Thermal Efficiency of Gas-Fired Generation in California: 2016 Update

Senate Bill 1389 (Bowen and Sher, Chapter 568, Statutes of 2002) directed the California Energy Commission adopt an Integrated Energy Policy Report (IEPR) every two years. This staff paper supports the IEPR technical analyses by describing general trends in the average thermal efficiency of natural gas-fired generation in California from 2001 through 2015. Over this 15-year period, California’s systemwide thermal efficiency for natural gas power plants improved by 23 percent. The successful development of new combined-cycle plants continues to be the primary reason for the improvement. The overall thermal efficiency of the state’s current portfolio of noncogeneration natural gas power plants has resulted in 27 percent more energy being generated using almost 2 percent less natural gas compared to 15 years ago.