Early-stage Techno-economic Assessment of DHC Networks and Individual Systems: The FAST-DHC web-tool and its application to an Austrian case study

The FAST DHC (Feasibility Assessment Tool for District Heating and Cooling) project, funded through the IEA DHC Annex XIV, has developed a publicly available web-based tool for early-stage techno-economic assessment of heating and cooling systems. This presentation shows the final version of the FAST DHC tool and demonstrates its use through a live case study.
The tool allows a quick comparison between 4th generation district heating (4GDH), thermal source networks (TSNs) and individual solutions for heating, cooling and domestic hot water (DHW). Designed for planners, municipalities and consultants, it supports early decision making through simplified input. To make the tool usable where little system-specific data is available, it includes a range of default values for technologies, demand assumptions and costs, which users can refine as more information becomes available.
To reflect the seasonal mismatch between supply and demand, the tool uses four
representative time steps, one for each season. Unlike many existing planning tools, cooling is an essential component. With rising temperatures and the increasing use of low-temperature solutions, this has become a key consideration for long-term planning. The system model is structured in layers that include supply, transformation, distribution, storage and demand. Results are presented in terms of comparative indicators such as levelized energy cost and total annual cost. Users can test different scenarios by adjusting
boundary conditions, tariffs and technology options. A live demonstration of an Austrian case study shows how the FAST DHC tool can help identify cost-effective configurations in real-world conditions.