Comparative Study of Oscillating Surge Wave Energy Converter Performance: A Case Study for Southern Coasts of the Caspian Sea

Abstract

The search for renewable energy supplies for today’s global energy demand, particularly ocean wave energy for coastal areas, has become undeniably widespread in the last two decades. The Caspian Sea represents an immense opportunity for using ocean renewable energy, especially considering its long shoreline. In this study, the locations with maximum potential wave energy were chosen in the central, eastern, and western zones of the Caspian Sea’s southern coasts. Accordingly, the wave and bathymetric data were used as the input to calculate the oscillating surge wave energy converter’s flap geometric dimensions based on previous studies. Then, the geometric model was designed, and then the wave energy converters were modeled in the Wave Energy Converter Simulator (WEC-Sim) module in the MATLAB software. Furthermore, eight models in each sea state were simulated to find the best value of the PTO damping coefficient, which led to the highest capture factor. Finally, all the external forces on the WEC’s flap and the converter’s power output results were compared, taking into account the effects of the flap height on the total power output. It was found that Nowshahr port has more potential than the Anzali and Amirabad ports, as the converter’s absorbed power proved to be 16.7 kW/m (Capture factor = 63%) at this site. Consequently, by conducting a comparative analysis between the selected sites, the excitation, radiation damping, and power take-off forces were scrutinized. The results show that the highest applied forces to the converter’s flap occurred at Nowshahr port, followed by the Anzali and Amirabad ports, due to the directional characteristics of the waves at the central coasts of the Caspian Sea.

An empirical model for forecasting electric generation for nearshore energy potential in Thailand

“…The study uses the oscillating surge wave energy converters flap geometric dimensions as the data to simulate in the MATLAB software. The results found that the Nowshahr port has more potential than the Anzali and Amirabad ports, under the condition's absorbed power of 16.7 kW/m (Capture factor = 63%) at these sites [11]. The methods in references above use the different models and study at the different environment sites.…”

Review of WEC-Sim development and applications

“…Eight Persian Gulf locations based on a 20-year wave horizon were assessed. Also in 2020, Amini et al assessed the deployment of an oscillating flap-type WEC in the Caspian Sea [99]. They used SWAN to obtain input waves, ABAQUS to find the optimal flap width and height at each site, and compare device performance to evaluate the optimal site for wave energy production.…”

Geometry Optimization of Heaving Axisymmetric Point Absorbers under Parametrical Constraints in Irregular Waves

“…However, waves in real seas are irregular as a result of their random behavior. Here, an irregular wave is treated as the superposition of regular-wave components with discrete wave frequencies, the amplitude of which is determined from a wave spectrum [22,23]. One of the most commonly used wave spectrums is the Pierson-Moskowitz spectrum, which describes fully developed wind seas and can be expressed as…”

“…In the inner loop, the buoy mass ratio mn is optimized for a given buoy geometry and sea state and under the constraint on buoy mass as defined in Equation (22). It should be clarified that, in this loop, mn is optimized based on the optimal value of cp and kc, which means that when calculating the performance of the WEC for any values of mn, both cp and kc are optimized for this specific mn accordingly.…”