The paper describes a proposed simulation-based methodology to spatially integrate plants powered by Renewable Energy Sources, based on the current regulatory framework regarding suitable areas. The achievement of European decarbonization targets requires a rapid and spatially coordinated deployment of Renewable Energy Sources, strongly conditioned by territorial constraints, authorization processes, and grid‑integration needs. In this context, recent European and national regulatory frameworks promote the identification of “suitable areas” and acceleration zones in order to streamline permitting procedures and reduce development bottlenecks. However, the large volume of connection requests submitted to Transmission System Operators often exceeds policy targets and it is not fully aligned with landscape characteristics and permitting features of the areas, posing significant challenges for efficient grid planning. This paper presents a GIS‑based simulation methodology aimed at quantifying the potential RES capacity eligible for authorization within a given territory by explicitly integrating spatial compatibility and authorization propensity. The proposed approach introduces a synthetic indicator – referred to as the Renewable Energy Density Index – obtained through the integration of four territorial dimensions: topography, environmental and landscape constraints, land use, and attractiveness for RES installations. Authorization likelihood is modelled through technology‑specific probability matrices and combined via a multiplicative overlay, enabling the computation of an aggregated Renewable Energy Spatial Capacity Allowable over user‑defined spatial domains. The methodology is applied to a case study, with a focus on photovoltaic technologies, demonstrating its capability to capture heterogeneous territorial conditions and to provide capacity estimates consistent with existing installations while identifying residual deployment potential. The results highlight the relevance of spatial resolution and authorization drivers in assessing renewable potential and confirm the suitability of the framework as a decision‑support tool for territorial energy planning and transmission system development under the current regulatory framework.