Entergy Integration Study Update Jonathan Rose Cathey Carter Warren Lasher Regional Planning Group November 14, 2008

Purpose To update the Phase II Entergy Integration Study (completed 12/2006) with input assumptions that are consistent with a contemporaneous study being conducted by SPP Study is nearly complete and report is in review. November 14, 2008 Regional Planning Group

Entergy Area Overview November 14, 2008 Regional Planning Group

Study Assumptions Base case built from 2012 case of 2007 5-Year Plan Delivered natural gas price: $7/MMBtu Includes all generating units in ERCOT and Entergy operating today or with signed interconnection agreements as of July 1, 2008 Cost estimates for transmission improvements provided by Entergy-Texas, Inc. November 14, 2008 Regional Planning Group

Asynchronous Ties Ties provided for SPP reliability and for contractual obligations and power purchase agreements. 100 MW asynchronous tie at Quarry, halfway between Grimes and Crockett. 827 MW asynchronous ties at Hartburg. 244 MW on the 500-kV Hartburg bus. 583 MW on the 230-kV Hartburg bus. November 14, 2008 Regional Planning Group

Major Reliability Projects Extend the existing ERCOT 345-kV Kuykendahl – King line to the Entergy Porter substation; install one 345-kV/138-kV autotransformer at Porter. ($54,710,000) New single-circuit 345-kV line from the ERCOT Roans Prairie substation to the Entergy Grimes substation. ($8,030,000) New 345-kV line from Quarry to Entergy Rivtrin substation. ($33,000,000) Rebuild the Entergy 69-kV line from Fawl to Kirbyville as a 138-kV line and tie to the Entergy 138-kV Kirbyville substation. ($16,510,000). Rebuild the existing Entergy 138-kV line between the Porter and Oakridge substations. ($5,429,000). Upgrade the existing Entergy 138-kV line between the Navasota and Longmire substations ($27,827,000). Upgrade the existing 69-kV lines from the Sourlake to Dome substations, the Dome to Batson substations, and the Gallier to Elizabeth substations ($11,586,000) Total cost of all reliability projects (including asynchronous ties): $486 million November 14, 2008 Regional Planning Group

Major Reliability Projects November 14, 2008 Regional Planning Group

Economic Projects Add a second 500-kV/230-kV autotransformer at the Hartburg substation ($19,800,000) Install one 345-kV/138-kV 800-MVA autotransformer at Porter rather than the 400-MVA auto, as called for in the reliability project list. ($10,800,000) Second 230-kV circuit from the Hartburg to Sabine substations on new towers. ($30,180,000) Close the Dayton-Crosby 138-kV line and upgrade the line to a rating of 531 MVA. ($11,834,000) Construct a new substation at Canal, tapping the 345-kV line connecting the Cedar and N Belt substations. Construct a 345-kV line between the Cypress, China and Canal substations. Install new autotransformers at China and Cypress substations. ($225,600,000) Total cost of economic-driven projects: $298 million. Modeled production cost benefits: $63 million. November 14, 2008 Regional Planning Group

Economic Projects November 14, 2008 Regional Planning Group

Scenarios All CREZ wind (an additional 11,553 MW) Delivered natural gas price: $11/MMBtu Reduced asynchronous tie capacity at Hartburg (244 MW) Cottonwood generator in the Eastern Interconnect Additional 345-kV line from Deweyville to Canal (Kelson proposal) November 14, 2008 Regional Planning Group

Questions? November 14, 2008 Regional Planning Group