Scientometric Review of the 3D Energy Transition: Decarbonization, Digitalization, and Decentralization in Energy Systems

This article presents a scientometric review that quantifies the contribution of the three-dimensional energy transition, that is decarbonization, digitalization, and decentralization, to the research field of energy systems over the period 2001 to 2025. Records were retrieved from Scopus using a two-level query that first captured the general energy systems domain and then stratified it into the three components. Standardized preprocessing, cleaning, and keyword harmonization were applied. Descriptive indicators trace publication growth and portfolio shares, and network mapping with VOSviewer visualizes keyword co-occurrence and topic evolution. Results show substantial expansion of the field and a shift of the research mainstream toward the 3D topics. Decarbonization accounts for approximately half of the corpus, digitalization for about one fifth, and decentralization for a smaller but persistent share. Integration between energy transition components increases over time, with the strongest coupling along the decarbonization and digitalization axes, and a compact but growing 3D core emerges. Topic maps indicate an early policy and renewables nucleus, followed by acceleration in storage, hydrogen, power electronics and control, data-driven operations, cyber security, and market mechanisms for local flexibility.