Floating Tidal Turbine Fences

Lead Research Organisation: University of Oxford
Department Name: Engineering Science

Abstract

Large scale power generation from tidal currents will require the deployment of large numbers of tidal turbines arrayed in close proximity to one another. This presents significant challenges; turbine-in-wake interactions, as well as significant opportunities; arraying turbines side-by-side in closely spaced fences can significantly enhance their performance. Extreme weather survivability and the ability to maintain offshore systems are key to delivering economic and durable tidal energy systems.

A potential solution to these challenges is floating systems supporting multiple closely spaced turbines. Such systems will provide rapidly deployable, retrievable and maintainable multi-turbine systems that deliver high performance.

This project will conduct a preliminary assessment and feasibility study of floating closely spaced tidal turbine arrays. Specifically the project will seek to optimize the hydrodynamic performance of multiple closely spaced turbines supported from a single platform and determine their load and response when subjected to combined wave and tidal flows. The project will also seek to determine the suitability and stability of mooring systems under such loads and the platform's static and dynamic response leading to definition of permissible operating regimes.

Planned Impact

This project addresses novel infrastructure to facilitate cost-effective deployment of tidal stream turbines at commercial scale. This will support the development of the UK and Chinese tidal stream energy industries by demonstrating confidence in the future technical and economic potential for large-scale generation. We will conduct fundamental research to underpin the development of floating structures to support multi-turbine fences. This approach to turbine deployment offers the potential for marked reduction of cost of tidal stream energy through increased performance and reduced lifetime cost resulting from reduced maintenance costs etc. Specific technical outputs will include:
i. Hydrodynamic optimization of short fences of tidal turbine arrays together with performance and loads resulting from operation in combined tidal flows with waves.
ii. An engineering model to assess the suitability, stability and safe operating limits of floating tidal turbine systems.

Direct beneficiaries will include both the industrial and academic parts of the tidal energy sector, whilst the wider beneficiaries include society as a whole through the provision of cleaner, more affordable renewable energy. As well as the social and economic impact of supporting a developing industry sector, the project will enhance both UK and Chinese research reputation, capabilities and skills. The methods and understanding of the fundamental flow and fluid-structure interaction problems that will be delivered by this project will underpin the evolution from single seabed supported to multi-turbine floating platforms, and will help to promote UK and Chinese academia and industry to the forefront of the marine energy industry.

The UK and Chinese governments are committed to the commercialisation and wide spread deployment of tidal energy devices. The multi-turbine deployments investigated in this study will provide high performance with reduced costs associated with cheaper mooring foundation systems, leading to substantially reduced cost of energy, which is aligned with both government's renewable energy development policies. This project will lead to increased UK-China collaboration in an area that has been identified as a high priority area by both nations.

Publications

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Vogel C (2017) Multi-rotor tidal stream turbine fence performance and operation in International Journal of Marine Energy

 
Description The grant has led to the development of a conceptual design for a 1MW floating multi-rotor tidal stream turbine system. The design incorporates bespoke rotors designed to maximise constructive interference effects through close proximity operation of the rotors. The rotors are mounted on a floating system designed to support the high thrust loads experienced by such closely mounted rotors together with wave loads.
Exploitation Route The concept design requires developing to a higher TRL level through computational and physical demonstration eventually leading to the adoption of key technologies in engineering design.
Sectors Energy

 
Description Research Fellowship
Amount £1,024,449 (GBP)
Funding ID EP/R007322/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 01/2018 
End 12/2022
 
Description Research Project
Amount ¥3,000,000 (CNY)
Organisation National Natural Science Foundation of China 
Sector Public
Country China
Start 01/2018 
End 12/2021
 
Description Supergen Flex Fund
Amount £97,300 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 03/2018 
End 02/2019
 
Description Harbin Collaboration 
Organisation College of Shipbuilding Engineering
Country China 
Sector Academic/University 
PI Contribution Provision of loading data for tidal turbines operating in sheared currents with and without free surface waves
Collaborator Contribution Development of floating platform systems to support the tidal rotor designs provided by Oxford.
Impact Floating multi-rotor turbine system design
Start Year 2014
 
Description "Tidal Stream Energy - Challengs and Opportunities" invited speaker at "Powering the Future" UK-China Innovation Forum, Shanghai, Sept 16 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact This was an invited talk at the UK-China Innovation Forum, in Shanghai in September 2016, to report on successful previous UK-China collaborative projects. The talk initiated interest amongst other energy researchers and organizations from both the UK and China.
Year(s) Of Engagement Activity 2016