Peakers

Peakers are power plants that operate primarily to meet short-term spikes in electricity demand or to provide fast‑response capacity to the grid. They are designed to start quickly and ramp output rapidly, allowing them to relieve congestion, stabilize frequency, and back up intermittent renewable generation. Because they run mainly during high-demand periods or when other units are unavailable, they typically have higher operating costs and lower thermal efficiency than baseload or mid-merit plants.

Common technologies for peaking duty include simple-cycle natural gas combustion turbines, dual-fuel turbines, diesel engines, and, in some systems, hydroelectric peaking plants with rapid gate operations. Some plants can start within minutes; others may take longer but still offer faster response than coal-fired units. Peakers may participate in capacity markets and provide ancillary services such as frequency regulation, spinning reserve, or voltage support.

Economics of peakers reflect their role: they are most economical when used sparingly or only during peak periods, while storage, demand response, and more flexible generation displace part of the peaking load over time. With higher penetrations of wind and solar, peakers often shift toward providing rapid ramping capacity and backup for variable output, while some facilities are retired or repurposed.

In other contexts, the term peaker is unusual for audio equipment; the proper term for sound-reproducing devices is speaker.