*4.1. Description of the Design and Economic-Financial Parameters*

The proposed tidal energy farm will consist of 42 1.2 MW TECs, each of which will have an open rotor configuration with their axes parallel to the flow (Figure 14a). It is possible to separate the gondola of the TEC from the structure, which facilitates maintenance tasks. However, the orientation of the gondola is fixed when it is mounted on the structure, and it is consequently mandatory to have a pitch controllable blade system with the aim to maximize the energy that is captured in both current directions. The blades have a diameter of 20 m, while the TEC is attached to the seabed by gravity. The TEF will consist of four rows, and there will be 11, 10, 11, and 10 TECs in each row (Figure 14b). This will make it possible to minimize the shadow effects in the last rows while maximizing the total amount of energy captured by the TEF.

**Figure 14.** Proposed TEF: (**a**) view and; (**b**) configuration.

The vessel chosen to perform the installation and maintenance procedures on the TEF throughout its service life, which is expected to be 20 years [55], is an HF4 vessel. The base port is that of Cherburg (France), which was chosen for its operative qualities and is located 39 km from the TEF. Finally, the AEP obtained for the TECs in the different rows of the TEF is depicted in Figure 15, in which the following physical parameters have been used to compute an estimation of the AEP of the TEF: *Zr* = 20 m, *Zh* = 40 m, *Ct* = 0.716, *As* = 452 m2, *Ar* = 314 m2, *At* = 4000 m<sup>2</sup> (a separation of 100 m between devices and a total depth of 40 m), *D* = 20 m, *x* = 30 m, *CP* = 0.45, *ρ* = 1025 kg/m3, *ηPTO* = 0.39, *ηAF* = 0.97 and *ηPES* = 0.946. Furthermore, the case study makes several economic-financial assumptions:


**Figure 15.** Energy generated by TECs placed in the rows of the TEF.

*4.2. Results for Gravity-Based First Generation TECs Maintained with Manual and Automated Maneuvers*

Table 1 illustrates the summary of the costs (additional information concerning the achievement of the numerical values of these cost structures can be found in two of the GIT-ERM research group's previous works) [19,46] of the TEF using manual and automated maneuvers. The results concerning the viability and profitability of the proposed project are shown as follows, together with the sensitivity study applied.

**Table 1.** Summary of the cost of the TEF (Tidal Energy Farm) composed of TECs in the case of manual and automated maneuvers (*C*1, *C*2, *C*<sup>3</sup> and *C*<sup>4</sup> are applied for the first time of the project while *C*<sup>5</sup> is applied annually).

