Globally, cities are experiencing an unprecedented socio-economic, demographic, and environmental transition that brings with it negative environmental externalities, such as climate change and environmental degradation. Smart energy city (SEC) has emerged as the latest urban development strategy in European countries. It can vastly accelerate cities' decarbonisation efforts, which can have several co-benefits. Capitalising on advances in information and communication technologies (ICT), various SEC projects have been initiated and seek to integrate ICT into the urban system. Although there are a significant number of SEC demonstration projects, there has been a scant examination of the performance and overall effect of these projects in addressing core sustainability endogenous principles. This research provides an in-depth analysis of the components of the SEC projects, highlighting the strengths and shortcomings. By highlighting the "Smart INitiative of cities Fully cOmmitted to iNvest In Advanced large-scale energy solutions" (SINFONIA) project in Bolzano, we aimed to determine the extent to which the current practical processes are achieved in reality. Our methodology entailed a structured literature review of the different components of SEC projects, followed by a content analysis based on the 5W1H (why, what, who, how, where, and when) conceptual framework. The data collection methods adopted included a review of specific open-access sources and project deliverables of each of the selected SEC projects, personal observation of the case study city, and interviews with SEC project experts. We analysed the SEC projects components against fundamental sustainability principles of integration, implementation, equity (intra-generational, procedural, and inter-generational), and scalability and replicability to assess their potential for creating sustainable urban settlements. The study found that the critical components of SEC projects are strategically aligned with sustainability dimensions. However, although ICT integration in urban planning and development provides the core determinants of the components, stakeholder engagement and dynamic business models are critical for successful implementation. Furthermore, through scalability and replicability of SEC projects, diversification of sustainability principles can be actualised throughout the entire city and in other geographical regions to ensure long-term intra-generational and inter-generational equity.