Monte-Carlo simulations calculate the photon collection of fluorescent collectors in photovoltaic systems. We focus on two collector geometries: solar cells mounted at the collector sides, and solar cells covering the back of the collector. A mirror covers the bare back sides of both systems. On top lies optionally a photonic structure, which acts as an energy selective filter. Ideal systems in their radiative limits are compared to systems where loss mechanisms in the dye, at the mirror, or the filter are included. The examination of loss mechanisms in photovoltaic systems with fluorescent collectors enables us to estimate quality limitations of the used materials and components.