This is a feasibility study that examines various aspects of building a wind farm on Malmön in Norrköping. The feasibility study deals with interests of conflict, park design, electrical connections, production calculation, financial calculations and operating- and timetable. The report is divided into two distinct parts. First a theoretical part, which deals with conflicting interests, park design and electrical connections. Second a part with simulations dealing with production calculations, and financial calculations. Opposing interests are mapped so that problem areas can be found, and help put focus on the right places at a future environmental impact assessment (EIA). There are a number of areas where planners have to assess on an EIA, this thesis point on the most important areas. There are a few areas of national interest and the Natura 2000 protection. Part of the area of the planned park is also within Norrköping Airport area of influence and an assessment must be made by the civil aviation authority (CAA) to determine if a wind farm on the location would affect the air traffic and if so, what part of the location would be affected. Furthermore, there is the area of a flight route for birds as well as an area that is a common livelihood for birds. These should be examined to see if wind power in the area can become a problem for these birds. A production calculation has been implemented in the program WindPRO. This feasibility study has dealt with three different park designs with the wind turbine, Vestas V-126 3.3MW, which is the largest low wind turbine we found. Based on wind data, data for wind turbines, distance between turbines and other data we can do a calculation of how much energy the wind farm produces annually. Calculations were also made In WindPRO regarding sound levels and shadow creation. This is so that the wind farm will be designed so target values for noise and shadows are met. All park designs in this project has been designed so that the sound and shadow benchmarks for buildings nearby are met. Based on production estimates, an economic calculation been carried out. The different park designs have between 7 and 11 wind turbines with an annual energy production of between 58 and 91 GWh per year. The wind turbines have been estimated to cost approximately 25 Mkr each, plus about 10 % of turbine cost for foundations, roads, power lines and other similar expenses. One calculation was made for the case the electric connection could be done directly to some of the industries in the location, for this simulation the cost over the wind mill was about 15 %. Under all these conditions, the project should be financially sustainable, with a payback period of about 6-11 years and a return of investment of 1-7 %.

When planning new wind farms, the cost for the internal electrical grid is estimated to account for 8-9 % of the total investment cost. On top of that, the cost for accumulated reduced income over several years (due to electrical losses), has to be added. The economic lifespan is relatively long (about 20 years) which means that an error in the loss calculation could lead to a bad decision basis. The accumulated reduced incomes due to electrical losses can be higher than the initial investment cost for the internal electrical grid. Today, Statkraft Sweden is using a template number when estimating the electrical losses in a wind farm. The actual losses are probably lower than the template number which could lead to an unnecessary high loss cost when planning a new wind farm. The aim of this M.Sc. thesis is to develop a better method than the one currently used to estimate the electrical losses in an early stage of the planning process. With necessary information of the proposed wind farm, an early calculation can be done.The user will then have the option to make changes in the wind farm to minimize losses, long before the wind farm is actually built. In the initial stage of the thesis, the components generating losses was modeled using available literature. Next, a MATLAB-program was constructed where the user could build a proposed wind farm consisting of wind turbines, cables and transformers. The program was named Wind Farm Electric System Calculator (WFESC). Finally, WFESC was verified with measurement data from one of Statkraft’s wind farms in Småland, Sweden. WFESC can simulate the electrical losses and production from a wind farm. The simulation takes turbine information, cable types and transformer specifications into account. The user gets detailed information about the different types of losses which makes it possible to minimize losses in the wind farm. In a comparison, WFESC presents a result that differs 5 % from measured data acquired from one of Statkraft’s wind farms in Sweden. The difference between data produced with WFESC and measured data emerges from approximations done in WFESC and difficulties in estimating cable temperatures in a wind farm. The conclusion is that WFESC estimates the internal electrical losses well and can be used when planning a wind farm.

Detta examensarbete behandlar ett uppsamlingsnät för en ny vindkraftpark som planeras i norra Sverige av företaget AB.Parken skall bestå av 101 stycken vindkraftverk som skall förbindas samman med ett kabelnät och anslutas till en transformatorstation. Rapporten behandlar två förslag på hur nätet skall dimensioneras och förläggas. Uppdelningen av vindkraftverken i kluster illustreras av kartor och enlinjescheman.Valda förläggningsätt och dimensioneringar motiveras med kabelberäkningar och grundläggande teori gällande kabeldimensionering. Kabeltyp samt längder för båda förslagens samtliga radialer presenteras i tabeller tillsammans med en enklare kostnads jämförelse.Simuleringar för uppsamlingsnäten utförs i programmet Power World Simulator. För att kontrollera riktigheten i värdena från simuleringen utförs kontrollberäkningar på en radial med pi-modellen.Beräkningarna visar att dimensioneringen är utförd så förluster och spänningsökningar är väl inom gränsvärden för båda förslagen. Uppsamlingsnätets totala reaktiva tillskott är väl inom gränserna för vad vindkraftverken kan kompensera för.Förslag på fortsatt arbete för detta projekt vore att se över konstruktionen av transformatorstationen samt skydd för uppsamlingsnätet. / This report contains a suggestion for a projected wind farm in northern Sweden.The farm contains 101 wind turbines that shall be connected together with a collection grid and connected to a substation.The report contains two different suggestions of dimension and location of the cables for the grid. The turbines are divided into clusters and shown in maps and single line diagramsChosen suggestions and dimensions are reasoned with calculations and basic theory regarding cable sizing. The chosen cable types and lengths for both suggestions are shown in table form, together with a simplified cost comparison.After simulations have been run in power world simulator programme, the values was checked for authenticity with the π-circuit formula.The calculations shows that the selection of cables have accomplished low losses, and the increase of voltage is well within limits for both suggestions.The contribution of reactive power in the collection grid is also within the limits of what the wind turbines can compensate.A suggestion for future work on this project could be the design and dimension of the substation and the safety equipment.