Promoting efficient district heating in Estonia

Comparative Analysis Between District Heating and Geothermal Heat Pump System

Metamorphoses of cogeneration-based district heating in Romania: A case study

Techno-economic model for district heating systems

Over 600 million square meter heating area use the district heating system in Beijing up to 2013. The construction and operation level of many heating systems are diverse. It leads to the difference in the heating energy consumption and cost. The obstacles that impacts on the energy efficiency improvement for the district heating system in Beijing were presented. The primary job to reduce the gross heating energy consumption is to evaluate the energy efficiency of the heating system, reasonably. The aim of the paper was to provide an improved method to evaluate the energy efficiency of a district heat system.The energy conversion between the different typical parts of a heating system was discussed: the source, the primary network, the secondary network, the heat exchanger station and the building. Also, six district heating system in Beijing was evaluated by the method to illustrate the proposed technique.

Highly efficient cogeneration and district heating systems have a significant potential for primary energy savings and the reduction of greenhouse gas emissions through the utilization of a waste heat and renewable energy sources. These potentials are still highly underutilized in most European countries. They also play a key role in the planning of future energy systems due to their positive impact on the increase of integration of intermittent renewable energy sources, for example wind and solar in a combination with power to heat technologies. In order to ensure optimal levels of district heating penetration into an energy system, a comprehensive analysis is necessary to determine the actual demands and the potential energy supply. Economical analysis of the grid expansion by using the GIS based mapping methods hasn’t been demonstrated so far. This paper presents a heat demand mapping methodology and the use of its output for the district heating network expansion analysis. The result are showing that more than 59% of the heat demand could be covered by the district heating in the city of Velika Gorica, which is two times more than the present share. The most important reason of the district heating's unfulfilled potential is already existing natural gas infrastructure.

Machine-learning-based multi-step heat demand forecasting in a district heating system

District heating systems (DHSs) which utilize excess heat play an important role in energy infrastructure in many European countries. In contrast to Europe, the DHS is not common and excess heat is not reused effectively in Japan. Almost all the DHSs in Japan were designed as first-generation district heating (1GDH) systems or 2GDH systems. No 4GDH systems have been introduced in Japan. The present study designs a 4GDH system utilizing excess heat from a wide area of Northern Japan and evaluates its feasibility. First, available heat amounts from two excess heat resources were calculated: waste incineration plants and thermal power plants. Second, heat demand from both residential and commercial sectors was estimated using a 1 km mesh, and a heat load curve was created for each mesh based on load curve data. Third, the DHS was designed with excess heat plants as a supply-side heat resource, and spatial information of the demand side made use of the geographical information system (GIS). Further analysis was conducted on selected DHSs in three cities in order to evaluate those systems’ feasibility based on energy efficiency, CO2 emissions, and economic aspects. The result shows that 70.5 PJ of heat can be supplied by DHS in Northern Japan, replacing imported fossil fuels such as petroleum and LPG with regional excess heat. The designed DHS could supply heat with equivalent costs compared to European countries.

District heating and cooling (DHC) systems play an important role under the new European Union (EU) energy transition strategy. Thermal energy networks are helping to stimulate the development of alternative technologies based on a broad range of renewable energy sources. The present study analysed the current situation of DHC systems in Spain and provides an overview of the challenges and future opportunities that their use will entail. Its objective is to assess thermal energy conversion and management from a holistic perspective, including a study of existing energy infrastructures. The focus of this study lies on Spain given the country’s abundance of natural resources such as renewable energy sources including solar energy, biomass and geothermal energy, among others, as well as its strategic location on the map of the EU. Based on the analysis of the three factors for energy conversion in a district heating system, namely resources, technology, and management, the methodology provided an assessment of the different factors involved in running a DHC system. The results show an estimated total production for DHC networks of 1448 MWth, of which 72% is supplied purely by renewable energy sources.

District heating (DH) is a proven heat generation and distribution technology that enhances energy efficiency and reduces carbon emissions at scale, making it a key component of sustainable energy strategies. Compared to traditional heat generation methods such as using onsite fossil-fuelled combustion boilers or electrically driven heating systems, DH offers superior environmental advantages, particularly when renewable energy and waste heat are deployed as primary fuel energy mix. To comprehensively evaluate the sustainability of DH, life cycle assessment (LCA) is widely adopted to determine environmental impacts across all life cycle stages, from material extraction to disposal. This systematic review identifies the absence of a unified, adaptable framework for LCA application in DH systems. To address this, the study proposes a structured multi-level framework, interpreting methodological diversity across component, facility, and network levels. Component-level studies offer insights into specific technologies and materials; facility-level assessments focus on operational performance and energy sources; network-level evaluations provide holistic system impacts. Aligning studies within these analytical levels enables fairer comparisons, supports cross-regional learning, and promotes methodological integration. Recurring challenges include inconsistent methodologies, varying system boundaries, and limited local data. Emerging technologies such as hybrid systems, smart grids, and energy storage remain underrepresented in LCA studies. Tools like SimaPro, GaBi, and OpenLCA are widely used, yet the rapid evolution of DH systems calls for more tailored applications. This review supports the development of standardised, yet flexible LCA practices and proposes a refined multi-level framework to guide comprehensive, context-specific evaluations. It emphasises the importance of validating approaches across diverse contexts and strengthening LCA’s contribution to the design of sustainable, low-carbon DH solutions for urban energy systems. Multi-level LCA approach categorises DH systems into component, facility, and network levels. Current LCA research on DH systems focuses on Europe, with gaps in Asia and the US. Tools like SimaPro, GaBi, and OpenLCA support detailed LCA analyses of district heating. LCA for DH systems faces challenges like data gaps, system boundaries, and variability. The proposed workflow enables tailored, actionable LCA assessments for diverse DH systems.

Dynamic response of gravity-driven flow in multi-section absorption heat pump

Fault Detection and Diagnosis (FDD) in District Heating (DH) systems is vital for improving operational efficiency. As DH networks evolve towards Fourth-Generation District Heating (4GDH), their reliance on lower operational temperatures intensifies the need for robust FDD. However, implementing effective FDD faces challenges due to the lack of labelled fault data and the complexity of DH substations. This paper introduces a novel FDD methodology using Transfer Learning (TL) to bridge the gap between faulty bearings, controlled DH substation experiments and real-world operational data. We propose a fault signature method that aligns the data to reduce the domain gap, revealing similarities between faulty bearings’ vibration patterns and Δ T readings in DH substations. The TL-enhanced models demonstrated robust performance, achieving F1 scores up to 98% on lab data and 91% on real-world operational data, respectively. These results mark a notable advancement in FDD of DH substations, as our method offers accurate fault detection and valuable insights across diverse operational contexts, ranging from valve issues, faulty sensors, wrong control strategies and normal behaviour. Notably, temperature dynamics resemble behaviour akin to faulty bearing vibrations, highlighting their potential as a critical indicator of a faulty substation, enabling more effective FDD in DH systems. • Transfer learning framework using faulty-bearing, lab-emulated district heating, and real-world district heating data for substation fault detection. • A novel daily-signature generation pipeline bridging mechanical vibration and thermal temperature patterns. • The temperature signatures exhibit high variance and vibration-like patterns when a substation is faulty, as opposed to a stable, normal operational substation. • Models achieve high fault detection performance with an F1 score of 98% on lab emulation and 91% on real-world DH substation data.

Collaborative scheduling and flexibility assessment of integrated electricity and district heating systems utilizing thermal inertia of district heating network and aggregated buildings

The energy consumed by buildings for air conditioning accounts for a large percentage of global energy consumption. To promote efficiency and sustainability, the scientific community is making great efforts to develop renewable technologies. A well-known but unfortunately underestimated solution is the development of centralized heating and cooling systems that consistently reduce energy consumption.The work proposes a comparison between three heating configurations covering the demand of a settlement in the Latvian region: 1) centralized district heating (DH) system; 2) 5th generation district heating & cooling (5GDHC) system and 3) individual home heating (HH) systems. Thermal and electrical loads are evaluated by transient simulations of a residential area with 80 buildings for the Riga climate and compared with the same settlement in a Mediterranean region (Milan, IT). The energy plants are based on different technologies: combined heat and power (CHP) plants, gas-fired boilers, and domestic heat pumps.The analysis includes the option of power exchange with the national grid. A transient numerical model has been developed for each solution. Every component is modelled according to performance maps provided by the manufacturers, allowing an accurate simulation in both design and off-design operating conditions. The study includes energy, economic and environmental aspects.The result of the simulation highlights the large difference between the two locations, not only in terms of annual load, but also in terms of load distribution. On an annual basis, the Latvian residential complex requires almost twice as much energy as the Italian one. The thermal losses in the district systems are 4.21% in Milan solution and 5.65% in Riga. The district heating system coupled with heat pump represents the best layout in terms of primary energy consumption in both locations, with energy savings of 50% compared to other solutions. The use of 5GDHC is a good compromise that could increase the use of renewable energy. The adoption of cogeneration plant is a good choice in case of centralized district system that allows the installation of high efficiency genset. On the contrary, for small application as residential, the installation of cogeneration system results expensive and the conversion efficiency does not justify the installation.

District heating system with power generation is integrated in the electricity system since combined heat and power (CHP) plants are used for heat supply. Nowadays, the changes happen in the electricity system and conventional CHP plant operation. They are caused by wide integration of renewable energy sources (RES) in energy production process, feed-in tariffs for RES, the implementation of market mechanisms, and the incremented requirement in energy efficiency and flexibility of power plants. This creates new opportunities and conditions for district heating (DH) and power system cooperation though the use of DH flexible technologies, i.e., power-to-heat (P2H) technologies (electric boilers (EB) and heat pumps). The use of P2H technologies is limited and they are not costs-efficient due to electricity tariff formed components. Two Targets of EB use at power plant are evaluated, omitting these components, to show the usefulness and significant of these technologies for conventional generation.

Effects of the operation regulation modes of district heating system on an integrated heat and power dispatch system for wind power integration