The goal of the European Union is to make strides towards a circular economy. This means recycling or re-using as much of the material in the economic system as possible. The wind industry faces a great challenge in the years to come as huge quantities of increasingly larger wind turbines reach the end of their service-life. When old wind turbines have been decommissioned, most parts are scrapped and recycled into other applications. The turbineblades however are made from glass- and carbon fibre polymers and are not as easily recycled. Recent bans of putting the blades into landfills steer the industry toward finding new applicationfor the old wind turbine blades. Re-purposing the blades as bridges, shelters, houses and towers has been suggested, as well as re-cycle the material or recover the blades as energy. Regardless of what method is preferred, the wind turbine blades need to be transported to a re-purpose or recycling facility. Because of the distribution of wind turbines within countries, the optimal location of such facilities can be hard to evaluate. The centre-of-gravity method (evaluating the centre-of-mass) has been suggested as a way of evaluating the optimal location of such facilities. The method is built upon the assumption that the wind turbine blade can be easily downsized, transported and accommodated in a single transport. In order to achieve this, the present thesis has compared and evaluated different methods of segmenting the wind turbine blade (mechanical, thermal and chemical) as well as different loading and compressing methods. The mechanical separation methods tend to be more suitable than the thermal and chemical counterparts. The choice of loading methods is dictated by the resulting fraction size of the wind turbine blade after separation. The mass density of the resulting blade could be increased with a suitable way of compression (hydraulic or gravity).

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The aim of this project was to analyze howthe voltage magnitudes of an electrical grid is affectedwhen wind power production varies in an area aroundthe river of Ångermanälven. The goal of the project wasto keep the voltage deviation within 10 % from the setbase value. A secondary goal was to make a profitabilityassessment between power losses and costs related tothe power grid.A transmission grid model was built around Ångermanälven and simulations were made in MATLAB,with the open-source tool package called MATPOWER,to simulate the properties of the grid. Thesesimulations included real hourly historical data fordemand and power generation. Voltage deviation andlosses in the transmission grid for the system was thendetermined with power flow analysis.For the base case, the voltage deviation was keptwithin the limit of a maximum deviation of 10 %. Thebase case was thereafter upgraded to improve transmissionefficiency and resiliency. Increasing the basevoltage resulted in lower losses and voltage deviationsbelow 5 %. To make the grid more resilient and fulfillthe N-1 and N-2 criteria, additional transmission lineswere added. However, these were deemed necessary fora reliable grid, even though the upgrades increased thetotal cost of the system. / Strävan med detta projekt varatt analysera hur spänningsnivån för ett elnätpåverkas av varierande vindkraftsproduktion för ettområde kring Ångermanälven. Målet med projektetvar hålla spänningen inom 10 % från den sattabasspänningen. Ett sekundärt mål var att göra enlönsamhetsbedömning mellan effektförluster och kostnaderrelaterade till elnätet.En model av transmission nätet byggdes kring Ångermanälven och simuleringar utfördes i MATLAB,med hjälp av ett open-source verktyg kallat MATPOWER,för att simulera nätets egenskaper. Simuleringarnainkluderade verklig historisk timvis data förbehov och kraftproduktion. Spänningsavvikelser ochförluster i transmissionsnätet fastställdes med belastningsfördelning.För basfallet hölls spänningsavvikelserna inom denmaximala gränsen på 10 %. Basfallet uppgraderasdärefter för att förbättra transmissionseffektivitet ochtillförlitlighet. Ökning av basspänningen resulterade ilägre andel förluster och spänningsavvikelser på under5 %. För ett mer tillförlitligt nät och för att kunnauppfylla N-1 och N-2 kriterierna, installerades extraledningar. Dessa ledningar ansågs nödvändiga för attuppnå ett tillförlitligt elnät, även om det innebar ettkrav på ökade investeringskostnader för systemet. / Kandidatexjobb i elektroteknik 2021, KTH, Stockholm

These days more renewable energy sources are beingintegrated into the power system, while nuclear power and otherconventional energy sources are being demounted. This comeswith some obstacles, e.g. the renewable energy sources do nothave the same ability to produce reactive power as conventionalenergy sources do. The purpose of this study is to investigate howthe voltage in a power grid would behave with only renewableenergy sources as generators. A fictive power grid was madeto represent a real power grid based in the region of Dalarna,Sweden. Maintain a stable voltage by only using wind andhydropower was the goal of the study, but also to have an self-sufficient grid that does not have to import power from nearbyregions. By using numerical analysis in Matlab with real data,the grid was simulated. The result was that the fictive grid wasnot able to be entirely self-sufficient as it had to import powerfrom nearby regions. In the constructed grid the voltage neverdeviated more than 1 % from the nominal voltage. In conclusion,the study fulfilled all the goals other than making it independent. / Dessa dagar integreras fler förnybara energikällor i elnätet medan kärnkraft och andra konventionella energikällor demonteras. Detta kommer med några hinder, t.ex att de förnybara energikällorna inte har samma förmåga att producera reaktiv effekt som de konventionella energikällorna kan. Syftet med denna studie är att undersöka hur spänningen i ett elnät skulle uppföra sig med endast förnybara energikällor som generatorer. Ett fiktivt elnät skapades för att representera ett verkligt nät baserat i en region i Dalarna, Sverige. Att ha en stabil spänning genom att bara använda vind- och vattenkraft var studiens syfte, men också att nätet skulle vara självförsörjande och inte behöva importera effekt från grannområdena. Genom att använda numerisk analys i Matlab med verkliga värden simulerades nätet. Resultatet var att det fiktiva nätet inte kunde vara helt oberoende eftersom det var tvunget att importera effekt från de närliggande regionerna. Spänningarna i det konstruerade nätet avvek aldrig mer än 1 % från den nominella spänningen. Sammanfattningsvis uppfyllde nätet alla mål förutom att göra det självförsörjande. / Kandidatexjobb i elektroteknik 2020, KTH, Stockholm

The East African Community (EAC) is an intergovernmental organisation comprised of six countries, five of which are classed as having a low development level and one of which is classed as medium. The region has low rates of human development and electrical connectivity but is committed to meeting the universal access and clean energy goals of Sustainable Development Goal 7. This thesis seeks to explore the renewable energy potential of the EAC at a regional level. There is little study of the energy situation of the EAC as a specific region, contrasting this work to the majority of similar analyses that focus on the national or sub-Saharan level. The potential for solar PV and wind power in the EAC was examined through an analysis of existing energy systems, a simplified multi-criteria analysis through geographical information systems, and a comparison with similar work by the International Renewable Energy Agency (IRENA). The region was shown to have a small but growing electricity sector and a primary energy system dominated by traditional biomass. The mapping analysis identified large areas across all studied countries as potentially suitable for on- or off-grid renewable energy. It also highlighted issues with the results of IRENA’s work in its current form. Solar PV and wind energy potential across the EAC is shown to be high, with a low carbon electricity sector consequently a possibility for the region in the future. / Den Östafrikanska Gemenskapen (EAC) är en mellanstatlig organisation av sex länder. Fem av de länderna har en låg utvecklingsnivå och en är klassificerad som medelnivå. Regionen har låg mänsklig utveckling och tillgång till elkraft men har bestämt att uppfylla globala målen 7: säkerställa tillgång till ekonomiskt överkomlig, tillförlitlig, hållbar och modern energi för alla. Denna uppsats utforskade potentialen för förnybar energi i den EAC på en regional nivå. Potentialen för solenergi och vindkraft i EAC undersöktes genom en analys av befintliga energisystem, en förenklad multikriterianalys genom geografiska informationssystem (GIS) och en jämförelse med liknande arbete från den International Renewable Energy Agency (IRENA). En liten men växande elsektor och ett primärt energisystem dominerat av traditionell biomassa identifierades i regionen. Kartläggningsanalysen identifierade stora områden i alla studerade länder som lämpliga för förnybar energi på, eller utanför, elnätet. Analysen fann också problem med resultaten från IRENAs arbete med Global Atlas of Renewable Energy projektet. Det finns god potential för sol- och vindkraft i EAC och möjligheten av ett lågkoldioxidenergisystem är diskuterade som en potential framtid för regionen.

This study assesses the viability of temporarily halting wind turbine operations as amitigation measure to protect bird populations during migration periods. Conducted in thenorthern Baltic, it examines the migration patterns, timings, and altitudes of various birdspecies, aiming to identify the most critical times for implementing turbine stoppages.Utilizing statistical analyses, including F-tests to evaluate migration intensity differencesamong species, the report proposes that strategic, short-duration shutdowns cansignificantly reduce avian collisions. The research emphasizes the importance of species-specific approaches and evaluates the cost-effectiveness of various bird collision reductiontechniques, such as blade painting and thermal detection for dynamic shutdowns. Thisapproach seeks to balance the ecological impact of wind turbines with the necessity forrenewable energy development, offering practical solutions that could enhance biodiversityconservation efforts without substantially compromising energy production efficiency.

This study assesses the viability of temporarily halting wind turbine operations as amitigation measure to protect bird populations during migration periods. Conducted in thenorthern Baltic, it examines the migration patterns, timings, and altitudes of various birdspecies, aiming to identify the most critical times for implementing turbine stoppages.Utilizing statistical analyses, including F-tests to evaluate migration intensity differencesamong species, the report proposes that strategic, short-duration shutdowns cansignificantly reduce avian collisions. The research emphasizes the importance of species-specific approaches and evaluates the cost-effectiveness of various bird collision reductiontechniques, such as blade painting and thermal detection for dynamic shutdowns. Thisapproach seeks to balance the ecological impact of wind turbines with the necessity forrenewable energy development, offering practical solutions that could enhance biodiversityconservation efforts without substantially compromising energy production efficiency.

This research delves into the feasibility and effectiveness of utilizing wind-powered shading systems in architectural design to enhance energy efficiency and promote environmental sustainability. With an ever increasing demand for energy in commercial buildings, particularly in heating, cooling, and lighting, innovative solutions are crucial in addressing these challenges. The proposed solution centers on dynamic shading systems that adjust autonomously to environmental factors, thanks to advancements in construction and information technologies. Piezoelectric wind harnessing devices are at the heart of this investigation, powering kinetic shading systems that offer a renewable and eco-friendly alternative to traditional energy sources. However, implementing such systems presents technical challenges such as device optimization, compatibility with dynamic movement, and reliability in real-world applications. Through empirical research and experimentation, these challenges are comprehensively explored and addressed. The study seeks to assess the practicality and effectiveness of wind-powered shading systems in reducing energy consumption, improving thermal comfort, and enhancing overall building performance. By considering factors such as architectural integration, heat, light management, and adaptability to environmental conditions, the research aims to contribute to the advancement of sustainable building practices. Ultimately, the findings provide valuable insights into the potential of wind-powered shading systems to mitigate energy usage and promote environmental stewardship in architectural design. / Master of Architecture / This Thesis Explores the design and evaluation of origami-inspired kinetic shading system driven by piezoelectric technology to convert wind power to electricity. By examining the behavior and utility of this piezoelectric dynamic folding shading system, it enhances our understanding of how to integrate renewable energy into building designs for a more sustainable future.

Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: In this study the recently proposed slip-synchronous permanent magnet generator (SS-PMG), is considered as an alternative to other wind generator topologies. The SS-PMG is connected directly to the grid without the need for a power electronic converter and it can also be connected directly to the turbine without a gearbox. Due to the SS-PMG requiring no gearbox or power electronic converter it is evident that this type of generator have a significant advantage regarding reduced maintenance and operation costs. The SS-PMG consist of two integrated permanent magnet generating units, a directly turbine connected slip permanent magnet generator (slip-PMG) and a directly grid connected permanent magnet synchronous generator (PMSG). In this, study many of the implementation aspects of the SS-PMG are addressed. It is found that the short-circuit torque and current profiles of both the slip-PMG and PMSG are significantly influenced by the end-winding inductance and PM end-effects. A new analytical method is proposed for the calculation of the end-winding inductance in this study and a new approach is devised to take the PM end-effects into account. A very important aspect considered in this thesis, is the stability of the SS-PMG connected directly to the grid regarding turbine, generator and grid voltage disturbances, which influences the design of the PMSG and slip-PMG units. Furthermore, it is important that the final SS-PMG design comply to the relevant grid code specifications. For both the PMSG and slip-PMG an extensive design optimisation is done, with several novel wind generator concepts introduced. In this study the dynamic behaviour, grid connection aspects and operational principles of the SSPMG are verified by means of practical tests in the laboratory and for the SS-PMG interfaced with an existing 15 kW wind turbine system in the field. / AFRIKAANSE OPSOMMING: In hierdie studie word die onlangs voorgestelde, glip-sinchroon permanent magneet generator (GSPMG), oorweeg as ’n alternatief vir ander wind generator topologieë. Die GS-PMG word direk aan die netwerk gekonnekteer sonder die nodigheid van ’n drywingselektroniese omsetter en dit kan ook direk aan die turbine gekoppel word sonder ’n ratkas. Omdat die GS-PMG geen ratkas of drywingselektroniese omsetter benodig nie, is dit duidelik dat hierdie tipe generator ’n geweldige voordeel het rakende verminderde onderhoud en operasionele kostes. Die GS-PMG bestaan uit twee geïntegreerde permanent magneet generator eenhede, ’n direkte turbine gekoppelde glip permanent magneet generator (glip-PMG) en ’n direkte netwerk gekonnekteerde permanent magneet sinchroon generator (PMSG). In hierdie studie word baie van die implementerings aspekte van die SS-PMG aangeraak. Daar word gevind dat die kortsluit draaimoment en stroom profiele van beide die glip- PMG en PMSG geweldig deur die end-wikkeling induktansie en PM randeffekte beïnvloed word. Dus, word ’n nuwe analitiese metode voorgestel vir die uitwerk van die end-wikkeling induktansie in hierdie studie en ’n nuwe benadering word voorgestel om die PM randeffekte in ag te neem. ’n Baie belangrike aspek om te oorweeg in hierdie tesis, is die stabiliteit van die GS-PMG direk aan die netwerk gekoppel rakende turbine, generator en netwerkspanning steurnisse, wat die ontwerp van die PMSG en glip-PMG eenhede beïnvloed. Dit is ook belangrik dat die finale SS-PMG ontwerp voldoen aan die relevante netwerkkode spesifikasies. Vir beide die PMSG en glip-PMG word ’n deeglike ontwerpsoptimering gedoen, met talle nuwe wind generator konsepte voorgestel. In hierdie studie word die dinamiese gedrag, netwerk konneksie aspekte en operasionele kenmerke van die GSPMG geverifieer met behulp van praktiese toetse in die laboratorium en vir die SS-PMG geïntegreer met ’n bestaande 15 kW wind turbine stelsel in die veld.