District energy systems: Challenges and new tools for planning and evaluation

The change from a centralized to a decentralized energy supply creates new challenges in the planning of such energy supply concepts. Specialized planning tools that can cope with the complex requirements and multi-layered boundary conditions of local energy use are therefore needed. Existing methods need to be further developed and optimized to suit the complex stakeholder structures encountered in innovative district projects, as well as for research purposes. This paper presents selected aspects and challenges in the development of an application-oriented planning tool. Using a North German district as a case study, the usability of a Building Information Model as an aggregated data platform is tested in the context of a residential energy district planning process. In addition, the modeling of heating grids using a combination of Geographic Information System and open source thermodynamic tools is presented. Economic valuation methods are examined to determine the extent to which the value of flexibility and access to local flexibility markets can be taken into account. Finally, an approach for evaluating the ecological aspects of the district energy supply is presented, based on the dynamic assessment of imported and exported energy quantities.