## 2 Techno-Economic Analysis at 2030  
### Materials and Methods  
The model chosen to perform the economic analysis is the LCoE, an economic index widely used in the energy sector to estimate the average cost of energy produced during the entire lifetime of a given plant, and which considers the investment, financing, and operation and maintenance costs of a plant at all stages of its life cycle, in ratio to the total energy production guaranteed by it over the same period of time. More precisely, in the context of this study, an LCoE model that allows comparisons to be made without evaluating the specific financial variations over the various years, proposed by the U.S. National Renewable Energy Laboratory (NREL) [15], was adopted. This model is simply called LCoE, but still reported as LCoE in the following. The LCoE is calculated with the following formula:  
\[\text{LCoE}=\{(\text{CAPEX}\times\text{CRF}+\text{fixed OPEX})/(8760\times\text{CF})\}+\text{variable OPEX} \tag{1}\]  
where: CAPEX (M&/MW) is the CAPital Expenditure, specific investment costs valued in the \"overnight capital cost\" method; CRF (pure number) is the Capital Recovery Factor; fixed OPEX (M&/MW/\(y\)) is the Operational Expenditure, the annual fixed maintenance and operating costs; CF (%), or Capacity Factor, is the percentage of the annual hours in which the plant produced at maximum power; variable OPEX (M&/MWh) are the annual variable maintenance and operating costs. All of these parameters, which define the variability of the LCoE, are influenced by a variety of different factors. In the first approach presented here, the study considers some of the factors that may be relevant to compare, in terms of electricity cost, different geographical areas in Italy, and the Italian context with other European ones. The first step of the study was to define a reference offshore floating wind park at 2030. In this study, this park was defined starting from the average characteristics of the offshore wind parks with fixed monopile foundations installed in 2019 in the North Sea [2], and taking into account possible technology development, in particular, concerning the size of the wind turbine. The 10 MW DTU (Danmarks Tekniske Universitet) reference turbine described in [16] was chosen. The reference park features are listed below:  
* The park is constituted by 100 turbines for an overall size of 1000 MW;
* The hub height of the turbines is 119 m;
* The water depth is 150 m;
* The lifetime of the plant is 30 years. As already mentioned above, considering that there are still no commercial floating offshore wind farms, all considerations relating to input parameters are affected by a certain degree of uncertainty that is common to all the research in the sector. CAPEX is one of the variables that most affects the calculation of the LCoE: its economic value is derived from the sum of a whole series of factors that contribute to the definition of costs related to the purchase, installation, and implementation of all the components that make up a system. As already mentioned above, CAPEX are parametrized as a function of the distance from shore, concerning installation, operation, maintenabnce and the cost of external cables for the grid connection to the shore. A reference base CAPEX value, which includes the cost of export cables and their installation, was first obtained from an average of the two values reported in [11; 17], and it is 2.4 ME/MW. The cost of export cables, including installation, commissioning, and maintenance, was conservatively fixed at 1 ME/km [18]; while the specific costs of cables and installation was calculated as an average of the two formulas reported in [19] for the two technologies considered. The resulting formula for the installation cost (CI) used in the study is the following one  
\[\text{CI}=0.300637678+1.10606\times 10^{-5}\times\text{wd}+0.000585152\times \text{d} \tag{2}\]  
where: wd is the depth (m) and d is the distance from the coast (km).