The current state and future outlook of digitalization for the operation of district heating systems: A review

In the transition toward a green energy system, district heating (DH) systems are pivotal in enhancing the flexibility, resilience, and capacity of integrating local and renewable energy sources in urban areas. District heating networks have traditionally been operated with limited controls to ensure the required supply and optimize economic and environmental performance. In recent years, a new digital infrastructure has emerged in response to new policies, and technological advancements in digital solutions are essential to sustain the tran sition towards a 4th generation district heating (4GDH) system. This review article comprehensively assesses the current landscape and future prospects of digitalization levels in the operation of DH systems. It provides an overview of the latest improvements in digital technologies and their application in optimizing the operation and management of DH networks. The review delves into various aspects, including digital control strategies, data analytics, fault detection and diagnosis, and predictive maintenance with current applications and developments of digital twins and artificial intelligence (AI). The analysis of results in the literature was organized and clus tered into specific macro areas: digitalization of the demand side, digitalization at the system level, and digi talization of infrastructure. Furthermore, the study provides an overview of digitalization implementations based on the experiences of early adopters as a benchmark for the replicability and opportunity of new business models.