The two-volume set LNCS 16393 + 16394 constitutes the proceedings of the 5th Energy Informatics Academy Conference, EI.A 2025, held in Kuala Lumpur, Malaysia, during December 2025. The 39 full papers and 14 short papers included in these volumes were carefully reviewed and selected from 115 submissions. They are organized in the following topical sections: Part I: Building Energy Forecasting & Modeling; Digital Infrastructure & Interoperability for Energy Systems; Local Energy Communities, Microgrids & Distributed Energy Resources; Data Centres, AI & Sustainable Energy Footprints; and  Context-Aware Digital Innovations for Energy Transitions.  Part II: Cybersecurity & Communications in Digital Energy Systems; Energy Storage & Circular Resource Management; Methods, Governance & Responsible Digitalization in Energy; Thermal Storage and Flexibility in Buildings; and Digital Innovation for Resilient Low-Carbon Industry.