Power enhancement of pontoon-type wave energy convertor via hydroelastic response and variable power take-off system

Abstract

Wave energy has gained its popularity in recent decades due to the vast amount of untapped wave energy resources. There are numerous types of wave energy convertor (WEC) being proposed and to be economically viable, various means to enhance the power generation from WECs have been studied and investigated. In this paper, a novel pontoon-type WEC, which is formed by multiple plate-like modules connected by hinges, are considered. The power enhancement of this pontoon-type WEC is achieved by allowing certain level of structural deformation and by utilizing a series of optimal variable power take-off (PTO) system. The wave energy is converted into useful electricity by attaching the PTO systems on the hinge connectors such that the mechanical movements of the hinges could produce electricity. In this paper, various structural rigidity of the interconnected modules are considered by changing the material Young's modulus in order to investigate its impact on the power enhancement. In addition, the genetic algorithm optimization scheme is utilized to seek for the optimal PTO damping in the variable PTO system. It is observed that under certain condition, the flexible pontoon-type WEC with lesser connection joints is more effective in generating energy as compared to its rigid counterpart with higher connection joints. It is also found that the variable PTO system is able to generate greater energy as compared to the PTO system with constant/uniform PTO damping.