The invention relates to a monitoring device for monitoring an energy parameter in a distribution station, wherein the monitoring device is designed to be attached to a voltage conductor in the distribution station, comprising: a device identifier for uniquely identifying the monitoring device, which device identifier is designed to be read out from immediate spatial proximity; a measurement unit for measuring an electrical current and/or a voltage of an alternating current flowing through the voltage conductor; an evaluation unit for determining the energy parameter based on the measured electrical current and/or voltage; and a communication unit for receiving a request from a readout device and for transmitting the energy parameter to the readout device if the received request comprises access information that is based on the device identifier. The invention further relates to a readout device as well as a monitoring system, a method for monitoring an energy parameter as well as a method for reading out a monitoring device.