Testing of a prototype substation for a 5th generation district heating and cooling network

5th generation district heating (5GDH) networks can be an effective way to increase the penetration of renewable energy and achieve decarbonisation in the heating and cooling sector. This article describes 5GDH networks by focusing on network substations, the complexity of which increases compared to a conventional district heating substation due to the presence of a decentralised heat pump and a bidirectional pumping system. The purpose of the article is to show the components and layout of a prototype substation and a pilot network, realised to recover low-temperature waste heat and cover the heating and cooling demand of a building. The results present the performance and energy consumption of the prototype during the first heating season in which the prototype is in operation. The prototype was tested through two kinds of tests: tests under design and off-design conditions. In tests under design conditions, the average COP of the heat pump is between 3.3 and 4.2, while the values drop to 2.6 - 3.1 considering the overall COP. The off-design tests were performed to define the performance of the heat pump for a wider temperature range. For these tests, the COP is between 2.9 and 6.1.