A3 - Resource and environmental characterisation in physical modelling facilities

Designing for offshore conditions requires detailed analysis of the impact of wind, waves, currents and turbulence on the loads and performance of ORE devices. Numerical modelling can inform certain design aspects, but this needs to be supported and validated by controlled and repeatable laboratory testing. This testing provides data that represents regular and extreme loading, device performance and survivability. Testing in wave basins and wind tunnels is particularly useful where complex or coupled effects are present, such as turbulence or wind and waves. However, this testing is always performed at reduced geometric scale and there can be challenges with reproducing and then characterising the field conditions in the laboratory facility. Refining laboratory facilities using new modelling technologies, allows more realistic simulation of offshore scenarios.

Laboratory facilities are increasing the realism of their simulations. New techniques allow complex aspects of the ocean environment to be modelled in the lab, such as combined wave and current characteristics, turbulence parameters, and combinations of wind, wave and current.

Potential impact on both OPEX and CAPEX via improved reproduction of complex field conditions leading to improved fidelity and reduced uncertainty in performance and extreme loading. Specifically, demonstration in hostile and extreme conditions at significant laboratory scale is important to deliver confidence in design and investment decisions.

On-going work at FloWave to characterise tank conditions and their representation of field conditions.

• FloWTurb: Response of Tidal Energy Converters to Combined Tidal Flow, Waves, and Turbulence
• Marinet2 project on cross-tank comparisons which may overlap with refining in tank conditions.

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Active research projects:

• Connectivity of Hard Substrate Assemblages in the North Sea (CHASANS) - Funded by NERC: NE/T010886/1: The aim of this project is to enhance our understanding of the connectivity of marine growth across artificial substrata in the North Sea. Team expertise in biofouling monitoring, oceanographic modelling, and population genetics will be used to generate a multidisciplinary dataset to validate biologically realistic models of larval connectivity. These models will be used to predict how networks of offshore renewable energy and oil & gas infrastructure in the North Sea function in biofouling dispersal and metapopulation structure.
• Biodiversity characterisation and hydrodynamic consequences of marine fouling communities on marine renewable energy infrastructure in the Orkney Islands Archipelago, Scotland, UK: As part of ongoing commitments to produce electricity from renewable energy sources in Scotland, Orkney waters have been targeted for potential large-scale deployment of wave and tidal energy converting devices. Orkney has a well-developed infrastructure supporting the marine energy industry; recently enhanced by the construction of additional piers. A major concern to marine industries is biofouling on submerged structures, including energy converters and measurement instrumentation. In this study, the marine energy infrastructure and instrumentation were surveyed to characterise the biofouling. Fouling communities varied between deployment habitats; key species were identified allowing recommendations for scheduling device maintenance and preventing spread of invasive organisms. A method to measure the impact of biofouling on hydrodynamic response is described and applied to data from a wave-monitoring buoy deployed at a test site in Orkney. The results are discussed in relation to the accuracy of the measurement resources for power generation. Further applications are suggested for future testing in other scenarios, including tidal energy.

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Supergen ORE Hub - Flexible Funding Research

• LoadTide
  Lead Institution: University of Edinburgh
  This project will directly solve the challenge of measuring the fatigue performance of tidal turbine blades by generating, for the first time globally, statistically robust accelerated cyclic loading data for the lifetime of a fullscale tidal blade. This will be carried out at economic cost over a short timescale that will enable developer designs to be more quickly refined than is currently possible. Tidal turbines operate in a harsh marine environment, characterised by significant levels of flow unsteadiness, with tidal blades needing to withstand both deterministic (e.g. shear profile, tidal fluctuations) and stochastic (e.g. waves, turbulence) induced loads. The resulting fatigue loading is a significant cause of blade failure. Understanding these loads and their impact on blade structural performance is crucial in order to avoid premature failure and to increase confidence in tidal blade design, leading to reduced cost of energy. This project will model, define and apply these fatigue loads to develop a process for full-scale tidal blade testing
  

• Satellite Climate Observation for Offshore Renewable Energy Cost Reduction (SCORE)
  Lead Institution: University of Edinburgh
  Satellite-based measurement has long been identified as having a potential role in enabling cost reduction of marine renewables, but applications have been largely limited to wind resource assessment and wake modelling. This project aims to take satellite data usage in offshore renewable energy (ORE) to the next level by better linking satellite data, models driven by such data, decisions driven by the model outputs, and quantifying this impact on a Levelised Cost of Energy. By mapping linkages between key decision horizons in ORE life cycle to satellite capability will produce a visual map of where satellite data can best impact ORE project decisions. This map will direct the data analysis activities towards the project decisions having the best potential for improvement and quantify any reductions in uncertainty. These improvements will then be captured and monetised in a range of cost models
  

• Novel Approaches for Physical Model Testing of Floating Wind Turbine Platforms
  Lead Institution: University of Strathclyde
  The “standard” approach to modelling wind loads on a floating offshore wind turbine in a hydrodynamic test is via direct physical simulation, using a correctly-scaled working model of the turbine operating in a scaled wind field above the test tank. This poses a number of challenges. Generating a wind field of high controllability and large volume over the tank is difficult and expensive, and scaled model testing can led to manufacturing challenges. An alternative possibility is to utilize “software-in-the-loop” (SIL) in which an active control system drives an actuator in real time to generate system excitation forces in a model test. While it offers a number of benefits, a significant number of challenges remain for this type of testing. This project aims to address the challenges of existing SIL approaches by developing and validating novel approaches to, and practices for, SIL modelling of floating wind turbines in physical model tests.

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We would also like to invite UK researchers and industry stakeholders within ORE to submit links to research projects, both past and present, for inclusion within the landscape.

Therefore, if you have a UK-based research project within an area of ORE that you feel is relevant to a specific research theme or challenge within the Research Landscape, click HERE to submit your research project to the research landscape.

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PhD projects in Offshore Renewable Energy

In order to better understand the breadth of ORE research currently being conducted in the UK, the Supergen ORE Hub has collated from its academic network, UK Centres for Doctoral Training and Industrial partners, a list of PhDs currently being undertaken in ORE.

Access a PDF of the list and find out more about including your PhD.