Systems and methods disclosed herein allow efficient reallocation of PoE when a PSU for a PSE fails. A PSE initially receives power from at least two PSUs and provides PoE to at least two PDs. When power from one of the PSUs becomes unavailable, the PSE refrains from providing PoE to a first PD, but continues providing PoE to a second PD. The PSE sends a communication to the second PD requesting that the second PD allow the PSE to allocate less power to the second. If the second PD confirms that allocating less power to the second PD is acceptable, the PSE reduces the amount of power allocated to the second PD and allocates at least some of the power saved by the reduction to the first PD.