Tidal energy operational and spatial planning optimisation

Lead Research Organisation: Imperial College London
Department Name: Earth Science and Engineering

Abstract

The UK, is committed to reduce greenhouse gas emissions by 80% by the year 2050 relative to 1990 levels, and to meeting 15% of its energy from renewable sources by 2020. Research suggests that the combined operation of tidal stream and range power schemes can exceed 12% of the UK's energy demand from a sustainable, clean energy source. In comparison with other renewable energy sources this comes with complete predictability which means that tidal can play a vital role in meeting the nation's energy needs. At the time of writing this proposal, pilot projects for tidal stream and range based energy generation are in the advanced stages of planning and development within the UK. The first tidal stream turbines installed within a pilot array in the Pentland Firth off of Scotland have just started to generate power. For tidal range-based technologies, the UK Government's "Hendry review", released on the 10th of Feb 2017, recommended that tidal lagoons (tidal range structures) can play an important role in the UK's energy mix. This provides a roadmap towards the development of the Swansea Bay lagoon as a pathfinder project and the first tidal range energy structure of this type worldwide. Construction could commence in 2018, with much larger industrial projects to follow subsequently.

We are thus at a crucial stage in the development of a new tidal-based renewable energy sector where the UK currently leads the world. This project seeks to build on this strong position by providing timely research on the environmental and ecological impacts of new, larger tidal developments in a manner that supports decision making by stakeholders, including coastal engineers, financiers, and primarily those concerned with environmental impacts. This project builds upon a strong foundation of recent work at Imperial College London that has provided the preliminary demonstration of computational methods for the representation of turbine arrays and tidal range structures within multi-scale models, as well as the optimisation of array designs and tidal plant operations to maximise power or profit, while minimising environmental impacts.

The proposed research will focus on the optimal spatial planning and operational control of prospective tidal range projects. Recent computational modelling findings suggest that up-scaling the development of marine energy infrastructure beyond the pilot scale poses a formidable challenge. Industrial proposals need to comprehensively evaluate and compensate for impacts on environmental processes that relate to water quality for sensitive species and tidal dynamics alterations. A quantification of environmental impacts (e.g. tidal flushing, Dissolved Oxygen) via simulation software can become computationally demanding when multiple processes are modelled at a large scale. Opportunities to reduce the computational load could stem from the fact that many of the environmental constraints can be described as objective functions. The optimisation proposed will be fully coupled to the underlying tidal dynamics, so that changes to tidal range structure design and control can feed back to the hydro-environmental processes and vice-versa.

The research will be conducted at the interface of academia and industry, and will be informed by marine energy developers, technical consultants and experts in environmental and coastal processes. Input from industry will be in the form of observed and model data that will be compared against the results of the tidal energy optimisation software. The data will also inform the optimisation method's constraints, and will be used to validate corresponding coastal models that aim to assess optimised designs of a series of industrial tidal range energy proposals. The overarching motivation of the research will be to inform environmental impact assessment practices and the sustainable development of upcoming clean energy technologies that will be developed by the UK's industry.

Publications

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