E5 - Design tools for arrays
E - Survivability, Reliability and Design
There is insufficient confidence in prediction of energy yield from arrays of new technologies to underpin investment Current models cannot efficiently achieve array optimisation of ORE systems.
Computationally tractable techniques for system or component design accounting for flow-modification by other devices and arrays Models need to be developed for effective analysis and optimisation of ORE arrays.
Context and Need
Reducing the costs in installation, operation, maintenance meanwhile improving the energy yield can improve confidence in project financial projections. This can be achieved by developing single ORE structure into efficient arrays. Numerical models are needed to predict the optimal arrangement of arrays.
Existing models for wind or wave farms need to be integrated meanwhile including the floating motion responses in order to optimise the ORE farms. Better models are needed to adapt the existing onshore/nearshore farms to offshore farms. Better and more efficient methods are needed, considering optimisation's for the array layout, control of individual or blocking devices, mooring/PTO sharing, foundations, electrical network and the lifecycle logistics, etc. These can minimise the cost of electricity. Integration with ecological models and with sediment dynamics models is needed to understand the ORE farm effects on environment.
It is widely accepted that large numbers of devices will need to be installed in relatively close proximity for large-scale power generation. Turbines and devices must be designed for operation within clusters and arrays, taking account of the modification of design conditions due to other devices and arrays. Array configurations and operating strategies must be developed to maximise fatigue life and performance whilst minimising operating risks and costs.
The challenge is to develop sufficient confidence in design tools to underpin investment in commercial-scale arrays of each ORE type / for effective exploitation of the major ORE sites
Efficient numerical models need to developed for array optimisation or ORE systems, which include: optimal control; understanding device conditions; hydrodynamic interaction; uncertainty quantification, yield optimisation; blocking and efficient arrays in real channels; mooring or power take off sharing. Better understanding of the hydrodynamics of array interaction, layout performance and design, including moorings and anchors is needed through physical wave tank tests and numerical modelling.
- to predict array performance
- to establish designs required for array deployments and hence CAPEX
- to establish the potential market size for alternative ORE types and hence scope for learning
- to maximise ecological and environmental acceptance of the exploitation of ORE sites.
- to establish design conditions for systems operating in arrays.
To enable evaluation of novel siting options such as clustering of design types within a site, optimisation of array layout and ORE device control strategies and selection of design parameters for in-array operation to maximise economies of scale production.
Impact on CAPEX as the arrangements of the ORE farms will be optimised and therefore the design can be less conservative. Impact on OPEX as the mooring/PTO will be efficiently shared within the ORE farms and therefore reduce the O&M cost. Impact on all areas as a result of cost savings and more efficient arrangement of the ORE farms.
- EPSRC - Dynamic Loadings on Turbines in a Tidal Array (DyLoTTA), FloWTurb: Response of Tidal Energy Converters to Combined Tidal Flow, Waves, and Turbulence, EcoWATT
- NERC - Flow & Benthic Ecology 4D (FLOWBEC) (partly)
- EU - Enabling Future Arrays in Tidal (EnFAIT)
- WAMIT, MILDwave, SWAN, CFD etc. integrated with optimisation algorithm like Genetic Algorithms, Gloworm Swarm Optimisation etc. One research project, DTOcean, focuses on developing Optimal Design Tools for Ocean Energy Arrays
- The Performance Assessment of Wave and Tidal Array Systems (PerAWaT) project: The PerAWaT project, launched in October 2009 with £8m of ETI investment. The project produced validated software tools capable of significantly reducing the levels of uncertainty associated with predicting the energy yield of major wave and tidal stream energy arrays.
- SELKIE (GAD-CFD) - Within the Selkie project, this research aims to improve and use the GAD-CFD numerical modelling framework to inform the understanding of the tidal flow of sites of interest and potential wake interactions within turbine arrays. A SELKIE blog post related to the GAD-CFD model: https://www.selkie-project.eu/blog/orbital-marine-power-find-great-benefits-in-selkie-gad-cfd-tool/
- Within the EPSRC-funded project Morphing Blades, new-concept blades are developed to mitigate the effect of unsteady loadings on tidal turbines, and numerical models are developed to accurately predict unsteady loadings experienced by conventional turbines and turbines equipped with morphing blades. The project has demonstrated the potential of morphing blades to cancel or substantially mitigate unsteady load fluctuations without affecting the mean load and the power harvested. Morphing blades can both be used to cancel (/mitigate) high frequency load fluctuations such as those due to, for instance, turbulence, as well as to cap the maximum power at rated flow conditions and replace active pitch control. New numerical codes specifically designed to accurately predict unsteady loadings are developed, including design codes based on blade element momentum theory (BEMT), as well as research tools such as Reynolds-averaged Navier Stokes solvers and Large Eddie Simulations.
The following ongoing projects are related:
- Wave Energy Transition to Future by Evolution of Engineering and Technology (WETFEET)
- Advanced Design Tools for Ocean Energy Systems Innovation, Development and Deployment
- Development of screw anchors for floating Marine Renewable Energy system arrays incorporating anchor sharing
- Modelling, Optimisation and Design of Conversion for Offshore Renewable Energy (UK-China MOD-CORE)