## 5 Hydraulic and Energetic Behavior  
Extensive investigation on wave energy converters that convert wave power into electricity is required to improve competitiveness of wave energy, one of the most promising renewable energy resources [14]. To study the hydraulic-energetic behavior, the first step is to select the types of wave energy converters that best suit the needs of the project. Given the high interest of harnessing wave energy, there are more than a hundred patents for wave energy converters [15]. However, only 20 of these devices have become prototypes in scale since, in general, the necessary maturity level had not been reached until recently. To determine what technology is the most appropriate, an analysis was carried out based on the different classifications of existing wave energy converters. Among those conditions, robust and fixed structures are being considered in this study, as it is necessary to look at their survival, taking into account the high aggressiveness of the wave climate where they will be installed, and consequently, their gradual degradation. It is important to keep in mind that the main objective is to achieve the maximum possible electricity output, taking advantage of opportunities that may arise in the use of the existing breakwaters for the installation of the devices. It is worth pointing out the importance of the devices in not impeding the traffic inside and outside the port water surface as well as in preventing the occupation of the seabed. Based on these facts, the OWC system (Oscillating Water Column) and SSG (Sea Slot-Cone Wave Energy Converter) are the ones that best adapt to these requirements (see Figure 8). The OWC system seems successful because it can be constructed in the breakwater, it does not involve seabed invasion and it does not decrease functionality [16]. Furthermore, it has few moving and emerging parts; thus implying a lower maintenance cost. The SSG System is also appropriate as it can be installed in the breakwater without impeding the regular port traffic. It is characterized by its robustness and low cost [17]. Figure 7: Location of ports (blue squares) and REDEXT buoys (red circles) and REDCOST buoys (yellow circles). By subjecting any structure to the action of the waves, it is subjected to incident energy. That wave energy can be reflected, absorbed or transmitted according to the physical characteristics of the obstacle (size, shape, material and permeability) as well as its location. Taking into account that the wave energy converter is planned to be installed in the breakwater, it is essential to know the typology of the breakwater to determine the effectiveness of the device [18; 19; 20]. In the case of rubble mound breakwaters, there are holes between the different pieces or the armor and the filters, which allow the entrance of the water, resulting in a transmission of energy through the different layers. There is also a process of small reflection, because it is a rock mass. In addition, there is a part of the energy that is dissipated or absorbed in the slope of the rubble mound breakwater. Thus, in that type of breakwater, the absorption is high, the transmission is average and the reflection is very low. In the case of vertical breakwaters, as they are formed by concrete caissons, a reflection of the waves is produced when the wave impacts the structure, which means that the wave energy returns back to the sea in different directions. Absorption coefficient depends primarily on the porosity of concrete. Thus, the reflection is the most important phenomenon, while the transmission and the absorption are very low. OWC devices have the same energy behavior as a vertical breakwater because they are caissons with a reflective wall, after which accumulates the column of oscillating water [21]. Similarly, reflection of waves is the main process for SSGs and it can be claimed that they contribute to the correct functioning of the device.