Energy use in cities has attracted signi cant research in recent years. However such a broad topic inevitably results in number of alternative interpretations of the problem domain and the modelling tools used in its study. This paper seeks to pull together these strands by proposing a theoretical de nition of an urban energy system model and then evaluating the state of current practice. Drawing on a review of 219 papers, ve key areas of practice were identi ed { technology design, building design, urban climate, systems design, and policy assessment - each with distinct and incomplete interpretations of the problem domain. We also highlight a sixth fi eld, land use and transportation modelling, which has direct relevance to the use of energy in cities but has been somewhat overlooked by the literature to date. Despite their diversity, these approaches to urban energy system modelling
share four common challenges in understanding model complexity, data quality and uncertainty, model integration, and policy relevance. We then examine the opportunities for improving current practice in urban energy systems modelling, focusing on the potential of sensitivity analysis and cloud computing,
data collection and integration techniques and standards, and the
use of activity-based modelling as an integrating framework. The results indicate that there is signi cant potential for urban energy systems modelling to move beyond single disciplinary approaches towards a sophisticated integrated
perspective that more fully captures the theoretical complexity of urban energy systems.