Territorial energy planning increasingly requires analytical tools capable of supporting transparent, scenario-based decision-making across multiple spatial and temporal scales. Although large volumes of energy data are available, public administrations often lack interfaces that allow such data to be explored, compared, and interpreted in a structured and policy-relevant manner. This limitation is particularly evident in the context of European energy and climate frameworks, such as National Energy and Climate Plans (NECPs) and Sustainable Energy and Climate Action Plans (SECAPs), which demand integrated assessment of energy performance indicators. This thesis presents the design and implementation of a multi-scale decision support interface for scenario-based territorial energy analysis.