*3.1. Costs Calculation of HVAC Cables Transmission*

The HVAC cable transmission concept is a popular way for offshore wind farms, and the principal cost drivers include capital costs *Ccap.AC*, operation and maintenance costs *Copex.AC*, and loss costs *Closs.AC*. The calculation is given by

$$\mathcal{C}\_{A\mathcal{C}} = \mathcal{C}\_{cap.AC} + \mathcal{C}\_{open.AC} + \mathcal{C}\_{loss.AC} \tag{1}$$

#### 3.1.1. Capital Costs

In the concept of HVAC cable transmission, *Ccap.AC* covers the relative substation foundation costs *Cstation.AC*, underwater cable foundation and installation costs *Ccable.AC*, and reactive power compensation foundation costs *Creacpc.AC*, estimated by

$$\mathcal{C}\_{cap.AC} = \mathcal{C}\_{station.AC} + \mathcal{C}\_{cable.AC} + \mathcal{C}\_{reacpc.AC} \tag{2}$$
