Abstract
Wave energy has the potential to power large and small factions of economies around the world alike. Current methods for determining the amount of wave energy resource available to wave energy converter (WEC) devices entail capturing the look of the sea state at large by presenting characteristic wave heights, periods, and directions for the simplest of assessments. This method is proven to suffice in estimating the power available to large-scale WECs, operating to convert megawatts (MW) of power at a time, since WECs operate optimally when moving at the same scale as the surrounding ocean environment. However, large devices are costly and must possess a high survivability factor since their deployment locations are extremely energetic. Small-scale WECs (operating on the scale of a few 100 to a few 1000s of kW) on the other hand, typically operate in moderate motion, decreasing the amount of design and funds that must go toward survivability measures. In addition, smaller devices equate to less investment expenditures required for the build. This notion has driven research and industry in the direction of designing and testing small WECs for less demanding power applications. Some barriers to progress are created when attempting to quantify the power available to these small devices using the current standard methods for wave resource assessment. Devices that do not operate on the MW scale would not be able to function in an extreme sea state. Thus, it is essential to devise new methods for wave resource assessment in respect to small WECs and their capture abilities. In this study, instead of using only gross wave power (which typically overestimates power available for small devices), power limits for small WEC bodies were applied to determine devicesโ power capture abilities in five study locations. Budalโs upper bound, ๐๐, was utilized, which describes the power available to a small WEC based on its volume stroke. Budalโs upper bound was used with the radiated power limit, ๐๐, a power limit that describes the maximum amount of wave power a WEC can absorb according to its radiation pattern, to filter the wave power available in the sea for the โbaseline case.โ The โexpanded caseโ utilized these two power limits along with gross power, ๐๐๐๐๐ ๐ , to determine the amount of absorbable power available, also known as net power, ๐๐๐๐ก. These two cases were explored and compared to the current standardized wave resource assessment methods. The baseline and expanded cases for power available to small WECs demonstrated significantly less resource than International Electrotechnical Commission (IEC) methods, which overestimated the absorbable power for the devices. Further, the expanded case yielded a more realistic analysis of absorbable power than the baseline case since it included gross power in its filtering process. This helps bring further understanding to where and when wave power is available to small WECs. Determining the spacio-temporal effects of WEC scale expands the potential applications of wave energy by focusing not just on less frequent, large waves, but also on more common, less energetic high frequency ocean waves. These findings also support development of blue economy applications for wave energy converters, including harnessing wave power for ocean observation buoys, aquaculture farms, and other standalone applications.