## 1 Introduction  
Climate change has become the greatest threat to humanity and nature in this century, and this is being driven by the increase in greenhouse gas emissions, especially from the energy sector, which accounts for more than 60% of the global total [1, 2]. Therefore,energy systems worldwide have inevitably undergone radical changes with the transition to sustainable, renewable, and clean energy sources [3; 4]. Meanwhile, following the Paris Agreement, in November 2021 the 26 th Conference of the Parties (COP26) adopted the Glasgow Climate Pact, and the declaration was made on gas reduction and investments for decarbonization [5]. The financial institutions of governments participating in COP26 agreed to stop public support for the fossil fuel energy sector and, in the future, to increase support for clean renewable energy conversion. South Korea is also participating in the gradual abolition of coal power plants, and the cessation of new construction and investment [6; 7; 8]. This decarbonization trend in South Korea is led by the 3 rd Basic Energy Plan, the Renewable Energy 3020 Implementation Plan to increase the proportion of renewable energy to 20% by 2030, and the Korean Green New Deal, which aims to achieve a green transition by establishing a carbon-neutral promotion base and the realization of carbon neutrality with the goal of 2050 [9; 10]. Among the various means for building a decarbonized society and responding to climate change, the energy transition to renewable energy is recognized as the most important method, because it is converging to grid parity as price competitiveness is continuously improved, compared to fossil fuels. Among them, wind energy is promoting the step-by-step process of measuring wind resources and supporting feasibility studies in up to 13 regions for the site selection of large-scale offshore wind farms. Through this plan, a total of 17.7 GW wind farm facilities will be built by 2030 [11; 12; 13]. Meanwhile, domestic and foreign wind turbine manufacturers have developed generators with unit capacity of more than 10 MW and obtained type certification since 2018 [14; 15]. Vestas V236-15 MW, GE Haliade-X 14.0, Siemens-Gamesa SG14-222 DD, and Mingyang MySE 16.0-242 wind turbines have already been certified for prototype production and commercialization. All these super-large offshore wind turbines have a rotor diameter that exceeds 220 m. In a similar fashion, global wind turbine manufacturers are continuously developing products in the direction of expanding the capacity of the single turbine [16; 17]. This is because in constructing a wind farm, it is more economic and more advantageous to install a small number of wind turbines, each with a large capacity, than to install many wind turbines, each with a small capacity. According to Rystad Energy Research and Analysis, if a 14 MW class turbine is used instead of a 10 MW wind turbine to construct a 1 GW wind farm, it will cost about USD 100 million in turbine manufacturing cost, foundation substructure manufacturing cost, installation cost, and cable array cost, and savings can be obtained [18]. As the wind farm can be scaled up by the cost savings, turbine manufacturers continue to develop larger-capacity turbines. As the capacity and scale of wind turbines increase, accurate measurement of power curves, and the calculation of expected power generation are required, and conflicting interests arise in that regard [19; 20]. Traditionally, to calculate the expected power generation of a wind turbine, only the wind speed at a single height corresponding to the hub height is considered, under the assumption that atmospheric stability is in a near-neutral state [21; 22; 23]. This was proper in the past to apply to small wind turbines with short blade lengths, and in calm offshore or flat land without obstacles, the difference in wind speed by height is small.