A first-order dynamics and cost comparison of wave energy converters combined with floating wind turbines.

Abstract

Attaching a wave energy converter to a floating wind turbine (FWT-WEC) produces cost savings by sharing the mooring lines, electric transmission lines, and site permitting. We investigate if certain parameters can produce synergistic dynamics: maximized WEC power, minimized WEC cost, and minimized FWT motion. Our approach is to model the dynamics using first-order linear coupled equations of motion and long wave-length approximations. We compute representative annual response statistics of FWT-WEC systems for WEC's at various locations, and with different motion directions and power takeoff systems. It seems unlikely that a dynamically synergistic FWT-WEC configuration exists. However, the results of each FWT-WEC pair suggests that the WEC's could be used as building blocks for triple combined tuned mass damper-FWT-WEC or ballast-FWT-WEC systems to achieve both low-cost wave power and reduced FWT motion.