Direct Generation (DG) is the application of novel electrostatic generation technologies. In the application of wave energy, Dielectric Elastomer Generators (DEGs) and Dielectric Fluid Generators (DFGs) can directly transform movement (stretching, twisting, bending) of a material, into electrical energy. This offers opportunities for significant cost reduction of WEC technologies.
You can understand more about the Direct Generation system architecture here.
In round 1 of the DG Concept Creation Competition, WES sought to investigate the potential benefits and opportunities of these technologies.
Five projects have successfully completed round 1 of the competition, sharing a budget of £250,000 to develop their design concepts. These concepts underwent refinement through analytical and numerical modelling approaches which informed high-level estimates on the performance and cost of energy. Throughout this process, the teams identified the R&D requirements to progress these technologies further, with the aims of further collaboration with the appropriate R&D partners.
The round 2 application process is open until 23rd May 2024.
This process is only open to the lead organisations from round 1 projects but the round 1 project leads can adapt their teams relative to round 1, potentially creating opportunities for other organisations with expertise in specific areas, e.g. elastomers, flexible electronics, manufacturing, soft robotics and metamaterial development. The linked websites and round 1 summaries are as follows:
The “EBB:FLOW” project between 4c Engineering and Cheros Srl, sponsored by Wave Energy Scotland, has led to the development of an innovative new direct generation WEC Concept. Over a structured 14-week period, the team engaged in a series of methodical work packages, beginning with concept development and progressing through selection, feasibility analysis, and final reporting. The project brought together the wave energy and structured innovation experience of 4c Engineering and the world-leading direct generation expertise of Cheros Srl. The team focussed on exploiting the properties of dielectric fluid generation (DFG) cells within a promising novel WEC design.
Throughout the project, the team navigated a range of technical and collaborative challenges, including parallel development of the individual DFG modules and the full WEC architecture. To address these challenges, the concept selection phase was extended beyond the original duration. With the additional work, a breakthrough was made, resulting in the development of the final concept. This change from the original plan showing the importance of flexibility and adaptability in project management, particularly on an international academic-industry partnership. To fully understand the commercial potential of this concept will require a continuation of the development of the concept, both at the DFG cell level and the full WEC, with a focus on detailed refinement, material testing, and scalability assessments. The short to medium term goal is to progress from theoretical models to practical, testable prototypes, laying the groundwork for advancement to the ultimate goal of a commercially viable novel wave energy conversion technology.
The team at AWS have nearly two decades of experience in the wave energy sector. For this design competition they partnered with 4c Engineering, Cheros, SRI International and Pelrine Innovations which brought a wealth of knowledge and experience in dielectric elastomer generators and their application in wave energy. A key cornerstone of this project was developing a design that had a realistic basis of design. This would involve setting out the commercial requirements for a real-world site location at Costa Head, whilst ensuring external practicalities were realistic for the expected lifetime. The team performed a thorough literature review along with knowledge capture sessions to identify the necessary input information for concept design generation and subsequent down-selection.
The selected concept is scalable and modular whilst allowing for DEG replacement throughout operational life. The design has been visualised with the creation of a 3D CAD model and high-level system breakdown which informed estimates on the annual energy production and bill of materials. This information allowed for a high-level techno-economic analysis to take place suggesting competitive levels of performance and the step-change necessary for cost reductions of WECs. The team identified a series of critical R&D requirements relating to DEG fatigue and methods to optimise the lifetime energy of the design. The potential pros and cons for environmental and societal aspects were compared with a traditional WEC, suggesting the physical footprint can be reduced significantly through the use of DEGs. Future work will aim to answer these R&D requirements which will allow for further development of the wave capture mechanism.
Southampton and UTC
The team formed by the University of Southampton (UoS) and Nottingham Rolls-Royce University Technology Centre (UTC) in Manufacturing and On-wing Technology has multidisciplinary expertise in maritime engineering, soft robotics, manufacturing, control theory and wave energy. Taking the unique advantage of cutting-edge innovation in universities, they have pioneered ground-breaking designs for Dielectric Elastomer Generators (DEG) and Dielectric Fluid Generators (DFG) based Wave Energy Converters (WECs). These designs, structured within modular frameworks, hold significant promise for scalability and mass production repeatability.
Through an iterative process integrating Computational Fluid Dynamics (CFD) simulations and rapid laboratory testing, the team has continually refined and optimized the proposed concepts, achieving rich results in not only conceptual design, but also co-design schemes, non-causal control methods, and hydrodynamic simulations. Furthermore, the team has facilitated a robust knowledge transfer from soft robotics and conventional WEC systems to the direct generation WECs. By embracing collaborative efforts and leveraging cutting-edge technologies, the attained outcomes propel a revolutionary transition towards the direct generation of WECs, in line with their collective vision for the future of wave energy.
The Round 1 project was led by the WaveX team, a tech-start-up with prior experience of developing seabed embedded flexible structures to harvest wave energy. They collaborated with Cheros and Michelin which brought both dielectric elastomer and manufacturing expertise to the project.
They list core requirements which include high wave energy capture and the ability to us both DEG and DFGs effectively. Owing to these characteristics, the team selected a design which provides good power capture and replaces expensive rigid materials with a full elastomeric structure using pioneering rigidification techniques developed by Michelin.
The design was iterated using time-domain numerical models that were able to effectively calculate the required dimensions to meet the target power requirements. Within this modelling work, a sensitivity analysis was performed with parameters such as the material stretch and applied electrical field modified to understand the trade-off between size and amount of DEG material required.
The preliminary FEED study investigated the choice of materials and their corresponding assembly method, whilst understanding the sustainability of the selected materials. To understand the competitiveness, the team performed a techno-economic analysis with different materials and device configurations. The outcomes of the project suggest the potential of DEGs to reduce cost centres, provide a high degree of operational bandwidth and improvements in practical aspects such as deployment, which delivers on their mission to provide the step-change for low-cost wave energy.
The Stage 1 project was led by TTI Marine Renewables Ltd (TTI-MR), a company with expertise in designing offshore marine renewable energy systems and flexible structures. They were supported by the University of Manchester (UoM) Electrical Engineering and Materials departments, who brought specialised material development expertise to the project. During Stage 1, the team engaged in various activities, including defining requirements, analysing prior art, creating and ranking concepts, and studying the governing physics. A technical risk-based approach was taken to qualify concepts and inform R&D priorities for the future. The team also considered the sustainability of materials and the socio-economic aspects of candidate DEG materials and the system as a whole. The concept identification process involved a formal brainstorming workshop facilitated by TRIZ experts Oxford Creativity Ltd. TRIZ, or "Theory of Inventive Problem Solving," is a methodology that aims to generate innovative solutions by analysing patterns of invention and identifying principles that can be applied to new situations. TRIZ was used in the Stage 1 project to rank concepts before conducting quantitative engineering analyses for short-listed concepts. With in depth knowledge of the governing physics TTI-MR were able to develop an initial time domain model, which was used to build a power density matrix of the selected concept and calculate energy yield for the chosen wave environment. A key outcome of this process was the selection of a new and innovative wave energy concept with very promising potential. The concept was chosen because it maximizes the use of DEG material in the device while minimizing the need for relatively expensive rigid structures and mechanical elements. Cost and energy yield analysis demonstrated significant headroom in the levelised cost of energy when compared with published target for wave power. The concept is designed to have good survivability and performance potential under average wave conditions. Additionally, the technology is readily scalable, making it applicable to different markets and sites. However, as with any new technology, there are technical challenges to overcome, such as the durability and power density of the candidate DEG materials. These challenges are not considered insurmountable and highlight the need for ongoing material research and concept development to realise the commercial potential of the technology.
Round 2 will fund up to two projects, up to £200k each to guide and deliver enabling R&D projects, allowing the teams to begin responding to the R&D agendas they developed in Round 1. The work carried out by the consortia they build will be balanced across the following three areas:
- Use of concept design and evaluation to guide enabling R&D activities
- Delivery of enabling R&D (material, metamaterial and module development)
- Development of partnerships and pursuit of greater external funding for further enabling R&D and further technology development
The call guidance document is available here.