The Simulation of Wave Energy Conversion by Floating Point Absorber Buoy in Indonesian Sea Waves

Referring to National Energy Policy or Government Regulation No. 79/2014, Indonesia has set out several plans to increase the New and Renewable Energy (NRE) share in the primary energy mix to 23% by 2025 and 31% by 2050. Ocean wave energy is one of the potential renewable energy sources. This study presents the simulation of ocean wave energy conversion of Indonesian sea waves, specifically along the west coast of Sumatra, the southern coasts of Java, and Bali waters. The Wave Energy Converter Simulator (WEC-Sim) simulated five hot spots of high wave energy using the floating-point absorber buoy RM3 model. These five hotspots are South Pagai Island II (101.25°E-4.25°S), Enggano Island (102.25°E-5.5°S), Cilacap (109.06°E-7.94°S), Jember (113.68°E-8.56°S), and Bali (115°E-8.75°S). RM3 is the third reference model of wave energy converter developed by The U.S. Department of Energy (DOE), The National Renewable Energy Laboratory (NREL), and The Sandia National Laboratory (SNL). Meanwhile, the WEC-Sim software uses the Cummins equation in the 6 degrees of freedom (DOF) modeling process. In this simulation, the Pierson-Moskowitz (PM) spectrum was used to model irregular waves. The WEC's power take-off (PTO) mechanism was simulated as a hydraulic system where the hydraulic power absorbed depends on the differential pressure of the hydraulic piston and the piston area. This simulation used the rotary electrical generator with an energy conversion efficiency of 98% in electricity generation. According to the selected location, the simulation was running for 400 seconds of time simulation and 0.01 seconds of time step with the predefined parameters, such as significant wave height and wave period. The average value of electrical powers generated during the simulation were 15.85, 15.53, 18.13, 14.10, and 15.69 kilowatts (kW) while the total of accumulated electrical powers were 634, 621, 725, 564, and 627 megawattss (MW) for South Pagai Island II, Enggano Island, Cilacap, Jember, and Bali.