Power-to-heat solutions like heat pumps and electric boilers are foreseen to be possible future tools to stabilise international power markets with high proportions of variable power supply. Temporary low cost electricity can be used for heat generation at times with high availability of wind and solar power through substitution of ordinary heat supply, hence contributing to increased energy system sustainability. Power-to-heat installations in district heating systems are competitive due to low specific investment and installation costs for large electric boilers, heat pumps, and heat storages. Several large-scale heat pumps were installed in Swedish district heating systems during the 1980s, since a national electricity surplus from new nuclear power existed for some years. The aim of this paper is to summarise the accumulated operation experiences from these large Swedish heat pumps to support and facilitate planning of future power-to-heat solutions with heat pumps in district heating systems. Gained experiences consider; installed capacities, capacity utilisation, heat sources used, refrigerant replacements, refrigerant leakages, and wear of mechanical components. The major conclusion is that many of the large thirty-year-old heat pumps are still in operation, but with reduced capacity utilisation due to internal competition from waste and biomass cogeneration plants in the district heating systems.

Maintained balance between supply and demand is a fundamental prerequisite for proper operation of electric power grids. For this end, power systems rely on accessibility to various balancing technologies and solutions by which fluctuations in supply and demand can be promptly met. In this paper, balancing approaches in the case of surplus electricity supply, due to long-term, seasonal, or short-term causes, are discussed on the basis mainly of compiled experiences from the Swedish national power grid. In Sweden, a structural long-term electricity surplus was created in the 1980s when several new nuclear plants were commissioned and built. One of four explicit domestic power-to-heat solutions initiated to maximize the utilization of this surplus electricity, as export capacities were limited, was the introduction of large scale electric boilers and compressor heat pumps in district heating systems. In retrospective, this solution not only satisfied the primary objective by providing additional electricity demand to balance the power grid, but represents today – from an energy systems perspective – a contemporary example of increased system flexibility by the attainment of higher integration levels between power and heat sectors. As European power supply will be reshaped to include higher proportions of fluctuating supply technologies (e.g. wind and solar), causing occasional but recurring short-term electricity surpluses, the unique Swedish experiences may provide valuable input in the development of rational responses to future balancing challenges. The main conclusions from this study are that district heating systems can add additional balancing capabilities to power systems, if equipped with electrical heat supply technologies, hereby contributing to higher energy system flexibility. Consequently, district heating systems also have a discrete but key role in the continued integration of renewable intermittent power supply technologies in the future European energy system.

This paper presents an assessment of the excess heat recovery potential from EU metro stations. The assessment is a sub-study on low temperature recovery opportunities, explored in the H2020 ReUseHeat project, and consists of spatial mapping of 1994 underground stations with quantitative estimates of sensible and latent heat, monthly and annually, attainable in rejected platform ventilation exhaust air. Being a low-temperature source, the assessment conceptually anticipates recovery of attainable heat with compressor heat pumps to facilitate the temperature increase necessary for utilisation in district heating systems. Further, the paper explores the influence on useful excess heat volumes from low-temperature heat recoveries when distributed at different temperature levels. The findings, which distinguishes available (resource) and accessible (useful) excess heat potentials, indicate an annual total EU28 available potential of ~21 PJ, characterised by a certain degree of seasonal temporality, and corresponding accessible potentials of ~40 PJ per year at 3^rd generation distribution, and of ~31 PJ at anticipated 4^th generation conditions. Despite lower accessible volumes, utilisation in 4^th generation systems are naturally more energy efficient, since relatively less electricity is used in the recovery process, but also more cost-effective, since heat pumps, at lower temperatures, can be operated at capacities closer to design conditions and with less annual deviations.

With the adoption of the EU Climate Law in 2021, the EU has set itself a binding target to achieve climate neutrality by 2050 and to reduce greenhouse gas emissions by 55 percent compared to 1990 levels by 2030. To support the increased ambition, the EU Commission adopted proposals for revising the key directives and regulations addressing energy efficiency, renewable energies and greenhouse gas emissions in the Fit for 55 package.

The heating and cooling (H&C) sector plays a key role for reaching the EU energy and climate targets. H&C accounts for about 50 percent of the final energy consumption in the EU, and the sector is largely based on fossil fuels. In 2021, the share of renewable energies in H&C reached 23%. The decarbonisation of heating and cooling is addressed across several directives and regulations at EU level.

The aim of this study is to support the analytical basis for the development and implementation of policies to ensure a seamless pathway to the full decarbonisation of the heating and cooling sector by 2050 in buildings and industry.

Six different strategies have recently been proposed for the European Union (EU) energy system in the European Commission’s report, Energy Roadmap 2050. The objective for these strategies is to identify how the EU can reach its target of an 80% reduction in annual greenhouse gas emissions in 2050 compared to 1990 levels. None of these scenarios involve the large-scale implementation of district heating, but instead they focus on the electrification of the heating sector (primarily using heat pumps) and/or the large-scale implementation of electricity and heat savings. In this paper, the potential for district heating in the EU between now and 2050 is identified, based on extensive and detailed mapping of the EU heat demand and various supply options. Subsequently, a new ‘district heating plus heat savings’ scenario is technically and economically assessed from an energy systems perspective. The results indicate that with district heating, the EU energy system will be able to achieve the same reductions in primary energy supply and carbon dioxide emissions as the existing alternatives proposed. However, with district heating, these goals can be achieved at a lower cost, with heating and cooling costs reduced by approximately 15%. © 2013 Elsevier Ltd.

Many strategies have already been proposed for the decarbonisation of the EU energy system by the year 2050. These typically focus on the expansion of renewable energy in the electricity sector and subsequently, electrifying both the heat and transport sectors as much as possible. In these strategies, the role of district heating has never been fully explored system, nor have the benefits of district heating been quantified at the EU level. This study combines the mapping of local heat demands and local heat supplies across the EU27. Using this local knowledge, new district heating potentials are identified and then, the EU27 energy system is modelled to investigate the impact of district heating. The results indicate that a combination of heat savings, district heating in urban areas, and individual heat pumps in rural areas will enable the EU27 to reach its greenhouse gas emissions targets by 2050, but at a cheaper price than a scenario which focuses primarily on the implementation of heat savings.

This pre-study presents the findings concerning a considerable outlined expansion of the district heating sector within the current EU27 member states until 2050. Heat deliveries are presumed to grow by a factor of 2.1 until 2030 and by a factor of 3.3 until 2050.

The current energy policy context is that the latest energy communication from the European Commission (Energy Roadmap 2050) contains only a very modest growth in the future for district heating systems and additional industrial heat use from industrial CHP plants. A small increase is foreseen for industrial demands, while heat deliveries to the residential and service sectors are expected to decrease. In total, the heat delivered is expected to increase by less than one per cent per year, giving a total increase of 20% until 2030 and of 40% until 2050.

In this prestudy, more ambitious growth rates are assessed for district heating in the EU27 between 2010 and 2050. The chosen methodology in this pre-study contains a combination of hour-by-hour energy modelling of the EU27 energy system and mapping of local conditions, which is essential for district heating analysis. However, the link between these two actions has not been fully utilised in this pre-study due to the limited working time available: The mapping action has only indicated the input to the energy modelling action.

Many strategies have already been proposed for the decarbonisation of the EU energy system by the year 2050. These typically focus on the expansion of renewable energy in the electricity sector and subsequently, electrifying both the heat and transport sectors as much as possible. In these strategies, the role of district heating has never been fully explored system, nor have the benefits of district heating been quantified at the EU level. This study combines the mapping of local heat demands and local heat supplies across the EU27. Using this local knowledge, new district heating potentials are identified and then, the EU27 energy system is modelled to investigate the impact of district heating. The results indicate that a combination of heat savings, district heating in urban areas, and individual heat pumps in rural areas will enable the EU27 to reach its greenhouse gas emission targets by 2050, but at a cheaper price than a scenario which focuses primarily on the implementation of heat savings.

Background and Objective

The evolution of district heating (DH) has gone through three generations since the first introduction of distirct heating. It is characterized by the type of transport media and the network temperature levels: the 1^st generation DH system is steam-based system, the 2^nd generation DH uses high network supply temperature above 100^oC, and the 3^rd generation DH represents the current DH system with medium network supply temperature between 80^oC to 100^oC. Up until now, the 4^th generation DH as the low-temperature district heating (LTDH) is emerging as a new system which is going to replace the existing 3^rd generation DH system. Comparing with the existing DH system, the LTDH reduces the network supply temperature down to consumer required temperature level, thus greatly improves the quality match between the energy supply and the energy demand. Meanwhile, LTDH coupling with reduced network temperature and well-designed DH network can reduce network heat loss by up to 75% comparing with the current system. This makes DH economically competitive comparing with local heat generation units in the areas with low heat density or with low-energy buildings.

The traditional approach to evaluating a DH system often focuses on the production/supply aspect and only afterwards on the final users. The LTDH concept switches the perspective, starting from end-user thermal comfort and a quality match between energy supply and energy consumption, and aiming to find the best and most economical way to satisfy the heat demand through efficient distribution networks and supply systems based on waste heat and RE. The new concept therefore starts by identifying suitable in-house substations for low-energy-demand buildings at low supply temperature, goes back to design efficient and reliable networks, and finally considers environmentally-friendly heat production units.

This report describes the concept of LTDH, collects and discusses successful examples of implementation LTDH in the building heating sector. The objective of this report is to raise awareness and provide insights that will stimulate the research, development and implementation of LTDH systems. It will help to increase public recognition and assist policy makers and energy planners, both at local and governmental level, in promoting cost-effective and environmentally friendly DH systems, and in planning and realizing long-term sustainable urban area development. To this end, the report addresses the following research issues:

1. What are the main advantages of LTDH?

2. What technology options are available for LTDH, and what are the associated challenges to consider?

3. How can the risk of Legionella be mitigated in LTDH?

4. What lessons can be learned from early LTDH projects?

5. What heat distribution costs are associated with LTDH?

This work aims at showing the potential of waste and renewable heat recovery in Italy through detailed mapping of these sources. The ambition of this analysis is to highlight the areas with important heat recovery potential and to show how the matching with suitable heat demand would allow its exploitation through district heating expansion. The importance of waste heat and renewable heat potentially recoverable to reduce primary energy consumption in the civil sector is widely recognized. Nevertheless, these potential is widely unexploited in Italy. The processes and energy sources have been analysed in terms of geographical location, quantification of available heat and recovery costs with a special focus on temperature levels. The main distinction between low temperature and high temperature heat sources has been applied in order to identify the heat recovery characteristics and the consequent additional costs for temperature upgrades. The inputs of the analysis performed in this work come from national database, which has allowed obtaining more detailed and wider results with respect to international existing studies on the same subject. Two different approaches have been used to map potential heat: one to identify and quantify existing waste heat recovery and one to assess and estimate energy coming from potential new plants. The analysed sources belonging to the first category are industrial processes, waste to energy plants, waste water treatment plants and datacentres, while biomass, geothermal energy and electrolysis plants estimation belong to the second one. Results shows that the national available waste and renewable heat amount to 270 TWh which is an important outcome in comparison with a national heat demand for the residential and tertiary sector of 400 TWh. Out of this results, according to a nuts 3 regional aggregation of heat demand, 95 TWh could be recovered in DH. The reduction from theoretical potential of 270 TWh to 95 TWh is due to geographical matching of heat demand and available waste heat and on some hypothesis related to the diffusion of DH. This work shows the huge unexpressed potential of waste heat reutilisation in Italy and how the mapping of recoverable heat and not only its quantification is essential to properly estimate the utilization potential.

This work aims at showing the unexploited potential of waste and renewable heat in Italy through detailed mapping of these sources. The ambition is to highlight the areas with an important heat recovery potential that could be exploited through DH expansion. The recoverable heat sources have been analysed in terms of geographical location, and recovery aspects with a special focus on temperature levels and technological implications for temperature upgrades. The methodology presented in this work addresses not only the theoretical potential of waste heat and renewable heat use in DH, but also several technical aspects to get a result as closer as possible to the realistic potential at national level. Two different approaches have been used to map potential heat: one to quantify existing waste heat recovery from industrial processes, waste to energy plants, wastewater treatment plants and one to estimate the energy coming from potential new plants based on biomass, geothermal energy and solar thermal. Results shows that for a total heat demand for the civil sector of 329 TWh, out of which 114 TWh come out being suitable for a DH connection, the national available waste and renewable heat that could be integrated in DH amounts to 156 TWh. These results show the significant unexpressed potential of waste heat use in Italy and how its mapping is essential to properly estimate the utilization potential. This work has been commissioned by AIRU, Italian DH association. Copyright © 2021 Elsevier Ltd.

The evaluation of the district heating network investment costs requires the knowledge of its topology. However, when assessing district heating potential, the topology is not known a priori and a simulation is required. One method for modelling future heat networks involves the use of Minimum Spanning Tree, from the graph theory. In this work, the MST is used together with real networks lengths to elaborate an updated equation describing the effective width in correlation with the number of building ratio instead of plot ratio. The reason motivating the use of simulated networks lies in the goal of analysing sparse areas where there’s a general lack of data. In this study, the census cells vertexes and local roads layout are used as inputs for the application of the MST in order to simulate DH network layouts in areas where DH is not present. The method has been validated by running simulations in areas where DH is already present, allowing the comparison of the respective lengths. The validation shows a variable but systematic overestimation of the simulated lengths. The study of the error has brought to the definition of a correlation between accuracy of results and the share of buildings with centralized heating systems suitable for DH connection. The updated version of the effective width confirms the exponential tendency and gives higher results for Italian cities then for Scandinavian ones, showing an important impact of the city structure in the curve. The city of Milano is finally used as a case study to show the effects of using the updated effective width curve.

This paper presents a novel approach to modeling the gradual reduction in heat demand and the evolving expansion of district heating (DH) grids for assessing the DH potential in EU member states (MS). It introduces new methodological elements for modeling the impact of connection rates below 100% on heat distribution costs in both dense and sparse areas. The projected heat demand in 2050 is derived from a decarbonization scenario published by the EU, which would lead to a reduction in demand from 3128 TWh in 2020 to 1709 TWh by 2050. The proposed approach yields information on economic DH areas, DH potential, and average heat distribution costs. The results confirm the need to expand DH grids to maintain supply levels in view of decreasing heat demand. The proportion of DH potential from the total demand in the EU-27 rises from 15% in 2020 to 31% in 2050. The analysis of DH areas shows that 39% of the DH potential is in areas with heat distribution costs above 35 EUR/MWh, but most MS have average heat distribution costs between 28 and 32 EUR/MWh. The study reveals that over 40% of the EU's heat demand is in regions with high potential for implementing DH.  © 2023 The Author(s)

The economical sustainability of DH compared to individual heating systems depends on the cost of producing heat, transporting and distributing it. Assessing economically sustainable potential of district heating DH thus requires the ability to combine this costs, detecting the relative distance of sources and demands and the density of demand, comparing it to the alternative solution. In this work we present an open model, based on the Oemof modelling framework, which is able to take into account the possibility of connecting sources and demands on national scale level with a high spatial resolution. The model considers the investment and operating costs of production and distribution of heat in competition with the individual heating systems costs specific to each area. The end result is the most economically viable heat supply configuration, identifying the demand shares where the most cost-effective solutions are individual systems or DH and its composition in terms of energy sources. The model is part of the method used for the assessment of district heating potential in Italy. The latter is based on GIS maps of both energy demand, waste and renewable heat sources. Of the 114 TWh of potential demand for DH, 38 TWh are those that the optimisation suggests could be economically served by DH. The composition is mostly waste heat, 22 TWh, geothermal heat, 11 TWh and a minority of solar thermal, 2 TWh with 3 TWH of natural gas CHP back up.

Facilities of energy-intensive industries including those for the production of steel, cement, paper, glass, chemicals and others are spread across Europe. The combination of high flue gas temperatures, continuous operation and highly concentrated point sources make the excess heat from such industrial plants a very attractive source for district heating. Despite this, excess heat sources from industry are currently only rarely exploited and major potentials are being wasted. Here, we aim to contribute by providing the most detailed, comprehensive assessment of the excess heat potentials available for Europe. More specifically, we aim to analyse the available excess heat from heavy industry in Europe and assess its suitability for use in district heating systems. Our approach uses GIS-based mapping of 1608 industrial sites in Europe combined with a process-specific assessment of their excess heat potential. The heat sources are then matched with data on heat demand density and existing as well as potential district heating networks. The scope of this analysis covers the major industrial excess heat sources (large heavy industry facilities) and the most important excess heat streams: flue gases. Our results show a total potential of 425 PJ of excess heat available at a temperature of 95°C, with 960 PJ available at a lower temperature (25°C). This equals about 4% and 9% of total industrial final energy demand in 2015, respectively. Matching this potential with a GIS analysis of heat demand densities and current district heating systems reveals that 151 PJ of excess heat could be used within a 10km range at a temperature of 95°C, which is compatible with most existing district heating systems. As district heat today has a total final energy consumption of 1,945 PJ, this means that about 8% of district heating in the EU28 could be supplied by excess heat sources from energy-intensive industries.

The ongoing transformation in European district heating systems fromthe usage of fossil-based technologies to non-fossil heat supplies issummarised by a collection of 70 possibilities linked to decarbonisation. These possibilities are exemplified by 284 implemented, planned, orproposed cases. The 70 possibilities for decarbonised district heatinginclude using heat, connecting customers, moving heat, storing heat, removing carbon dioxide, and supplying heat together with somefeatures for the entire value chain, to heat usage from heat generation orrecycling. This collection of 70 possibilities is neither complete nor doesit contain any recommendations for the possibilities or advocate forspecific possibilities.

The purpose of this project was to provide an extensive inventory ofdecarbonisation activities recently performed by district heating operators andother heat suppliers. These decarbonisation activities include the directsubstitution of heat obtained from the combustion of fossil fuels and indirectactions for obtaining more efficient district heating systems. These indirect actionsreduce costs and increase revenue, thereby improving the competitiveness ofdistrict heating. The time horizon, which is linked to the EU’s target for thereduction of greenhouse gas emissions by 55% compared to 1990 levels, is 2030. This inventory of early decarbonisation projects concerning district heatingsystems has revealed the following three key conclusions.

First, decarbonisation activities can be divided into substituting and supportingpossibilities. Substituting possibilities in heat supply include linear supply fromrenewables, heat recycling from processes that generate excess heat, and non-fossilways of meeting peak heat demands during very cold days. The linear heat supplyis based on geothermal heat, solar heat, and electricity supply. Heat recycling ispossible from various processes related to biorefineries, hydrogen supply, petrochemical plants, electricity distribution, district cooling, data centres, batteryfactories, food supply chains, and sewage waters. Heat storage can make heatdelivery more independent of heat supply and provide additional opportunities toreduce peak loads. Supporting possibilities mainly comprise activities forobtaining lower temperatures in heat distribution networks to increase profitabilitywhen using low-temperature heat sources. These activities are performed whenconnecting customers, moving heat, and using heat. Another supporting activity is the removal of biogenic carbon dioxide from the natural carbon cycle, although anappropriate international accounting system for its removal is still missing.

Second, the decarbonisation possibilities of district heating systems differ fromthose of traditional systems based on fossil fuels. The availability ofdecarbonisation possibilities for district heating depends on local conditions,whereas fossil fuels are transported from available global resources and are usedworldwide. Hereby, decarbonised district heating systems will not be as uniformas traditional systems based on fossil fuels. The local conditions lower the degrees of freedom for the implementation of substituting possibilities in existing buildingsand systems. Hence, it is important to adopt new methods for utilising the highestdegree of freedom possible in new buildings and systems.

Third, the common denominators for the 70 identified possibilities are degrees offreedom for decarbonisation, action plans for achieving lower heat distributiontemperatures, the use of heat pumps for upgrading low-temperature supplies tomeet high-temperature demands, smart digitalisation options, clear supplyresponsibilities, favourable institutional frameworks, and digital planning models. These seven common denominators are efficient tools for obtaining decarbonisedand more efficient district heating systems in the future. These redesigned and newsystems will be somewhat different than traditional systems, which have beenbased on a district heating technology that was originally elaborated for systemsbased on fossil fuels.

Den pågående omvandlingen av europeiska fjärrvärmesystem från användning av fossilbaserad teknik till icke-fossil värmeförsörjning sammanfattas med en utvald samling av 70 möjligheter kopplade till fossilfrihet. Dessa möjligheter exemplifieras med 284 genomförda, planerade eller föreslagna fall. De 70 möjligheterna för koldioxidfri fjärrvärme omfattar att använda värme, ansluta kunder, flytta värme, lagra värme, avskilja koldioxid och tillföra värme tillsammans med några aspekter för hela värdekedjan till värmeanvändning från värmeåtervinning eller värmegenerering. Uppsättningen av 70 möjligheter är varken komplett eller innehåller några rekommendationer för vilka möjligheter som bör användas. Syftet med detta projekt har varit att tillhandahålla en omfattande inventering av tidiga aktiviteter för att erhålla fossilfri fjärrvärme som nyligen utförts av fjärrvärmeföretag eller andra värmeaktörer. Dessa aktiviteter omfattar både direkt substitution av värme som tidigare erhållits från förbränning av fossila bränslen och stödjande indirekta åtgärder för att erhålla mer effektiva fjärrvärmesystem. Dessa stödjande åtgärder minskar kostnaderna eller ökar intäkterna som förbättrar fjärrvärmens konkurrenskraft. Tidshorisonten har varit 2030, kopplat till EU:s mål för minskning av växthusgasutsläppen med 55 % jämfört med 1990 års utsläpp. Denna inventering av tidiga projekt för fossilfri fjärrvärme har givit följande tre viktiga slutsatser. För det första, aktiviteter för fossilfri fjärrvärme kan delas in i ersättande och stödjande möjligheter. Ersättande möjligheter i värmeförsörjningen inkluderar linjär försörjning från förnybar energi, värmeåtervinning från processer som genererar restvärme och icke-fossila sätt att möta spetsbehov under mycket kalla dagar. Den linjära värmeförsörjningen baseras på geotermisk värme, solvärme och eltillförsel. Nya aktiviteter för värmeåtervinning är möjliga från många olika samhällsprocesser, såsom bioraffinaderier, vätgasförsörjning, petrokemiska anläggningar, eldistribution, fjärrkyla, datacenter, batterifabriker, livsmedelsförsörjning och avloppsvatten. Värmelager kan göra värmeleveransen mer oberoende av värmetillförseln, vilket också ger ytterligare möjligheter att minska spetsbelastningar. Stödjande möjligheter innehåller främst aktiviteter för att erhålla lägre temperaturer i värmedistributionsnät, vilket ökar lönsamheten vid användning av lågtempererade värmekällor. Dessa aktiviteter utförs när man använder värme, ansluter kunder och flyttar värme. En planerad stödaktivitet är också avskiljning av biogen koldioxid från det naturliga kolkretsloppet, även om ett lämpligt internationellt ersättningssystem för detta fortfarande saknas. För det andra, karaktären hos möjligheterna till fossilfritt skiljer sig från de traditionella erfarenheterna baserade på fossila bränslen. Tillgången på möjligheter till fossilfritt beror på lokala förhållanden, medan fossila bränslen transporterades från tillgängliga globala resurser, vilket gav full frihet att använda fossila bränslen var som helst i världen. Härigenom kommer fossilfria fjärrvärmesystem inte bli så 4likartade som traditionella fjärrvärmesystem var med fossila bränslen. De lokala förutsättningarna för fossilfri fjärrvärme ger något lägre frihetsgrader för implementering av ersättande möjligheter i befintliga byggnader eller system. Därför är det viktigt för framtiden att utnyttja den högre frihetsgrad som är möjlig i nya byggnader och system genom att använda nya metoder mm. För det tredje, de gemensamma nämnarna för de 70 identifierade möjligheterna är antal frihetsgrader för fossilfrihet, handlingsplaner för att erhålla lägre temperaturer i värmedistributionsnät, olika sätt att använda värmepumpar för att uppgradera låga framtemperaturer för att tillgodose högre temperaturbehov hos kunderna, möjliga smarta digitaliseringsalternativ, tydliga leveransansvar, gynnsamma institutionella ramar samt digitala planeringsverktyg. Dessa sju gemensamma nämnare är effektiva verktyg för att få mer effektiva fossilfria fjärrvärmesystem, eftersom den traditionella fjärrvärmetekniken en gång i tiden utformades för system baserade på användning av fossila bränslen. 

This paper compares the socioeconomic potential of heating systems that could be developed in the Lyon urban area (France). The district heating (DH) systems investigated in this paper use low-carbon heat sources: large-scale heat pumps (LSHP) or nuclear combined heat and power plants (NCHP). They are compared with electric boilers and central gas boilers in terms of greenhouse gas emissions and heating costs. The heating systems are dimensioned to supply the projected 2030 heat loads for two different land surface areas (extensive and compact). The key input data is the empirical residential and tertiary heat demand per square kilometre for 2015, extrapolated to 2030 to account for the potential decrease in the heat demand (energy-efficient buildings). Given the assumptions made in this paper, the heating system that obtains the best balance between CO₂ emissions and heating cost relies on an NCHP located about 30 km from Lyon. Cases in which the heat has to be transported over longer distances are considered, hence providing insights for metropolitan areas with similar size and density as the Lyon area. Implications for stakeholders and policy makers are discussed, so that to optimize future French energy systems through the most efficient use of available technologies. © 2018 Elsevier Ltd. All rights reserved.

This paper aims to evaluate and compare the potential cost savings and greenhouse gas (GHG) reduction of district heating (DH) systems using heat from nuclear combined heat and power plants (NCHP) in Europe. Fifteen DH + NCHP systems, spread throughout seven countries, are studied. The selection was made in collaboration with ‘the Ad-Hoc Expert Group on the Role and Economics of Nuclear Cogenerationin a Low Carbon Energy Future’ from the Organisation for Economic Co-operation and Development. Firstly, the linear heat density of the modelled DH networks was determined, including locations with poorly developed DH networks. A large potential for extending DH networks was identified for France and the United Kingdom despite the expected decrease in the heat demand due to building renovation. Secondly, the costs and GHG emissions of DH + NCHP systems were evaluated via a cost benefit analysis. It concluded that 7 of the 15 projects would be cost-effective if 25% of the total urban heat demand was supplied. Implementing NCHP-based systems would reduce GHG emissions by approximately 10 Mt eCO₂/a. Four additional DH + NCHP systems could become competitive if a larger share of the total demand was supplied. Finally, a sensitivity analysis was performed to evaluate the uncertainty affecting the key parameters. © 2018 Elsevier Ltd

This report identifies different typology-based approaches and methods for decarbonising the energy sector of cities. Respectively, typologies were evaluated, and design approaches were developed. In a first step, already existing typologies were evaluated, including a study by the Technical University of Darmstadt and examples from the City of Vienna. In a next step, conceivable structuring criteria and decarbonisation approaches from existing work within the DCP project were identified and summarised. These include structuring criteria such as heat demand density, renewable energy sources or types of refurbishment activities. On this basis, a new typology was developed. Five highly weighted criteria could be derived from the results of the expert survey, including structural energy efficiency, coverage of district heating, potential for renewable sources, potential for waste heat and heat demand density. These criteria formed the basis for the development of the novel typology. The first typology represents areas with high compatibility with highly weighted criteria, the third typology represents areas with comparably low compatibility, while the second typology is associated in between. Based on the developed typology, six design approaches were presented in this report. One short-term and one long-term approach for each typology include recommendations as well as concrete measures for strategic decision-making.

The ambitious policy in Denmark on having a 100% renewable energy supply in 2050 requires radical changes to the energy systems to avoid an extensive and unsustainable use of biomass resources. Currently, wind power is being expanded and the increasing supply of electricity is slowly pushing the CHP (combined heat and power) plants out of operation, reducing the energy efficiency of the DH (district heating) supply. Here, large heat pumps for district heating is a frequently mentioned solution as a flexible demand for electricity and an energy efficient heat producer. The idea is to make heat pump use a low temperature waste or ambient heat source, but it has so far been very unclear which heat sources are actually available for this purpose.

In this study eight categories of heat sources are analysed for the case of Denmark and included in a detailed spatial analysis where the identified heat sources are put in relation to the district heating areas and the corresponding demands. The analysis shows that potential heat sources are present near almost all district heating areas and that sea water most likely will have to play a substantial role as a heat source in future energy systems in Denmark.

The aim of this book is to consolidate information from low temperature waste heat recovery demonstration sites. Apart from technical validation, the ReUseHeat project has generated knowledge about the urban waste heat potential in Europe, main stakeholders and different business aspects. Five stakeholder groups are targeted. These are urban waste heat owners, District Heating (DH) companies, policy makers, investors and customers. In the first chapter of the book, the concept of urban waste heat is introduced and the urban waste heat potential in Europe is presented. Thereafter (chapter two), information on business aspects is provided (stakeholders, value chain, risks, contracts and business model characteristics). Chapter three showcases the demonstrator concepts (waste heat recovery from data centre, hospital, metro and awareness creation about urban waste heat recovery) and performance data. Throughout the writing of the handbook, it was identified that it is important to compare the cost of different heating alternatives, to facilitate customer decision making. Therefore, a model was derived to compare costs of heating alternatives. It is presented in chapter four. Urban waste heat recovery is news. It is therefore important that stakeholders are made aware of the possibility to use the locally available heat and to start collaborating in new ways. To ensure as much stakeholder engagement as possible, the writing process of this book encompassed a six-month stakeholder involvement process. The stakeholder input is presented in chapter five. In chapter six, thoughts on the future development of district energy, policy implications and major learnings from the project are presented. This book was written within the ReUseHeat project. The work on the book was initiated after the first out of five years of activity to ensure that the consortium would be engaged in its development and to capture the knowledge generated on an ongoing basis. The final version of the book was ready and placed on the ReUseHeat webpage in September 2022. The project webpage remains in operation until 2024. The book not only exists in digital format. 600 copies were also printed and distributed to relevant stakeholders. All partners of the consortium have contributed to the writing of the book.

Energy‐intensive industries across the EU‐28 release unused heat into the environment. This excess heat can be utilized for district heating systems. However, this is the exception today, and the potential contribution to the decarbonization of district heating is not well quantified. An estimation of excess heat, based on industrial processes, and spatial matching to district heating areas is necessary. We present a georeferenced industrial database with annual production and excess heat potentials at different temperature levels matched with current and possible district heating areas. Our results show a total potential of 960 PJ/a (267 TWh/a) of excess heat when the exhaust gases are cooled down to 25 °C, with 47% of the 1.608 studied industrial sites inside or within a 10 km distance of district heating areas. The calculated potentials reveal that currently 230 PJ/a (64 TWh/a) of excess heat is available for district heating areas, about 17% of todayʹs demand of buildings for district heating. In the future, widespread and low‐temperature district heating areas increase the available excess heat to 258 PJ/a (72 TWh/a) at 55°C or 679 PJ/a (189 TWh/a) at 25°C. We show that industrial excess heat can substantially contribute to decarbonize district heating, however, the major share of heat will need to be supplied by renewables. © by the authors. Licensee MDPI, Basel, Switzerland.

This work studies the transformation of energy grids of the European Union (EU) in the frame of the energy transition. Three energy grid types are considered namely the electricity, thermal and gas grids. Regarding electricity grids, we investigate the required reinforcements of the low-voltage networks (e.g. replacing the distribution transformer by one of higher nominal power, replacing cables by cables of larger cross-section) in order to integrate residential low-carbon technologies such as heat pumps, photovoltaic systems and electric vehicles. To do so, we develop a methodology for the quantification of EU low-voltage grid reinforcement costs following residential low-carbon technologies integration. This methodology uses urbanisation data to determine the share of dwellings in rural and urban areas in EU28 countries (EU27 + United Kingdom). It is also based on a model that quantifies the grid reinforcement cost as a function of the low-carbon technologies integration scenario for representative rural and urban grids. This model is composed of three sub-models, namely the dwelling, grid and economic models. We also collected data from 24 open access grids (i.e. grids of which the specifications are freely accessible online) and 23 scientific articles and reports to determine the parameter values of the grid and economic models for EU28 countries. Finally, we provide example applications that illustrate the methodology by computing the grid reinforcement costs from heat pumps and photovoltaic systems integration in Belgium and Italy. Results indicate that, in the largest majority of cases, both for Belgian and Italian grids, the reinforcement cost per dwelling remains below 350 € per dwelling (total cost for the whole lifespan of 33 years). The only case where more significant reinforcement costs occurred (> 350 €/dwelling and up to 1150 €/dwelling) is for the Belgian rural grid with heat pump integration rates larger than 40%. When it comes to thermal grids, we investigate the deployment of district heating, a heat supply technology that by its fundamental idea incorporates energy efficiency and thus can trigger important greenhouse gas emissions reduction. For this purpose, we proposed an approach to map the cost of thermal grids deployment per heat demand unit in the EU. This approach is based on the concept of representative thermal grids which corresponds to a principal equation that defines the distribution capital costs as the ratio of empirically derived specific investments costs and the linear heat density. In the sEEnergies project, this concept is expanded to comprise better cost models based on actual district heating network layouts at the spatial resolution of 1 hectare. While in the Heat Roadmap Europe project, the variables were generated only for the 14 EU Member States with largest annual volumes of building heat demands, the present approach covers all EU27 Member States plus United Kingdom. In this deliverable, we focus on the current year, while the deliverable 4.5 focuses on the future years. Regarding gas grids, we present the key technical and economic characteristics of the existing gas grids and storages in the EU28 countries. We focus not only on infrastructure for natural gas but also for biogas, biomethane, syngas and hydrogen, which could play an important role in the decrease of greenhouse gas emissions. This techno-economic review provides important information to assess the cost of retrofitting and developing gas grids depending on the decarbonisation scenarios.

ReUseHeat partners Halmstad University and Aalborg University have mapped European Union’s urban waste heat potential in a new map named the European Waste Heat Map (UK included). This unique tool displays all low-grade heat sources available in cities and includes also industrial waste heat and heat from waste incineration plants. Last update 2022-05-31.

This report presents in brief the development and content of the Pan-European Thermal Atlas (Peta), with focus on the current update in response to project deliverable 6.5, which concerns for the final levels of district heating for each of the 14 member states to be recommended in WP6.

The update refers to data that has been rendered in work package 2 (WP2) and consists of three main parameters: a high-resolution model of the heat demand and its density; the specific investment costs for district heating systems, and allocated volumes of industrial and energy sector excess heat for current and prospective district heating areas. All of these parameters represent spatially derived information that has been provided as data matrices to the energy systems modelling colleagues in WP6, as a basis for their assessment of national heating and cooling scenarios for the 14 member states (deliverable 6.4).

In terms of dynamic maps, a new dynamic layer, labelled: Recommended DH levels, has been added to the Peta 4.2 online web map application on August 31, 2018, where it now is publicly available. This new layer contains recommendations to develop district heating at the local scale, based on current heat demand densities, temporally and spatially accessible excess heat from industries, from waste-to-energy facilities, from current power plant locations, and in terms of access to locally available renewable energy resources.

In November 2018, the Pan-European Thermal Atlas is scheduled for a comprehensive update, rendering the third version (Peta 4.3), to be released at the 4th International Conference on Smart Energy Systems and 4th Generation District Heating conference (SES4GDH) in Aalborg, Denmark, on November 13-14. Apart from several other new dynamic layers to be introduced in this coming update (see sub-section 1.2.3), the new layer on recommended district heating levels, added here to the current Peta 4.2, will also be part of this general update.

In 2016 the first Strategy for Heating and Cooling of the European Union has shown that district heating and cooling networks can integrate renewable energies in an increasingly energy-efficient built environment. At the same time, the heating and cooling sector is probably the most diverse and least mapped component of the European energy system. The aim of the Pan-European Thermal Atlas is to improve the knowledge base for the geographical distribution of heat and cooling demands across Europe. Demand densities of the demanded thermal services themselves, the spatial coherence of these demands, and their location relative to sources of heating greatly affect the economy of district heating schemes compared to individual solutions. The objective is therefore to develop a comprehensive model, which can be used to a) quantify heat demands by density, b) group coherent areas with demands into prospective supply zones, c) produce supply curves for these zones, and d) ultimately calculate local energy mixes on the basis of allocated excess heat as well as renewable energy sources. The developed method spatially disaggregates national demand data to high-resolution geospatial data on urban structures. The resulting atlas allows for an advanced quantitative screening process, which can establish the basis for energy systems analyses relying on geographically explicit information on the heating demand and supply volumes and costs. The present paper presents version 4 of the Pan-European Thermal Atlas, which takes another step towards higher spatial resolution and confidence in comparison to its predecessors, version 1 to 3. For the first time, a 100m resolution heat atlas of Europe is being presented, which may help describing the heating sector in the required spatial resolution. By means of spatial statistical analyses using ordinary least square linear regressions, multiple spatial inputs such as population, degree of built-up and its derivatives are turned into a coherent model of the urban tissue. Plot ratios form the basis of models of heat demand in single and multi-family residential buildings as well as the service sector. Prospective district heating areas have been delineated, and the resulting zoning of heat supply has been linked to a resource-economic analysis, which allows for cost-supply studies in disaggregated form. The present heat atlas version 4 is now available for 14 countries that altogether represent 90% of the heat demand in the 28 European Union member states. First results are being presented with emphasis on the achieved methodological improvements. Moreover, a newly developed online mapping system is being presented, which will assist in mapping the new geography of heating and cooling demands and supplies. © 2018 Elsevier Ltd. All rights reserved.

The present paper describes a quantitative method for preparing local heat supply strategies. Detailed spatial data on heat demand and supply are generated using combined top-down and bottom-up modelling for 14 member states of the European Union, which constitute 91% of its heat demand in buildings. Spatial analysis is used for zoning of heat supply into individual and collective heating. Continuous cost curves are used to model economically feasible district heating shares within prospective supply districts. Excess heat is appraised and allocated to prospective district heating systems by means of a two-stage network allocation process. Access to renewable energy sources such as geothermal, large-scale solar thermal, as well as sustainable biomass, is analysed. The result is a comprehensive and detailed set of heat supply strategies in a spatially discrete manner. The findings indicate that in the 14 European Union member states, up to 71% of building heat demand in urban areas can be met with district heating. Of this, up to 78% can be covered with excess heat, while the remainder can be covered with low enthalpy renewable energy sources. The conclusion shows the possibility of a largely de-carbonised heat sector as part of a smart energy system for Europe.  © 2019 Elsevier Ltd

The present report describes in overview how the Pan-European Thermal Atlas (Peta) was developed further into a spatial information system for the geography of energy efficiency potentials in the building, transport, and industry sectors, as well as the associated infrastructures. The resulting online atlas allows for visualisation of energy efficiency potentials between sectors in a common mapping environment. The additions and updates to the Pan-European Thermal Atlas (originally developed for the Heat Roadmap Europe projects) into a cross-sectoral mapping platform necessitated updates to the data layers, the layout, and the documentation. Layers with heat demand data from the building sector were updated, now to include all of the EU28, while a new map layer depicting the possible reduction of specific heat demand in buildings, as a measure of the current energy efficiency potential in this sector, is currently under development but not yet part of this deliverable (see sections 2.2 and 2.4 for further information). This new layer will be added to Peta 5.0.1 as soon as possible. For the transport and industry sectors, current year energy efficiency potentials were possible to assess and map in the present context. In the transport sector, findings were translated into geographical distributions of potentials and materialise as a set of geospatial map layers. In the industrial sector, energy efficiency in industry has been quantified partly for on-site energy savings, partly for off-site excess heat recovery in district heating systems, and the results have been turned into geographical representations in the form of energy efficiency surfaces. The Peta online mapping system is prepared to include further layers from future deliverables, such as thermal, gas, and electrical grids. Finally, the mapping of future scenarios will be made available using the present online mapping environment. 

The Pan-European Thermal Atlas version 5.2 (Peta, version 5.2). Peta is an online visualization tool for spatial data relating to energy efficiency in buildings, industry, and transport sectors. Developed as part of the sEEnergies project. Copyright Flensburg, Halmstad and Aalborg Universities 2022. 

The future population distribution informs decisions on investment in district heating. Across Europe, demographic change has been associated with structural changes of the past. Trends towards urban or rural migration, urban sprawl or the depopulation of city centers will continue. Using gridded population data since 1990, past development is mapped using spatial disaggregation to grid cells by intensity of urban development. An empirical method proposed captures increment of population in each grid cell and relates it to the focal statistics of the cell neighbourhood. A positive population trend in populated cells leads to a future population increase and a spill over into new development areas, while a negative trend leads to lower future population. New areas are modelled based on the principles of proximity and similarity using neighbourhood trends and land cover suitability, adjusted to national and regional population trends. The result is a set of future 1-hectare population grids, which have been used to model the distribution of future heat demands. The distribution of heat demand densities, the zoning of heat supply, and the potential for individual heat pumps have been modelled. Results show that reductions of heat demands and demographic developments leave a window of opportunities to develop heating infrastructures with known technology in the present decade, after which 4th Generation District Heat technology is required to decarbonise the heating sector.

The present report accounts for the spatial models of energy efficiency and the geospatial analysis carried out to quantify and locate energy efficiency potentials across sectors. In the building sector, future heat demands on national scales are being distributed using the age class of built-up areas and innovative models of future population distribution. District heat distribution capital costs combined with heat demand densities allow for the assessment of economic potentials of future district heating. Efficiency potentials in the transport and industrial sectors have been associated to locations, and transmission infrastructures have been mapped. Combining all these aspects, spatial analytics help understanding the opportunities and constraints that arise from the geography of energy systems. Energy efficiency in the three sectors has been mapped at different scales. Cost curves for district heating have been prepared for member states. For use in energy systems analysis, a matrix has been developed that relates energy efficiency in buildings and district heating potentials. Areas of interest for the conversion of natural gas to district heating have been mapped, combining present gas use with infrastructural aspects. Local potentials of district heating have been quantified for almost 150,000 settlements, and potential heat sources from industrial and wastewater treatment plants as well as locally available renewable energy sources have been allocated to potential district heating areas. Finally, to visualise and compare energy efficiency across sectors, technologies, and countries, the sEEnergies Index shows local potentials for improving energy efficiency and utilising synergies in all settlements of the EU27 plus the UK. In conclusion, the report documents how dissemination can be facilitated using the online geospatial information and mapping applications prepared in the sEEnergies Project.   

This paper presents the preliminary results of the District Heating Atlas, an online tool to collect and visualize key metrics of district heating systems in Germany. Since the scarce available public information on district heating systems is widely spread and not accessible via central data, the District Heating Atlas shall be the platform to enter and call up information centrally. With its online platform it provides a user interface where relevant information can be entered and system components of the currently recorded 82 district heating systems can be compared. So far, nearly 50% of the thermal energy fed into district heating is covered by the District Heating Atlas. The analysis shows that the data availability is more than 60% for five of the ten key metrics recorded. On the one hand, missing correlations between the key metrics show the diversity of the district heating systems and make it difficult to formulate general valid statements that could help to calculate missing data. On the other hand, this means that district heating systems are very diverse in their structure and thus offer versatile potential for sector coupling. In addition, district heating systems must be individually optimised in order to best utilize their potential for flexibility for the entire energy system. Finally, the first comparisons with information from the biggest district heating association in Germany show a high match with the currently collected data set. ©2021 The Author(s). Published by Elsevier Ltd. 

This thesis presents a set of methodologies and approaches to investigate and determine the extent by which district heating can contribute to improved energy system efficiency and reduced carbon dioxide emissions in future Europe. The main motivation for suggesting large-scale implementation of district heating as a structural energy efficiency measure to obtain these objectives originates essentially in the predicament that a majority of European buildings today remain highly dependent on fossil fuels to provide energy needed for space heating and hot water preparation. In parallel, vast annual volumes of rejected excess heat from European power plants and industries are mainly neglected and lost unutilised to the ambient surroundings, why extended recovery and utilisation of such secondary energy assets realistically could replace significant shares of current inefficient supplies by fuel substitution. A prerequisite, however, for the viability of this logical prospect, is that infrastructures by which to facilitate excess heat recovery and subsequent network heat distribution are in place, which by no means is the average case in contemporary Europe.

Hereby, the investigation is structured orderly by first establishing whether district heating can be a competitive alternative on current urban European heat markets, facilitated by a distribution capital cost model, where after the energy systemic benefits of expanding district heating are characterised and used to estimate a plausible expansion potential based on comparative analysis. Next, energy system modelling of continental EU27 by the year 2050, with district heating expanded in alignment with this potential, is performed to assess the total energy system cost benefits relative an alternative scenario focusing mainly on individual energy efficiency measures. Finally, spatial mapping to identify current primary target regions from which large-scale implementation of district heating could emanate is conceived and performed by use of a geographical information systems interface.

The findings are generally supportive of a realisation of the objectives, mainly so by establishing a three-fold directly feasible expansion potential for district heating in city areas, but recognise also several additional, mainly non-technical, issues and challenges necessary to address in a successful transition to more energy efficient supply structures in future Europe.

Input (ppt) on expected H/C supplies & demands in 2050 for EU

•       District heating

–      Enabling infrastructures for energy efficiency

–      Future smart energy systems

•       The climate challenge

–      If the rhetoric is true, change is needed!

•       The human predicament

–      Bellum omnium contra omnes

–      Tabula rasa and the empirical paradox

–      Das ding an sich and the deepest thought

•       Transition principles

–      Resignation and the end of all wars

–      Compassion, the only act with moral worth

•       Conclusion

–      Peace, love and district heating

The Member States of EU27 need to accelerate the integration of energy efficient technology solutions to reach the 20% energy efficiency target set for 2020. At current pace, projections indicate that only half of expected primary energy reductions will be reached. To meet the energy demands of growing populations and a vibrant economy, while simultaneously reducing primary energy supplies, the European continent faces a new kind of challenge never previously encountered. The identification and application of feasible, competitive, and comprehensive solutions to this problem are of highest priority if the remaining gap is to be closed in time. How is this multi-dimensional and complex dilemma to be dissolved? In this work, expanded use of district heating technology is conceived as a possible solution to substantially reduce future primary energy demands in Europe. By extended recovery and utilisation of vast volumes of currently disregarded excess heat from energy and industry sector fuel transformation processes, district heating systems and combined generation of heat and power can improve the general efficiency of the European energy balance. To investigate the possible range of this solution, this thesis introduces a set of methodologies, theoretical concepts, and model tools, by which a plausible future excess heat utilisation potential, by means of district heat deliveries to residential and service sectors, is estimated. At current conditions and compared to current levels, this potential correspond to a threefold expansion possibility for directly feasible district heating systems in European urban areas and a fourfold increase of European excess heat utilisation.

This report presents the updated and final results from the work performed in Task 1.2 of the ReUseHeat project to assess the accessible EU28 urban waste heat recovery potential from seven unconventional waste heat sources: data centres, metro stations, food production facilities, food retail stores, residential sector buildings, service sector buildings, and waste water treatment plants. The report focusses on recent data and model updates for the EU28 in total (EU27 plus the United Kingdom), as well as for the project demonstration sites, while less focus is directed towards the original methods and approaches developed for these models; all of which have been described in previous accounts. In terms of data updates, monitoring data from demonstration site operations and public responses to our online project questionnaire on real-world urban waste heat recovery initiatives, are presented and evaluated in overview summary. Regarding model updates, the assessments of urban waste heat potentials from data centres and metro stations have been refreshed by use of new underlying input data, by the configuration of existing and the addition of new model parameters, as well as by reference to later year energy statistics. For the modelling of the total EU28 potential, utilising a dataset for the geographical representation of current urban district heating areas more detailed than the previous one, renders by spatial analytics, under the same “inside or within 2 kilometres of urban district heating areas” default setting as used before, an updated and more accurate assessment of the distances and the vicinity by which low-grade urban waste heat sources are located relative current demand locations. We maintain in this report also our application of the two concepts “available” waste heat and “accessible” waste heat, which, in combination with spatial constraints, are used to distinguish between resource potentials and utilisation potentials. For the total count of activities elaborated in this update (70,862 unique point-source activities compared to the original 70,771), the total available waste heat potential is assessed at some 1849 petajoule per year (~514 terawatt-hours), compared to the original 1842 petajoule per year. At the default spatial constraint setting, the final available waste heat potential is estimated at ~800 petajoule per year (~222 terawatt-hours) from a thus reduced subset of 22,756 unique point-source locations (960 petajoule per year from 27,703 unique facilities in the original), which here corresponds to a final accessible EU28 waste heat utilisation potential anticipated at 1173 petajoule (~326 terawatt-hours) annually (previous assessment at 1410 petajoule annually). For improved dissemination and exploitation of project results, a new web map; the European Waste Heat Map, has been developed and made available at the ReUseHeat project web page where point source data from this work may be viewed and shared. © The Authors.

This report is the second out of three consecutive accounts of a coherent methodological framework developed in the EU Horizon 2020 project Decarb City Pipes 2050 to define heating and cooling decarbonisation design approaches for cities based on urban typologies. The first and third accounts are, respectively, the deliverable reports D2.5 (Decarbonisation design-approaches based on urban typologies) and D2.7 (Recommendations for cities' H/C supplies & demands in 2050). The framework has been developed by identifying possible thematic synergies between the objectives of the concerned deliverables, by combining different method elements, and by organising a collaborative work strategy among the involved project partners. This report presents, in overview and detail, the input data synonymously used within the framework for the determination of urban typologies, for the modelling and mapping of heating and cooling outlooks for 2050, for the quantification of a cross-city synthesis, as well as for formulating recommendations for cities´ heating and cooling demands and supplies in 2050. The study focusses on the urban areas of seven European project cities (Bilbao (ES), Bratislava (SK), Dublin (IE), Munich (DE), Rotterdam (NL), Vienna (AT), Winterthur (CH)), for which EU-scoped, publicly available input data, to the extent possible, has been gathered according to ten structuring criteria parameters. Heating and cooling outlooks for 2050 are established for each project city based on the used input data and illustrated in the form of tables, graphs, and maps, and constitute the first element of a quantitative cross-city synthesis (city comparison). The second element (city ranking) is facilitated by application of a multi-criteria decision model, which here consists of combining the Analytical Hierarchy Process method (AHP) and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS).

This report presents the work performed in Task T1.2 of the ReUseHeat project to assess the accessible EU28 urban excess heat recovery potential from four unconventional excess heat sources: data centres, metro stations, service sector buildings, and waste water treatment plants. The report presents in overview and detail the concepts, data, basic premises, and methods, used to produce the results from this work. In all, excess heat potentials are modelled and spatially mapped for a total of some 26,400 unique activities, but by application of two new concepts: available excess heat and accessible excess heat, by which total potentials are distinguished from practical utilisation potentials, a significantly reduced count of some 6800 unique facilities represent the final cut. Common for these facilities are that they all are located inside or within 2 kilometres of urban district heating areas. For the total count of activities, the full available excess heat potential is assessed at some 1.56 EJ per year. At the restrained conditions, thus representing a conservative estimate, the final available excess heat potential from the four unconventional sources is estimated at 0.82 EJ per year, which here corresponds to a final accessible excess heat potential anticipated at 1.24 EJ annually.

This report presents the revised work performed in Task T1.2 of the ReUseHeat project to assess the accessible EU28 urban excess heat recovery potential from seven unconventional excess heat sources: data centres, metro stations, food production facilities, food retail stores, residential sector buildings, service sector buildings, and waste water treatment plants. The report presents in overview and detail the concepts, data, basic premises, and methods, used to produce the results from this work. In all, excess heat potentials are modelled and spatially mapped for a total of some 70,800 unique activities, but by application of two new concepts: available excess heat and accessible excess heat, by which total potentials are distinguished from practical utilisation potentials, a significantly reduced count of some 27,700 unique facilities represent the final cut. Common for these facilities are that they all are located inside or within 2 kilometres of urban district heating areas. For the total count of activities, the full available excess heat potential is assessed at some 1.84 EJ per year. At the restrained conditions, thus representing a conservative estimate, the final available excess heat potential from the seven unconventional sources is estimated at 0.96 EJ per year, which here corresponds to a final accessible excess heat potential anticipated at 1.41 EJ annually.

Efficiency in the heat sector and the built environment can be achieved by building retrofits, the replacement of buildings, and the development of district heating as a means of structural energy efficiency. Hereby, excess heat and low-grade renewable heat sources can be integrated in the heat sector. The present report describes the future heat sector of Europe from end-use via infrastructure to heat sources. Future heat demands on national level have been modelled by sEEnergies project partners. In the present work, these demands are being distributed to future urban areas. Population forecasts have been combined with local empirical data to new 100m resolution population grids. They form the basis for the calculation of heat demands for the years 2030 and 2050 on the same geographical level. Potential areas, where district heating could be developed, have been zoned as prospective supply districts (PSDs) and basic statistics of heat demand have been calculated. Then, based on empirical district heating network data from existing district heating networks in Denmark, a new investment cost model for distribution and service pipes has been developed. Based on previous work in the Heat Roadmap Europe research project, the cost model has been improved with a better understanding of the concept of effective width. With the integration of country-specific construction cost data this results in an improved district heat distribution capital cost model for all Member States of the European Union plus the United Kingdom. The spatially explicit combination of district heat potentials and costs results in cost-supply curves for all countries as the basis for the assessment of the economic potential of future district heating. Finally, available excess heat sources from industry, waste incineration, wastewater treatment plants, and current powerplant locations are being allocated to prospective supply districts. Renewable heat potentials, including deep geothermal heat, solar thermal heat, and residual, local biomass, have also been assigned to these prospective heat supply areas. The results of the present work have been published as a web map.

This study presents a methodology to assess annual excess heat volumes from fuel combustion activities in energy and industry sector facilities based on carbon dioxide emission data. The aim is to determine regional balances of excess heat relative heat demands for all third level administrative regions in the European Union (EU) and to identify strategic regions suitable for large-scale implementation of district heating. The approach is motivated since the efficiency of current supply structures to meet building heat demands, mainly characterised by direct use of primary energy sources, is low and improvable. District heating is conceived as an urban supply side energy efficiency measure employable to enhance energy system efficiency by increased excess heat recoveries; hereby reducing primary energy demands by fuel substitution. However, the importance of heat has long been underestimated in EU decarbonisation strategies and local heat synergies have often been overlooked in energy models used for such scenarios. Study results indicate that 46% of all excess heat in EU27, corresponding to 31% of total building heat demands, is located within identified strategic regions. Still, a realisation of these rich opportunities will require higher recognition of the heat sector in future EU energy policy. © 2014 Elsevier Ltd.

This report is the main account for the methodologies, assumptions, data, and tools used in the WP2 mapping of the fourth Heat Roadmap Europe (HRE) project during its first reporting period (March 2016 to August 2017). During this period, the work with the major tasks assigned to WP2 in the project, including e.g. highly resolved spatial demand and resource atlases for the 14 MS´s of the EU under study, has resulted in a wide array of intermediate, complementary, and final outputs. Mentionable among these are for example hectare level projections of demand densities (residential and service sector heating and cooling demands) and investment costs for district heating and cooling systems, as well as feature polygon representations of current district heating cities in these countries. However, since the core focus here is to describe the methodological approaches and data sets used in the work, and not explicitly to present the results of the application of these, only a limited representative selection of study results are included in this report. For more exhaustive output presentations of the WP2 productions (apart from deliverables D2.1 and D2.2), all final output datasets generated are made available as operational layers in the online web map application Peta4 (the fourth Pan-European Thermal Atlas).