  Usually the study of energy-transfer in the light harvesting complex is
limited by a single-exciton motion along the antenna. Starting from the
many-body Schr\"odinger equation, we derived Lindblad-type Master equations
describing the cyclic exciton-electron dynamics of the light harvesting
complex, originated from charge reduction of a donor. These equations,
resembling the Master equations for the electric current in mesoscopic systems,
go beyond the single-exciton description by accounting for the multi-exciton
states accumulated in the antenna, as well as the charge-separation,
fluorescence and initial photo-absorption. Although these effects take place on
very different time-scales, we demonstrate that their inclusion is necessary
for a consistent description of the exciton dynamics. We applied our results to
evaluate the energy (exciton) current and for the fluorescent current depending
on the light-intensity.
