Optimal District Heating Network Expansion Planning with Resilience Considerations

The use of carbon neutral heat sources such as industrial waste heat or large-scale heat pumps requires district heating networks. The automated planning of new district heating networks is a task frequently addressed in the scientific literature. However, district heating networks already exist in almost all metropolitan areas in Central Europe. The main challenge in metropolitan areas is to find the optimal district heating network expansion to connect new consumers to the already existing district heating network. The expansion may lead to overloading of existing pipes or generation units, which has to be considered in the planning process. Furthermore, for larger district heating networks with more than one generation unit, the proper operation of the district heating network must be ensured even if an outtake occurs at one of the generation units. Therefore, resilience has to be considered in the planning process. In this work, we present an algorithm for automated and optimal expansion planning of district heating networks. The algorithm guarantees that the district heating network expansion does not lead to overloads in the existing or in the added pipes. In addition, a possible outtake of one generation unit is considered in the planning process, resulting in a resilient district heating network. The algorithm is tested using a case study with more than 3000 consumers and ten generation units.