In 2016, 22 TWh/a, equating to 7% of the total Austrian energy demand (311 TWh/a, including electricity, industry and transportation), was provided by DH (DH). 28% or 87 TWh/a of this energy demand was used for spatial heating in Austria, 23% or 72 TWh/a for thermal processes in industry. The achievement of mid- and long-term international and national climate goals such as the Paris Climate Agreement and Klima- und Energiestrategie Österreichs 2018 is a major challange, in which consequently flexible and sustainable DH systems play a central role. Our current heat supply and the supply quality and robustness of DH systems is guaranteed by the versatility and ease-pf-se of fossil fuels. In a future sustainable and fully decarbonized DH system, the same supply standard must be maintained in an affordable way in an even more complex system (storage, renewables, volatility, prosumers, etc.) without fossil fuels. This can be only achieved by increased flexibility of the overall system and a smart interaction of all its technical (e.g. supply units, storage, control) and non-technical (e.g., business models, user integration approaches) components.
DH systems allow for integration of renewable energy sources and are highly suitable for measures to increase flexibility in terms of renewable supply sources, advanced operation strategies and application of thermal storage. These benefits could be further increased if system-wide and holistic approaches as well as scientific methods such as simulation and optimization during conceptualization, implementation and operation would be applied. For implementation of flexible and sustainable DH systems further research and demonstration is needed for flexibility measures such as thermal storage, heat pumps, smart control, sector coupling with electricity and wastewater infrastructure in combination with increased share of renewable heat and holistic system and planning approaches.
Within Thermaflex, these research needs are addressed on base of several demonstartion cases, which provide the background for developing, implementing and optimizing innovative DH concepts and technical solutiond. The results of Thermaflex will lead to more efficient and effective demonstrators due to close cooperation with research partners and technology / knowhow provider in the Thermaflex consortium during the whole innovation and implementation process. Thermaflex will use the linked demonstrators "100% renewable district heating Leibnitz", "Big Solar Salzburg", "Salzburg Absorption Heat Pump", "Virtual Heating Plant Gleisdorf", "Wien high-temperature heat pump Spittelau", "Wien Waste heat recovery from sewage water" and "Energy Island Weiz" to showcase, validate and optimize the developed concepts. We will use the results and experiences from implementation and operation to derive Best Practices, highlight promising concepts and pathways and show quantitatively technical, economic and ecological benefits and impacts of the demonstrators. Thermaflex will thus lift the demonstartors through the cooperation and support of a strong consortium of renowned research partners and universities, energy supplier and DH operators as well technology and knowhow providers during the whole implementation to a higher level. Additionally, Thermaflex provides the means to replicate these concepts and thus leads to a massive roll-out of flexibility options for DH systems in Austria and Europe.