The main problem addressed by this report is the lack of data and of documented data flows supporting the design and implementation of a regional energy strategy. The scarcity of existing documentation/best practices focusing on the role that geospatial data and technologies - particularly INSPIRE data - can play in the context of a regional energy strategy is also tackled. The report provides insights on three main aspects of the problem: - It provides an overview of the territorial competences in the field of energy in the Member States (national vs regional), as well as a summary of the public data sources potentially relevant to a regional energy strategy; - It presents a deep analysis of a real case of regional energy strategy, consisting in the Regional Energy Efficiency Strategy of Castilla y León (EEE-CyL-2020) in Spain; - Based on the previous analyses, it explores the potential of harmonised and interoperable geospatial data, including from the INSPIRE Directive, to support the regional energy policy cycle in the European Union. A key message is that creating or renewing a regional energy strategy could greatly benefit from location interoperability. Location interoperability can facilitate data sharing for better cross-sector modelling, considering the potential interlinkages between the different strategic sectors in the region and the implemented measures. This cross-sectoral modelling would allow capturing how changes occurring in a specific sector may impact other sectors. This study has been executed in the frame of the Energy & Location Applications of the ELISE (European Location Interoperability Solutions for e-Government) action of the ISA2 (Interoperability solutions for public administrations, businesses and citizens) Programme.