In a modern power plant, how is heat energy primarily used to generate electricity?

In a modern power plant, heat energy is primarily utilized to boil water, generating steam that drives a turbine. This process is fundamental to many types of power plants, particularly thermal power plants, which include coal, natural gas, and nuclear facilities.

When heat is applied to water, it transforms into steam, which expands and exerts pressure as it moves through pipes. This high-pressure steam is directed towards turbine blades, causing them to rotate. The mechanical energy generated from this turbine rotation is then converted into electrical energy through a generator connected to the turbine.

This method is efficient and has been the cornerstone of electricity generation for many decades. It highlights the importance of converting thermal energy into mechanical energy efficiently, allowing for large-scale electricity production to meet societal demands.

The other options do not accurately describe the primary process of electricity generation in power plants. For example, directly heating oil to power turbines is not the standard method utilized in modern facilities, while reducing friction or creating a vacuum are not the primary mechanisms for electricity generation.