Energy transition becomes implementable when decisions on renewable energy development are consistent with spatial realities and territorial constraints and their implications for the energy system as a whole are evaluated. Despite the rapid expansion of GIS-based renewable energy potential assessment and energy system modeling studies, the integration of these two research streams has not yet been coherently explained. This study comparatively examines the evolution patterns, collaboration structures, and conceptual pathways of these fields and identifies points where spatial analysis can be linked to system-level planning. Bibliographic data from Scopus-indexed articles published during 2011–2026 were extracted into two independent datasets and analyzed using VOSviewer and Bibliometrix. The first dataset included 8,277 documents and 250,254 citations on renewable energy siting and potential assessment, while the second comprised 1,536 documents and 62,552 citations on energy system modeling and planning. In the first field, GIS, site selection, multi-criteria decision-making, solar and wind energy, sustainability, and land-use constraints form the network core; in the second, energy transition, decarbonization, scenario analysis, storage, smart grids, and energy communities are prominent. Comparative analysis revealed that the fundamental gap in the literature is the lack of a clear data flow from “spatially developable capacity” to an “implementable energy system scenario.” Accordingly, this study proposes an interpretive framework for translating GIS outputs and suitability assessments into energy model inputs and establishing reciprocal feedback from system-level results to spatial priorities.