How do steam turbines drive generators in fossil-fuel power plants?

In fossil-fuel power plants, steam turbines serve as the prime mover that converts thermal energy into the mechanical energy required to drive an electric generator.1

The process functions as follows:

• Steam Generation: Fossil fuels are burned to heat water, creating high-pressure, high-temperature steam in a steam generator.12
• Mechanical Conversion: This steam is directed into the turbine, where it impinges against a series of vanes or blades attached to a rotor. The force exerted by the steam turns the rotor, which is mounted on a shaft.3
• Driving the Generator: The rotating shaft is connected to an electric generator. As the turbine spins the shaft, the generator converts this mechanical rotational energy into electricity.1
• Maintaining Speed: To ensure a stable power supply, the turbine must maintain a constant rotational speed (such as 3,600 or 1,800 revolutions per minute for 60-cycle systems). If the electrical load changes, the system adjusts the steam mass flow rate by opening or closing inlet valves to keep the turbine speed consistent.4