You might think from current news coverage that most power is now generated by renewable energy and that natural gas-based generation is sailing off into the sunset. Nothing could be further from the truth.
The latest update from the U.S Energy Information Administration (EIA) shows natural gas holding firm as the single-largest source of energy used to generate electricity in the nation at 43% in 2023.
Natural gas-fired power plants also came second only to solar for U.S. generating capacity additions for the year. As Mark Twain might have said, the “ rumors of the death of natural gas-based power are greatly exaggerated.”
Nuclear energy moved up to second place in the U.S at 18%. Coal’s demise is highlighted by falling to third place and representing only 16% of the energy mix. Despite all the emphasis on renewable energy supply, wind (10%) and solar (4%) remain minor sources of U.S. energy.
Increasing domestic supply of natural gas, at relatively low prices, is one of the main reasons for the growth of natural gas-fired power plants, says EIA. The flexibility of natural gas-fired generation is supported by four power plant technologies: combined-cycle gas turbines, simple cycle gas turbines, steam turbines, and internal combustion engines.
Combined cycle plants, the largest segment of the natural gas-fired fleet, are primarily used to generate low-cost base load and intermediate load power over extended periods; the other three plant types are mainly used to meet peak demand.
In 2023, the electric power sector added 9.274 GW of new natural gas-fired turbine capacity to the U.S power grid; with combined cycles supplying 7.376 GW and internal combustion engines only 142 MW.
Combined cycle plants offer the highest efficiency – over 64% for today’s advanced technology units. As shown by EIA data for 2023, CC plants typically have a capacity utilization factor of over 50% with an average fleet-wide capacity factor of 56% and highest factor of approximately 66%.
Over the last 10 years, between 2014 and 2023, the most efficient plants had heat rates of less than 7,000 Btu/kWh) compared to 7,500 Btu/kWh for older facilities. Those built before 1999 can exceed 10,000 Btu/kWh — at least one-third higher than today’s plants.
For a useful download of current plant pricing, with examples of Simple Cycle and Combined Cycle plant configurations, see the following: Estimating Capital Costs of Utility-Scale Gas Turbine Power Generation.
