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

Abstract

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.

Planned Impact

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.
 
Description A established tool for the design of floating tidal turbine including resources identification, preliminary design of turbine and dynamic response of floating platform;
An experimental testing on Vertical axis turbine under combined wave and current conditions;
A numerical modelling of VAT energy performance and catamaran dynamic motion response under various wave and current conditions.
Exploitation Route The outcome of this project has seen a few journal and conference publications; a design software tool which can be used either for education purposes or for preliminary industrial design.
Sectors Education,Energy

 
Description The outcome of this research contributes significantly to energy sectors both in China and UK.
First Year Of Impact 2016
Sector Education,Energy,Environment
Impact Types Economic

 
Description EPSRC Resource Allocation Panel (RAP): Access to ARCHER
Amount £80,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 07/2015 
End 07/2016
 
Description Global Research Engagement, EPSRC Impact Acceleration
Amount £5,000 (GBP)
Organisation University of Strathclyde 
Sector Academic/University
Country United Kingdom
Start 06/2016 
End 07/2017
 
Title Computational Fluid Dynamics tool for Vertical Axis Turbine Modelling 
Description Via this project, Strathclyde University developed a numerical modelling tool to estimate the VAT output power, which could be used to guide experimental design and testing of relevant VAT. 
Type Of Material Technology assay or reagent 
Year Produced 2015 
Provided To Others? Yes  
Impact The numerical methodology developed could be used for future design of relevant VAT. Detailed flow field, including vortices interaction phenomena are obtained, which is helpful to shed insight on the flow control mechanism to improve device efficiency. 
 
Title Experiment 
Description With the funding support, UoS team designed and built up a 3-bladed Vertical Axis Turbine, which is totally new in UoS. Towing tank testing on the turbine hydrodynamic output power was carried out. The experimental results were compared with numerical modelling CFD data and analytical results. 
Type Of Material Improvements to research infrastructure 
Provided To Others? No  
Impact With the funding support, UoS team designed and built up a 3-bladed Vertical Axis Turbine, which is totally new in UoS. Towing tank testing on the turbine hydrodynamic output power was carried out. The experimental results were compared with numerical modelling CFD data and analytical results. This established a solid foundation for future relevant vertical axis turbine research to be carried out in NAOME department in Strathclyde University. 
 
Title Numerical modelling tool for floating platform 
Description Numerical modelling tool for investigation dynamic response of floating platform and its influence on the supporting turbine has been developed. 
Type Of Material Technology assay or reagent 
Provided To Others? No  
Impact The method developed can be used for a wider range of floating platforms with their applications in offshore wind turbine industry. One industry project is undergoing in this area with funding support from EDF Energy in France. 
 
Title Tidal resources assesment and modelling 
Description OUC further developed their existing software, carried on a study on the sea site which will be used for the floating tidal turbine 
Type Of Material Technology assay or reagent 
Year Produced 2015 
Provided To Others? Yes  
Impact The results and methods developed are vital to identify an appropriate tidal site to install a tidal turbine so that the performance of turbine is guaranteed. 
 
Description Harbin Engineering University 
Organisation Harbin Engineering University
Country China 
Sector Academic/University 
PI Contribution Both experiment and CFD modelling work carried by University of Strathclyde provided useful and additional information to HEU for the design of floating tidal turbine devices
Collaborator Contribution HEU partner contributed their expertise in tidal turbine design and optimization
Impact Joint conference publication; an integrated software
Start Year 2009
 
Description Ocean University China 
Organisation Ocean University of China
Country China 
Sector Academic/University 
PI Contribution Turbine modelling and experimental testing gave OCU to validate their resources modelling results.
Collaborator Contribution OUC partner contributed their expertise in tidal resources assessment and estimation
Impact See joint publications
Start Year 2014
 
Description HEU partners visited Strathclyde University in March 2015 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact HEU partners visited UoS in March 2015. They visited Kelvin Hydrodynamics lab, observed the experimental testing of Vertical Axis Turbine built up in UoS. Suggestions and comments were made. Discussions on the integral software and floating platform & mooring systems modelling were carried out. Blade Element Method for tidal turbine blade is compared with UoS CFD results.
Year(s) Of Engagement Activity 2015
 
Description OUC partners attended 9th International Workshop on Ship and Marine Hydrodynamics at Stathclyde University in August 2015 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact OUC partners attended PI organised International conference held at Glasgow in August 2015. By doing this, OUC partners had a wider exposure to participants at this conference. A visit to Kelvin Hydrodynamics lab and department of Naval Architecture, Ocean and Marine Engineering was conducted. Mutual interested research topics were discussed
Year(s) Of Engagement Activity 2015
 
Description PI attended China-UK tidal energy workshop at Dalian Technological University in China in Jan 2015 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact By attending this workshop, the relation between PI and partners are enhanced. PI also took this opportunity to give two technical talks at Dalian Technological University. In depth discussion on the technical problems related to offshore engineering was carried out. Common interested problems such as Vortex Induced Vibration , etc. were discussed.
Year(s) Of Engagement Activity 2015
 
Description PI visited HEU and OUC in China 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact PI visited two Chinese partner institutions in July 2015. Technical talks were given at each institutions. Discussions with partners' institution colleagues were carried out. PI visited relevant experimental facilities at two institutions. Potential research collaborations in future were discussed.
Year(s) Of Engagement Activity 2015