The overall
system comprises an
electrical energy storage device (6) as a subsystem and other subsystems of at least one facility (1) of the
metal industry. In order to transmit electrical energy, the subsystems (1, 4, 6) are directly or indirectly connected to one another and to the electrical power
supply network (2). The control device (7) can know a current state (Z1, Z4, Z6) of the subsystem (1, 4, 6), and a planned first amount of acquisition (E2) of electrical energy from the power
supply network (2) with respect to a first
time range (T1) and a planned first operating mode (B1, B4) of the other subsystem (1, 4). The control device (7) determines an expected final state (Z6 ') of the
electrical energy storage device (6) ending with respect to the first time period (T1) on the basis of the planned first acquisition quantity (E2) and the planned first operating mode (B1, B4). The control device (7) specifies a planned second acquisition quantity (E2 ') of the electrical energy taking into account an expected final state (Z6') of the
electrical energy storage device (6) and a planned second operating mode (B1 ', B4') of the other subsystems (1, 4) known to the control device (7) and for a second
time range (T2) directly following the first
time range (T1). The control device (7) operates the other subsystems (1, 4) during the two time ranges (T1, T2) on the basis of a planned first operating mode and a planned second operating mode (B1, B4, B1 ', B4'), and obtains electrical energy from the power
supply network (2) as a function of a planned first detection quantity and a specified second detection quantity (E2, E2 '). In order to specify a planned second acquisition quantity (E2 ') of electrical energy, the control device (7) determines a demand (E1', E4 ') of electrical energy for operation of the other subsystem (1, 4) during a second time range (T2) on the basis of a planned second operating mode (B1', B4 '), and determines the demand (E1', E4 ') of electrical energy for operation of the other subsystem (1, 4) during the second time range (T2), taking into account the demand (E1', E4 ') of electrical energy for operation of the other subsystem (1, 4) during the second time range (T2). E4 ') and an expected final state (Z6') of the electrical
energy storage device (6) and a target state (Z6 *) of the electrical
energy storage device (6), which is expected at the end of the second time range (T2), a planned second acquisition amount (E2 ') of electrical energy from the electrical supply network (2) during the second time range (T2) is defined.