Guidebook for the Digitalisation of District Heating: Transforming Heat Networks for a Sustainable Future, Final Report of DHC Annex TS4:Optimised Operation and Maintenance of District Heating and Cooling systems via Digital Process Management

The district heating and cooling sector, which accounts for more than half of total energy consumption in many industrialised countries, is experiencing new challenges with the current transformation of the energy systems. The requireddecarbonisation will result in a more complex energy system, as a few large plants which utilise fossil fuels will be replaced by many small production plants distributed around the system, that use renewable or waste energy sources.Many of these sources are volatile; their output is affected by weather and other factors. Furthermore, district heating and cooling systems must be operated more efficiently and flexibly to ensure a consistent and cost-effective thermal energy supply, as well as effective participation power system balancing market. Because of the necessary changes in the energy system, district heating becomes increasingly beneficial to both end users as well as other energy sectors, and the number of connections is increasing in many countries in conjunction with the phase-out of fossil fuels such as oil and gas for space heating and hot water supplies. In this changed environment, increased adoption of digital technology in the district heating and cooling sector provides a chance to make systems smarter, more flexible, efficient and reliable, hence accelerating the necessary integration of additional renewable and waste energy sources into supply systems. This change affects the entire district heating energy chain, from generation to end user usage, and supports the transformation of the overall energy system.The digitalisation of district heating systems represents a paradigm shift in the production, distribution, and consumption of heat. Sensor technology, IoT connectivity, and AI algorithms advancements provide prospects for higher energy efficiency, system stability, and increased integration of renewable energy sources. However, for successful deployment, issues such as data privacy and system integration must be addressed. The future of district heating is to embrace digitalisation and capitalise on its promise for creating sustainable, smart, integrated and resilient energy systems.The IEA DHC Annex TS4 is a three-year international research project aimed at promoting the opportunities for integrating digital processes into district heating and cooling systems and clarifying the role of digitalisation for different parts of the operation and maintenance of these supply systems. The report provides background material and current knowledge on the digitalisation of district heating systems for the target groups of decision makers in utilities, district heating operators, system suppliers, the district heating and energy supply industries, as well as the scientific community. It has been demonstrated how digital technology can improve the entire energy system, along with increasing efficiency and the integration of more renewables into the system. Digital applications will assist district energy system operators fully optimise their plants and, network operations, as well as their participation in the wider energy market in the future, while additionally empowering the end user. Buildings and how end users utilise thermal energy provide a framework for potential improvements, such as system temperature decrease in district heating systems. The demand side optimisation is viewed as a critical part of the project, asthe operation of the end-user sets a limit on the optimisation of the supply system. Furthermore, the recent implementation of new rules that promote the digitalization of the demand side have opened up novel possibilities for monitoring and managing heating and cooling systems in buildings, paving the way for the district heating industry's sustainable transformation. As a result, the current state of digitalisation in buildings is benchmarked and documented with case studies, as well as experience demonstrating how low temperatures, improved operation, and fault detection in substations and thermal distribution systems can be achieved.The investigation of the role that digitalisation can play in the district heating and cooling system as a whole, as well as in the rest of the energy system, offers several key insights. At the system level, digitalisation can be divided into two categories. The first is operational optimisation, which means that digital assets directly intervene in network or component control. In contrast to the rule-based control loops that are commonly used to control network components, digital tools can be utilised to optimise system operation. The second is analytics-based optimisation strategies that are being researched in addition to operational optimisation. Analytics refers to the analysis of (huge amounts of) measurement data to ensure the network's failsafe and optimal operation. Analytics digital tools provide information on system behaviour, often in an offline mode. Based on this data, actions can be done to improve the behaviour. The analyses offered provide an accurate overview of how digitalisation is implemented in various elements of a district heating and cooling system. Of course, the current state of adoption of various digital technologies in the sector is not uniform. The concept of Digital Twins in particular, facilitates the development of digital services that support district heating and cooling infrastructure operators in their everyday operations. As a result, concrete application areas for Digital Twins in DHC operation and maintenance are highlighted. A selection of best practise examples of using Digital Twins for the deployment of digital technologies for DHC infrastructure are additionally provided to demonstrate the practical value of this strategy. Digitalisation of district heating networks requires not only technological implementation in existing infrastructures, but also rethinking of current operational strategies. Simultaneously, processes for monetising innovative technology must be initiated. Following that, how digitalisation can lead to the creation of new and innovative economic opportunities in the operation of current district heating networks is explained. Representative business models for the various stages of district heating generation, distribution, and consumption are additionally offered, as well as an outlook on business models of other digitalised sectors and markets. As demonstrated throughout the report, data processing will continue to play an increasing role in district heating supply. However, this necessitates a greater focus on the legal requirements and obligations pertaining to data protection and data security. The legal requirements are complex and differ in the various countries and regions of the world. An overview of the relevant European legal framework is provided, as well as an excursus on the South Korean circumstance. The material gathered and summarised in this guidebook demonstrates that digitalisation is an essential enabling technology for increasing the flexibility and efficiency of district heating and cooling systems and facilitating the wider integration of renewable and waste energy for the decarbonisation of our energy supply. More research and development is required to evaluate the practical and widespread application of digital technology in various situations and environments: It is very important to identify ways to overcome the impediments. This encourages additional discussions to ensure that more digitalisation solutions are implemented and operational in district heating and cooling systems. Digitalisation of district heating and cooling systems is an essential technology for decarbonising the thermal energy system, and with growing complexity or the demand for system flexibility and a green/renewable heat supply, it is just vital