A computation system for calculating the electrical energy (E i) of an alternating current flowing in at least one secondary electrical conductor (42A, 44A, 46A,..., 42N, 44N, 46N), the secondary conductor (42A,..., 46N) being electrically connected to a primary electrical conductor (34; 36; 38), the primary conductor (34, 36, 38) and each secondary conductor (42A,..., 46N) having substantially the same alternating voltage (U1, U2, U3), the alternating current having at least one phase. this computation system including: - a first device comprising a radio transmitter, a measuring member for measuring the voltage of the primary conductor (34, 36, 38), first sampling means for sampling the value of the measured voltage (U1, U2, U3), message transmitting means for transmitting, following a period of transmission (P transmission) of a first message, the transmission period (P transmission) corresponding to a multiple of voltage periods (P voltage), the voltage period (P voltage) being equal to the inverse of the frequency of the alternating voltage (U1, U2, U3), and voltage determination means for determining a set of at least one variable value representative of the measured voltage, said data set being determined based on the value of the voltage measured during a given transmission period (P transmission), with the first message containing said data set; - at least one second device (62A,..., 62N) comprising a current intensity sensor (76A,..., 76N) for determining the intensity (I1A,..., I3N) of the current flowing in the corresponding secondary conductor (42A,..., 46N), second sampling means (119A,..., 119N) for sampling the value of the measured intensity; (I1A,..., I3N); and - at least one computing member (123A,..., 123N) for calculating the electrical energy (E i) for each phase of said current flowing in the corresponding secondary conductor (42A,..., 46N), the computing member being connected to at least one corresponding second device (62A,..., 62N) and including a radio receiver (80A,..., 80N) and message reception means for receiving the first message, each computing member (123A,..., 123N) being configured for calculating a value for the electrical energy (E i) during the given transmission period (P transmission) on the basis of said data set contained in the first message and samples of the intensity associated with the given transmission period (P transmission), characterised in that the voltage determination means are configured for determining said data set based further on a correction coefficient (σ i) associated with the given transmission period (P transmission), the correction coefficient (σ) being, for each phase, a function of a value representative of the voltage (U i) only for each corresponding voltage period (P voltage) where said representative value is greater than a predetermined threshold value (ε), the value representative of the voltage being the value of the modulus of the fundamental of a Fourier series decomposition of the voltage (∥ U i,1, k ∥). - a first device comprising a radio transmitter, a measuring member for measuring the voltage of the primary conductor (34, 36, 38), first sampling means for sampling the value of the measured voltage (U1, U2, U3), message transmitting means for transmitting, following a period of transmission (P transmission) of a first message, the transmission period (P transmission) corresponding to a multiple of voltage periods (P voltage), the voltage period (P voltage) being equal to the inverse of the frequency of the alternating voltage (U1, U2, U3), and voltage determination means for determining a set of at least one variable value representative of the measured voltage, said data set being determined based on the value of the voltage measured during a given transmission period (P transmission), with the first message containing said data set; - at least one second device (62A,..., 62N) comprising a current intensity sensor (76A,..., 76N) for determining the intensity (I1A,..., I3N) of the current flowing in the corresponding secondary conductor (42A,..., 46N), second sampling means (119A,..., 119N) for sampling the value of the measured intensity; (I1A,..., I3N); and - at least one computing member (123A,..., 123N) for calculating the electrical energy (E i) for each phase of said current flowing in the corresponding secondary conductor (42A,..., 46N), the computing member being connected to at least one corresponding second device (62A,..., 62N) and including a radio receiver (80A,..., 80N) and message reception means for receiving the first message, each computing member (123A,..., 123N) being configured for calculating a value for the electrical energy (E i) during the given transmission period (P transmission) on the basis of said data set contained in the first message and samples of the intensity associated with the given transmission period (P transmission),