Climate change and the increase of carbon dioxide in the atmosphere is an ongoing problem affecting the earth globally. To break this trend and revert the changes a continuous upgrade of the current energy system is needed, one way of doing this is by using models to simulate new systems. One of the areas that needs optimization is heat distribution systems and district heating. In this master thesis a model for simulation of district heating is built and tested for several case studies. This thesis is part of a larger research project which aims at integrating multiple models regarding mobility and energy systems to simulate a smaller society. The distribution system model was created using matrices to describe the connections within the system and then used to calculate mass flow, pressure drop, temperatures and heat losses. Results show that placement of new users in the grid heavily impact the mass flow and pressure drop throughout the system. Moreover, the result also shows that a reduction of the temperature requirement at one user has the possibility to drastically lower the temperature through the system and lower the heat losses significantly. Before further use of this model verification with commercialized software is strongly suggested.

In different countries, such as Ukraine and Sweden, there have been differences in the way of administrating the systems which dictate the way of living and the way the societies function. Different approaches have been adopted over the time when it came to setting up the rules for how the state´s vital organizations, such as tax administration, health care, police, army, education system and many others should work and function. The idea in many modern countries is the same, but the ways and procedures can differ a great deal from country to country. This applies to the sphere of district heating services as well. The purpose of this thesis is to gain understand with the help of economic theory why heating tariffs are managed in a country that has had transition from plan economy to market economy the way they are, and how the management of heating tariffs could be improved when taking into account the experience of a country with long established market economy. During field studies performed in Sweden and Ukraine, particularly in the city of Donetsk, a comparative analysis of the two heating tariff systems have been performed in order to outline and highlight the differences between them and to answer the main questions of the study. The results include the status report of the situation concerning the district heating tariff systems in Sweden and Ukraine, comparative analysis of the two systems and suggestion on improvements of the district heating tariff system in the city of Donetsk. The outcomes and suggested improvements do not provide the full picture and all the aspects of the situation, due to the fact that more extensive studies, involving larger resources, would have to be conducted in the area. However, the report provides a good starting point for further studies within the field of district heating tariffs in Ukraine and Sweden.

Climate change is making energy an important matter for scientists, politics and industries. Public concerns and energy supply limitations are changing the rules of energy markets. Fossils fuels are becoming expensive and energy policy makers encourage the development of renewable energies. Every energy sector is impacted by those changes. With a significant potential in reducing greenhouse-gas emissions and fossil fuels dependency, the heating market is moving towards greener solutions. It is within this context that Dalkia is developing district heating solutions. This French company is one of the two large actors in the heating market in France and try to keep being part of the energy sector. This thesis work was realized within Dalkia and focuses on a study case: Sevran district heating network. This network provides about 50 GWh of heat with a 60% share of renewable energy (biomass). Developing this network is one way of increasing the renewable share in France. This master thesis tackles two extension possibilities. The study case starts with drawing the state of the existing district heating network. This allows to know a consumption limit in order to keep the 60% share of renewable energy. The district heating network is then modelled with a software called Termis to know hydraulic limits. Extension projects are simulated with this same model to evaluate their technical feasibility. An economical study is finally performed. The study concludes that both extensions are technically feasible, but only one is economically relevant for Dalkia. This master thesis was also the opportunity to observe the French heating market from an industrial point of view. Sevran study case is a typical example of how district heating companies are changing considering economy, energy policies and public acceptance.

This report is a case study about geothermal energy system and its application forthe hospital in the city of Gävle. Today the hospital uses district heating and -coolingas their main energy source.There is a report about the hospital in the city of Umeå where geothermal energyhas been installed. Both hospitals have the same need when it comes to using heatand cooling all year round. The hospital in Umeå installed geothermal energy sothat they got a less vulnerable energy system. The emissions of CO2 were also lowereddue to this installation.This report aims to answer the following research question.How geothermal energy can be a option of choice for the hospital I the city ofGävle?The report presents a literature study on subject close to this research question. Focusfor the report is to find out if increased electricity consumption is better than usinglocal district heating- and cooling. The report from the geothermal installation inUmeå has on big difference and that is from which fuels the district heating is produced.In Gävle the energy comes from biomass which gives that the emission factoris almost zero.The calculations and modelling are performed in Excel and the results presented ingraphs.The results are positive both from an economical view and environmental perspective.If the total electricity price doesn’t increase more than 36% per year then geothermalenergy is more cost effective. Looking at the emissions of CO2 equivalentswith an emission factor of 90.4 kg per MWh electricity the COP-factor should notbe lower than 7.5. If that can be reached, then geothermal energy performs betterthan district heating- and cooling.

In 2018, Stockholm Exergi, the largest district heating producer in Stockholm, used around 36% of imported fuel from other countries. With a large amount of imported fuel, fuel management is taking a vital part for Stockholm Exergi to ensure district heating supply stability. To manage fuel planning, Stockholm Exergi will calculate fuel demand forecasting for the next three years by using an optimization tool called “BoFiT”. But high optimization time is the main issue for the current midterm model. More than six hours are spent on regular model optimization. Therefore, midterm model optimization is typically run overnight. If there is an error occurring while the model is running, more time might be lost. From a preliminary study on the midterm model optimization time, the time spent in the calculation process is accounted for 80% of the total optimization time. In BoFiT, the midterm visual model is transformed into the mathematical model to solve for optimum results. The idea of decreasing the midterm model optimization time is the activation of LP relaxation in BoFiT. With LP relaxation activation, the computation time in the calculation process will be minimized. However, the usage of LP relaxation is giving some of the consequences to the optimization results.  Based on the study of the midterm model optimization time, the usage of LP relaxation can decrease the time spent in the calculation process for 67.72%. When considering the overall optimization time, 48.60% of the optimization time was reduced by LP relaxation activation. The statistical analysis in 2018 BoFiT optimization showed that results from relaxed optimization have slightly lower accuracy than the results from normal optimization in heat and electricity production. However, the relaxed optimization results in fuel consumption are considered comparable for most of the fuel except by fossil oils. For midterm optimization, heat and electricity production forecasting from normal optimization and relaxed optimization are comparable. For fuel demand forecasting, fossil oils give the most significant different results in terms of forecasting analysis. However, the wood chip has the most considerable difference in the demand for midterm fuel planning. The result from relaxed optimization showed that it requires 305.89 GWh more than that from normal optimization. With a vast amount of wood chip consumption, it could have high effects on the wood chip preparation and storage for Stockholm Exergi.

In recent years, the electrification of technology that is traditionally powered by fossil fuels has become a popular means to reduce greenhouse gases (GHG). Although the intentions are well founded, the strain on the electrical grid is seldom taken into consideration. When there is increased load on the grid, it is typically met by fossil fuel peaking power plants or additional fossil fuel infrastructure. Depending on the electrical generation technology deployed and the power plant efficiency, electrification can result in an increase in GHG emissions. To make better informed decisions for GHG reductions, policy makers and engineers are in need of smart energy systems, such as the Integrated Community Energy and Harvesting (ICE-Harvest) system. ICE-Harvest systems work with and can respond to changes on the electrical grid, providing demand response. The system creates electrical demand when renewable generation sources are available, reduces demand when fossil fuel generation is present, and can offset centralized generation using distributed combined heat and power resources. In this thesis, steps to design a micro-thermal network (MTN) for the ICE-Harvest system are outlined and different operational strategies are explored that respond to grid behaviour in real time. How fast the thermal network reacts to grid level variations is defined as the response time. The physical response of the thermal network is a temperature set point change. A design map was developed presenting multiple parameters that contribute to the response time, the trade-offs between them, and the corresponding temperature difference achievable. Through developing models in the equation-based object-oriented software Dymola, the viability for real time temperature set point changes in micro-thermal networks was explored. The MTN and the energy transfer stations (ETSs) that transfer energy between the thermal network and the buildings have been modeled. Yearly system simulations were conducted to analyze the corresponding performance of the MTN in terms of electrical requirements and overall GHG emissions. An operational range of the system was presented demonstrating the flexibility of the ICE-Harvest system. The simulation results have identified the ICE-Harvest system as a viable means to provide demand response to the grid and to reduce GHG emissions. Future work and recommendations will be made to improve the response of the system and further reduce electrical consumption and GHG emissions. / Thesis / Master of Science in Mechanical Engineering (MSME)

För majoriteten av Umeå universitetscampus finns en anslutningspunkt för fjärrvärme från Umeå Energi. Under januari 2024 uppstod problem när fjärrvärmeeffekten överskred den abonnerade nivån under några extremt kalla dagar, vilket resulterade i straffavgifter från leverantören. Projektets syfte är att analysera och lösa överbelastningsproblemen genom att hitta och jämföra olika förbättringar för värmesystemen på campus. Effektsignaturer analyserades för utvärdering av variationen i den inköpta fjärrvärmen på Umeå universitetscampus, för drift under och utanför verksamhetstid. Resultaten visar en maximal potentiell effektreduktion på 29,4% vid DVUT (dimensionerande vinterutetemperatur). En strategisk driftstrategi kan tillämpas genom att ändra styrsystemets globala tidsschema till röd dag för att uppnå effektreduktion i byggnader utan närvaro. Detta motsvarar en maximal potentiell ekonomisk besparing på 1,7 miljoner kronor för den totala effektreduktionen. Effektkartläggning av Fysikhusets värmesystem utfördes. Resultatet vid DVUT visade att radiatorerna endast stod för 30% av fjärrvärmeeffekten, LA001 (ventilationsaggregat i Fysikhuset, laborationssalar) 64% och LA002 (ventilationsaggregat i Fysikhuset, kontor) 6%. Fysikhusets variation i fjärrvärmebehov under och utanför verksamhetstid vid DVUT visar en minimal skillnad på endast 0,3%, vilket främst beror på värmesystemens utformning och verksamheten som bedrivs. Radiatorernas effektbehov i Fysikhuset vid DVUT analyserades vid sänkning av inomhustemperatur från 21°C till 18°C. Resultaten visar en effektreduktion på 8,7kW och en ekonomisk besparing på 5 746kr, jämfört med radiatorernas normala effektbehov på 43,5kW. Sänkning av ventilationsflöde i Fysikhuset enligt BBR (Boverkets byggregler) visar potential för betydande effektreduktion, med möjlighet att minska ventilationen upp till 61,8% under närvaro och 89,1% utanför närvaro, vilket kan leda till en ekonomisk besparing på mellan 4 700 - 59 500kr. Beräkningar visar att för varje grad (°C) sänkning av tilluftstemperaturen i Fysikhusets ventilation kan en effektreduktion på LA001 och LA002 uppnå 4kW och 3,7kW per grad respektive, vid DVUT. / For most of the buildings on Umeå University campus there is one main connection point for district heating from Umeå Energi. In January 2024 problems occurred when the district heating output exceeded the subscribed level during some extremely cold days, resulting in penalty charges from the supplier. The purpose of the project is to analyse and solve the overload problems by finding and comparing different improvements for the heating systems on campus. Power signatures were analysed for evaluation of the variation in the purchased district heating at Umeå University campus, for operation during and outside business hours. The results show a maximum potential power reduction of 29,4% at DVUT (dimensioned winter outdoor temperature). An operating strategy can be applied by changing the control system's global time schedule to public holiday to achieve a power reduction in unoccupied buildings. This corresponds to a maximum potential financial saving of SEK 1,7 million for the total effect reduction. Power mapping of the building “Fysikhusets” heating system was carried out. The results at DVUT showed that the radiators accounted for only 30% of the district heating power, LA001 (ventilation unit in Fysikhuset, laboratory rooms) 64% and LA002 (ventilation unit in Fysikhuset, offices) 6%. The district heating demand variation in Fysikhuset during and outside of operating hours at DVUT shows a minimal difference of only 0,3%, which is mainly due to the design of the heating systems and the operations that are carried out in the building. A power reduction on the radiators in Fysikhuset was analysed by lowering the indoor temperatures from 21°C to 18°C, the results showed a power reduction of 8,7 kW and a financial saving of SEK 5 746. Compared to the radiators normal power requirement of 43,5kW. Reduction of ventilation flow in Fysikhuset according to BBR (Boverket´s building regulations) shows potential for significant power reduction, with the possibility of reducing ventilation up to 61,8% during attendance and 89,1% without attendance, which can lead to a financial saving of between SEK 4,700 - 59,500. Calculations show that for each degree (°C) lowering of the supply air temperature in Fysikhusets ventilation, a power reduction on LA001 and LA002 can reach 4kW and 3,7kW for each degree respectively, at DVUT.

Recently, there has been an uptake of integrating solar thermal into district heating (DH) systems. It has been recognized as one of the paths towards a more sustainable future. However, there are some countries where the adoption is very slow, regardless of its market readiness. Adoption and diffusion literature points to the need to investigate slow adoption examples to contribute to the already existing knowledge. Consequently, this thesis investigates influencing factors, barriers, and drivers for the slow adoption of solar thermal into DH systems.   A case study was carried out to identify influencing factors for the slow adoption of solar thermal within DH systems. The case was chosen based on purposive and extreme sampling as it referred to the adoption of the first large-scale solar thermal into DH systems in France. Stratified purposive sampling, in combination with snowball sampling, was used to acquire eleven interviews. Thematic analysis was utilized to analyse the findings.   Results identified four themes, Technology, Environmental Regulations, Management of DH systems, and Financials, where each theme contained several subthemes. Barriers and drivers were developed from the subthemes. Among the most prominent barriers were the combination of lack of experience and a rigid legal framework, resulting in the barrier of ex-post integration, which implies considering the whole DH system when integrating new technologies. Another identified prominent barrier was cheap fuels which include biomass, as well. Environmental policies were found to both help and hamper the adoption. A driver, called a champion, mainly pushed the adoption of solar thermal within the studied case.    In conclusion, several barriers and drivers can influence the adoption of solar thermal into DH systems, and taking them into account should facilitate its adoption. Next, investigating a slow adoption case proved to be a valuable venue for acquiring new knowledge. Lastly, based on the empirical results of the studied case, solar thermal could not be labelled as an environmental innovation, which has alarming implications for achieving sustainable development goals in the future.

Blockchain is described as having endless theoretical potential. In reality however, it is hard toestablish how blockchain can be utilized and what opportunities blockchain may create. Theunclear future of blockchain constitutes a challenge for many companies. Many large incumbentsare uncertain of how to implement blockchain technology in their organization and are anxiousabout the consequences of the new technology. The purpose of this exploratory study is to evaluateblockchain applications for a district heating company in Stockholm to understand favorable areas,necessary criteria for successful implementation and how blockchain could enable new businessopportunities in the district heating market. To be able to reach the purpose of the thesis aliterature study and an empirical study were performed. The literature study is in the form of anextensive investigation about the areas of blockchain and district heating. The empirical studyincludes 17 interviews, both internal interviews with employees at Stockholm Exergi and externalinterviews conducted with professionals with knowledge about blockchain, district heating and theenergy sector. Furthermore, two workshops, in collaboration with Stockholm Exergi, wereperformed at the end of the thesis to evaluate and prioritize the developed blockchain applications.This thesis proposes 32 blockchain applications within 10 areas in the district heating industry.The applications are categorized after their potential, in three categories; green for the blockchainapplications that are valuable to investigate further, orange for the applications that potentiallycould be interesting to investigate further, and red for the applications that are not interesting toinvestigate further. Some applications focus on solving inefficiencies within district heating andsome on exploiting the benefits of blockchain. Eight applications are categorized with greenprioritization, and thus presented in more detail. To take into account that blockchain probablywill have a greater impact in the future, a future scenario was developed and used in the situationalanalysis for the applications. Furthermore, a framework was developed with the aim to be a toolfor a district heating company to utilize while considering if a blockchain implementation wouldbe beneficial, and if so, in what way. The framework is focused on district heating companies butcan be utilized by other actors as well.Our recommendation for a district heating company in Stockholm is to wait one or two yearswhile staying updated. Especially important for the companies are to stay updated on whether newblockchain standardizations will emerge in the energy sector. However, if a district heatingcompany want to initialize a blockchain project we advise the companies to start a pilot projectthat does not affect the current business model but has the potential to be scaled. Since theblockchain technology enhances collaboration, it is important to consider which partners shouldbe included and how the application can create value for all involved parties. However, due to theuncertainty of the technology, companies need to be well aware of that assumed created value maynot be reached as expected. Furthermore, district heating companies also need to bear in mindthat other parameters, for example additional technologies, policies or infrastructure systems, maybe necessary to implement in order to create value from a blockchain solution. / Blockchain beskrivs ofta som något med ändlös teoretisk potential. I verkligheten är det dock svårtatt fastställa hur blockchain kan användas och vilka möjligheter blockchain kan skapa. Den osäkraframtiden för blockchain är en utmaning för många företag att förhålla sig till. Inte minst för storaetablerade företag då blockchain kan användas för att decentralisera en centraliseradmarknadsstruktur. Syftet med denna undersökande studie är att utvärdera blockchainapplikationerför ett fjärrvärmeföretag i Stockholm, för att förstå gynnsamma områden,nödvändiga kriterier vid genomförande och hur blockchain skulle kunna möjliggöra nyaaffärsmöjligheter på fjärrvärmemarknaden. För att uppfylla uppsatsens syfte genomfördes enlitteraturstudie och en empirisk studie. Inom litteraturstudien genomfördes en omfattandeundersökning av blockchain och fjärrvärme. Den empiriska studien bestod av 17 intervjuer, bådeinterna intervjuer med anställda från Stockholm Exergi och externa intervjuer med experter inomblockchain, fjärrvärme och energisektorn. Vidare genomfördes under slutfasen två workshops isamarbete med Stockholm Exergi, för att utvärdera och prioritera de skapade blockchainapplikationerna.Rapporten presenterar 32 blockchain-applikationer inom 10 olika områden inomfjärrvärmeindustrin. Applikationerna är kategoriserade efter sin potential i tre grupper, grön för deapplikationer som kan vara fördelaktiga för ett fjärrvärmeföretag och bör fortsätta undersökas,orange för de applikationer som sannolikt inte skulle vara fördelaktiga och röd för de applikationersom inte är intressanta för ett fjärrvärmeföretag att fortsätta undersöka. Vissa applikationerfokuserar på att lösa de ineffektiviteter som finns för fjärrvärme och vissa på att utnyttja fördelarnamed blockchain. Det åtta applikationer med grön prioritering presenteras mer detaljerat. Ettframtida scenario togs fram för att ta hänsyn till att blockchain sannolikt kommer att ha störrepåverkan i framtiden. Detta används som hjälpmedel när situationsanalysen för applikationernagenomförs. Dessutom utvecklades ett ramverk som har som syfte att vara ett verktyg för ettfjärrvärmeföretag att utnyttja när en blockchain implementering övervägs. Ramverket är inriktatpå fjärrvärmeföretag men kan även användas av andra aktörer.Vår rekommendation till ett fjärrvärmeföretag i Stockholm är att vänta ett eller två år, samtidigtsom de håller sig uppdaterade om marknadsförändringar för blockchain. Särskilt viktigt för ettfjärrvärmeföretag är att hålla sig uppdaterad om huruvida nya blockchain-standardiseringar uppstårinom energisektorn. Om ett fjärrvärmeföretag vill initiera ett blockchain-projekt, rekommenderarvi att starta med ett pilotprojekt som inte påverkar den nuvarande affärsmodellen, men harpotential att skalas. Eftersom blockchain-teknologin möjliggör samarbete är det viktigt attöverväga vilka partners som kan ingå i lösningen och hur applikationen kan skapa värde för allaberörda parter. Företag måste emellertid vara väl medvetna om att det förväntade värdet kanskeinte uppnås på grund av teknologins osäkerhet. Dessutom måste företagen också överväga attandra parametrar, till exempel andra teknologier, politik eller infrastruktur, är nödvändiga, för atten blockchain implementering ska skapa värde.

The concept of future sustainability is driving efforts toward the efficient improvement of energy systems. District heating systems play a key role in balancing the energy system by improving performance and flexibility. As system efficiency increases, fuel consumption decreases, resulting in reduced greenhouse gas emissions and mitigating potential climate impacts, especially when using fossil fuels. In Sweden, district heating has shown significant growth, with a 75 % increase in total heat production over the last 30 years. Furthermore, carbon dioxide emissions have been reduced by approximately 50 % for each delivered kWh in the past 20 years, while renewable energy sources have doubled in the district heating sector. This thesis focuses on optimizing the cooling process to achieve lower return temperatures and higher system efficiency. It also emphasizes the importance of implementing an efficient heat consumption strategy to reduce peak loads and improve overall system efficiency. This approach involves managing demand to minimize peak heat requirements and distribute the load evenly throughout the day, leading to a more resource-effective and efficient system. The case study examines district heating supplied by VB Energy to Ludvikahem AB buildings, using data from Dec 2022 to Jan 2023. Quantitative data from district heating substations and the district heating plant are collected and analyzed to generate qualitative insights. The study proposes theoretical optimization measures based on the findings. The evaluation of substation performance reveals 20 poorly performing substations with various issues. Eight of these substations have technical problems related to substation components, while another eight experience management issues not aligned with specific activity profiles. The load shifting simulation demonstrates a 3% reduction in heat rate peak levels, resulting in approximately 7 kW of subscribed heat rate savings. Energy usage savings reach approximately 0.9%, leading to an increase in energy usage effectiveness. The cost savings amounted to about 3000 SEK over two months for a single building. This research emphasizes the importance of routine control, inspection, and documentation of substation performance to ensure optimal efficiency. Furthermore, indicates that the poorly performing substations that contribute to inefficiencies in the district heating network. Additionally, real-time regulation and load-shifting strategies are vital for optimizing customer consumption and maintaining an efficient district heating system, benefiting both suppliers and consumers.