According to the U.S. Energy Information Administration (EIA) website article published on March 1, 2023, the average monthly capacity factor for simple-cycle, natural gas turbine (SCGT) power plants in the United States has grown annually since 2020. Average capacity factors surpassed 20% for two consecutive summer months in 2022—the first time on record—to meet peak electricity demand, based on data from Electric Power Monthly.
SCGT power plants typically operate year-round but are most active during the summer when electricity demand reaches its peak and varies the most. For the past five summers, SCGT power plants operated at a 17% average capacity factor from June through August. The average monthly capacity factor during the rest of the year fell to around 10% as a result of less electricity demand and more consistent wind-powered electricity generation.
SCGT power plants burn natural gas in a single turbine to produce electricity. They are the second-largest source of U.S. natural gas-fired power generation, after combined-cycle natural gas turbine (CCGT) power plants. SCGT power plants are less efficient and require more fuel per unit of output compared with CCGT power plants because CCGT plants capture excess heat from the combustion process and deliver that heat to a steam turbine to produce additional electricity.
Electric grid operators can use SCGT power plants to respond quickly to fluctuating demand for electricity. The need for more electric grid support during the day is growing as the share of electricity generation from intermittent renewables grows. SCGT power plants can meet demand if there is a lull in wind or solar output. SCGT power plants can best provide grid support because they can produce electricity quickly to immediately fill gaps in electricity output on the grid, and they can ramp down just as quickly. Other natural gas-fired electricity generators, such as CCGT or steam boiler plants, can take two to three times longer than SCGT power plants to start and ramp up to full load.
An estimated 2,121 megawatts (MW) of new SCGT capacity entered service in 2021, and EIA expects another 1,196 MW entered service in 2022. Texas accounted for nearly half of the 2021 and 2022 capacity additions because of its need for more fast-starting generating capacity. Texas is experiencing both rising power demand and greater variability in supply.
Total U.S. SCGT operating capacity was 132,274 MW in December 2022, based on the EIA latest Electric Power Monthly.
