WPP design and analysis - An assessment of wake effects and power fluctuations from large scale wind power plant clusters

Sammanfattning: For the last decades, the wind energy industry has been growing rapidly. More of the production is moving offshore, and in the Baltic Sea some key areas have been identified as particularly suitable for wind power plants. The European Commission have initiated the Baltic Integrid project to assess the potential of building meshed HVDC grids between the Baltic countries and use these areas for wind power plants and connection hubs. The plan for 2030 and beyond is that clusters of plants will be built closely around common connection points. The thesis includes a case study and design of a wind power plant cluster at Södra Midsjöbanken, with a total installed power of 5,2 GW. The results show that these plants are going to shade each other from the oncoming wind. Some areas will be more attractive than others, and depending on how the plants are optimized, they could make neighboring areas undesirable. To reach maximum benefit for society, there might be a need for regulations on how to optimize wind power plants in clusters. A turbine and cable layout is suggested for the cluster, and an economic assessment suggests that the LCOE will be 55,7 €/MWh, about two to three times lower than the average price today. Through the analyses in this thesis, it is shown that there is a correlation between larger turbines and lower wake losses. To increase production and reduce the price of wind energy, it is therefore important that we strive to develop and implement larger turbines. Large scale wind power plant clusters may produce overwhelming power fluctuations to the electric grid. A model developed for the thesis show that unpredicted wind fronts travel gradually through the area and can inject around over 5 GW of power in less than 14 minutes to the grid.