In fixed PV installations, the azimuth and tilt of the panels are normally chosen with the objective of maximizing the plant capacity factor. In this paper, we show that when considering distribution networks with densely clustered PV plants, there exist installation criteria other than the conventional that achieves larger amount of PV generated electricity without violating distribution network constraints. In particular, we formulate an optimization problem to determine the siting, sizing, azimuth and tilt of the panels in order to maximize the PV production over a year while respecting the power grid voltage and line ampacity constraints. As a case study, we consider a Swiss distribution network and synthetic irradiance data for the considered area using a clear-sky model. We use the case study to compare the conventional way of installing PV panels vs the proposed method and show that the latter can nearly achieve a 6% increase in the generated PV electricity.