THE BIG PICTURE: A Big Switch The widespread transition from coal to natural gas for new generation is exemplified by the morphing fleets of some of the biggest U.S. generators. Figures show the amount of power generated by each company using coal (top) and natural gas (bottom). Sources: POWER, NextEra, Duke Energy, Tennessee Valley Authority (TVA), Southern Co., American Electric Power (AEP), Dominion, Energy Information Administration (EIA) -Sonal Patel is POWER's senior writer. DUKE ENERGY 2006: 70.7% (104.9 TWh) 2011: 58.5% (84.1 TWh) NEXTERA 2006: 4.6% (6.5 TWh) 2011: 3.5% (6.0 TWh) TVA 2006: 64% (99.6 TWh) 2011: 52% (74.6 TWh) SOUTHERN 2006: 70% (140.7 TWh) 2011: 52% (96.7 TWh) AEP 2006: 86% (161.9 TWh) 2011: 78% (137.8 TWh) DOMINION 2006: 47% (49.1 TWh) 2011: 34% (34.2 TWh) COAL SHARE OF U.S. GENERATION (EIA projection) 2010: 45% 2035: 38% DUKE ENERGY 2006: 1.7% (2.6 TWh) 2011: 9.5% (13.6 TWh, (includes oil generation) NEXTERA 2006: 55% (78.2 TWh) 2011: 57.7% (99.2 TWh) TVA (includes oil/diesel generation) 2006: <1% (0.6 TWh) 2011: 5% (6.8 TWh) SOUTHERN 2006: 13% (26.1 TWh) 2011: 30% (55.8 TWh) AEP 2006: 6% (10.4 TWh) 2011: 11% (18.7 TWh) DOMINION 2006: 7% (7.0 TWh) 2011: 20% (19.8 TWh) GAS SHARE OF U.S. GENERATION (EIA projection) 2010: 24% 2035: 28% 10 www.powermag.com POWER | September 2012http://www.powermag.com