Flexible Responsive Systems in Wave Energy: FlexWave

Completed

Renewable Energy Sources(Ocean Energy)

Basic and strategic applied research

PHYSICAL SCIENCES AND MATHEMATICS (Metallurgy and Materials)
PHYSICAL SCIENCES AND MATHEMATICS (Applied Mathematics)
PHYSICAL SCIENCES AND MATHEMATICS (Computer Science and Informatics)
ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering)

Not Cross-cutting

Prof D Greaves
School of Marine Science and Engineering
University of Plymouth

Standard

EPSRC

12 August 2021

11 January 2025

41 months

£673,385

Energy

South West

Energy : Energy

Prof D Greaves, School of Marine Science and Engineering, University of Plymouth

Dr S Cheng, Sch of Eng, Comp and Math (SECaM), University of Plymouth
Dr M R Hann, Sch of Engineering, University of Plymouth
Dr M Meng, Sch of Eng, Comp and Math (SECaM), University of Plymouth
Dr E Ransley, Sch of Eng, Comp and Math (SECaM), University of Plymouth
Dr S Zheng, Sch of Eng, Comp and Math (SECaM), University of Plymouth

Project Contact, Offshore Renewable Energy Catapult
Project Contact, Wave Energy Scotland
Project Contact, Wave Venture Ltd
Project Contact, LOC Group (London Offshore Consultants)
Project Contact, National Renewable Energy Laboratory (NREL), USA
Project Contact, Bombora Wave Power Europe
Project Contact, BP Exploration Co Ltd
Project Contact, Checkmate Flexible Engineering
Project Contact, Rod Rainey & Associates
Project Contact, Single Buoy Moorings Inc.
Project Contact, Private Address
Project Contact, Seawind Ocean Technology Ltd
Project Contact, Griffon Hoverwork Ltd

Wave energy convertors (WECs) offer opportunities for niche (powering aquaculture and offshore stations) and grid-scale applications. However, disruptive innovation is essential to unlock the potential of wave energy, achieve step change reduction in cost of energy, and prove competitiveness against other renewable energy options. Here we investigate the opportunity to transform the development of WEC systems by utilising intelligent design concepts that exploit novel use of deformable materials. WECs based on deformable materials may offer improved performance, survivability, reliability, and reduced cost compared with steel or concrete alternatives for the following reasons:1. To achieve a given resonant frequency, a flexible fabric device can be smaller and lighter.2. Hydrodynamic characteristics of such a device can be modified by controlling its internal fluid pressure, enabling it to be tuned to suit incident wave conditions. These adjustments can be made by an on-board intelligent responsive system.3. Controlled non-linear changes of geometry would enable a deformable fabric structure to accommodate or shed high loads without reaching critical stress concentrations, improving survivability and reducing installation and lifetime costs.4. Flexibility opens up the possibility to use a range of PTOs, such as novel distributed embedded energy converters (DEECs) utilising distributed bellows action, electro active polymers, electric double layer capacitors or micro-hydraulic displacement machines.5. A lightweight flexible structure with largely elastic polymer construction is unlikely to cause collision damage, and so is therefore a low risk option for niche applications, such as co-location with offshore wind devices.The performance of flexible responsive systems in wave energy, their optimisation in operating conditions, and their ability to survive storm waves, will be assessed through a programme of wave basin experiments and numerical modelling of different flexible WEC concepts. Survivability is a critical hurdle for all WEC concepts as by their nature they need to respond in energetic sea states while avoiding critical stresses in extreme seas. For a flexible responsive structure, this means avoiding concentration of stress (naturally avoided by collapse/folding) or of strain (avoided by use of a distributed PTO during operational conditions).Numerical models will be developed that account for complex interactions between wave action, deforming membrane structure, and internal fluid. The models will be informed, calibrated, and validated using results from materials testing and fundamental hydro-elastic experiments. Advantages and disadvantages of rubber-based, polyurethane and other reinforced polymer materials will be assessed in terms of manufacturing cost, join, bonding, and fatigue performance in the marine environment. The research will draw on origami theory and the technology of deployable structures to avoid problems with wrinkling, folding, or aneurysm formation, and an entirely new design may emerge through this innovative approach. We aim to demonstrate a pathway to cost reduction for flexible fabric WECs optimising for performance, structural design and manufacture for both utility scale and niche applications.

06/10/21