How does a turbine generate electricity?
When you think of a “turbine,” you probably think of the huge spinning blades that are used for modern wind power. But a turbine can be any type of machine with spinning blades. In the past, people often used windmills or waterwheels (Figure 1) as turbines to turn mechanical devices, such as mills for grinding grain into flour.
Figure 1: Windmills and waterwheels have long been used to produce mechanical energy. The windmill shown here is in Utrecht, Netherlands and the waterwheel is at Anderson Mill in Texas, USA. Credit: Creative Commons.
Today, nearly all power plants produce electricity by converting the energy of a spinning turbine (its kinetic energy) into electrical energy. Video 1 shows how a wind turbine is used to generate electricity. Hydroelectric power works similarly, except it is flowing water instead of wind that spins the turbines.
Video 1 - This short video shows how a modern wind turbine generates electricity. Credit: Andy Dunau.
But what about other types of electrical power plants, such as those that burn fossil fuels or use nuclear energy? These power plants also use spinning turbines to generate electricity, but instead of being spun by wind or water, these turbines are usually spun by steam or other hot gases created by heat. In a fossil fuel power plant, that heat comes from combustion (burning), usually of coal or natural gas (Video 2). In a nuclear power plant, the heat comes from nuclear fission or fusion (as discussed later in this section).
Video 2 - This Smithsonian video uses the dismantling of an old power plant to explain the basic operation of a steam-driven turbine. For greater detail, you can find many other videos online, but this one is a good starting point.