A method for management of electric power supply to a power grid node, the method comprises: - using a plurality of electrical energy storage devices as an electrical energy storage unit; - measuring in each electrical energy storage device, by means of at least one monitoring device, voltage, current and temperature values thereof; - acquiring, by means of a management unit in connection with the monitoring device, the values measured by the monitoring device and processing these values by performing, using a computer algorithm, at least a calculation of a degradation state of each electrical energy storage device based on the values acquired and measured, wherein the degradation state of each electrical energy storage device comprises the percentage of the capacity with respect to the nominal capacity and the number of cycles remaining until substitution; and - determining, by the management unit, if a power profile for performing at least one supply of electrical energy to the electrical power grid to satisfy a specific need of the power grid, or electrical service, may or may not be supplied, by at least one power electronics unit associated with the electrical energy storage unit or at least one of the electrical energy storage devices, characterized in that the method further comprises: - calculating a degradation state of the power electronics unit based on parameters calculated thereof, wherein said parameters comprise at least a number of hours of use and/or an indicative value of a reduction in their power; - processing the values measured by the monitoring device by performing a calculation of a state of function (SoF) of the electrical energy storage unit, wherein the state of function (SoF) is an index that indicates the capacity to provide the at least one electrical service, wherein the state of function (SoF) is calculated according to at least one result obtained from: the degradation state of the electrical energy storage devices, the degradation state of the power electronics unit, and the conditions and/or needs of the power grid for at least one electrical service; - supplying the power profile if the calculated state of function (SoF) is equal to or greater than a first pre-established threshold value. - using a plurality of electrical energy storage devices as an electrical energy storage unit; - measuring in each electrical energy storage device, by means of at least one monitoring device, voltage, current and temperature values thereof; - acquiring, by means of a management unit in connection with the monitoring device, the values measured by the monitoring device and processing these values by performing, using a computer algorithm, at least a calculation of a degradation state of each electrical energy storage device based on the values acquired and measured, wherein the degradation state of each electrical energy storage device comprises the percentage of the capacity with respect to the nominal capacity and the number of cycles remaining until substitution; and - determining, by the management unit, if a power profile for performing at least one supply of electrical energy to the electrical power grid to satisfy a specific need of the power grid, or electrical service, may or may not be supplied, by at least one power electronics unit associated with the electrical energy storage unit or at least one of the electrical energy storage devices, characterized in that the method further comprises: - calculating a degradation state of the power electronics unit based on parameters calculated thereof, wherein said parameters comprise at least a number of hours of use and/or an indicative value of a reduction in their power; - processing the values measured by the monitoring device by performing a calculation of a state of function (SoF) of the electrical energy storage unit, wherein the state of function (SoF) is an index that indicates the capacity to provide the at least one electrical service, wherein the state of function (SoF) is calculated according to at least one result obtained from: the degradation state of the electrical energy storage devices, the degradation state of the power electronics unit, and the conditions and/or needs of the power grid for at least one electrical service; - supplying the power profile if the calculated state of function (SoF) is equal to or greater than a first pre-established threshold value. - calculating a degradation state of the power electronics unit based on parameters calculated thereof, wherein said parameters comprise at least a number of hours of use and/or an indicative value of a reduction in their power; - processing the values measured by the monitoring device by performing a calculation of a state of function (SoF) of the electrical energy storage unit, wherein the state of function (SoF) is an index that indicates the capacity to provide the at least one electrical service, wherein the state of function (SoF) is calculated according to at least one result obtained from: the degradation state of the electrical energy storage devices, the degradation state of the power electronics unit, and the conditions and/or needs of the power grid for at least one electrical service; the degradation state of the electrical energy storage devices, the degradation state of the power electronics unit, and the conditions and/or needs of the power grid for at least one electrical service; - supplying the power profile if the calculated state of function (SoF) is equal to or greater than a first pre-established threshold value.