Fifth generation district heating and cooling: A comprehensive survey

District heating (DH) networks are a key component of low-carbon urban heating in the future, as greenhouse gas emissions and sustainability concerns drive the heating sector to transform itself. DH is not a new technology, but it has been constantly evolving. The latest generation of DH facilitates the distribution of low-temperature renewable heat sources. In recent years, most studies have focused on managing peak demand, improving low-carbon technologies, and improving load prediction. However, there is a risk of misinterpretation, as recent generations of DH, which operate at significantly lower temperatures than conventional DH, are being developed simultaneously. This review aims to analyze the different definitions of the fifth-generation district heating and cooling (5GDHC) and introduce a straightforward concept of this new technology. It also describes the potential strengths, weaknesses, and challenges of integrating 5GDHC into existing systems, as well as practical recommendations. Finally, it analyzes the crucial components and notable characteristics of 5GDHC to provide a clear picture of its evolution and uniqueness.