Satellite District Heating and Cooling (DHC) systems offer an alternative structure to conventional, centralized DHC networks. Both use a piping network carrying steam or water to connect disparate building heating and cooling loads together, providing a platform for improving energy efficiency, reducing emissions, and incorporating alternative means of energy generation. However, satellite DHC networks incorporate thermal production units that are distributed amongst the buildings nodes, which offers greater operational flexibility and reduced capital cost savings for applications using existing building stock. This study was focused on the development of the methodology behind a comprehensive energy model that can assess the practical and financial viability of satellite DHC network scenarios. A detailed scenario application of the model demonstrated significant energy savings and investment potential. Additionally, environmental assessment methods and alternative generation technology were explored in supplementary studies of Deep Lake Water Cooling (DLWC) and building-scale Combined Heat and Power (CHP).

<p>Managing the highly dynamic and interdependent systems within a district energy system is an intricately complex undertaking. A district energy manager is expected to make decisions that will result in the achievement of the district’s goals, often with limited capital and personnel resources. What has been lacking in the tools available to a district energy manager is an established decision-making framework with which to process the complex internal and external variables involved to effectively develop and evaluate options to make successful decisions.<br><a></a></p> <p> </p> <p>While capitalizing on the experience of seasoned district energy managers and a literature review of current methodologies, this dissertation assesses the strengths and weaknesses of the methodologies currently available to managers of district energy systems and presents a new and more comprehensive decision-making framework. A system of systems engineering approach is applied, and multiple relevant case studies are analyzed. Procedures for significantly mitigating many of the external risks to a district energy system are developed and documented. </p> <p> </p> <p>The main contribution of this dissertation is a unique decision-making framework with a holistic approach encompassing the complexity, emergence, and interdependency of district energy subsystems. This framework will aid a district energy manager in making successful decisions which meet the goals of the district.</p>

Fernkälte bietet das Potenzial, wirtschaftlich und ökologisch vorteilhaft zur Deckung des stetig zunehmenden Klimakältebedarfs beizutragen. Im Rahmen dieser Arbeit wurde ein dynamisches thermohydraulisches Netzmodell „ISENA“ entwickelt, mit dem während der Planung und des Betriebs von Fernkältesystemen auftretende Fragen, beispielsweise in Bezug auf Wirtschaftlichkeit und Energieeffizienz, beantwortet werden können. Das Netzmodell setzt sich aus einem quasistationären hydraulischen Modell und einem instationären thermischen Modell zusammen, das auf der Verfolgung von Wasserpfropfen durch das gesamte Netz basiert (Lagrange-Ansatz). Mit diesem Modellierungsansatz können numerische Fehler sowie Bilanzungenauigkeiten vermieden werden, sodass sich eine höhere Ergebnisgüte im Vergleich zu bisher bekannten Netzmodellen erreichen lässt. Ebenfalls neu entwickelt wurde das Teilmodell zur Abbildung der Wärmeströme über die Wände unterirdischer Rohrpaare (Kälteverluste und -gewinne). Dieses Modell erlaubt die Bestimmung der instationären Rohrwand-Wärmeströme für wärmegedämmte unterirdische Rohrpaare, Rohrpaare mit gedämmtem Vor- und ungedämmtem Rücklauf sowie ungedämmte Rohrpaare. Anhand von Validierungs- und Verifikationsrechnungen wird gezeigt, dass ISENA verlässliche Ergebnisse liefert und für die praktische Anwendung geeignet ist. Abschließende Beispielrechnungen geben einen Einblick in die Untersuchungsmöglichkeiten, die das neue Modell bietet – unter anderem im Hinblick auf den Vergleich von Pumpenregelungsvarianten, den Einfluss von Rohrdämmung und Erdreicheigenschaften auf Kälteverluste und -gewinne sowie die Einbindung von Hochtemperatur-Kälteverbrauchern in den Netzrücklauf. / District cooling can provide economic and ecological benefits while supplying the increasing cooling demand for air conditioning. In the present thesis, a dynamic thermo-hydraulic model “ISENA” is presented which may be used in order to answer questions arising during design and operation of district cooling networks—e. g., that are related to economic and energy efficiency. The network model consists of a quasi-static hydraulic module and a transient thermal module being based on the tracking of water segments through the entire network (Lagrangian method). With this approach, numerical errors and inaccuracies in the balance of conserved quantities could be avoided, which eventually leads to a better reliability of the results as compared to that obtained from other network models. Additionally, a new sub-model has been developed for predicting the transient heat flux through the walls of buried pipes in order to model thermal gains and losses. This model covers un-insulated, insulated and combinations of insulated as well as un-insulated pipes. Calculations performed for the purpose of validation and verification are presented in order to demonstrate that ISENA provides reliable results and hence is suitable for practical applications. Finally, example simulations show the various possibilities provided by the new model—for example, concerning the comparison of different strategies for pump control, the influence of pipe insulation and soil properties on thermal gains and losses as well as the connection of buildings equipped with high temperature cooling systems to the return line of the network.

In this dissertation, an assessment is conducted of the potential benefits of combined heat and power (CHP) based district energy (DE) grids in energy systems of different scale having significant fossil fuel fired electrical generation capacity. Three studies are included in the research. In the first study, the potential benefits of expanding CHP-based DE grids in a large scale energy system are investigated. The impacts of expanding wind power systems are also investigated and a comparison between these technologies is made with respect to fossil fuel utilization and CO2 emissions. A model is constructed and five scenarios are evaluated with the EnergyPLAN software taking the province of Ontario, Canada as the case study. Results show that reductions in fuel utilization and CO2 emissions of up to 8.5% and 32%, respectively, are possible when switching to an energy system comprising widespread CHP-based DE grids. In the second study, a high temporal resolution numerical model (i.e. the SS-VTD model) is developed that is capable of rapidly calculating distribution losses in small scale variable flow DE grids with low error and computational intensity. The SS-VTD model is validated by comparing simulated temperature data with measured temperature data from an existing network. The Saanich DE grid, located near Victoria, Canada, is used as the case study for validation. In the third study, the potential benefits of integrating high penetrations of renewable energy via a power-to-heat plant in a small scale CHP-based DE grid are investigated. The impacts of switching to a CHP-based DE grid equipped with an electric boiler plant versus a conventional wave power system are compared with respect to fossil fuel utilization and CO2 emissions. The SS-VTD model is used to conduct the study. The energy system of the Hot Springs Cove community, located on the west coast of Vancouver Island, Canada is used as the case study in the analysis. Results show that relative to the conventional wave power system, reductions in fuel utilization and CO2 emissions of up to 47% are possible when switching to a CHP-based DE grid. / Graduate

Du fait de la flexibilité énergétique qu'ils offrent et de leur potentiel de diminution des émissions de GES et de polluants, les réseaux de chaleur (RdC) sont un des leviers d'actions des politiques énergétiques locales en constante progression. Leur déploiement et/ou rénovation n'est pas qu'une question technico-économique classique, dans la mesure où ils sont au cœur d'un ensemble d'acteurs interconnectés, aux objectifs spécifiques, tous parties prenantes des politiques énergétiques locales. Dans ce contexte, les outils permettant à ces différents acteurs l'évaluation des actions liées aux RdC sont très importants. Ils doivent permettre l'évaluation de scénarios de conception, d'actions de rénovation, de performance et de suivi... Parmi les outils permettant ces évaluations, les approches par modélisation sont souvent trop spécifiques à une situation, un type de réseau un acteur... Le travail réalisé consiste à développer un outils de modélisation de RdC, offrant la flexibilité recherchée. "HeatGrid" permet de modéliser des architectures de réseaux variées. A chaque pas de temps, le fonctionnement du réseau est simulé grâce au formalisme de la programmation linéaire. Cet outil peut être utilisé en phase de conception ou d'exploitation d'un réseau. L'approche de modélisation permet d'évaluer et de comparer sous les aspects économiques, énergétiques et techniques d'un RdC sous différents scénarios. Plusieurs exemples sont simulés et analysés dans le but d'illustrer le potentiel du modèle. / Because of the energy flexibility that they offer and their potential to reduce GHG emissions, disctrict heating (DH) networks are a tool of local energy policies in constant progression. Their develpment and/or renovation is not only a classic technico-economical question, insofar as interconnected stakeholders of local energy policies, taking into account specific objectives, are concerned by DH networks. In this context, tools which enable these different stakeholders to evaluate actions related to DH networks are essential. They must be helpful for the assessment of renovation actions, the monitoring and the evaluation of performances....Among the tools that allow theses evaluations, the modelling approaches are often too specific to a situation, a type of network, a stakeholder... The work of the thesis consists in developing a DH modeling tool that has this desired flexibility. The proposed tool "HeatGrid" can model various network architectures. At each time step, the network running is simulated via linear programming formalism. This tool can be applied either at the design stage of a DH or at the operating stage. The model based approach enables the evaluation and comparison of economic, energy and technical aspects of the DH system in different scenarios. Several examples are simulated and analyzed in order to illustrate the potential of the model.

Thermal energy storage (TES), the storage of heat or cooling, is a cost-effective energy storage technology that can greatly enhance the performance of the energy systems with which it interacts. TES acts as a buffer between transient supply and demand of energy. In solar thermal systems, TES enables the power output of the plant to be effectively regulated, despite fluctuating solar irradiance. In district energy systems, TES can be used to shift loads, allowing the system to avoid or take advantage of peak energy prices. The benefit of TES, however, can be significantly enhanced by dynamically optimizing the complete energy system. The ability of TES to shift loads gives the system newfound degrees of freedom which can be exploited to yield optimal performance. In the hybrid solar thermal/fossil fuel system explored in this work, the use of TES enables the system to extract nearly 50% more solar energy when the system is optimized. This requires relaxing some constraints, such as fixed temperature and power control, and dynamically optimizing the over a one-day time horizon. In a district cooling system, TES can help equipment to run more efficiently, by shifting cooling loads, not only between chillers, but temporally, allowing the system to take advantage of the most efficient times for running this equipment. This work also highlights the use of TES in a district energy system, where heat, cooling and electrical power are generated from central locations. Shifting the cooling load frees up electrical generation capacity, which is used to sell power to the grid at peak prices. The combination of optimization, TES, and participation in the electricity market yields a 16% cost savings. The problems encountered in this work require modeling a diverse range of systems including the TES, the solar power plant, boilers, gas and steam turbines, heat recovery equipment, chillers, and pumps. These problems also require novel solution methods that are efficient and effective at obtaining workable solutions. A simultaneous solution method is used for optimizing the solar power plant, while a static/dynamic decoupling method is used for the district energy system. / text

Fernkälte bietet das Potenzial, wirtschaftlich und ökologisch vorteilhaft zur Deckung des stetig zunehmenden Klimakältebedarfs beizutragen. Im Rahmen dieser Arbeit wurde ein dynamisches thermohydraulisches Netzmodell „ISENA“ entwickelt, mit dem während der Planung und des Betriebs von Fernkältesystemen auftretende Fragen, beispielsweise in Bezug auf Wirtschaftlichkeit und Energieeffizienz, beantwortet werden können. Das Netzmodell setzt sich aus einem quasistationären hydraulischen Modell und einem instationären thermischen Modell zusammen, das auf der Verfolgung von Wasserpfropfen durch das gesamte Netz basiert (Lagrange-Ansatz). Mit diesem Modellierungsansatz können numerische Fehler sowie Bilanzungenauigkeiten vermieden werden, sodass sich eine höhere Ergebnisgüte im Vergleich zu bisher bekannten Netzmodellen erreichen lässt. Ebenfalls neu entwickelt wurde das Teilmodell zur Abbildung der Wärmeströme über die Wände unterirdischer Rohrpaare (Kälteverluste und -gewinne). Dieses Modell erlaubt die Bestimmung der instationären Rohrwand-Wärmeströme für wärmegedämmte unterirdische Rohrpaare, Rohrpaare mit gedämmtem Vor- und ungedämmtem Rücklauf sowie ungedämmte Rohrpaare. Anhand von Validierungs- und Verifikationsrechnungen wird gezeigt, dass ISENA verlässliche Ergebnisse liefert und für die praktische Anwendung geeignet ist. Abschließende Beispielrechnungen geben einen Einblick in die Untersuchungsmöglichkeiten, die das neue Modell bietet – unter anderem im Hinblick auf den Vergleich von Pumpenregelungsvarianten, den Einfluss von Rohrdämmung und Erdreicheigenschaften auf Kälteverluste und -gewinne sowie die Einbindung von Hochtemperatur-Kälteverbrauchern in den Netzrücklauf.:1 Einleitung 1.1 Situation 1.2 Aufbau und Betrieb von Fernkältesystemen 1.3 Netzmodellierung und -simulation 1.4 Präzisierte Aufgabenstellung 2 Stand der Wissenschaft und Technik 2.1 Begriffe und Definitionen 2.2 Rohrleitungen 2.2.1 Technik 2.2.2 Modellierung 2.3 Peripherie 2.3.1 Kälteabnehmer 2.3.2 Durchfluss- und Differenzdruckregler 2.3.3 Erzeuger 2.3.4 Pumpen 2.3.5 Bypass 2.4 Netz 2.4.1 Netzstruktur 2.4.2 Hydraulisches Verhalten 2.4.3 Thermisches Verhalten 2.4.4 Beispielsysteme 2.5 Zwischenfazit 3 Modellerstellung 3.1 Grundlagen 3.2 Rohrleitungen 3.2.1 Hydraulisches Rohrmodell 3.2.2 Modellierung des Rohrwand-Wärmestroms 3.2.3 Thermisches Rohrmodell 3.3 Peripherie 3.3.1 Kälteabnehmer 3.3.2 Durchfluss- und Differenzdruckregler 3.3.3 Erzeuger 3.3.4 Pumpen 3.3.5 Bypass 3.3.6 Rücklaufabnehmer 3.4 Netz 3.4.1 Hydraulisches Modell 3.4.2 Thermisches Modell 3.4.3 Gesamtmodell 3.5 Programmtechnische Umsetzung 4 Modellvalidierung und -verifikation 4.1 Vorbetrachtungen 4.2 Kernmechanismen 4.2.1 Hydraulik 4.2.2 Konvektiver Energietransport 4.2.3 Wärmeübertragung über die Rohrwand 4.2.4 Wärmezufuhr bei Kälteabnehmern 4.3 Schlussfolgerungen 5 Beispielsimulationen 5.1 Vorgaben 5.2 Referenzfall 5.3 Varianten 5.3.1 Pumpenregelung 5.3.2 Netz-Vorlauftemperatur 5.3.3 Rohrgeometrie und Erdreicheigenschaften 5.3.4 Rücklaufabnehmer 6 Zusammenfassung und Ausblick Literaturverzeichnis Abbildungsverzeichnis Tabellenverzeichnis Anhang A Existierende Modelle A.1 Hydraulikberechnung mit Regelelementen A.2 Rohrwand-Wärmeströme A.3 Freie Konvektion bei Stillstand im Rohr B Numerisches Modell für Rohrwand-Wärmeströme B.1 Referenzmodell B.2 Bestimmung der Neipor-Parameter B.3 Tabellierte Neipor-Parameter C Modell ISENA C.1 Pfropfenteilung C.2 Programmtechnische Umsetzung C.3 Rohrklassen C.4 Stoffdaten / District cooling can provide economic and ecological benefits while supplying the increasing cooling demand for air conditioning. In the present thesis, a dynamic thermo-hydraulic model “ISENA” is presented which may be used in order to answer questions arising during design and operation of district cooling networks—e. g., that are related to economic and energy efficiency. The network model consists of a quasi-static hydraulic module and a transient thermal module being based on the tracking of water segments through the entire network (Lagrangian method). With this approach, numerical errors and inaccuracies in the balance of conserved quantities could be avoided, which eventually leads to a better reliability of the results as compared to that obtained from other network models. Additionally, a new sub-model has been developed for predicting the transient heat flux through the walls of buried pipes in order to model thermal gains and losses. This model covers un-insulated, insulated and combinations of insulated as well as un-insulated pipes. Calculations performed for the purpose of validation and verification are presented in order to demonstrate that ISENA provides reliable results and hence is suitable for practical applications. Finally, example simulations show the various possibilities provided by the new model—for example, concerning the comparison of different strategies for pump control, the influence of pipe insulation and soil properties on thermal gains and losses as well as the connection of buildings equipped with high temperature cooling systems to the return line of the network.:1 Einleitung 1.1 Situation 1.2 Aufbau und Betrieb von Fernkältesystemen 1.3 Netzmodellierung und -simulation 1.4 Präzisierte Aufgabenstellung 2 Stand der Wissenschaft und Technik 2.1 Begriffe und Definitionen 2.2 Rohrleitungen 2.2.1 Technik 2.2.2 Modellierung 2.3 Peripherie 2.3.1 Kälteabnehmer 2.3.2 Durchfluss- und Differenzdruckregler 2.3.3 Erzeuger 2.3.4 Pumpen 2.3.5 Bypass 2.4 Netz 2.4.1 Netzstruktur 2.4.2 Hydraulisches Verhalten 2.4.3 Thermisches Verhalten 2.4.4 Beispielsysteme 2.5 Zwischenfazit 3 Modellerstellung 3.1 Grundlagen 3.2 Rohrleitungen 3.2.1 Hydraulisches Rohrmodell 3.2.2 Modellierung des Rohrwand-Wärmestroms 3.2.3 Thermisches Rohrmodell 3.3 Peripherie 3.3.1 Kälteabnehmer 3.3.2 Durchfluss- und Differenzdruckregler 3.3.3 Erzeuger 3.3.4 Pumpen 3.3.5 Bypass 3.3.6 Rücklaufabnehmer 3.4 Netz 3.4.1 Hydraulisches Modell 3.4.2 Thermisches Modell 3.4.3 Gesamtmodell 3.5 Programmtechnische Umsetzung 4 Modellvalidierung und -verifikation 4.1 Vorbetrachtungen 4.2 Kernmechanismen 4.2.1 Hydraulik 4.2.2 Konvektiver Energietransport 4.2.3 Wärmeübertragung über die Rohrwand 4.2.4 Wärmezufuhr bei Kälteabnehmern 4.3 Schlussfolgerungen 5 Beispielsimulationen 5.1 Vorgaben 5.2 Referenzfall 5.3 Varianten 5.3.1 Pumpenregelung 5.3.2 Netz-Vorlauftemperatur 5.3.3 Rohrgeometrie und Erdreicheigenschaften 5.3.4 Rücklaufabnehmer 6 Zusammenfassung und Ausblick Literaturverzeichnis Abbildungsverzeichnis Tabellenverzeichnis Anhang A Existierende Modelle A.1 Hydraulikberechnung mit Regelelementen A.2 Rohrwand-Wärmeströme A.3 Freie Konvektion bei Stillstand im Rohr B Numerisches Modell für Rohrwand-Wärmeströme B.1 Referenzmodell B.2 Bestimmung der Neipor-Parameter B.3 Tabellierte Neipor-Parameter C Modell ISENA C.1 Pfropfenteilung C.2 Programmtechnische Umsetzung C.3 Rohrklassen C.4 Stoffdaten

The Autonomic Power System (APS) grand challenge was a multi-disciplinary EPSRC-funded research project that examined novel techniques that would enable the transition between today's and 2050's highly uncertain and complex energy network. Being part of the APS, this thesis reports on the sub-project 'RR2: Avoiding High-Impact Low Probability events'. The goal of RR2 is to develop new algorithms for controlling risk exposure to high-impact low probability (Hi-Lo) events through the provision of appropriate risk-sensitive control strategies. Additionally, RR2 is concerned with new techniques for identifying and modelling risk in future energy networks, in particular, the risk of Hi-Lo events. In this context, this thesis investigates two distinct problems arising from energy risk management. On the one hand, we examine the problem of finding managerial strategies for exercising the operational flexibility of energy assets. We look at this problem from a risk perspective taking into account non-linear risk preferences of energy asset managers. Our main contribution is the development of a risk-sensitive approach to the class of optimal switching problems. By recasting the problem as an iterative optimal stopping problem, we are able to characterise the optimal risk-sensitive switching strategies. As byproduct, we obtain a multiplicative dynamic programming equation for the value function, upon which we propose a numerical algorithm based on least squares Monte Carlo regression. On the other hand, we develop tools to identify and model the risk factors faced by energy asset managers. For this, we consider a class of models consisting of superposition of Gaussian and non-Gaussian Ornstein-Uhlenbeck processes. Our main contribution is the development of a Bayesian methodology based on Markov chain Monte Carlo (MCMC) algorithms to make inference into this class of models. On extensive simulations, we demonstrate the robustness and efficiency of the algorithms to different data features. Furthermore, we construct a diagnostic tool based on Bayesian p-values to check goodness-of-fit of the models on a Bayesian framework. We apply this tool to MCMC results from fitting historical electricity and gas spot price data- sets corresponding to the UK and German energy markets. Our analysis demonstrates that the MCMC-estimated models are able to capture not only long- and short-lived positive price spikes, but also short-lived negative price spikes which are typical of UK gas prices and German electricity prices. Combining together the solutions to the two problems above, we strive to capture the interplay between risk, uncertainty, flexibility and performance in various applications to energy systems. In these applications, which include power stations, energy storage and district energy systems, we consistently show that our risk management methodology offers a tradeoff between maximising average performance and minimising risk, while accounting for the jump dynamics of energy prices. Moreover, the tradeoff is achieved in such way that the benefits in terms of risk reduction outweigh the loss in average performance.

La population mondiale fait face, globalement, à une urbanisation expansive. Cet étalement urbain, souvent mal contrôlé, menace aussi bien l’environnement que la santé, la qualité de vie et la sécurité alimentaire des humains. Il est possible de le limiter en lui préférant la densification urbaine. Néanmoins, la complexité des phénomènes en jeu dans un tel contexte nous incite à penser que les responsables d’opérations de densification urbaine ont besoin d’outils pour les aider à faire les choix les plus pertinents possibles. Dans un premier temps, l’état de l’art présenté dans cette thèse montre que l’outil idéal n’existe pas, et que l’optimisation multicritère par algorithme génétique est une technique adaptée à l’aide à la conception de bâtiments. Les caractéristiques souhaitables pour une méthode d’assistance des concepteurs de projets de densification urbaine sont alors précisées. Nous recommandons de baser cette méthode sur le couplage entre un algorithme génétique et un outil capable de réaliser des simulations thermiques dynamiques (STD) de quartiers. Les capacités des logiciels de STD Pleiades+COMFIE (P+C) et EnergyPlus (E+) sont situées par rapport à ces exigences, puis un premier test d’optimisation d’un projet de densification urbaine en associant EnergyPlus à un algorithme génétique est présenté. Certaines lacunes de cette méthode peuvent être comblées par la plateforme en cours de développement dans le projet ANR MERUBBI. Dans un second temps, nous analysons donc les résultats d’une étude comparative entre P+C, E+ et l’outil MERUBBI, menée sur un projet de densification d’un îlot à forte densité urbaine. Ils montrent que ce dernier est fiable et particulièrement pertinent pour l’évaluation précise des interactions entre bâtiments. Dans un troisième temps, nous abordons la problématique de la diminution des temps de calcul, enjeu crucial pour que notre méthode d’aide à la conception soit réellement accessible aux professionnels du bâtiment. Nous proposons une technique de réduction de la période de simulation que nous présentons en détail. Enfin, la méthode d’optimisation développée est appliquée à la résolution de différents problèmes de conception du projet sus-cité, en utilisant E+. Nous montrons en quoi l’utilisation de l’outil MERUBBI enrichira cette approche, avant de conclure sur des perspectives de développement de notre méthode pour améliorer son interactivité. / The world’s population is facing an expansive urbanization. This urban sprawl, which is often not well managed, is endangering the environment as well as human health, quality of life and food security. It can be controlled by favouring urban densification. Nonetheless, the complexity of the phenomena involved in such a context leads us to think that supervisors of urban densification operations need some tools to help them make the most relevant choices. This thesis begins with a literature review that shows the ideal tool does not exist, and explains why multi-objective optimization using a genetic algorithm is a suitable technique for building design aid. Then we clarify the desirable features of an assistance method for urban densification projects designers. We recommend to base this method on the coupling of a genetic algorithm with a district-scale dynamic thermal simulation (DTS) tool. We compare capabilities of EnergyPlus (E+) and Pleiades+COMFIE (P+C) DTS software with these requirements, then we present a first urban densification project optimization test associating EnergyPlus with a genetic algorithm. The platform under development in the ANR MERUBBI project can offset certain shortcomings of this method. Hence, in a second phase we analyze the results of a comparative study of P+C, E+ and the MERUBBI tool, carried out using a high-density district densification project as a test case. It shows that the latter is reliable and particularly relevant to precisely assess interactions between buildings. In a third phase we address the problematic of reducing the computing time, a major issue to make our design aid method truly accessible to building professionals. We propose a way of reducing the operating period length and present it in detail. Finally, our optimization method is used to solve various design problems of the above-mentioned project, using E+. We show how the use of the MERUBBI platform will enrich this approach before concluding with development ideas to make our method more user-friendly and interactive.

Cities and districts contribute to a large fraction of the total energy consumption in Sweden. The residential- and service sector accounted for almost 40% of the total energy consumption in 2018. The increasing urbanization also puts more importance on the energy supply, distribution and consumption in these areas. One way of planning an energy system in urban areas is to have integrated energy systems where synergies between different technologies and energy carriers are utilized. Such a solution can increase the flexibility of the energy system and thus help integrate more intermittent renewable energy sources. The aim of this study was to suggest tools for planning energy systems in districts. This was done by performing a literature review regarding the design of energy systems and the identification of barriers and opportunities for the integration of different production- and distribution technologies. The focus was on systems for heating, cooling and electricity. The proposed tools are three Excel-based modules. The first module is a qualitative model that presents the reviewed technologies and their connections. It also includes synergies between different energy carriers and sectors for consumption and production. The second module is qualitative model related to market mechanisms, juridical, organizational and institutional aspects. The third module is a table containing the barriers and opportunities. Furthermore, relevant stakeholders are identified to be district heating companies, building owners, joint associations, municipalities, district cooling companies and photovoltaic plant owners. The proposed tools can be used in the first stage of planning when the technologies are selected. To show how the suggested tools can be applied, a case study was performed. The study case is a district being planned in Stockholm, Sweden. For the analysis, a model for a hypothetical heating system was required. Two models were developed for the heat supply system using the modelling environment OpenModelica. The main objective of the case study was to compare the techno-economic and environmental performance of different scenarios. Three different scenarios were considered for covering the total heating demand in the district. In the first scenario the total heating demand is covered only by local heat pumps. In the second scenario the space heating demand is covered by heat pump(s) coupled with a thermal energy storage (hot water tank). An electric boiler is used as backup. In the third scenario, the electric boiler is replaced by district heating as backup. A sensitivity analysis was included for different numbers of heat pumps and different sizes of thermal energy storage in the two last scenarios. The economic and environmental results in this study were strongly dependent on the assumptions regarding prices and emission factors. The result of the case study indicates that the third scenario causes the lowest CO2 emissions. An increased size of the thermal energy storage causes a higher compressor electricity consumption thus more emissions. However the total emissions from the system depends on the backup component. For this result, the emission factor related to Swedish electricity mix and the emission factor stated by a district heating company in Stockholm was used. The cheapest alternative in terms of annual operational cost of energy is the first scenario with only heat pumps. However, from the scenarios which also includes thermal energy storage, the second scenario with three heat pumps and a 100 m3 large thermal energy storage, presents the lowest cost. This system design in scenario 2 is only 0.6% more expensive than the first scenario. For the energy prices, the assumption for electricity is based on hourly values from Nordpol and for heat, the values presented in a normal price list from a district heating company is assumed. Regarding the technical performance of the system the result indicates that the contribution from the thermal energy storage as it is modelled in this case study is not significant on anannual basis. However it is observed that a larger thermal energy storage unit covers a higher fraction of the power demand during the hours it is utilized. / Städer och stadsdelar står för en stor del av totala energikonsumtionen i Sverige. Bostads- och servicesektor stod för ungefär 40% av totala energikonsumtionen under 2018. Den ökande urbaniseringen lägger också mer vikt vid energiproduktion, distribution och konsumtionen i dessa områden. Ett alternativ för planering av energisystem i urbana områden är att ha integrerade energisystem där synergier mellan olika teknologier och energibärare kan utnyttjas. Den typen av system skulle kunna öka flexibiliteten i energisystemet och därför förenkla integrering av oförutsägbara förnybara energikällor. Syftet med denna studie var att föreslå verktyg för planering av energisystem i stadsdelar. Detta gjordes genom en litteraturstudie angående utformningen av olika energisystem samt identifiera hinder och möjligheter för att integrera olika produktions- och distributions teknologier. Fokus låg på systemen för värme, kyla och elektricitet. Det föreslagna verktygen är tre Excel baserade moduler. Den första modulen är en qualitative modell som presenterar de studerade teknologier och deras kopplingar. Den innehåller också synergier mellan de olika energibärarna och konsumtions- och produktionssektorn. Den andra modulen är en qualitative modell, men relaterad till marknad mekanismer, juridiska, organisatoriska och institutionella aspekter. Den tredje modulen är en tabell som beskriver hinder och möjligheter för några av teknologierna. Utöver det de relevanta aktörerna identifierades. För värme-, kyla- och elektricitet marknaden är de fjärrvärmeföretagen, fastighetsägare, samfälligheter, kommuner, fjärrkyla företagen, solcells ägare. De föreslagna verktyget kan användas för planering av energisystem i ett första skede när teknologier ska väljas.  En fallstudie genomfördes för att visa hur det föreslagna verktyget kan användas. Fallstudien en stadsdel som planeras i Stockholm, Sverige. För att genomföra en analys behövdes en modell för ett hypotetiskt värmesystem. Två modeller utvecklades för värmesystemet genom att använda modelleringsmiljön OpenModelica. Det huvudsakliga målet med fallstudien var att jämföra den teknoekonomiska- och miljöinriktade prestandan för olika scenarierna. Tre olika scenarier övervägdes för att täcka totala värmebehovet i stadsdelen. I det första scenariot täcks det totala värmebehovet endast av lokala värmepumpar. I andra scenariot täcks värmebehovet för uppvärmning av värmepump(ar) kopplade till en värmelagrings komponent (ackumulatortank). En elpanna användes för reserveffekt. I tredje scenariot är elpannan ersatt av fjärrvärme. En känslighetsanalys var utförd för olika antal värmepumpar kopplade till olika storlekar av värmelagrings-komponenten i de två sista scenarierna. De ekonomiska och miljörelaterade resultatet i den här studien är starkt beroende av antaganden gällande priser och utsläppsfaktorer. Resultatet indikerar att det tredje scenariot har de lägsta CO2 utsläppen. Ökad värmelagringsstorlek bidrar till att värmepumpen förbrukar mer elektricitet och därför ökar de relaterade utsläppen. Däremot beror de totala utsläppen i systemet på vilken reservkraft som används. För dessa resultat användes utsläppsfaktorn för svensk elmix samt utsläppsfaktorn från ett fjärrvärme företag i Stockholm. Den billigaste alternativet gällande årlig driftsenergikostnad är det första scenariot med endast värmepumpar. Däremot, bland de scenarion som innehåller värmelagring, har det andra scenariot med tre värmepumpar och 100m3 stor värmelagringsenhet den lägsta kostnaden. Detta system är endast 0.6% dyrare än det första scenariot. För energipriser har timvärden från Nordpol antagits för elektricitet och för värme har normalprislistan från ett fjärrvärmebolag i Stockholm antagits. Angående den tekniska systemprestandan, indikerar resultatet att bidraget från värmelagringsenheten som den är modellerad i den här fallstudien inte är signifikant på årsbasis. Det observeras emellertid att en större värmelagringsenhet täcker en större andel av effektbehovet under de timmar som enheten används.