Peaking power plant
A peaking power plant (or peaker) is a power station that only runs during high demands of electricity throughout the day during peak hours. Because of that, the price of electricity it generates is generally higher than the electricity generated by base load power plant, which operates continuously throughout the year.
Kearny Generating Station, a former coal-fired base load power plant, now a gas-fired peaker, on the Hackensack River in New Jersey
Peaking power plant for Kids. Kiddle Encyclopedia.