#	Pagina
attuale pagina	/open-h2020/projects/208955/results.html

Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - OpTiCA (Optimisation of Tidal energy Converter Arrays)

Teaser

Summary

As technology readiness level of Tidal Energy Converters (TECs) increases, moving from prototype demonstration to commercialisation, research efforts are focusing on TEC arrays layout optimisation to reduce costs and become competitive in comparison with other energy systems. Even though there are several prototypes of different scales that have been tested in the last years (lab conditions) there is limited data on deployments in real conditions. This negatively affects the accurate formulation of constrained problems on array schemes, resulting in incomplete layout optimisation models. This project aims to provide a significant contribution towards the understanding of (a) the effects of TECs interactions with the environment; (b) the capabilities and limitations of common strategies used for the numerical modelling of TECs; and (c) how to mathematically formulate optimisation models to solve the TEC array layout problem considering technical, socio-economic and environmental constraints. From the methodology point of view, constraint optimisation models will be mathematically formulated considering data collected from in-field measurements from prototypes tested in real environments and with surrogates built from validated numerical simulations. The outcomes of the project will contribute to de-risk financial investment.
Within OpTICA a numerical model was used to develop an optimisation method for TEC arrays which was successfully applied to a test case, proving that it can be used worldwide. The method demonstrates that the optimisation routine must be coupled with the system hydrodynamics to improve power capture and assess impacts on circulation patterns. It was also found that there is the need to test and operate, for longer periods, TEC arrays prototypes in relevant and operational environments to further advance the understanding of both the influence of the environment on the devices performance and their environmental impact. This will allow to improve the tuning of numerical tools for the correct representation of TECs, as well as sophisticating mathematical optimisation models to solve the TEC array layout problem.

Work performed

The work performed on this action was divided in several tasks and goals.
The first task to be performed was the development of Project and Data Management Plans, which was done within the first 6 months of the action. The DMP describes the data management life cycle for all data sets that have been collected, processed or generated by the action. The PMP consisted in defining how to manage the project carefully, monitoring the implementation and good execution of all project activities.
Secondly, a 1/10th scale floating TEC with rated power 1 kW named EvopodTM (E1) from Oceanflow Energy Ltd was installed at the Faro-OlhÃ£o Inlet, in Ria Formosa (Portugal). Its performance and environmental impacts were monitored for around 5 months, giving the possibility to obtain valuable data that was used in following tasks. Overall, data gathered showed that the Faro-OlhÃ£o Inlet has a promising tidal stream energy resource and that the environmental impacts associated with the operation of one device were minimal.
Modelling of TEC arrays was performed focusing on validating numerical models that simulate the presence of TECs using data obtained at the field (see above paragraph). Three specific modelling tools were used, these are: 1) OrcaFlex software to assess different mooring characteristics and hydrodynamic response of the floating turbine. This work was carried out during a planned secondment at Oceanflow Energy Ltd headquarters in Newcastle (UK) under the supervision of the companyâ€™s CEO Mr. Graeme Mackie. The purpose of this secondment was to gain skills using OrcaFlex software. Additionally, modelling of offshore floating wind platform, StarFloatTM, was conducted using the same software. 2) A vertical averaged (2DH) model of Ria Formosa based on Delft3D to study the effects of arrays made of several Evopods on the hydrodynamics and sediment transport patterns of the water body. This work entailed the calibration of a momentum loss coefficient used in Delft3D to parameterise the presence of TECs. 3) A Blade Element Momentum model of E1 based on OpenFOAM that allowed to study rotor performance and wake recovery. This work was carried out during a secondment at Swansea University with the supervision of Prof. Ian Master.
A main topic of the research performed was the development of optimisation models for TEC arrays, which consisted in formulating and testing mathematical optimisation models to improve the design of TEC arrays deployment and effectiveness. This was achieved using the data at the field and the tools afterwards developed, as expressed above. There were two main approaches. The first approach consisted in using Surrogate Based Optimisation (SBO) to determine the optimum size of a TEC array considering performance and environmental constraints. The second approach entailed the use of heuristic methods to determine the optimum power cable routing for an already optimised TEC array layout.
Finally, the project was also active regarding dissemination and public engagement, by disseminating OpTiCA results using different communication channels, which included: talks for high school students; guest lectures at graduate level; presentations at specialised events and congresses; radio shows; and a project website. http://msca-optica.eu/
Further details can be obtained visiting the OpTiCA project\'s website: http://msca-optica.eu/

Final results

The innovation of OpTiCA consisted in providing understanding of what are the effects of tidal stream energy on the environment, and how to design efficient and sustainable TEC array layouts. This has been achieved by deploying and monitoring, for the first time, a floating TEC in a complex multi-inlet coastal lagoon. Data gathered from the deployment has permitted to advance the state-of-the-art, specifically in the following aspects:
1) A numerical approach (sink term) used for the representation and assessment of TECs was calibrated with real data instead of lab data. Results showed that common approaches underestimate the effect of TECs on hydrodynamics.
2) Two innovative optimisation strategies were proposed to assist the design of TEC arrays, allowing the inclusion of different types of constraints. The first method is focused on aspects of turbine layout, while the second is directed to solve the power cable layout. The main advantage of the SBO approach is that the optimisation process is coupled with the hydrodynamics of the deployment site, allowing the characterisation of both the TEC array near- and far-field effects.
The potential impacts of the project results are significant. At a generic level, OpTICA developed a method for optimising TEC arrays based on numerical models, which can have a wide impact on the marine renewable energy sector. At a regional level, OpTiCA project results have permitted to identify the Faro-OlhÃ£o Inlet as a promising site for testing and operate small scale TECs devices. As a result, efforts are being put to establish the Faro-OlhÃ£o Inlet as an international recognised site for testing small scale tidal energy converters as part of the MARINERG-i Infrastructure network. Furthermore, project outcomes could contribute to the sustainable development of the island communities located nearby the testing site.