Rapid exhaustion of fossil fuels, concern about environmental issues, enforces renewable distributed generations (RDGs) in the existing power system network. Appropriate allocation of these sources in the distribution network needs proper planning. In this paper an efficacious method for optimal placement of solar DGs is presented. Proper probabilistic models are used for modelling the solar irradiance, and determine the exact output power from the photo voltaic (PV) array. Different seasons are considered for the analysis. The main objectives are power loss reduction, voltage profile enhancement. First the best locations for placement of PV arrays are identified using voltage stability factor (VSF) method. Flower pollination algorithm, a new meta heuristic technique is used for determining the optimal number of PV arrays placed at these identified locations. The proposed methodology is tested on IEEE 33 and 69 bus systems and compared with other methods for validation.