ERCOT 2009 Five-Year Transmission Plan Update Jeff Billo RPG Meeting November 13, 2009

2009 Five-Year Transmission Plan: Where we’re at   2014 2013 2012 2011 2010 Conditioned Case N-X Analysis G-1 + N-X Analysis TO/ MP Input Reliability Project Backout Reliability AC Case Economic Analysis AC Case with All Upgrades = Complete = In Process = Not Started November 13, 2009 RPG Meeting

2009 Five-Year Transmission Plan Update Significant project changes since last update Changed back to addition of second Collin 345/138-kV autotransformer instead of Mustang 345-kV station and autotransformer project Upgrade required by 2013 summer peak Mustang project was dependent on Krum West-Anna 345-kV CREZ project which may not be completed by 2013 summer peak Could not economically justify lower Panhandle project to redirect McAdoo and Whirlwind wind generation to the CREZ ERCOT cost estimate ~ $66M Final Annual PC Savings = $4.4M Capital cost/ Annual PC Savings = 15 > 6 Whirlwind Spur Matador ~ Cottonwood (Pan A-D) McAdoo Miscellaneous project changes since last update based on comments from Transmission Owners See recent 5YTP POI website postings November 13, 2009 RPG Meeting

West/ North Curtailment 2009 5YTP Wind Curtailment Wind curtailment in latest economic case for each year Sum of Wind Generated GWh/ Sum of Wind Profile GWh Note: wind curtailment figures were based on a model with generic wind profiles and are not necessarily a prediction of what the actual wind curtailment will be in future years 2010 2011 2012 2013 2014 West/ North Curtailment 18.4% 17.1% 18.7% 0.66% 0.60% South Curtailment 0.02% 0.16% 0.07% 0.00% Total Curtailment 17.3% 15.8% 0.61% 0.55% November 13, 2009 RPG Meeting

Initial reliability analysis done in UPLAN which is DC 2009 5YTP AC Cases Why create an AC case? Initial reliability analysis done in UPLAN which is DC Overloads may exist when VAR flow is added Voltage analysis required UPLAN cannot run some contingencies (ie. multi-section line with load throwover) Other studies use 5YTP cases for analysis Reliability cases Start with 5YTP conditioned cases for each year Add all reliability projects Run Powerworld SCOPF to create a security constrained dispatch Add additional projects for unresolvable constraints November 13, 2009 RPG Meeting

ERCOT will use the 5YTP as demonstration of this assessment 2009 5YTP AC Cases 5YTP Voltage Analysis NERC TPL Standards require the Planning Authority (ERCOT) and Transmission Planner to (summarization): Annually perform a near term (years one through five) assessment of the transmission system that… Includes reactive power resources to ensure that adequate reactive resources are available to meet system performance and… Address any planned upgrades needed to meet the performance requirements of Category B of Table I ERCOT will use the 5YTP as demonstration of this assessment November 13, 2009 RPG Meeting

Complete feedback from TOs/ Market Participants Documentation 2009 5YTP Next Steps Finalize AC cases Complete feedback from TOs/ Market Participants Documentation Analyze 2009 5YTP successes and areas for improvement Incorporate into 2010 5YTP Please send comments to j bill o@er cot.co m (remove spaces) November 13, 2009 RPG Meeting

Questions? November 13, 2009 RPG Meeting