An aggregation method to model district heating networks in large-scale multi-energy simulations

District Heating Networks (DHNs) are set to play a key role in future decarbonized energy systems, as they are an economical flexibility provider for the power system. However, the literature supporting the relevance of DHN often overlooks one major issue regarding DHN modeling: how to represent thousands of isolated and diverse DHNs in a model simple enough, yet accurate, to be able to run multi-energy studies at a wide scale? This paper presents a new way of modeling numerous DHNs by aggregating unitary models with the addition of mathematical constraints. This aggregation process constitutes a significant improvement compared to previous DHN modeling literature by explicitly considering demand-side aggregation. First, the method and its theoretical background are exposed. Then, we assess the aggregated model’s performance using a new error assessment approach. In the discussion, we apply the method to a European multi-energy case study to better understand the implications of DHN modeling on the rest of the energy system. The results validate that the aggregated model reliably represents DHN’s behavior while substantially reducing computation time. For this case study, the artificial flexibility inherent to aggregation is reduced by 82%, while the computational effort compared with exhaustive modeling is still reduced by 50%.