO Storm Report Start April 27 at 5:05 a.m. – 12:25 a.m.19 hours Tornadoes in SOCO69 Tornadoes in Alabama 62 Associated with this storm system211 There was a morning set of storms Around 16:00 a second burst of storms emerged Most of the damage occurred in two short-time bursts

2012 System Operator Conference 15 Damage Report DamageSOCO TVA Transmission structures Transmission lines out Substation major damage8 Substations out318 Customers out of power426,640850,000 Generation sites effected1312 Load lost MW1500

2012 System Operator Conference 16 Interface (Tie-Line) Impacts Tie-line - a circuit connecting two Balancing Authority (BA) areas There are 13 TVA/SOCO ties After the second wave of storms 4 reading with semi-normal readings 7 radial into or out of SOCO

2012 System Operator Conference 17 Generation Impacts Operating generation with very limited, or no, transmission TVA’s Browns Ferry Gorgas – Miller Smith Dam Carters – Rocky

2012 System Operator Conference 18 Lack of Transmission to Nuclear Plants TVA’s Browns Ferry Nuclear Plant 7 of kVlines lost 1 of 2161 kV lines lost Only Athens 161 was line left in service All three units forced off2500 MW This was done safely!

2012 System Operator Conference 19 Browns Ferry

2012 System Operator Conference 20 Lack of Transmission to Coal Plants Gorgas and Miller3600 MW radial 3 of 4500 kV Miller-Clay 8 7 of 8230 kV Gorgas-Miller 6 #1 tie 3 of 3161 kV 8 of 9115 kV Tuscaloosa radial Georgia also lost lines out of several plants

2012 System Operator Conference 21 Gorgas - Miller

2012 System Operator Conference 22 Redispatch generation Reconfigure transmission system Adjust interfaces Shed load RC Toolbox – Control Actions

2012 System Operator Conference 23 Lack of Transmission to Hydro Plants Smith Dam 78 MW 2 of 2161 kV lines lost 1 of 1115 kV lines lost No transmission left in service No wire - no water Blackstart capability did not help

2012 System Operator Conference 24 Smith Dam

2012 System Operator Conference 25 Smith Dam

2012 System Operator Conference 26 Redispatch generation Reconfigure transmission system Adjust interfaces Shed load RC Toolbox – Control Actions

2012 System Operator Conference 27 Carters and Rocky 15 tornados in Georgia 83,000 customers out 11 – 115 kV lines out 7 – 230 kV lines out Carter’s 500 MW and Rocky 1000 MW were restricted in generation and pumping until lines were restored

2012 System Operator Conference 28 Limited Transmission to Load Serving load with limited transmission to Tuscaloosa 3 of kV lines lost 5 of 6115 kV lines lost The Gorgas-Yacht Club 3 was still in service

2012 System Operator Conference 29 Tuscaloosa

2012 System Operator Conference 30 Redispatch generation Reconfigure transmission system Adjust interfaces Shed load RC Toolbox – Control Actions

2012 System Operator Conference 31

2012 System Operator Conference 32 Tuscaloosa Picking up load too fast Holding NUCOR Steel off line (300 MW arc furnace)

2012 System Operator Conference 33 Bottoming Out 21:00 Loss of load due to storm damage We put everything to bed that we could Georgia was hesitant to release normally cycled units Cat II and Cat III on many units Request fleet to sell/give away 500 MW Georgia finally released units At the point of issuing a directive

2012 System Operator Conference 34 SOCO 500 kV and 230 kV System

2012 System Operator Conference 35 Quiz

2012 System Operator Conference 36 Restoration Support

2012 System Operator Conference 37 Lessons Learned Practice drills need to be broadened Mutual assistance – great stuff when you need it Tools can lie to you! Use an “experience filter” Double-staff the control center, day and night Place operators with knowledge of the damaged area on that desk

2012 System Operator Conference 38 Summary Make contingency plans; they are a great help Black start and emergency drills pay off big Get help coming Timely and accurate damage reports, set priorities Learn and make changes Coordination with neighbors, during and after the storm was a great benefit Mutual assistance, don’t leave home without it!

2012 System Operator Conference 39 PLAY VIDEO: APRIL_FURY_APCO

2012 System Operator Conference 40 Questions?