The selection of the location of a biomass plant is a critical concern because biomass feedstocks are geographically and spatially dispersed. Geographic Information System-Multi-Criteria Decision Analysis (GIS-MCDA) techniques are powerful methods that have been applied to various disciplines using suitable criteria. These methods can be used to solve power planning problems, such as determining the optimal locations of biomass plants in the context of renewable energy. In response to the promotion of renewable energy in European strategy, Extremadura (Spain) is boosting energy generation from biomass as an alternative to traditional generation to protect the environment. This study presents a combined application of GIS-MCDA and the Fuzzy-DEcision-MAking Trial and Evaluation Laboratory (F-DEMATEL) technique to identify suitable and favorable sites for biomass facilities in terms of long-term sustainability. The main criteria established in this approach are outlined, evaluated, weighted and allocated to three criteria groups: environmental, geophysical and socio-economic groups. In the F-DEMATEL participatory method, constraints and their weight coefficients, with regard to their influence, are calculated. The most suitable locations are obtained after applying the Weighted Linear Combination (WLC) method. In the final stage of the decision-making problem, a sensitivity analysis of the criteria set is conducted, and the weights are determined for four implementation strategies. The model is applied in a case study of Extremadura where forest and agriculture are the typical land uses. The results of the F-DEMATEL/GIS-MCDA analysis suggest that the optimal sites for the locations of biomass plants are situated near forests and in zones with low transport costs, which comprise only 9.247% (Sh) of the total study area. Currently, five plants are installed in this area; however, they are not located in the most suitable areas (Sh). The most influential criteria of the model are the vegetation cover, agricultural area, transport cost and potential demand criteria. This methodology can be used in other studies to verify suitable locations for biomass plants in areas with similar geographical and spatial characteristics and available spatial data. Additionally, the proposed method of renewable energy policy planning can be applied to decision-making problems in the private sector and at various government levels. Display omitted •An integrated model for determining the locations of sustainable biomass plants is developed.•The operational method considers energy and land use issues based on spatial assessment.•The five biomass plants in the case study area are not located in the most suitable areas.•A sensitivity analysis of the modified weight coefficients of criteria demonstrates the high stability of the model.•The optimal locations for biomass plants are near forested areas with low transport costs.