The coastal zone plays a crucial part in addressing two of the most pressing issues facing humanity: energy supply and water resources. Marine renewable energy and desalination are both characterised by the deployment of relatively small-scale technology (for example, tidal turbines, or desalination plant outfalls) in large-scale ocean flows. Understanding the multi-scale interactions between sub-metre scale installations and ocean currents over tens of kilometres is crucial for assessing environmental impacts, and for optimisation to minimise project costs or maximise profits. The vast range of scales and physical processes involved, and the need to optimise complex coupled systems, represent highly daunting software development and computational challenges. Geographically, the UK is uniquely positioned to become a world leader in marine renewable energy, but adequate software will be a key factor in determining the success of this new industry.

To address this need, this project will re-engineer a unique CFD to marine scale modelling package to provide performance-portability, future-proofing and substantially increased capabilities. To motivate this we will target two applications: renewable energy generation via tidal turbine arrays and dense water discharge from desalination plants. Both are characterised by a common wide range of spatial and temporal scales, the need for design optimisation and accurate impact assessments, and a current lack of the required software.

This project will build upon several world-leading open source software projects from the assembled multi-disciplinary research team. This team already has a long and successful track record of working together on the development of high quality open source software which is able to exploit large-scale high performance computing and has been used widely in academia and industry. In addition, the project has assembled a wide range of suitable project partners to aid in the delivery of the project as well as to promote longer term impact. These include complementary centres of excellence in cutting-edge software development, industry leaders in the targeted application areas, marine consultancies, and those contributing to environmental regulation.

Potential Impact:
This project will develop an open source tool that can fully couple the engineering scale with larger scale ocean dynamics. It will thus provide a capability largely lacking, but desperately needed, in both academia and industry. By delivering an additional optimisation capability the designs of these marine device developments can be improved for both economic and environmental benefit. Again this will be a unique ability for the community that can generate major impact.

In the case of marine renewable energy the UK is in an excellent position as the lead of this fledgling industry. Tides are predictable and so can provide an important component of the UK's energy needs with resulting energy security, reduced carbon emissions, and beneficiaries throughout the national supply chain. The first commercial-scale arrays are expected to be installed in UK waters before the end of the decade. This timeliness places us in an ideal position to provide major impact with this project. In particular, industry and regulators will be able to more confidently assess the viability of a given tidal site and potential environmental impacts. Further, they will have the ability to use optimisation to enhance a site's economic feasibility. This will improve the overall viability and number of potential sites, accelerating the competitiveness of tidal compared to other renewable and non-renewable sources of energy. Impact will be supported through our wide variety of project partners. This includes technology developers (Alstom) as well as site array developers (MeyGen). We are in a fortunate position to already collaborate closely with these companies, partly through their CASE partnership on PhD projects who will be able to help the take up of the developed methods within industry.

In the case of desalination (and other) outfalls the Institution of Chemical Engineers estimates that there are 13,000 desalination plants in operation or under construction in 150 countries, and that they will become more common on UK coastlines as population growth and the effects of climate change increase pressure on water supplies. This is expected to more than double by 2050 with the UK estimated to host 4 municipal plants and up to 800 smaller units. As with tidal energy, there is an urgent need to understand the impacts of a given outfall and to optimise its design, but software to achieve this is currently limited. Project costs for outfall pipe installation can be many 10s of 1000s of US dollars per metre. The ability to reduce the length of pipe while having improved confidence in adherence to environmental regulations could thus provide significant impact. This project will deliver the capability for the sector to simulate both the near and far field problems in the same framework (reduced training) and to more satisfactorily couple these. We have identified complementary project partners to accelerate impact and will invite further interested parties to training and dissemination events.