Additive manufacturing (AM), also known as 3D-printing is an automated manufacturing process in which the component is built layer upon layer from a predefined 3D computer model. In contrast to conventional manufacturing processes where a vast volume of material is wasted due to machining, AM only uses the material that the component consists of. In addition to material savings, the method has a number of potential benefits. Two of these are (1) a large design freedom which enables the production of complex geometries and (2) a reduced compexity in supply chain as parts can be printed on-demand rather than be kept in stock. This master thesis has been performed at Vattenfall Wind Power and aims to investigate the feasibility to reproduce and/or to refurbish one or two spare parts on a wind turbine by AM and if it can introduce any practical benefits. Components with a high failure rate and/or with an suitible design for AM have been investigated. A rotating union or fluid rotary joint (FRJ) was selected for further analysis. A comprehensive background study has been conducted. A current status of metal AM is described as well as a comparison between conventional and additive processes. Furthermore, current and future applications for AM witihin the wind turbine industry are presented. The mehodology "reverse engineering", main components in a wind power plant including the fluid rotary joint as well as fluid dynamics are also treated in the background study. As a part of the process, a fluid rotary joint with worse historical failure data was disassembled and examined. In order to find other design solutions that contributes to a better and more reliable operation, another better performing fluid roraty joint was investigated. Since detail drawings and material information are missing for the examined units, reverse engineering has been carried out to gather details of the designs. A concept for the first unit has been developed, in which improved design solutions has been introduced and a number of changes have been implemented in order to minimize material consumption and to adapt the design for AM. The concept has been evaluated by the use of numerical methods. Costs and build time have also been estimated for the developed concept. This project has illustated that it is feasable to manufacture spare parts by the use of AM. The developed concept demonstrates several improvements that are not possible to achieve with conventional manufacturing processes. Nevertheless, a number of limitations such as insufficient build volume, costs as well as time cosuming engineering effort and post-proccessing methods are present for AM. These restrictions, in combination with lack of 3D-models, limits the possibility to make use of the technology. However, the future looks bright, if the technology continues to develop and if subcontractors are willing to adapt to AM it will probably have a major breakthrough within the windpower industry. / Additiv tillverkning, "additive manufacturing" (AM) eller 3D-printing är en automatiserad tillverkningsmetod där komponenten byggs lager för lager från en fördefinierad 3D datormodell. Till skillnad från konventionella tillverkningsmetoder där en stor mängd material ofta bearbetas bort, använder AM nästintill endast det material som komponenten består utav. Förutom materialbesparingar, har metoden ett flertal andra potentiella fördelar. Två av dessa är (1) en stor designfrihet vilket möjliggör produktion av komplexa geometrier och (2) en möjlighet till en förenklad logistikkedja eftersom komponenter kan tillverkas vid behov istället för att lagerföras. Detta examensarbete har utförts på Vattenfall Vindkraft och har till syfte att undersöka om det är möjligt att tillverka och/eller reparera en eller två reservdelar genom AM och om det i så fall kan införa några praktiska fördelar. En kartläggning av komponenter med hög felfrekvens och/eller som kan vara lämpade för AM har genomförts. Av dessa har en roterande oljekoppling även kallad roterskarv valts ut för vidare analys. En omfattande bakgrundsstudie har utförts. En nulägesorientering inom området AM för metaller redogörs, här redovisas även en generell jämförelse mellan konventionella och additiva tillverkningsmetoder. Vidare behandlas aktuella och framtida användningsområden för AM inom vindkraftsindustrin. I bakgrundsstudien behandlas också arbetssättet "reverse engineering", huvudkomponenter i ett vindkraftsverk inklusive roterskarven samt flödesdynamik. Under arbetets gång har en roterskarv med sämre driftshistorik undersökts. I syfte att finna andra konstruktionslösningar som bidrar till en säkrare drift har en bättre presenterande enhet från en annan tillverkare granskats. Då viss detaljteknisk data och konstruktionsunderlag saknas för de undersökta enheterna har "reverse engineering" tillämpats. Ett koncept har sedan utvecklats för den första enheten där förbättrade konstruktionslösningar har introducerats samtidigt som en rad konstruktionsförändringar har gjorts i syfte att minimera materialåtgången och samtidigt anpassa enheten för AM. Konceptet har sedan evaluerats med hjälp av numeriska beräkningsmetoder. För det givna konceptet har även kostnad och byggtid uppskattats. Arbetet visar på att det är möjligt att ta fram reservdelar till vindkraftverk med hjälp av AM. Det framtagna konceptet visar på ett flertal förbättringar som inte kan uppnås med konventionella tillverkningsmetoder. Emellertid finns det en rad begränsningar såsom otillräcklig byggvolym, kostnader och tidskrävande ingenjörsmässigt arbete och efterbehandlingsmetoder. Dessa förbehåll i kombination med avsaknad av 3D-modeller begränsar möjligheterna att nyttja tekniken i dagsläget. Framtiden ser dock ljus ut, om tekniken fortsätter att utvecklas samtidigt som underleverantörer är villiga att nyttja denna teknik kan AM få ett stort genombrott i vindkraftsindustrin.

As the world try to combat the impacts of climate change governments have taken action by implementing a greater emphasis on renewable energy sources. To facilitate this transition to more sustainable energy sources new policies and planning practises are required. This study has focused on how two countries, Sweden and the Netherlands, work with implementing wind power by exploring what policies they have concerning wind power development, how the planning process work in practise and what challenges they face regarding policies and the planning process. The result of this study has shown that the Netherlands has made large efforts in providing policies and are working towards establishing a new regional body responsible for the transition towards renewable energy sources. Sweden on the other hand, has not made the same commitment to policies and is mostly focused on improving the planning process. / I och med att världens länder försöker bekämpa effekterna av klimatförändingen har regeringar världen över ökat sina satsningar på förnyelsebara energikällor. För att främja övergången till mer hållbara energikällor krävs nya policyers och planerings processer. Den här studien har fokuserat på hur två länder, Sverige och Nederländerna, arbetar med att implementera vindkraft genom att undersöka vilka policys som finns för vindkrafts utveckling, hur planeringsprocessen fungerar i praktiken och vilka utmaningar som finns gällande policys och planeringsprocessen. Resultatet av studien visar att Nederländerna har gjort stora ansträngningar i att tillgodose policys och håller på med arbetet att upprätta ett nytt regionalt organ som ska ansvara för övergången till förnyelsebara energikällor. Sverige däremot, har inte haft samma engagemang gällande policys utan har istället fokuserat på planeringsprocessen.

Wind power production is of growing importance to many countries around the world. To improve reliability and power grid stability related to wind power, forecasting of wind power is becoming an important commercial and research area. Machine learning methods are considered to be highly valuable when making predictions on time series data and as such have become prominent within wind forecasting as well. This thesis extends an existing neural network prediction system with new input data series, in particular the observed wind speed from the wind farm itself. The goal was to investigate the effect this new data series has, and whether or not it could be used to improve predictions as compared to the baseline prediction system defined within this thesis. To do this multiple methods of including the observed wind speed are developed, including a multi-stage network concept. These results are statistically tested to give more evidence for their comparison to baseline. The results show that the multi-stage network concept can use the observed wind speed to improve performance over the baseline case for specific prediction horizons. / Betydelsen för vindkraftsproduktion växer i länder runt om i världen. För att förbättratillförlitligheten och elnätstabiliteten i vindkraften blir dess prognoser viktiga kommersielltoch ett forskningsområde. Maskininlärningsmetoder anses vara mycket värdefullanär man gör förutsägelser om tidsseriedata och har därmed framträdat inom vindprognoser. Detta arbete utökar ett existerande prediktionssystem av neurala nätverk med ny indata,med särskilt den observerade vindhastigheten från själva vindkraftparken. Måletvar att undersöka effekten av denna nya dataserie, och huruvida den skulle kunna användasför att förbättra förutsägelserna jämfört med det befintliga referensprognossystemetdefinierat i denna uppsats. För att kunna göra detta utvecklas flera metoder för att inkludera den observeradevindhastigheten, inklusive ett flerstegs nätverkskoncept. Dessa resultat är statistiskt testadeför att ge mer grund i deras jämförelse med referensmodellen. Resultaten visar att detflerstega nätverkskonceptet kan använda den observerade vindhastigheten för att förbättraprestanda över referensmodellen för specifika prediktionshorisonter.

I och med klimatförändringar, är möjligheten att integrera stora andelar förnybar energi i elsystemet av yttersta vikt. Detta kandidatexamensarbete undersöker vattenkraftens regleringsmöjlighet när man integrerar vindkraft i ett slutet elsystem. Projektet inkluderar en fallstudie baserad på fem vattenkraftverk i en del av Skellefteälven i norra Sverige. Målet med projektet är att optimera vattenkraftensdrift med maximal andel vindkraft installerad i systemet. Detta utförs genom att maximera vattenkraftens vinster. Genom att i programvaran GAMS lösa ett linjärprogrammeringsproblem med timvis upplösning bestående av 168 timmar. När vindkraft implementeras upptäcks att den maximala installerade effekten vindkraft är 100 MW. Placeringen av vindkraften hade en påverkan på vinsterna i systemet, samt den maximala mängden. Fallstudien visar att det är elnätet som begränsar den maximala installerade effekten vindkraft och inte vattenkraftens reglerförmåga. Fallstudien visar dessutom att det är mindre lönsamt att bygga all vindkraft i en nod utan istället sprida ut vindkraften i elsystemet. / In the face of climate changes, integrating larger quantities renewable energy resources into the electrical grid is vital. This bachelor thesis project examines the regulatory ability in hydro power  when implenting wind power into a closed power system. The project includes a case study based on a part of River Skellefte älv in northern Sweden, including five hydro power plants. The goal of the project is to optimize the hydro power production with maximum amount of implimented wind power. This is done by maximizing the revenue from the hydro power plants electrical production. Through a linear programming problem consisting of 168 time steps of one hour each, an optimal scheduling for the hydro power plants is found, using the opitimization software GAMS. When implenting wind power to the system, the maximum installed wind power is found to be 100 MW. The placement of the wind power in the system affects the revenue of the power system, as well as the maximum installed wind power possible. The case study shows that it is the electrical grid that restricts the amount of wind power that can be implented, rather than the regulatory ability in the installed hydro power. The case study also indicates that it is less profitable to apply all wind power in the same node of the power system.

Hydrogen can be produced via water electrolysis, a process powered by electricity, and is often called green hydrogen if the electricity source is renewable. The purpose of this thesis is to investigate the levelised cost of hydrogen, LCOH, from two hypothetical scenarios of green hydrogen production at onshore wind farm sites. The hydrogen is used in steel manufacturing. One scenario is set in Chile, a country with excellent wind conditions, where a large wind farm of around 1 GW supplies both a hydrogen and ammonia production. Ammonia is used as a hydrogen carrier since it is easier to transport, and the ammonia is shipped to Sweden where it is decomposed into hydrogen. The Swedish scenario includes three cases with wind farms of 28.5, 114 and 285 MW (case 1, 2 and 3), where the sites are located close to the steel plant. Both the Chilean and Swedish scenarios consist of a base case and a sensitivity analysis, all simulated in MATLAB. Parameters such as equipment efficiency and cost, levelised cost of wind energy, shipping and transportation costs, electricity price and electrolyser size were analysed to see how they affect the LCOH.  The results showed that the Chilean case both could meet the hydrogen demand of a commercial steel plant and has a lower LCOH than most Swedish scenarios. The LCOH in the base case was 2.17 €/kg H2 for the Chilean case and 6.71, 6.29 and 5.14 €/kg H2, respectively, for case 1, 2 and 3. The sensitivity analysis showed that case 3 had a similar or lower LCOH than the Chilean case when it was connected to the grid, and could sell excess wind electricity, or for electrolysers of at least 100 MW. Case 3 could supply the smallest of the suggested steel plant sizes, and it would require an around three times larger wind farm and hydrogen production site to reach the level of the Chilean case. However, the Swedish case could be preferred if other factors, such as security of supply, local connection or the exclusion of fossil fueled transports, are more important than low cost and hydrogen volume.

With the rising cost of petroleum, concerns about exhausting the fossil fuels we depend on for energy, and the subsequent impacts that the burning of these types of fuels have on the environment, countries around the world are paying close attention to the development of renewable types of energy. Consequently, researchers have been trying to develop ways to take advantage of different types of clean and renewable energy sources. Wind energy production, in particular, has been growing at an increasingly rapid rate, and will continue to do so in the future. In fact, it has become an integral part in supplying future energy needs, making further advancements in the field exceedingly critical. A 2 MW wind energy conversion system (WECS) is presented and has been simulated via the dynamic simulation software Simulink. This WECS consists of a 2 MW permanent magnet synchronous generator connected to the transmission grid through a power conversion scheme. The topology of this converter system consists of a passive AC/DC rectifier as well as a PWM DC/AC IGBT inverter, used to interface the DC link with the grid. The inverter has an integrated current control system for power factor correction to improve output power stability. The described WECS enhances grid-side tolerance by buffering wind power disturbances demonstrated by its capability to isolate the grid from wind speed fluctuations. It also optimizes wind energy capture through harmonic filtering, enhancing output power quality. These findings have the potential to lead to further advancements including the capability for island operation and integration to a smart grid.

Ammonia production with offshore wind power has the potential to transform energy and fertilizer markets within the United States. The vast offshore wind resource can be converted directly into liquid ammonia using existing technologies. The liquid ammonia can then be transported around the country via rail, truck, barge or pipeline and used as either a fertilizer or a fuel. This thesis reviews the technologies required for all-electric, wind-powered ammonia production and offers a simple design of such a system. Cost models based on the physical equipment necessary to produce ammonia with wind power are developed; offshore wind farm cost models are also developed for near-shore, shallow, wind farms in the United States. The cost models are capable of calculating the capital costs of small industrial-sized ammonia plants coupled with an offshore wind farm. A case study for a utility-tied, all-electric ammonia plant in the Gulf of Maine is used to assess the lifetime economics of such a system. Actual utility grid prices and offshore wind are incorporated into a systems-level simulation of the ammonia plant. The results show that significant utility grid backup is required for an all-electric ammonia plant built with present-day technologies. The levelized cost of one metric ton of ammonia is high relative to ammonia produced with natural gas or coal, but is not as susceptible to spikes in ammonia feedstock prices. A sensitivity analysis shows that the total levelized cost of ammonia is driven in large part by the cost of producing electricity with offshore wind. Major cost reductions are possible for systems that have long lifetimes, low operations and maintenance costs, or for systems that qualify for Renewable Energy Credits.

The purpose of this thesis is to explore, how it is best to enter to the wind turbine manufacturingindustry and suggest a competitive strategy for that purpose.The thesis follows Michael E. Porter's Competitive Strategy framework. The market is analyzed using data and scenarios from World Energy Council, Global Wind Energy Council and European Wind Energy Association. As competitors, European-based wind turbine manufacturers belonging by their market share to Global Top 10 are analyzed. A five-point competitive strategy is drafted.Technological innovations and business model improvements are not analyzed in this thesis.The result of competitive strategy research performed in this thesis is, that a window to enter to wind turbine manufacturing industry is embedded into the process of establishing a new experience curve. The new experience curve is based on direct drive wind turbine concept. The thesis suggests that the market to enter the industry is European onshore wind turbine market.A major barrier entering the industry is well established relationships between old wind turbine manufacturers and customers whereas the newcomers lack of sufficient references. A strategy to hurdle the barrier is acquiring the references by forward integration. Therefore, to enter to the market, wind turbine company should own its own wind park as a base of references and new product testing. As wind parks product, electricity is a commodity and sold on a commodities market, the forward integration does not need major extra know how.Core competences for the emerging company include product engineering and quality management.

<p>Wireless LAN (WLAN) mesh networks are now being used to deploy Wi-Fi coverage in a wide variety of outdoor applications. In these types of networks, conventional WLAN mesh nodes must be operated using continuous electrical power connections. This requirement may often be very expensive, especially when the network includes expansive outdoor wireless coverage areas. An alternative is to operate some of the WLAN mesh nodes using an energy sustainable source such as solar or wind power. This eliminates the need for a fixed power connection, making the node truly tether-less and allowing for more flexibility in node positioning. The cost of the battery and the solar panel or wind turbine can be a significant fraction of the total node cost, therefore the resource allocation must be performed optimally.</p><p>In this thesis we investigate this problem. First, we present geographic provisioning results for solar and wind powered WLAN mesh nodes. The results suggest that in certain geographic locations a hybrid wind/solar powered WLAN mesh node is the optimum minimum cost configuration. The results also provide strong motivation for introducing power saving to the IEEE 802.11 standard. We then consider the problem of cost-optimal node placement in a hybrid network containing traditional and energy sustainable nodes. Our results show that there is a significant improvement in cost that can be obtained using the proposed methodology. Finally, we consider the problem of energy management in these networks. A control algorithm is proposed that uses access to publicly available meteorological databases. We show that the proposed algorithm minimizes node outage and performs favorably compared to the analytic performance bounds. Overall, the work in this thesis develops analytical and simulation models which investigate the key aspects pertaining to resource allocation in energy sustainable WLAN mesh networks.</p> / Thesis / Doctor of Philosophy (PhD)

Environmental experts agree that climate change is the biggest challenge facing our planet, and renewable energy and wind power are two important ways to curb it. Many governments promote these choices as environmentally friendly. There is a great deal of acceptance of wind power, with many people viewing it as an environmentally-friendly option that can help reduce emissions. Wind power has both positive and negative impacts on humans, with some findings indicating that the technology can have effects on human health. Some concerns include noise levels, visual impact from turbines, and potential effects of wind farms. Noise and shadows are the two most significant impacts in Sweden, while visual impact is more prevalent in India. Several improvements to the two countries' strategies have been made over the past few years. The proposed project has been created with the aim of promoting further development of wind power, which could have a significant impact on the environment and human health. Government incentives are being given to the deployment of renewable energy, such as wind power. This is in an effort to reduce carbon emissions and make a positive impact on the environment. In order to be used as sources in India, materials must be re-adopted and undergo standardized procedures. Public participation was promoted by the Swedish government in order to ensure that changes were made to the country's energy sources. This strategy was intended to foster a more open and participatory environment, which would ultimately lead Rephrase Energy should be included in the system, either as a producer or consumer.