1. SCENARIO 2 PRESENTATION 345KV ALTERNATIVES ROBERT LONA SENIOR CONSULTANT ERCOT SYSTEM PLANNING 1/25/2008

2. 2 ODESSA MCCAMEY BIG LAKE TWIN BUTTES SAN ANGELO RED CRK TO WESTGATE TO KENDALL SONORA TO KENDALL CREZ6B PUCKETT TAP RIO PECOS CREZ6ASWTEC CRANE BLUFF CRK TO STEVN5 TO LAMESATO SNYDER MORGAN5 MCCAMEY AREA CASE 106

3. 3 WESTGATE GILLESPIE LAMPASAS COMANCHE SW WILLOW FERGUSON MARSHALL FORD SONORA TO BIGLAKE SAN ANGELO RED CRK TWIN BUTTES TO BIGLAKE TO BLUFF CRK TO L_DIVIDE TO MCCAMEY HILL COUNTRY AREA

4. 4 AMARILLO PAMPA SPUR LAMESA MORGAN CRK MIDLAND MOSS ODESSA CLEAR CROSSING OKLAUNION ABILENE GRAHAM BLUFF CRK STEVN5 COMANCHESW COM PEAK BOWMAN TO SPRING JACKSBORO TO MCCAMEY WILLOW CRK PD CANYON MATADORTUCO SNYDER ASPERMT TO CEDAR BAYOU BOSQUE TO TEMPPC PANHANDLE AREA HVDC LINE ~ 540 Miles

5. 5 KRUMWEST SPRING DENTON CARROLTONHICKS WILLOW CRK JACKSBORO TO OKLAUNION LEWISVILLE TO MATADOR TO CEDAR BAYOU TO MATADOR PERCH ARGYLE HVDC LINE DFW AREA

6. 6 NEW TRANSMISSION BY CREZ ZONES CASE 106 PANHANDLE / DFW 25 – 345KV CKTS. (1818 MILES) 7 – 345KV AUTOS $2.78 BILLION MCCAMEY 17 – 345KV CKTS. (800 MILES) 8 – 345KV AUTOS $1.26 BILLION CENTRAL 13 – 345KV CKTS. (654 MILES) 2 – 345KV AUTOS $1.02 BILLION TOTAL 345KV CKTS. = 55 TOTAL 345KV AUTOS = 17 TOTAL CKT. MILES = 3,272 TOTAL COST = $ 5.06 BILLION

7. 7 AMARILLO PAMPA SPUR LAMESA MORGAN CRK MIDLAND MOSS ODESSA CLEAR CROSSING OKLAUNION ABILENE GRAHAM BLUFF CRK STEVN5 COMANCHESW COM PEAK BOWMAN TO SPRING JACKSBORO TO MCCAMEY WILLOW CRK PD CANYON MATADORTUCO SNYDER ASPERMT BOSQUE TO TEMPPC TO ZENITH TO NAVARRO CASE 112

8. 8 MATADOR ASPERMT BLUFCRK STEVN5 NAVARRO LIMESTONE VENUS BIGBRN WATMILLE FPP ZENITH BOSQUE TEMPPC HVDC LINE ~ 250 Miles

9. 9 NEW TRANSMISSION BY CREZ ZONES CASE 112 PANHANDLE / DFW 24 – 345KV CKTS. (1818 MILES) 7 – 345KV AUTOS $1.98 BILLION MCCAMEY 17 – 345KV CKTS. (800 MILES) 8 – 345KV AUTOS $1.26 BILLION CENTRAL 12 – 345KV CKTS. (654 MILES) 1 – 345KV AUTOS $1.40 BILLION TOTAL 345KV CKTS. = 53 TOTAL 345KV AUTOS = 16 TOTAL CKT. MILES = 3,011 TOTAL COST = $ 4.64 BILLION

10. 10 CASE COMPARISONS NEW OVERALL % ANNUAL CASE NEW CKTS. AUTOS CURTAILMENT MILES COST $B PC SAVINGS $B 106 55 17 2.14% 3,272 $ 5.06 $ 1.78 112 53 16 2.23% 3,011 $ 4.64 $ 1.77

11. 11 NEXT STEPS MODEL DC COMPONENT OF CASE 106 / 112 IN UPLAN DEVELOP EQUIVALENT AC CASES STABILITY ANALYSIS

12. 12 QUESTIONS ?