The average utilization rate (or capacity factor) for the entire U.S. fleet of combined-cycle natural gas turbine (CCGT) electric power plants has risen as the operating efficiency of new CCGT units has improved. The CCGT capacity factor rose from 40% in 2008 to 57% in 2022. Increased efficiency improved the competitiveness of newer CCGT units against other fuel sources and older CCGT units.