Page 285 - Renewable Energy Devices and System with Simulations in MATLAB and ANSYS

272 Renewable Energy Devices and Systems with Simulations in MATLAB and ANSYS ®
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FIGURE 11.4 A 1/7-scale point absorber developed by Columbia Power Technologies undergoing testing in
the Puget Sound, Washington [22]. (Photo from Columbia Power Technologies, NREL 19381, Corvallis, OR.)

FIGURE 11.5 Ocean Energy’s OWC device showing the air turbine that is used to generate energy [23].
(Photo from Ocean Energy Limited, NREL 17874, County Cork, Ireland.)

Several WEC prototypes have been built and deployed for testing. The examples of point absorber
implementations are shown in Figures 11.3 and 11.4, and an OWC implementation is shown in
Figure 11.5.
In the real world, the behavior of ocean waves is generally random in terms of amplitude, phase,
and directionality. Because of the oscillatory nature of waves, the instantaneous power generated by
a WEC oscillates from zero to a maximum twice per wave period, which is typically in the range
of 5–20 s.