This paper presents an approach for optimal placement and sizing of dispatchable and non-dispatchable renewable distributed generators (DG) units in a radial distribution network. In this work, wind and solar energy based DG units are considered as non-dispatchable DG, while biomass energy based DG units are considered as dispatchable. The formulated multi-objective problem comprises of technical performance indices for real power loss, maximum branch current capacity, voltage deviation, environment impact reduction index; and economic index. The appropriate weighting factors for different indices has been decided by Analytic Hierarchy Process (AHP). To solve the developed formulation, Particle Swarm Optimization (PSO) based approach has been used and applied on a 51-bus distribution networks. Also, in order to validate the use of AHP, the prioritization to different indices leads to formation of four scenarios and results are obtained in terms of the technical, economic and environmental parameters. The results obtained by the proposed method have been compared with other multi-objective problems considering different weighting factors to the indices and emerged as a simple and efficient approach. (C) 2017 Published by Elsevier Ltd.