District heating has been around for almost 150 years, with the first commercial system established in New York in 1877, yet it is still not widely used. The original systems used steam produced by a central fossil-fuel boiler. However, systems have evolved over time, and modern heating networks have more flexible infrastructure that can connect multiple energy and storage solutions to supply both heating and cooling. At present, district heating supplies approximately 10 per cent of global building heat demand, with most networks concentrated…