Nowadays continuous increase of energy consumption increases the importance of replacing fossil fuels with renewable energy sources so the CO2 emissions can be reduced. To use the energy in a more efficient way is also favorable for this purpose. Thermal Energy Storage (TES) is a technology that can make use of waste heat, which means that it can help energy systems to reduce the CO2 emissions and improve the overall efficiency. In this technology an appropriate material is chosen to store the thermal energy so it can be stored for later use. The energy can be stored as sensible heat and latent heat. To achieve a high energy storage density it is convenient to use latent heat based TES. The materials used in this kind of storage system are called Phase Change Materials (PCM) and it is its ability of absorbing and releasing thermal energy during the phase change process that becomes very useful. In this thesis a simulation model for a system of thermal energy transportation has been developed. The background comes from district heating systems ability of using surplus heat from industrials and large scale power plants. The idea is to implement transportation of heat by trucks closer to the demand instead of distributing heat through very long pipes. The heat is then charged into containers that are integrated with PCM and heat exchangers. A mathematical model has been created in Matlab to simulate the system dynamics of the logistics of the thermal energy transport system. The model considers three main parameters: percentage content of PCM in the containers, annual heat demand and transport distance. How the system is affected when these three parameters varies is important to visualize. The simulation model is very useful for investigation of the economic and environmental capability of the proposed thermal energy transportation system. Simulations for different scenarios show some expected results. But there are also some findings that are more interesting, for instance how the variation of content of PCM gives irregular variation of how many truck the system requires, and its impact on the economic aspect. Results also show that cost for transporting the heat per unit of thermal energy can be much high for a small demands compared to larger demands.

The real performance of ground source heat pumps systems are not precisely highlighted in most cases, especially when it comes to installations older than the contractors guarantee period of 5 years. This project analyses measured data, constructs durability diagrams and establishes an energy balance of a whole heating system located in Saltsjöbaden. The system, composed of 3 heat pumps with a total heating power of 270kW and an oil burner, is used to deliver comfort heat through radiators and ventilation as well as tap warm water production. The installation was originally designed with two oil burners now used as an auxiliary heat supplier. Two heat pumps were installed in 1999 and a third unit was added in 2009. However, the oil consumption has been higher than expected. An experiment with controlled oil burner operation confirmed the need of implementing a control strategy. Some weaknesses in the system are pointed out.

With an increasing awareness of energy consumption and CO 2emission in the population, several initiatives to reduce CO2emissions have been presented all around the world. The main part of these initiatives is a reduction of the energy consumption for existing buildings, while the others concern the building of eco-districts with low-energy infrastructures and even zero-energy infrastructures. In this idea of reducing the energy consumption and of developing new clean areas, this master thesis will deal with the high energy quality services for new urban districts. In the scope of this master thesis project, the new concept of sustainable cities and of clusters of buildings will be approached in order to clearly understand the future challenges that the world’s population is going to face during this century. Indeed, due to the current alarming environmental crisis, the need to reduce human impacts on the environment is growing more and more and is becoming inescapable. We will present a way to react to the current situation and to counteract it thanks to new clean technologies and to new analysis approaches, like the exergy concept. Through this report, we are going to analyze the concepts of sustainable cities and clusters of buildings as systems, and focus on their energy aspects in order to set indoor climate parameters and energy supply parameters to ensure high energy quality services supplies to high performance buildings. Thanks to the approach of the exergy concept, passive and active systems such as nocturnal ventilation or floor heating and cooling systems have been highlighted in order to realize the ‘energy saving’ opportunities that our close environment offers. This work will be summarized in a methodology that will present a way to optimize the energy use of all services aspects in a building and the environmental friendly characteristics of the energy resources mix, which will supply the buildings’ low energy demands.

The electricity sector is a major source of carbon dioxide emission that contributes to the global climate change. Over the past decade wind energy has steadily emerged as a potential source for low carbon energy source which are grown through time. As wind power generation increases around the world, there is increasing interest in adding intermittent power to the electricity grid and to design an off-grid wind energy system. The goal of the current thesis is to investigate techno-economically viable wind energy system that supplies electricity and Heat for a given residential community in Ethiopia. To ease the optimization process, HOMER software is used to identify the potential wind area and optimize cost effective wind energy system.

This dissertation demonstrates novel holistic approaches on how to link policy, clean energy innovations, and robust energy modeling techniques to help build more resilient and cost-effective energy systems for the Canadian Arctic region and remote communities in general. In spite of the diversity among Arctic jurisdictions, various energy issues and challenges are shared pan-territorially in the North. For instance, 53 out of 80 remote communities in the Northern territories rely exclusively on diesel-based infrastructures to generate electricity, with heating oil as their primary source of heat. This critical dependence on fossil fuels exposes the Indigenous peoples and other Canadians living in the North to high energy costs and environmental vulnerabilities which is exacerbated by the local and global catastrophic effects of climate change in the Arctic. Aside from being strong point sources of greenhouse gases and other airborne pollutants, this reliance on carbon-intensive sources of energy elevates risk of oils spills during fuel transport and storage. Further, conventional transportation mode via ice roads is now increasingly unreliable because of the rising Arctic temperatures which is twice the global average rate. As a result, most fuels are being transported by small planes which contribute to high energy costs and fuel poverty rates, or via boats which also increases the risk of oil spills in the Arctic waters. Methodologically, this thesis presents a multi-domain perspective on how to accelerate energy transitions among Northern remote communities. In particular, a multi-objective optimization energy model was developed in order to capture complex trade-offs in designing integrated electrical and thermal energy systems. In comparison with traditional single-objective optimization approach, this technique offers diversity of solutions to represent multiple energy solution philosophies from various stakeholders and practitioners in the North. A case study in the Northernmost community of the Northwest Territories demonstrates the applicability of this framework - from modeling a range of energy solutions (supply and demand side aspects) to exploring insights and recommendations while taking into account uncertainties. Overall, this dissertation makes a set of contributions, including: (i) Development of a robust energy modeling framework that integrates complex trade-offs and multiple overlapping uncertainties in designing energy systems for the Arctic and remote communities in general; (ii) Extension of previous Arctic studies - where focused has solely been on the electricity sector - by integrating heating technology options in the proposed modeling framework in conjunction with methods on obtaining `high performance' buildings in the North; (iii) Overall energy system performance evaluation when integrating heat and electricity sectors, as well as the role of battery storage systems and diesel generator on facilitating variable renewable energy generation among isolated communities; (iv) Formulation of a community-scale energy trilemma index model which helps design policies that are accelerating (or hindering) energy transitions among remote communities by assessing quantitatively challenges relating to energy security, affordability, and environmental sustainability; (v) Synthesized holistic insights and recommendations on how to create opportunities for Indigenous peoples-led energy projects while discussing interwoven links between energy system operations, relationship building and stakeholders engagement, policy design, and research (energy modeling and analysis). Collectively, the new methods and recommendations demonstrated herein offer evidence-based decision making and innovative solutions for policy makers, utility companies, Indigenous peoples, and other stakeholders in the Arctic and beyond. / Graduate

The question how a least-cost spatial allocation of sustainable electricity infrastructure may look like using different decision-making procedures (markets, different kinds of land-use and grid regulations) has not yet been analysed explicitly. We measure the sustainability of emerging energy landscapes providing power from renewable energy sources (RES) by an overall welfare function also comprising all kinds of space-related disutilities, i.e. spatial externalities - be they site-specific or related to the distance to a residential area (consumer centre). The presented agent-based model (ABM) concept aims at assessing different policy scenarios to govern the land-use for energetic purposes under the constraint of ensuring the electricity supply for a virtual landscape with RES. To derive optimal spatial allocation an agent-based modelling approach is implemented, which includes a virtual landscape, three settlements as demand centres and profit-oriented producers of renewable power. For the design of the electricity grid and the calculation of grid-related reinforcement costs a load-flow model is applied, being also able to map grid externalities during the RES expansion in space. The model allows RES producers to choose profit-maximising cells for plant installations until the given demand for power of the virtual landscape is met. Different policy scenarios allocate particular costs to agents (e.g. grid reinforcement costs, spatial externalities) or restrict the land-use with respect to ecological or social restraints. Furthermore, consumer centres have the possibility to follow own particular regional strategies, to increase their individual benefit. The overall efficiency of allocation (total cost level) as well as the distributional fairness (regional net costs) are evaluated for the policy scenarios and the regional strategies.

China is the largest energy consumer worldwide, with a fast-growing rate. But the energy and environmental problems brought by its unbalanced energy structure and low energy efficiency restrict the sustainable development of China. The Distributed Energy System (DES) is one of the internationally recognized solutions to the problems. To enhance the implementation of the DES under China’s scenario, the thesis develops computational models for the Combined Cooling, Heat, and Power (CCHP) and Separated Cooling, Heat, and Power (SCHP) systems for a Micro Energy Grid in northeast China using MATLAB. The objective is to minimize the overall expenditure, energy use, and carbon emission equivalents. The results show that the CCHP system reduces 18.62% of the overall expenditure and 35.02% of the carbon emission equivalents than the SCHP system. The CCHP system has a promising prospect in China with better Greenhouse Gas emissions reduction and economic performance. / Kina är världens största energikonsument, med en snabb tillväxttakt. Men de energi- och miljöproblem som orsakas av den obalanserade energistrukturen och den låga energieffektiviteten begränsar Kinas hållbara utveckling. Distribuerade energisystem (DES) är en av de internationellt erkända lösningarna på dessa problem. För att förbättra implementeringen av DES enligt Kinas scenario utvecklar avhandlingen beräkningsmodeller för kombinerad kylning, värme och kraft (CCHP) och separerad kylning, värme och kraft (SCHP) för ett mikroenerginät i nordöstra Kina med hjälp av MATLAB. Målet är att minimera de totala kostnaderna, energianvändningen och koldioxidutsläppen. Resultaten visar att CCHP-systemet minskar de totala utgifterna med 18,62 % och koldioxidutsläppen med 35,02 % jämfört med SCHP-systemet. CCHP-systemet har lovande utsikter i Kina med bättre minskning av växthusgasutsläpp och ekonomisk prestanda.

This paper examines the possibility of adding a photovoltaic(PV) power station to an already planned wind park in terms of profitability. At this time, southern Sweden’s grid is facing a number of challenges and is hurting economic development. Hybrid parks have showed to be able to tackle some of those challenges. This study has used a two-scaled methodology to analyse which solar PV size is the optimal to be co-located to the wind park of 24MW[Office1] . The results show that the 21MW size is the ideal one. In addition, to complement the findings, an analysis has been conducted to determine which battery size would be the optimal size to be added to the hybrid system. The results showed that a 1MW/1MWh battery storage would be the ideal size, however, it is possible that a 5MW/MWh battery storage might produce better results if peak shaving is included. All the scenarios in this study have been analysed in terms of IRR.

Klimatförändring ställer idag krav på högre energieffektivitet vilket lett till utbyggnaden av ett distribuerat energisystem. Samtidigt introduceras framväxande teknologier som digitala tvillingar till det nya energisystemet i hopp om att ytterligare effektivisera systemet. För att främja samarbete mellan industrin och akademin, och således stödja utvecklingen och implementeringen av digitala tvillingar, bör aktörernas syner sammanföras. Syftet med arbetet är därav att undersöka ifall det finns några likheter och skillnader mellan industri och akademi i hur de uppfattar användningsområdena och utmaningarna med digitala tvillingar av distribuerade energisystem. För att besvara forskningsfrågan utfördes inledningsvis en systematisk litteraturstudie. Studien utgör arbetets underlag för akademins uppfattning om digitala tvillingars användningsområden och utmaningar. Vidare utfördes fem intervjuer med olika industriaktörer med insikt i digitala tvillingar och distribuerade energisystem för att avgöra deras uppfattning om teknologin. Insikterna från litteraturstudien och intervjuerna ställdes sedan mot varandra för att identifiera eventuella likheter och skillnader. De användningsområden som identifierades av akademin och industrin var simulering, felidentifiering och prediktivt underhåll, visualisering och styrning, cybersäkerhet, optimering av kraftnätet samt prognostisering och estimering. Utmaningarna som identifierades av akademin var standardiserade ramverk för modellering och för datahantering, brist på passande sensorer, datalagringsmöjligheter, datorers beräkningskapacitet och cyberattacker. Industrin identifierade motstånd till ny teknologi, kompetensbrist, silotänk, teknologins värdeskapande, datahantering och cyberattacker som huvudutmaningarna med digitala tvillingar. Utifrån analysen har industrin och akademin en liknande uppfattning om digitala tvillingars användningsområden inom distribuerade energisystem men uppfattningen om utmaningarna med digitala tvillingar var, inom akademin, mer teknikbaserad medan den inom industrin var främst icketeknisk. / Today, the increasing threat of climate change has created a greater need for higher energy efficiency, which has led to the development of a distributed energy system. At the same time, emerging technologies such as digital twins are being introduced into the new energy system in the hope of further improving the efficiency of the system. To promote cooperation between industry and academia, and thus support the development and implementation of digital twins, the views of the actors should be brought together. The purpose of this work is therefore to investigate whether there are any similarities and differences between industry and academia in how they perceive the applications and challenges of digital twins of distributed energy systems.  To answer the research question, a systematic literature study was initially conducted. The study constitutes the basis for the academia's perception of the use cases and challenges of digital twins. Furthermore, five interviews were conducted with different industrial actors with insight into digital twins and distributed energy systems to determine their perception of the technology. The insights from the literature study and interviews were then compared to identify any similarities and differences.  The application areas identified by academia and industry were simulation, fault identification and predictive maintenance, visualization and control, cyber security, grid optimization, and forecasting and estimation.  The challenges identified by academia were standardized modelling and data management frameworks, lack of suitable sensors, data storage capabilities, computational capacity of computers and cyber-attacks. Industry identified resistance to new technologies, skills shortages, silo thinking, technology value creation, data management and cyber-attacks as the main challenges of digital twins. Based on the analysis, industry and academia have a similar perception of the use cases of digital twins of distributed energy systems but the perception of the challenges of digital twins was, in academia, more technology-based while in industry it was mainly non-technical.

This thesis studies preconditions for clean hydrogen energy deployment in energy systems of Spain, Sweden, The UK, and China, considering these countries' geographical, political, and economic peculiarities. Countries' readiness for hydrogen energy uptake assessment is based on a comprehensive analysis of energy systems in selected countries by taking an integrated whole-system approach analyzing hydrogen supply in different infrastructure configurations as well as hydrogen transportation and storage and hydrogen use in the energy ecosystem. The readiness index of each country is evaluated in technological, political, societal, and economic dimensions, which are interdependent and influence not only each other, but the entire outcome of the energy transition phenomena studied in this thesis. The analysis concludes that the political dimension is the dominant one, as the government has the power to steer finance toward a green transition, making the desired change, such as clean hydrogen energy industry formation in the country, happen. Current energy transition entails economic and institutional change and deep industrial restructuring, all of which require specific policy instruments and conditionalities, balancing risks and behaviours in the process of the energy transition. Based on the results of this study, the UK and China have the highest political readiness among the analyzed countries, which also results in their higher economic, technology, and societal readiness levels.