The invention relates to a power providing device (2) for providing power to a plurality of power receiving devices (31), a power distribution system including such power providing device (2), a method for providing power to a plurality of power receiving devices (31) and a corresponding computer program. During standby the power providing device (2) is beneficially supplied with power coming from a power source (1) dedicated or adjusted for the low energy consumption, e.g. a uplink port (23) or a shared power bus. The current drawn from such power source (1) (or the power provided to the downlink power receiving devices (31)) is measured and, for example, the derivative is used in order detecting a current increase just when it starts. This information may be used such the main power supply (29) gets started in order to be available for more power demand than available through the hierarchical powering coming from the standby power source (1).