The novelty of this study is to present the combined operational strategy of wind-solar- thermal (WST) system with pumped hydro storage (PHS) facility while mitigating the intermittency of wind and solar power. The design problem has been formulated in an environmental optimal power flow (EOPF) framework while addressing issues like emission minimization, operating cost reduction and voltage security maximization. The major challenge in the present hybrid power system (HPS) operating scenario is the evaluation of optimal scheduling and dispatching of electrical power without any violation of real-time operational constraints. Voltage secure and cost-effective power system operations with the integration of hybrid renewable power sources become extremely challenging in achieving reliable and environmental friendly solutions. The optimal operational paradigm for various hybrid configurations is evaluated using the particle swarm optimization (PSO) technique. This study performs a comparative performance analysis among three different hybrid configurations are (1) WST; (2) wind-hydro-thermal (WHT); and (3) WST-PHS in fulfilment of multiple operational objectives. Results show that the optimized schedule of WST-PHS configuration presents a remarkable savings (i.e., 3.835×105 US$/y to 8.307×105 US$/y) in the system operating cost, reduction of emission from 9.636 Ton/y to 20.148 Ton/y and voltage security enhancement by 1.51%–3.57% compared to other HPS. The trade-off curve among conflicting objectives is proposed using bi-objective optimization and fuzzy membership functions. The superior results obtained with WST-PHS configuration are validated in the IEEE-30 bus benchmark power system.