In this paper, an integrative approach is proposed to link integrated assessment modelling results with a novel portfolio analysis framework for robust modelling. The approach is applied for identifying optimal technological portfolios for power generation in the EU towards climate change mitigation, in a timescale until 2050. The technologies considered include photovoltaics, concentrated solar power, wind, nuclear, biomass and carbon capture and storage. The proposed approach links data from the Global Change Assessment Model (GCAM), namely subsidy curves for emissions reduction and energy security for the six power generation technologies until 2050, with other decision support methods, in the aim of managing the inherent uncertainty and assessing the robustness of the optimal portfolios. The modelling results are then integrated in a bi-objective evaluation model for portfolio analysis. The model treats uncertainty stochastically, using a Monte Carlo simulation algorithm and the Iterative Trichotomic Approach, and defines specific portfolios of electricity generation technologies as the most robust. The results are presented and discussed, mainly in terms of highlighting the robustness of the Pareto optimal solutions, which is essential for policymakers to be more confident when selecting technology portfolios that feature a high degree of uncertainty, regarding their vulnerability to different future developments. By aggregating the results to one robust technological portfolio, the proposed approach features the potential to subsequently be linked to a deterministic model.