Relative losses of electric power during transmission and distribution in electric networks are considered in the paper. The components of commercial losses of electric power and their structure are given. From the presented data of technical and commercial losses of some areas of power networks of «ПАО «MRSK of Volga» – «Chuvashenergo» following the results of one month 2020, calculated with the use of «RAP-Standard» program according to the statements of power sales, it follows that total losses are from 11,6 to 17%. By the example of two sections of power grid companies of PAO MRSK of Volga – Chuvashenergo and the Republic of Tatarstan a comparison of commercial losses before and after the installation of intelligent power metering devices was made. It is estimated that the difference in electric power losses after installation of «smart» electric meters at both sites of the above mentioned enterprises was significantly reduced: at one site from 14 to 5.1%, and at the other – from 17.3 to 9.4%. It is shown that specific losses after installation of intellectual metering devices in Verkhneuslonsky district settlement of JSC «Grid Company» Buinskie Power Networks per one metering device decreased by 19.7%.