## 4 Results and Discussion
### WEC Power Absorption  
The values of the parameters from the sensitivity tests were then fixed in order to evaluate the changes in the buoy's radius, systematically. These values were presented in the P1 and P7 cases in Table 1 (\(AR=0.7\), \(AD=1\), \(ID=0.001\), and \(OD=1.5\)). As we expected, the average power output increased with the buoy's radius, as can be seen in Figure 8a; perhaps, surprisingly, shorter-period waves (\(T=4\) s) delivered considerably more average power with this buoy system than waves of longer periods (\(T=8\) s). It is also apparent from Figure 8a that 4 s waves induce an exponential power increase with an increasing buoy radius, while the power values for the buoy with longer-period waves (\(T=8\) s) suggested a much slower increase rate. On the other hand, Figure 8b seems to suggest that the capture efficiency (\(y\)-axis) of a buoy whose size is a given fraction of the wavelength (\(x\)-axis) would be very similar for both \(T=4\) s and \(T=8\) s waves. Here, is important to note that the 1.5 m case for \(T=4\) s could not be run with a value of \(OD=1.5\) due to instabilities caused by the buoy's movement and increased size of the buoy on the mesh. Therefore, a value of \(OD=2\) had to be adopted, which could imply a 1.2% error for the mean values of the average power absorbed (see values of \(SI\) presented in Figure 7b). Figure 8: (**a**) Average power absorbed by the WEC at different radius sizes for both \(T=4\) s and \(T=8\) s wave periods. (**b**) Capture efficiency per buoy unit length for different values of the normalized buoy diameter (radius/wavelength) for both \(T=4\) s and \(T=8\) s wave periods. \(AR=0.7\), \(AD=1\), \(ID=0.001\), and \(OD=1.5\), \(**OD=2.0\). The results presented in Figure 8 have significant implications for the assessment of wave energy availability, and also for the manufacturing of WECs of the type presented in this paper. For example, if we only rely on the results of the wave energy flux (Equation (4)) of a given site, to assess the wave energy availability, we would expect that a site with longer-period waves (i.e., \(T=8\) s) would generate more energy than a site with shorter-period waves (i.e., \(T=4\) s) per unit wave height. Nevertheless, in these experiments, using a \(R=1\) m buoy, \(T=4\) s waves captured considerably more energy, a factor of 4.82, than \(T=8\) s waves (Figure 8a). This factor seems to increase in an exponential fashion with an increased radius. This implies that, in order to achieve the same capture efficiency, \(T=4\) s waves need much smaller buoy diameters than \(T=8\) s waves, making the devices cheaper to manufacture. For example, to achieve a capture efficiency of 0.16 at a 3 m depth, a \(T=8\) s wave would need a buoy with a radius of 3.36 m (\(R/\lambda=0.08\)), whereas of \(T=4\) s wave needs a buoy half the size (1.5 m). Therefore, with the technology we tested in this paper, regions where shorter-period waves dominated (enclosed seas) generated more energy and with a cheaper device than regions dominated by longer-period waves. These results are in agreement with the results observed elsewhere [51]. Consequently, with the results presented in this work, the availability of ocean wave energy has a high dependence on the technology used to harvest it, and should be considered in techno-economic assessments. To assess the amount of energy absorbed by the system, the results obtained from the calculation of the bulk energy balance (Equation (12)) were analyzed, where the values of \(K_{d}^{2}\) could be interpreted as the amount of energy that was absorbed by the WEC or dissipated through turbulent processes. Table 6 presents these results, compared to the energy transmitted through the buoy and reflected from it. The results of this analysis are consistent with the results presented in Figure 6, where the amount of energy absorbed by the system subjected to \(T=4\) s waves was considerably higher (\(\sim\)35%) than the energy absorbed by the same system, but subjected to \(T=8\) s waves.