To reduce fossil fuel consumption and carbon emission in the building sector, renewable and low carbon energy technologies are integrated in building energy systems to supply all or part of the building energy demand. In this research, an optimal supervisory controller is designed to optimize the operational cost and the CO2 emission of the integrated energy systems. For this purpose, the building energy system is defined and its boundary, components (subsystems), inputs and outputs are identified. Then a mathematical model of the components is obtained. For mathematical modelling of the energy system, a unified modelling method is used. With this method, many different building energy systems can be modelled uniformly. Two approaches are used; multi-period optimization and hybrid model predictive control. In both approaches the optimization problem is deterministic, so that at each time step the energy consumption of the building, and the available renewable energy are perfectly predicted for the prediction horizon. The controller is simulated in three different applications. In the first application the controller is used for a system consisting of a micro-combined heat and power system with an auxiliary boiler and a hot water storage tank. In this application the controller reduces the operational cost and CO2 emission by 7.31 percent and 5.19 percent respectively, with respect to the heat led operation. In the second application the controller is used to control a farm electrification system consisting of PV panels, a diesel generator and a battery bank. In this application the operational cost with respect to the common load following strategy is reduced by 3.8 percent. In the third application the controller is used to control a hybrid off-grid power system consisting of PV panels, a battery bank, an electrolyzer, a hydrogen storage tank and a fuel cell. In this application the controller maximizes the total stored energies in the battery bank and the hydrogen storage tank.

Att minska energianvändningen är något det pratats mer och mer om de senaste åren. Det finns olika sätt att minska energianvändningen på och ett av dessa är att återvinna värmeenergi. Det kan gälla både spillvärme och nyttig värme. Detta går att tillämpa i industrin, transportsektorn, hushåll och till vardags. Gemensamt för dessa processer är att det används stora mängder energi vilket till stor grad består av förluster till omgivningen eller att processerna inte optimeras. På senare tid har det forskats kring teknologi som kan ta vara på denna värmeenergi och på så vis minska förlusterna. En teknologi för detta är termoelektriska generatorer (TEG) som bygger på Seebeckeffekten för att generera elektricitet från temperaturskillnader. När ett TEG-element utsätts för värme på en sida och kyla på den andra sidan så genereras en elektrisk spänning. En elektrisk ström och effekt kan tas ur kretsen om elementet kopplas till en elektrisk last. Materialet i elementet består av halvledarmaterial med låg värmeledningsförmåga och en hög elektrisk ledningsförmåga. Teknologin har funnits länge men aldrig tillämpats i någon större grad. Nu på senare år har intresset ökat och kommersiella produkter med TEG-element har tagits fram. I detta arbete har en sådan produkt testats för att se hur lämpligt det skulle vara att använda dessa vid hushåll som inte är anslutna till elnätet och har en vedkamin för uppvärmning. TEG-enheten testas på en värmeplatta där ställbara temperaturer är möjliga för att testa prestandan vid temperaturerna 150° C, 200° C och 230° C. En krets sätts ihop för att kunna mäta av värden på spänning och ström vid olika laster som sätts med resistorer. Mätningarna görs med en ökning på 0,1 A vid varje mätning. Resultatet från dessa tester visar att maximal effekt på 14 W uppnås hos produkten vid 230° C. När modifiering av produkten görs för att öka temperaturskillnaden uppnås 17,8 W vilket tyder på att effekten ökar när delta T ökar. Den spänning som uppnås vid öppen krets var som högst 31 V och vid maximal effekt var den 17,8 V. Strömmen var då 1 A. De resultat som testerna gav levde inte upp till de 25 W som produkten sägs kunna ge. Produkten saknar även viktiga komponenter så som spänningsreglerare.Det går av både teori och tester avgöra att det är ett lämpligt sätt att använda sig av TEG-enheter för att generera små mängder elektricitet vid hushåll utan koppling till elnätet. / In recent years the topic of reducing the energy usage has been on the agenda. There are several ways of reducing the energy usage and one of these is to recycle heat energy. It could be both waste heat and useful heat. This can be implied to the industry, transport sector, households and on daily activities. The common factor between these is that large quantities of energy is used and to a large extent consists of losses to the surrounding or from processes that are not optimized. In recent time there has been done research around technology that can recycle and use this heat energy and in return reduce the energy usage. One technology to do this is thermoelectric generators (TEG) that are implementing the Seebeck effect to generate electricity from temperature differences. When a TEG-element have one side that is exposed to a heat source and one side being cooled down an electric voltage is being generated. An electric current and power can then be used from the circuit if the element is connected to an electric load. The material in the element exists of semiconductive materials with low heat conductivity and high electric conductivity. The technology has existed for a long time but has never been implemented to a larger extent. It is only in recent years that the interest has grown and some commercial products with TEG-elements has been developed. In this thesis one of these products has been tested to see how viable it would be to use these within a household that is not connected to the electrical grid and where the house is heated with a wood-burning stove. The TEG-product is tested on a heat plate where it is possible to set a desired temperature. The temperatures of 150° C, 200° C and 230° C are chosen for testing the performance of the product. A circuit is put together to be able to read the values of the voltage and current at different loads that are set with resistors. The measurements are done with an increase of 0,1 A for every measurement. The result from these tests shows that the maximum power of 14 W is achieved at 230° C on the hot side. But when modification of the product is made to increase the temperature difference a value of 17,8 W is attained. This indicate that the power is increasing when the temperature difference is increasing. The attained voltage at open circuit was as highest 31 V and at maximum power it was 17,8 V. The current was then 1 A. The results that the testing gave did not match the value of 25 W that the datasheet says the product can deliver. Also, the product is missing important components such as voltage regulator.It is possible from both the theory and the testing to see that it is suitable to use a TEG-product to generate small amount of electricity to households that are not connected to the electrical grid.

Tillskottsvatten i avloppsledningsnät medför stora kostnader i form av underhåll,ökad mängd kemikalier och energi som även belastar miljön. Syftet med detta examensarbetevar att få ökad förståelse av temperaturförhållanden mellan spillvattenoch mark för att förbättra modelleringen av tillskottsvatten. Hypotesen är att spillvattentemperaturensjunker vid inläckage då temperaturen på tillskottsvattnet ärlägre än spillvattnet. Ett spillvattenrör med en längd på ungefär 2,5 km i Umeåundersöktes med givare jämt fördelade längs sträckan. Metoden innebar att medmätvärden på temperaturerna för spillvattnet, luften i spillvattenröret och i markentillsammans med flödet och nivån på spillvattnet modellera värmeutbytet i COMSOLMultiphysics. Resultatet gav fyra liknande funktioner för både spillvattenregionenoch luftregionen som beskrev värmeutbytet mellan spillvattenröret och marken.Effektutbytena hade en linjär tendens som funktion av temperaturdifferensen mellanspillvatten och mark under mätperioden fram till maj månad men med en högspridning då effektutbytet är även beroende på flödet och inte bara temperaturdifferensen.Majoriteten av effektutbytet var mellan ytan på spillvattenröret ochspillvattnet. I regionen mellan luft och yta på spillvattenröret så var majoriteten aveffektutbytet ifrån strålningsutbytet mellan spillvattnet och ytan. Resultaten gaväven U-värden för regionen mellan spillvattenregionen och luftregionen i rörledningenoch dessa var omkring 4 W/(m2K) respektive 0,8 W/(m2K). Tillskottsvattnetmodellerades utifrån värmeutbytet och det visade på ökade flödesnivåer när det varvåtperioder med en noggrannhet på ± 1 kg/s. / Supplemental water in the sewer network entails large costs in the form of maintenance,increased amounts of chemicals and energy that also have a burden on theenvironment. The purpose of this thesis was to gain an increased understandingof temperature conditions between wastewater and soil to improve the modelingof supplemental water. The hypothesis is that the waste water temperature dropswhen leakage occurs and when the temperature of the additional water is lower thanthe wastewater. A wastewater pipe with a length of approximately 2.5 km in Umeåwas examined with sensors evenly distributed along the path. The method involvedmodeling the heat flow in COMSOL Multiphysics with measured values of thetemperatures for the wastewater, the air in the wastewater pipe and in the groundtogether with the flow and the level of the wastewater. The result gave four similarfunctions for both the wastewater region and the air region that described the heattransfer from the wastewater pipe to the ground. The heating effects had a lineartendency as a function of the temperature difference between wastewater and soilduring the measurement period up to the month of May, but with a high spread asthe heat transfer is also dependent on the flow and not just the temperature difference.The majority of the heat transfer was between the surface of the wastewaterpipe and the wastewater. In the region between the air surface on the wastewaterpipe, the majority was the heat transfer from the radiation between the wastewaterand the surface. The results also gave U-values for the wastewater region and theair region in the pipeline and these were around 4 W/(m2K) and 0.8 W/(m2K),respectively. The supplemental water was modeled on the basis of the heat transferand it showed increased flow levels when it was wet periods with an accuracy of ±1 kg/s.

This master thesis investigates the risks associated with Battery Energy Storage (BESS) projects to improve the insurance process for BESS projects in Sweden, aligning with the global shift towards renewable energy as mandated by the Paris Agreement. The primary objective of this report is to develop guidelines for small enterprises entering the BESS market, focusing on risk identification and stakeholder objectives to improve the insurance process. Some risks identified were a lack of knowledge and experience, unsatisfactory suppliers, and policy and regulatory uncertainties. Utilizing a system engineering approach, the study investigates the interactions and communication between stakeholders, including project developers, insurance brokers, and insurers. The research is conducted through interviews with these stakeholders and a comprehensive literature review. The findings highlight challenges in communication during the insurance process and identify key factors that project developers should consider to ensure smoother interactions, such as providing more detailed information about the requirements to receive insurance. The study reveals the unique challenges posed by the novelty of BESS technology in Sweden. It suggests that a standardized and improved insurance process for BESS projects can accelerate the adoption of renewable energy technologies. The study is delimited to the Swedish context, acknowledging that insurance market mechanisms and BESS technology implementations vary across different countries. The theoretical contributions include an analysis of insurance for BESS projects and an overview of the current insurance products available in the Swedish market. The practical contributions include a guideline for new BESS project developers with considerations they can take to ensure a smoother insurance process for their projects. / Denna masteruppsats undersöker de risker som är förknippade med projekt för batterienergilagringssystem (BESS) för att förbättra försäkrings processen för BESS-projekt i Sverige, i linje med den globala övergången till förnybar energi enligt Parisavtalet. Huvudmålet med denna rapport är att utveckla riktlinjer för småföretag som går in på BESS-marknaden, med fokus på riskidentifiering och intressenternas mål för att förbättra försäkrings processen. Några identifierade risker var bristande kunskap och erfarenhet, otillfredsställande leverantörer och osäkerheter i policy och regelverk. Genom att använda Systems Engineering undersöker denna studie interaktionerna och kommunikationen mellan intressenter, inklusive projektutvecklare, försäkringsmäklare och försäkringsbolag. Forskningen genomförs genom intervjuer med dessa intressenter och en omfattande litteraturstudie. Resultaten belyser utmaningar i kommunikationen under försäkrings processen och identifierar viktiga faktorer som projektutvecklare bör beakta för att säkerställa smidigare interaktioner, såsom att tillhandahålla mer detaljerad information om kraven för att få försäkring. Studien avslöjar de unika utmaningar som den nya BESS-tekniken medför i Sverige. Den föreslår att en standardiserad och förbättrad försäkrings process för BESS-projekt kan påskynda införandet av förnybar energiteknik. Studien är begränsad till den svenska kontexten och erkänner att försäkringsmarknadens mekanismer och BESS-teknikens tillämpningar varierar mellan olika länder. De teoretiska bidragen inkluderar en analys av försäkringar för BESS-projekt och en översikt över de nuvarande försäkringsprodukterna som finns tillgängliga på den svenska marknaden. De praktiska bidragen inkluderar riktlinjer för nya BESS-projektutvecklare med överväganden dekan ta för att säkerställa en smidigare försäkrings process för sina projekt.

Photovoltaic in the Czech Republic has gone through significant development during last few years. The thesis describes physical principle of converting solar energy into electrical energy using photovoltaic cells. Photovoltaic power plant is a set of technologic components connected together to utilize solar energy and convert it into electric energy that could be distributed to electric power network. Review of the photovoltaic development in the Czech Republic and the list of the biggest operational photovoltaic power plants present important data for assessment of the current status of photovoltaic technology in the Czech Republic. Chapter operations and maintenance of photovoltaic power plants summarizes the most common causes of failures and presents diagnostic tools for service requests. Due to legislative changes, hybrid photovoltaic power plants construction has been prioritized as it is economically more efficient now. Construction of new hybrid photovoltaic power plant was assessed analytically using SWOT analysis that evaluates strong and weak sides of the projects in comparison with opportunities and threats of construction. After evaluation of obtained data the next steps of the hybrid photovoltaic power plant’s construction plan are proposed. The first part of hybrid photovoltaic power plant design contains PVGIS program's data evaluation, which provides sunlight intensity information for specified area. Obtained data were used in the second part of the design to determine proper components selection for family house hybrid photovoltaic power plant. Finally the economic view of the design and return of investments were assessed.

Text in English / In recent years, there have been tremendous advances in information technology, robotics, communication technology, nanotechnology, and artificial intelligence, resulting in the merging of physical, digital, and biological worlds that have come to be known as the "fourth industrial revolution”. In this context, the present study engages such technology in the green economy and to tackle the techno-economic environmental impact assessments challenges associated with floating solar system applications in the agricultural sector of South Africa. In response, this exploratory study aimed to examine the development of a Geographical Information System (GIS)-based support platform for Environmental Impact Assessment (EIA) and due-diligence analyses for future planned agricultural floating solar systems, especially with the goal to address the vast differences between the environmental impacts for land-based and water-based photovoltaic energy systems. A research gap was identified in the planning processes for implementing floating solar systems in South Africa’s agricultural sector. This inspired the development of a novel GIS-based modelling tool to assist with floating solar system type energy infrastructure planning in the renewable energy discourse. In this context, there are significant challenges and future research avenues for technical and environmental performance modelling in the new sustainable energy transformation. The present dissertation and geographical research ventured into the conceptualisation, designing and development of a software GIS-based decision support tool to assist environmental impact practitioners, project owners and landscape architects to perform environmental scoping and environmental due-diligence analysis for planned floating solar systems in the local agricultural sector. In terms of the aims and objectives of the research, this project aims at the design and development of a dedicated GIS toolset to determine the environmental feasibility around the use of floating solar systems in agricultural applications in South Africa. In this context, the research objectives of this study included the use of computational modelling and simulation techniques to theoretically determine the energy yield predictions and computing environmental impacts/offsets for future planned agricultural floating solar systems in South Africa. The toolset succeeded in determining these aspects in applications where floating solar systems would substitute Eskom grid power. The study succeeded in developing a digital GIS-based computer simulation model for floating solar systems capable of (a) predicting the anticipated energy yield, (b) calculating the environmental offsets achieved by substituting coal-fired generation by floating solar panels, (c) determining the environmental impact and land-use preservation benefits of any floating solar system, and (d) relating these metrics to water-energy-land-food (WELF) nexus parameters suitable for user project viability analysis and decision support. The research project has demonstrated how the proposed GIS toolset supports the body of geographical knowledge in the fields of Energy and Environmental Geography. The new toolset, called EIAcloudGIS, was developed to assist in solving challenges around energy and environmental sustainability analysis when planning new floating solar installations on farms in South Africa. Experiments conducted during the research showed how the geographical study in general, and the toolset in particular, succeeded in solving a real-world problem. Through the formulation and development of GIS-based computer simulation models embedded into GIS layers, this new tool practically supports the National Environmental Management Act (NEMA Act No. 107 of 1998), and in particular, associated EIA processes. The tool also simplifies and semi-automates certain aspects of environmental impact analysis processes for newly envisioned and planned floating solar installations in South Africa. / Geography / M.Sc. (Geography)

This thesis undertakes a thorough exploration of business models for energy communities, specifically tailored to the unique requirements of the Swedish energy sector. Its objective is to identify and evaluate global business models for energy communities, focusing on their applicability within Sweden's regulatory, market, and socio-cultural contexts. Utilizing the Business Model Canvas as an analytical framework, the study initially identifies twelve distinct business model archetypes, ranging from community-based energy generation to models grounded in circular economy principles. Subsequently, it assesses their viability within Sweden's innovative and sustainability-focused energy landscape. The research is based on a qualitative methodology, incorporating a systematic literature review and comparative analysis to understand the complex dynamics of energy communities. By examining the structure of the Swedish energy system, the study pinpoints key factors influencing the success of energy- community models in Sweden, including regulatory frameworks, technological infrastructure, economic and financial viability, community engagement, and environmental sustainability. The findings emphasize six business models that closely align with Swedish values and objectives, highlighting the significance of community involvement, sustainability, and innovation in transforming Sweden's energy sector. These models include community-based energy generation, residential energy self-consumption, shared community energy generation, electric mobility cooperatives, collective financial initiatives, and circular economy-based approaches. In conclusion, the thesis proposes an Integrated Sustainable Energy Community Model (ISECM) as a comprehensive futuristic energy community model to guide Sweden's transition towards a more decentralized, participative, and sustainable energy future. This model integrates sustainable energy production, smart urban mobility, resource recovery, and digital integration. Further recommending strategic initiatives for implementation such as developing community platforms, forging strategic partnerships, and establishing environmental and social metrics. The research contributes to both academic and practical discussions on sustainable energy transitions, offering a strategic framework for leveraging community-based models to achieve Sweden's environmental and energy goals. It calls for active engagement from government, industry, academia, and communities to unlock the potential of innovative business models in advancing Sweden's energy sustainability agenda. / Denna avhandling genomför en omfattande utforskning av affärsmodeller för energigemenskaper, särskilt anpassade till de unika kraven i den svenska energisektorn. Syftet är att identifiera och utvärdera globala affärsmodeller för energigemenskaper med fokus på deras tillämplighet inom Sveriges regelverk, marknadsdynamik och sociokulturella sammanhang. Med hjälp av Business Model Canvas som analytiskt ramverk kartlägger studien tolv distinkta affärsmodellsarketyper, från gemenskapsbaserad energiproduktion till modeller baserade på cirkulär ekonomi, och bedömer deras livskraft i Sveriges innovativa och hållbarhetsinriktade energilandskap. Forskningen är grundad i en kvalitativ metodik, inkluderande en systematisk litteraturgenomgång och jämförande analys för att förstå de mångfacetterade dynamikerna inom energigemenskaper. Genom att utforska strukturen i det svenska energisystemet identifierar studien nyckelfaktorer som påverkar framgången för modeller av energigemenskaper i Sverige, inklusive regelverk, teknologisk infrastruktur, ekonomisk och finansiell livskraft, gemenskapsengagemang och miljömässig hållbarhet. Resultaten belyser sex affärsmodeller som ligger i linje med svenska värderingar och mål, och betonar vikten av gemenskapsinvolvering, hållbarhet och innovation i omvandlingen av Sveriges energisektor. Dessa modeller inkluderar gemenskapsbaserad energiproduktion, självkonsumtion av energi i bostäder, delad gemenskapsenergiproduktion, kooperativ för elektrisk mobilitet, kollektiva finansiella initiativoch modeller baserade på cirkulär ekonomi. Som avslutning föreslår avhandlingen en Integrerad Hållbar Energi Gemenskaps Modell (ISEGM) som ett holistiskt framtida energigemenskap för att vägleda Sveriges övergång mot en mer decentraliserad, deltagande och hållbar energiframtid. Denna modell inkluderar hållbar energiproduktion, smart stadsrörlighet, återvinning av resurser och digital integration. Som vidare rekommenderar strategiska initiativ för implementering, såsom utveckling av gemenskapsplattformar, skapande av strategiska partnerskap och etablering av miljö- och sociala mätvärden. Forskningen bidrar till akademiska och praktiska diskussioner om hållbara energiövergångar, och erbjuder ett strategiskt ramverk för att utnyttja gemenskapsbaserade modeller för att uppnå Sveriges miljö- och energimål. Den uppmanar till aktivt engagemang från regeringen, industrin, akademin och gemenskaper för att förverkliga potentialen i innovativa affärsmodeller för att främja Sveriges hållbarhetsagenda inom energi.

This Master Thesis is the research done in the country of Rwanda. The project leads to study the climate of this country in order to establish whether this climate could be used to produce energy from air and to implement the first wind turbine for serving the nation.   After an introduction about the historical background of wind power, the thesis work deals with assessment of wind energy potential of Rwanda in focusing of the most suitable place for wind power plants. The best location with annual mean wind speed, the rate of use of turbine with hub height for an annual production per year, the mean wind speeds for 6 sites of Rwanda based on ECMWF for climatic data for one year at relief of altitude of 100m and coordinates are reported too.   The result of energy produced and calculations were done based on power hitting wind turbine generator in order to calculate Kinetic energy and power available at the best location to the measurement over the period of 12 months, that could be hoped for long term.   With help of logarithmic law, where wind speed usually increases with increasing in elevation and the desired wind speeds at all 6 sites were used. The annual energy production was taken into account at the best site with desired wind speed at the initial cost of turbine as well as the cost of energy (COE).However, with comparison of the tariff of EWSA, the price of Wind designed in this Research per kWh is cheaper and suitable for people of Rwanda. / <p><em>Rwanda has considerable opportunities development energy from hydro sources, methane gas, solar and peat deposits. Most of these energy sources have not been fully exploited, such as solar, wind and geothermal. As such wood is still being the major source of energy for 94 per cent of the population and imported petroleum products consume more than 40 per cent of foreign exchange. Energy is a key component of the Rwandan economy. It is thus recognized that the current inadequate and expensive energy supply constitutes a limiting factor to sustainable development. Rwanda’s Vision 2020 emphasizes the need for economic growth, private investment and economic transformation supported by a reliable and affordable energy supply as a key factor for the development process. To achieve this transformation, the country will need to increase energy production and diversify into alternative energy sources. Rwandan nations don’t have small-scale solar, wind, and geothermal devices in operation providing energy to urban and rural areas. These types of energy production are especially useful in remote locations because of the excessive cost of transporting electricity from large-scale power plants. The application of renewable energy technology has the potential to alleviate many of the problems that face the people of Rwanda every day, especially if done so in a sustainable manner that prioritizes human rights.</em></p>