nPro: A web-based planning tool for designing district energy systems and thermal networks

District energy systems play a key role in the energy transition, especially for the decarbonization of the heating and cooling sector. However, there is a lack of suitable software tools to simulate and optimize district energy systems in the conceptual design phase. In this paper, the web-based tool nPro for planning district energy systems is presented which focuses on district heating and cooling networks and is available at www.npro.energy. The tool helps to generate tailor-made demand profiles for space heating, domestic hot water, space cooling, process cooling, as well as electricity demands (plug-loads and e-mobility). In addition, simulation models for district heating and cooling networks (including 5th generation district heating and cooling) are implemented. Key advantage over existing tools is that the scope of input data is tailored for the early planning phase when only a few design parameters and boundary conditions of a district are known. Small computation times allow for frequent iterations as they typically occur in the early planning phase. With its easy-to-use graphical user interface, the tool can also be used by non-specialists outside the academic community.