  We study the transfer of energy through a network of coupled oscillators,
which represents a minimalmicroscopic power grid connecting multiple active
quantum machines. We evaluate the resulting energy currentsin the macroscopic,
thermal, and quantum regime and describe how transport is affected by the
competitionbetween coherent and incoherent processes and nonlinear saturation
effects. Specifically, we show that thetransfer of energy through such networks
is strongly influenced by a nonequilibrium phase transition between
anoise-dominated and a coherent transport regime. This transition is associated
with the formation and breakingof spatial symmetries and is identified as a
generic feature of active networks. Therefore, these findings haveimportant
practical consequences for the distribution of energy over coherent microwave,
optical, or phononicchannels, in particular close to or at the quantum limit
