Why are gas turbines useful for meeting peak electricity demand?

Gas turbines are highly effective for meeting peak electricity demand primarily due to their rapid start-up capabilities. Unlike steam units, which require many hours to begin operation, a gas-turbine engine can be placed on-line within minutes.1

This responsiveness makes them ideal for running intermittently during short durations of high power demand on an electric system. While gas turbines generally have lower inherent efficiency compared to steam turbines, they offer lower initial costs for moderately sized units. For peak-load applications, these lower initial costs are a more significant consideration than fuel charges. Additionally, gas turbines require less space than alternative power generation technologies, further facilitating their use in medium-sized peak load plants.1