The textbook describes the basic theoretical foundations and practical tasks in the field of state policy of states to improve energy efficiency. The data concerning the basics of energy audit of thermal power facilities are presented. The methods of energy saving in the production and distribution of thermal and electric energy, as well as methods of using renewable energy sources and secondary energy resources are considered in detail. Information is given on energy saving in lighting systems, as well as a methodology for research on reducing electrical energy losses in the distribution network. Meets the requirements of the latest generation of federal state standards of higher education. It is intended for undergraduate and specialist students studying in the fields of 13.03.02 "Electric power engineering and electrical engineering", 12.03.01 "Instrument Engineering", 12.03.05 "Laser technology and laser technologies", 12.05.01 "Electronic and optoelectronic devices and special purpose systems".