The Multi-Float WaveSub Waver Energy Converter

Marine Power Systems (MPS) WaveSub Wave Energy Converter (WEC) addresses the energy trilemma by providing sustainable, cost effective, low carbon renewable energy by capturing the sub-surface orbital energy nature of waves. The patented device is tuneable to all sea states through a unique single / multi float power take-off system. Securing over £3M in grants and £2M in private investment, MPS has completed extensive testing of the single float WaveSub WEC at 1:30 scale, validating the computational simulations of power generation. MPS is currently embarking on the fabrication of a 1:4 scale WaveSub, with testing at FaBTest in 2016 / 2017. Initial techno-economic modelling using Carbon Trust Levelised Cost of Energy (LCOE) methodology shows WaveSub delivering a LCOE lower than existing WEC devices and competitive with conventional generation, with transition from single float (1.5MW) to multi-float (Multi-MW) device. This 12 month project with MPS and University of Bath (UoB) delivers the modelling, design, manufacture, test & validation of a 1:30 scale multi-float WaveSub device, with outputs informing the LCOE model that will unlock WaveSub's true commercial potential. Within the project, UoB will design and build the Power Take Off system for the multi-float device. Building on previous experience from a 1:30th scale single float device, the PTO for the multi-float concept will consist of multiple independently controlled electro-mechanical units designed in conjunction with other WaveSub systems (e.g. winching) for proper integration. The independent control of the units will provide the greatest flexibility for exploring different operational regimes. The unit will be controlled in real time and will allow motion, power capture and loading measurements. A range of control schemes will be implemented in order to validate numerical models and to evaluate whole system performance in all conditions. This could include linear damping, adaptive damping, and advand nonlinear schemes such as latching and declutching control.