Scaling tidal energy arrays

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Engineering


Tidal stream energy developers are seeking new ways to reduce their Levelised Cost of
Energy (LCOE). In the UK this is motivated by competitions for funding in one of the UK
Government Contracts for Difference (CfD) allocation rounds that subsidise investments
into low carbon energy options. Improving reliability and reducing maintenance
complexity has been identified as a possible route to achieving this by reducing the
Operational Expenditure (OpEx). One method adopted by many developers is to use
multi-rotor devices, where multiple turbines are housed on the same platform in order
to simplify operational challenges such as deployment, installation, maintenance, and
recovery. Additionally, increasing overall reliability through fewer active components
such as yawing and pitching mechanisms is being considered, which often means that
these multi-rotor structures are in a fixed position throughout their life. A multi-rotor
device is typically made up of multiple smaller diameter turbines, with a similar overall
device capacity as a single larger diameter turbine, but with improved Operations and
Maintenance (O&M). This change in design philosophy has the potential to significantly
reduce costs for developers. Additionally, with more flexibility in turbine layout, there
is some potential for exploiting positive relationships between neighbouring turbines
to extract additional power from the flow as seen in Ref. [1], [2], [3]. In these studies,
high local blockage ratios are utilised through operating adjacent turbines with a low
tip-spacing in channelled flows to extract higher efficiencies from the turbines. The
higher thrust loads experienced by the turbines during high blockage flow results in
additional torque being generated and greater efficiencies. The industrial applicability
of this phenomenon is investigated to understand at what blockage ratio these gains
are realised, and what might be able to be achieved in a realistic site setup, where the
blockage ratios are typically lower.

Planned Impact

The primary impact will be achieved by industrially-sponsored student research projects. These will be designed to deliver immediate benefits to project sponsors, and the wider sector, forming a critical mass in capacity, knowledge and innovation opportunities.

The Offshore Renewable Energy (ORE) sector has seen rapid growth over recent years, with asset installations and operations increasing significantly. The UK is a global leader in the research, development and engineering in ORE, delivering significant benefits for UK plc. Current UK offshore wind installed capacity is in excess of 5GW and is forecasted to grow to around 10GW by 2020, with expected capacity increases of 1GW/year until 2030. Across Europe, installations (excluding the UK) exceed 6GW capacity, with a further 9GW envisaged before 2020 and a growth rate of 2.5 GW/year up to 2030. Whilst offshore wind is at an industrial stage where it creates new jobs right now, tidal and wave energy hold the potential to further mature to provide the benefits from commercial deployments by 2040. ORE generation complements the low carbon energy portfolio, reducing CO2 emissions.

The sector will drive substantial economic benefit to the UK, provided development, research and training can keep up with the sector. Economic analysis conducted for the Sustainable Energy Authority of Ireland shows that 3FTE construction job years are created per MW of offshore wind deployed, and a further 0.6FTE are created through ongoing operations and maintenance, creating thousands of jobs per GW/year. Analysis by the ORE Catapult found that current offshore wind projects have an average 32% UK content. By 2040 the UK is to increase this content in areas of strength such as blade and tower manufacture, cable supply and O&M, by providing the needed investment, development and skills training. Supply chain analysis projects that 65% UK content could be possible by 2030, with further export opportunities, estimated to be worth £9.2bn per year by 2030. The current GVA to the UK per GW installed (at 32% UK content) is £1.8bn and estimates suggest a possible increase to £2.9bn by 2030. Future UK employment in the ORE sector has been modelled by Cambridge Econometrics. By 2032 the sector could support 58,000 FTE jobs in the UK, with 21,000 FTE jobs direct employment (up from 10,000 FTEs jobs currently) and another 37,000 FTE additional indirect jobs.

IDCORE will contribute to and improve ORE supply chain development, by providing dedicated R&D support to SMEs and developers, building industry and investor confidence and working with investors and asset owners. The program will result in new technical solutions, enhanced O&M service offerings and enhanced engineering design and analysis tools for the benefit of the industry partners and the wider sector.

The role of government strategy and policy development will be a crucial element of the training provided to IDCORE students. Used within their projects, and in interactions with sponsors, this knowledge will improve the outcomes for their work making it relevant to latest policy developments. It will also drive the development of robust evidence for government, improving policy making. Such engagement is supported by links created between the partners and the Scottish and UK Governments and organisations like Wave Energy Scotland and the International Energy Agency.

The development and demonstration of an effective EngD programme is important for the broader academic community, providing a model for engagement with industry and other stakeholders which is as effective in its impact on SMEs as it is with larger organisations.

The consortium has strong international links across Europe and in Chile, China, India, Japan, Mexico, and the USA. Promoting EngD programmes for renewable energy has the potential to lead to the formation of new sister programmes - expanding opportunities for staff and student exchange.


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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S023933/1 01/10/2019 31/03/2028
2588517 Studentship EP/S023933/1 01/09/2021 31/08/2025 Bryn Townley