What does fission refer to in the context of energy generation?

Fission refers specifically to a nuclear reaction that involves the splitting of atomic nuclei to release a significant amount of energy. In energy generation, particularly in nuclear power plants, fission is the process that occurs in nuclear reactors where heavy nuclei, such as uranium or plutonium, are split into smaller fragments, releasing energy along with neutrons. This process is harnessed to produce heat, which is then used to generate steam that drives turbines for electricity production.

The other options do not accurately represent the concept of fission. For instance, thermal energy creation may be a byproduct of various energy generation methods, but it does not specifically define fission. Wind energy production and solar panel efficiency pertain to renewable energy sources that rely on different physical principles and mechanisms than those involved in nuclear fission. Thus, while all these terms relate to energy generation, only the nuclear reaction directly describes the process of fission.