The electric power industry is the branch of power engineering that includes the generation and transmission of electric energy. The key role of this branch is explained by the advantages of electric energy over other kinds of energy – advantages such as the relative easiness of its long-distance transmission, distribution between consumers, and conversion to other kinds of energy (mechanical, thermal, chemical, optical, and so on). A distinctive feature of electric energy is that its generation and consumption are relatively simultaneous because the electric current propagates through the network with a speed close to the speed of light. In the foreseeable future, it will remain a principal kind of energy, providing engineering progress in all spheres of the lives of people. Electricity is generated by power plants through the use of energy carriers or the conversion of other kinds of energy. For example, heat in thermal power stations transforms water into steam, forcing the rotors of steam turbines. These turbines are connected to the rotors of generators, in which the mechanical energy of the turbines is transformed into electrical energy. Solar power stations transform the energy of sun rays into electrical or thermal energy, for example.