Advances in Integrated Energy–Water–Environment Systems and Energy Storage Systems

The energy transition increasingly requires holistic approaches that integrate electricity, heating and cooling, water management, industrial processes, transport, and environmental considerations within coherent system frameworks. Such integration is essential for achieving deep decarbonisation while maintaining reliability, affordability, and resource efficiency across diverse regional and sectoral contexts. This Special Issue of Energy Engineering presents selected contributions from the 2024 Conferences on Sustainable Development of Energy, Water and Environment Systems (SDEWES), reflecting recent advances in modelling, system integration, and technology deployment. The included papers address a broad spectrum of challenges relevant to integrated energy–water–environment systems. These include building-sector decarbonisation through hybrid heat pump configurations, geothermal revitalisation of existing oil and gas wells via deep borehole heat exchangers, and techno-economic comparisons of electrochemical batteries and supercapacitors for island energy systems. Further contributions investigate decentralised micro-hydropower solutions tailored to Amazonian conditions, advanced modelling of seepage characteristics in deep tight reservoirs accounting for creep effects, and multi-physical thermal modelling of lithium iron phosphate batteries for residential applications. In addition, hydrogen storage-supported energy system planning using detailed regional housing datasets and retrofit solutions for load balancing in legacy drilling-rig mud pump drives are explored. Collectively, the papers demonstrate how component-level innovation, data-driven planning, and system-level integration can jointly support flexible, resilient, and sustainable energy transitions. By covering diverse applications and geographical contexts, this Special Issue highlights the breadth of the SDEWES research community and provides insights that are relevant for researchers, system planners, and decision-makers working toward integrated energy–water–environment systems.