Which power plants for which application?
To provide a smooth, continuous supply of electricity, grid operators use a variety of power plants that can respond to demand changes in different time frames. There are three main categories as described below:
Baseload plants – These facilities run essentially all of the time. They often have cheap fuels and low operation costs and they can sometimes have long start up and shut down times. They often cannot change their power output quickly.
Intermediate/Load Following plants – These facilities can have their power output increased or decreased to match the electricity demands at the time.
Peaking plants – These facilities are used for only a short time each day and can respond very quickly (fastest of any power plants) to changes in demand. These plants are responsible for ensuring there are no black outs or brown outs during times of peak usage.
The graph below shows a typical electricity demand pattern for New Brunswick and the electricity generation facilities that are used to meet this demand. This is only an example, though, there are many ways to ensure reliability! (Thermal refers to facilities that boil water into steam to turn a turbine)