A feasibility study for establishing a design tool for floating tidal energy system

In the past decade, tidal stream energy converters have become a major focus for renewable energy R&D with a number of turbine farms now in its planning and development phase. The majority of existing designs for tidal energy devices utilize sea-bed mounted turbine energy converters. These underwater devices however present many challenges related to economic and technical viability in terms of their installations and maintenances cost.

In recent years, a floating type tidal energy device is being developed. The installation of such a device comprises of single or multiple turbines mounted on a floating platform anchored to the sea-bed with mooring lines.

Research and industry teams in China and UK have presented multiple demonstrations both on a model scale and a full scale floating tidal energy converter. All of the results add credibility to their technical feasibility and cost effective nature as compared to fixed turbines.

Despite the advantages of floating tidal current turbines (FTCT) over their fixed counterparts, the existing design guidance is not deemed to be ready for the commercial market. The key challenges include guaranteeing the safety of supporting platform and floating mooring lines, the survivability of large scale rotor under extreme sea conditions, the accurate assessment for the proper site selection and the reliable evaluation of environmental impacts. Existing industry design tools rely very much on the simplified models or individual component design rules which negatively impact the energy extraction process/amount/supply.

The proposed project aims to integrate the work already carried out at University of Strathclyde in UK in the field of offshore renewable energy and floating offshore structure with the work performed at (a) Harbin Engineering University in China in the area of floating tidal turbine and (b) Ocean University of China in China in the field of tidal resources and environment impacts assessment. The main goal of the proposed research is to explore whether an integrated method is feasible to better understand the fundamental physics associated with a coupled floating tidal energy system through numerical framework with experimental comparisons and validations. This would then potentially provide more accurate industry design guidelines for the future commercialized FTCTs and other floating marine energy devices.

Impact Summary

This proposed project will have a significant and long lasting impact on the marine offshore renewable energy industry, which in turn will benefit economy, environment and society at large, through a variety of innovative and novel activities, maximizing the rewards offered from collaborative research with China. It is hoped that the successful completion of this research collaboration would pave the way for other new jointly project which may involve industry partners. The accomplished research will make feasible the establishment of a long-term collaboration with the proposed and other academic institutions in the China.

This project will contribute to the education of a multidisciplinary workforce with the skills to develop future renewable energy technologies. During the course of the project, four Chinese Ph. D students and two UK students will be trained in the areas of offshore structure, renewable marine energy and marine hydrodynamics with both experiment and modeling skills. Our researchers will be able to sustain UK & China effort in these areas within industry, government laboratories or academia. The research findings will be incorporated into teaching at three universities and the pedagogical contributions shall help shape the engineers, scientists and industrialist of the future.

The proposed research is of high relevance and importance to the marine renewable industry both in the UK and China as it addresses the key issues relevant to the design for cost-effective renewable energy system. The immediate beneficiaries will be the technologist and engineers who deal with the design, operation and maintenance of floating energy devices. The advanced dynamic coupling model developed will provide more reliable results by reducing several design uncertainties and conservatism. The new methodologies and techniques developed through this project will also be of great interest to researchers and engineers within other academic research disciplines such as computational fluid dynamics and hydrodynamics, the wider marine industry and offshore renewable energy sector. One of the direct outputs of the research project is to provide advanced new analysis tools for offshore floating renewable energy system design. Where appropriate, project methods and findings will be proposed as new technical standards and regulations for ship and offshore classification (e.g., Lloyd's Register) and other regulatory societies, such as the offshore renewable energy industry.

The collaborations through this project will provide excellent opportunities for technology transfer to the Uk and China renewable energy industry. The PI and partners will engage with industrial researchers via our existing industrial collaborative projects on offshore renewable energy technologies, e.g. Reshydro Fluid Power Ltd USA, Lloyd's Register Group Limited and EDF Energy France. As a follow up of this project, the PI and partners will exploit with these and other companies the opportunity for knowledge transfer partnerships (KTP) projects.

To ensure the outcomes of research reaches a wide audience through the dissemination, the results of proposed mutual visits and knowledge exchanges will be disseminated through high impact academic and industrial journal papers or suitable conferences throughout the follow up collaboration. An interactive website for the programme will be constructed to report our latest results and methodologies. It will contain published materials, video footage and other social media. In addition the website will provide links to/from the websites of co-researchers, collaborators and related programmes/research centres within the UK and China. Chinese partners may translate the reports; publish in Chinese language in other mediums for wider reach.