Wave Energy Resource Assessment Based On Frequency And Time Domain Models

Since1970s, wave energy has been taken seriously as a significant renewableenergy. As a response to the emerging oil crises, several coastal industrial countriesundertook R&D programmes of wave energy resource. Although it is currently noteconomically competitive with more mature technologies such as wind energy, theinterest from governments and industry is steadily increasing.In this paper, based on wave buoy data along Chengshantou coastline, analysiswas carried out combining meanwave direction, signifcant wave height andfrequency, and the normal wave direction and strong wave direction were determined.SWAN wave model was validated with wave buoy data and applied to calculate thewave energetic pattern of Chengshantou testing field. Five case studies wereconsidered, representative of an extremely energetic situation (the peak of a storm)and average conditions of June to September2011, October to December2011,January to March2012and April to June2012. Based on the time-weighted averagewave power distribution of four cases corresponded to a whole year, wave energyconcentration areas were selected as prospective wave farm sites.In order to evaluate the efficiency of the Wave Energy Convert installed at theselected wave farm sites, a new time domain method for calculating wave powerbased on SWASH model was proposed in this paper. A sample wave parameters dataset was obtained from wave model SWASH to demonstrate the application of the timedomain method as well as the present frequency domain method. A comparisonbetween the results of each method was also performed and two influential parametersused in calculation had been analyzed. The results show that the frequency method isvery likely to overestimate the wave power at both deepwater and nearshore site. Thetime domain method is believed to be more superior in calculating the incident wavepower in a short term, and it may serve as a new methodology of calculating theincident wave power of WEC in order to evaluate its real time efficiency.