Proceedings of the European Wave and Tidal Energy Conference最新文献

{"title":"Multiquery analysis of a PeWEC farm","authors":"Beatrice Battisti, Giuseppe Giorgi, Gael Verao Fernandez, Peter Troch","doi":"10.36688/ewtec-2023-333","DOIUrl":"https://doi.org/10.36688/ewtec-2023-333","url":null,"abstract":"The maximization of the power output of an array of wave energy converters (WECs) and its impact on the surrounding area are two fundamental, strictly interconnected, aspects that must be considered in the design of a wave farm. The effect of those two elements combined, usually considered separately, is evaluated, in this study, for a small farm of floating devices. The numerical simulations are performed using a coupled model between the BEM solver Capytaine (near-field solution) and the wave propagation model MILDwave (far-field solution). The farm is located off the coast of Pantelleria Island and is composed of three PeWECs, WECs designed for the Mediterranean Sea. The power output and the perturbed wave field around the PeWEC farm are compared to the single device, for different distances among the WECs. Moreover, a Power Take-Off (PTO) is implemented for assessing the difference in the far-field effects between a controlled and an uncontrolled case. Results show that the wake produced by the PeWEC farm is more prominent and more complex with respect to the single device. The inclusion of the PTO contributes to further attenuate the wave field in the lee of the PeWEC farm.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128517728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the survivability of WECs through submergence and passive controllers","authors":"Elie Al Shami, Alexandre Frederic Julien Pichard, Mathieu Cocho, Miguel Santos Herran, Ian Gough","doi":"10.36688/ewtec-2023-298","DOIUrl":"https://doi.org/10.36688/ewtec-2023-298","url":null,"abstract":"The survivability of WECs during extreme seas and heavy storms has proven to be challenging during the deployment of devices as they often fail during extreme storms. The survival mechanism is often inherited with the device design and mode of operation. It is not economically and logistically viable for devices to be taken back onshore in case of storms. Some devices lock their PTOs during heavy storms and others lock all the moving parts all together, in the case of CETO, its design has an advantage where it can be submergepad. CETO is a buoyant actuator WEC composed of a buoy submerged close to the surface. Three tethers connect CETO to the sea-bottom through rotary PTOs, allowing the device to be wound down, submerged, and therefore, less exposed to the extreme loads at the sea surface during large storms. This paper will study the survivability of the device during extreme sea-states and will examine the required depth to bring its response back to operational conditions. This work will also look at the alteration of some passive controllers, such as a conventional spring to minimize the response of the device instead of maximising the power capture. With the PTO objective altered in extreme sea-states to minimize the response instead of capturing power, the possibility of harvesting power during extreme sea-states with the device submerged will be checked. Finally, the survivability strategy of CETO through submergence will be showcased with wave tank experiments conducted at IHC as part of the Europewave program.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121364873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards increased social acceptability of marine renewable energy","authors":"N. Dunphy, B. Lennon, A. L. Smith, M. Uyarra, Janete Gonçalves, Thomas Soulard, L. Zubiate","doi":"10.36688/ewtec-2023-351","DOIUrl":"https://doi.org/10.36688/ewtec-2023-351","url":null,"abstract":"The development and deployment of novel technologies, including those associated with marine renewable energy, are vital for the ongoing decarbonisation of our energy system. However, technology on its own is not sufficient to realise the energy transition away from fossil fuels. Non-technical barriers – such as regulatory, economic, environmental or social aspects – can be a substantial impediment to widespread adoption of renewable energy technologies. One such impediment, is public opposition to specific deployments of renewable energy and/or indeed to the use of particular technologies. Within the SafeWAVE project, we are cognisant of the importance of good community relations and the need to develop two-way communication with stakeholders to facilitate the successful scaling up of ocean energy device deployments. Accordingly we have worked to co-develop and demonstrate a framework for education and public engagement (EPE), specifically aimed at ocean literacy for communities in France, Ireland, Portugal and Spain. This EPE framework aims to go beyond social acceptance, which is often equated to acquiescence to a fait accompli, and is designed to contribute to the development of projects which exhibit inherent social acceptability. \u0000This paper presents the work within SafeWAVE project to develop the EPE framework with input from the communities. The first part of the paper reports on critical review of selected EPE programmes associated with marine energy test sites and infrastructure deployments, with methods adopted in each case analysed, key challenges faced identified, and best practices documented.  Next a framework for public education and engagement is presented, which builds on this review and draws from literature across multiple disciplines – including sociology, psychology, political science, education.  Finally, leveraging this developed knowledge the collaborative process of deriving tailored EPE programmes on ocean literacy around marine renewables for the four focal communities is outlined and described. These programmes are intended to reach out to, and engage with, local communities, interested stakeholders and the wider public on issues surrounding the deployment of ocean energy devices, including but not limited to: effects on local communities, implications for marine life, potential impacts for water users, etc. \u0000The paper concludes by discussing the experience of developing the bespoke programmes, outlining emergent feedback from trialling of key elements of the programmes, discussing experiences and proffering guidance based on lessons learned.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126553267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurements of the wake from a floating tidal energy platform","authors":"Maricarmen Guerra París, Alex E Hay, Benjamin Troncoso","doi":"10.36688/ewtec-2023-284","DOIUrl":"https://doi.org/10.36688/ewtec-2023-284","url":null,"abstract":"Wake measurements are critical for quantifying the hydrodynamic impacts of turbine presence and tidal energy extraction on the tidal flow. Turbine wakes are typically assessed using numerical models and controlled laboratory experiments, with only a few field studies available for the wakes of full-scale operating tidal turbines.\u0000 \u0000In this investigation we present field observations of the combined wake generated by the four-turbine array mounted onboard Sustainable Marine Energy Canada PLAT-I 4.63. Measurements were conducted downstream of the platform in Grand Passage, a tidal channel in the southwest of the Bay of Fundy in eastern Canada in October 2020. Velocity data were obtained by a suite of mobile Acoustic Doppler Current Profilers (ADCP), both vessel-mounted and free-drifting. Data were collected during ebb and flood tides (and therefore with time-varying inflow velocity), and under different turbine operating conditions. The collected data were organized according to the turbine inflow velocity for ebb and flood tide. For each tide, the wake and undisturbed flow regions to the sides of the wake were identified. Vertical profiles of velocity in the wake were compared to inflow velocity measured by a current-meter onboard PLAT-I and with measurements in the undisturbed flow to the sides of PLAT-I wake.\u0000 \u0000In all measurements the PLAT-I wake manifests as a reduction in flow speed at the depths spanned by the turbine rotors. The reduction is maximum near the platform for both ebb and flood. For flood, velocity profiles vertically mix less than 5 effective diameters downstream of the array, but velocities remain slower compared to the flow outside of the wake. Flow speed increases downstream, recovering approximately about 20 effective diameters from the platform. For ebb, the velocity reduction persists farther downstream compared to flood, there is less vertical mixing, and the wake shape is still present beyond 10 effective diameters downstream of the platform. Increased turbulence is also observed downstream of the platform, which recovers to levels similar to those of the surrounding undisturbed flow about 10 effective diameters downstream of the turbine for both ebb and flood. Comparisons of results between the two measurements approaches, and between the wake of clean and bio-fouled turbines are also explored.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127099856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectral control co-design of wave energy converter array layout","authors":"Y. Peña-Sanchez, Demián García-Violini, M. Penalba, Ander Zarketa, Vincenzo Nava, John V. Ringwood","doi":"10.36688/ewtec-2023-531","DOIUrl":"https://doi.org/10.36688/ewtec-2023-531","url":null,"abstract":"Wave energy systems are designed to maximise energy absorption from the oscillatory motion of waves, which can make a crucial contribution in a new carbon free generation matrix [1]. Thus, the global ocean energy market (including wave and tidal) is expected to grow by more than 700% by 2028 [2]. However, the harsh conditions faced in the ocean, the strong variability of the resource, and the high force/velocity ratios pose significant challenges to the development of the different ocean energy technologies. Therefore, to date, wave energy converter (WEC) technology is still under development and still needs a significant progress to enhance the energy conversion efficiency and, consequently, to become commercial viable. Crucially, to meet these existing challenges, there are a number of key considerations to progress the effectiveness and efficiency of WEC technologies. In particular, energy maximising control systems, to maximise energy absorption, and the optimisation of WEC array schemes, to take advantage of constructive interaction effects, are currently considered as some of the key drivers for the development of efficient WECs [1].\u0000Recent studies have shown that total design of WECs, analysing the impact of each individual component on the rest of the system, is a key methodology to achieve effective designs. For example, the levelised cost of energy (LCoE) is considered in the objective function in [3], analysing the interplay between the control system based on a spectral controller and the specifications of the power take-off (PTO) system defined as the maximum stroke and force. This methodology has been generally labelled as `co-design', or, when the development is carried out in a control-aware manner, `control co-design'. Similarly, in [4], the interaction between control and optimal WEC geometry is studied. In addition, as discussed before, another key driver in achieving effective wave energy system is the operation of WEC arrays. In particular, in [5] and [6] different array layouts are analysed in terms of computational efficiency and control, respectively.\u0000Considering the results in [5], where methods based on harmonic balance techniques are used to analyse the computational demand related to different array layouts, an assessment of the impact of different array layouts on the LCoE, is performed in this study. Figure 1 illustrates different array layouts (a), and the impact of different separation and number of WECs on the resulting LCoE (b). (Figure in PDF abstract)For the implementation of this study, a spectral control methodology is considered to virtually achieve optimal control solutions, even in constrained scenarios. In tandem, different layout templates, composed of multiple point absorber WECs, are considered. To achieve a clear global indicator based on the LCoE, each layout is analysed, in terms of the separation distance and the number of WECs, as well as capital and operation expenditure (CapEx and OpEx, respecti","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"13 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127395853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Filtering device for improving the quality of cooling water in turbine generator of Sihwa Tidal Power Plant","authors":"Taekyun Kim, H. Kwak, Jee Hun Bang, Mosol Kim, Beom sug Kim","doi":"10.36688/ewtec-2023-542","DOIUrl":"https://doi.org/10.36688/ewtec-2023-542","url":null,"abstract":"The turbine generator cooling water system of Sihwa Tidal Power Plant is an economical system in which the cooling water cools the turbine generator through a circulation pump and the rising temperature recirculates heat exchange with seawater through a surface cooler\u0000However, as the cooling water facility continues to operate and a long period of time passes, the cooling water quality in the piping deteriorates.\u0000In particular, increasing the concentration of Fe ions in the coolant may promote corrosion of circulating pipes, which may reduce the stability of the water turbine generator operation.\u0000Even if the coolant whose water quality has deteriorated is replaced, additional cleaning agents must be treated, but chemical treatment was difficult due to concerns over pipe damage.\u0000To overcome this, a filtering device for improving the water quality of cooling water was applied.\u0000Through the application of filtering devices for about a month, the water quality was improved by reducing the concentration of cooling water Fe ions by about 70%, and the facility maintenance cost was reduced by about $110,000 per year.\u0000We can greatly contribute to maintaining the economical cooling water system and securing the operational stability of water turbine generators by applying the cooling water filter.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127499320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Validation of the energy resource assessment with experimental data for the site selection of a tidal turbine in the Tagus River estuary.","authors":"Bénédicte Hoofd, Tiago Gomes, Ligia Pinto, Guilherme Vaz, Ramiro Neves, Antonio Botelho, Catarina Freitas","doi":"10.36688/ewtec-2023-258","DOIUrl":"https://doi.org/10.36688/ewtec-2023-258","url":null,"abstract":"Lisbon, the capital of Portugal, is located on the mouth of the Tagus River, where the current speed and direction are mainly governed by the local tides. The narrowest part of the river is located between Lisbon downtown and the western side of the city. This narrowing accelerates the water flow and makes it a potential site for a tidal energy system. A preliminary study based on numerical simulations using the software MOHID was conducted to assess potential energy yields throughout the estuary using freely available hindcast data. This allowed the selection of three potential sites for a tidal turbine in the Lisbon area based on yearly tidal and current energy density: off the coasts of Cacilhas, Bel´em, and Pa¸co de Arcos. However, even if the current model has been previously validated with experimental data, it was only done at two locations in the estuary that are far from the potential sites. Due to the complexity of the phenomena driving the current speed at these locations, additional validation is necessary before committing to a specific site. This paper presents the numerical analysis, the experimental campaign and the validation of the results at those three locations. Drifters with sails of 3.4m and 4.5m depth were released at least 8 times at each location and retrieved after 15 minutes of free drift. Each drifter was tracked with a GPS and the current speed and direction were derived from the drifters’ trajectory. The analysis of the experimental data shows good agreement with the model, even though an error of 0.3m/s is consistent throughout the tests. This paper concludes with a discussion on the model temporal and spatial discretisation and the forces included in the analysis that could be the source of the differences between the numerical and experimental data.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129035969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental validation of rollout-based model predictive control for wave energy converters on a two-body, taut-moored point absorber prototype","authors":"Zechuan Lin, Xuanrui Huang, Xi Xiao","doi":"10.36688/ewtec-2023-174","DOIUrl":"https://doi.org/10.36688/ewtec-2023-174","url":null,"abstract":"Model predictive control (MPC) has proven its effectiveness in improving the energy capture efficiency of wave energy converters (WECs) under physical constraints. Further application of MPC requires to speed up its online computation for an industrial controller. To this end, the rollout-based MPC (RMPC) for WECs has been developed. The idea of rollout is to decouple the optimization horizon and the prediction horizon, so as to achieve long-horizon performance with short-horizon optimization. In this paper, the RMPC that has previously only been validated by simulation is further put through wave tank testing. The experimental device is a realistic two-body, taut-moored point absorber prototype. The RMPC is based on a simplified model of the device and implemented in real time with wave force estimation and prediction. Experiment results confirm RMPC’s energy efficiency as well as constraint satisfaction, so its computational advantage against conventional MPC is highlighted.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129173973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new type of wave tank: prototype and proof of concept","authors":"Joannès Berque, I`ñigo Zarate, J. Blanco, Iñigo Bidaguren, I. Touzon, Luisa Fernández","doi":"10.36688/ewtec-2023-276","DOIUrl":"https://doi.org/10.36688/ewtec-2023-276","url":null,"abstract":"The prototype and proof of concept of a new type of wave tank are described. If successful, this innovation would enable many wave tank experiments for only a few percent of current costs. Tank testing remains indispensable for new designs, and its high cost is a significant inhibitor of offshore innovation. To date, all wave tanks generate and propagate scaled but real water waves towards a physical model. This new type of tank instead reproduces the velocity field that such waves would have, but only near the model. In practice, this can be approximately achieved only for cases where the marine structure is much shorter than the wavelength, and its draft shallow compared to the wavelength and depth. In such cases the wavefield is time-varying but approximately spatially uniform near the structure. Therefore, it can be reproduced by moving a container of water like wave orbitals; and ensuring slosh modes are minimised. A prototype was built, and after initial challenges in controlling slosh excitation, a proof of concept was successfully achieved: a cylinder was excited by surge oscillations and its response appears consistent with rough calculations. Range of potential applications of the new type of wave tank, lessons learnt by prototyping, and next developments are discussed. ","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127162900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Internal waves","authors":"K. Raghukumar, Craig Jones, Grace Chang, Jesse Roberts","doi":"10.36688/ewtec-2023-159","DOIUrl":"https://doi.org/10.36688/ewtec-2023-159","url":null,"abstract":"Internal waves are ubiquitous oceanographic features that occur in various forms across the world’s oceans. They manifest themselves as interface waves across ocean density layers that represent the interplay between buoyancy and gravitational forces, and are typically classified as linear and nonlinear internal waves. Nonlinear internal waves are characterized by isopycnal displacements that can exceed 30 m, and current velocities that approach 1 m/s. Internal wave energy converters, if developed, could have the advantage of no surface expression and provide for the availability of renewable ocean energy in regions of scant surface wave energy resources. \u0000Here, internal wave energies were computed at two locations: the New Jersey continental shelf and the coast of Central California. The available energy resource calculated for internal waves was then compared against surface gravity wave resources at each of these locations. Results suggest that the internal wave energy flux is comparable to that of surface waves on the New Jersey continental shelf during the summer of 2006 but is two orders of magnitude lower than that of surface waves in Central California during the summer of 2017. When expressed in terms of forces on a cylindrical structure, internal wave forces are an order of magnitude lower than that of surface waves on identically sized cylinders. However, the forces of the two resources are comparable when the diameter of the cylinder is doubled for the internal wave calculations. This suggests that while a larger energy converter would be required to harness internal wave energy, the larger size could be a reasonable tradeoff for advantages such as the lack of surface expression and the availability of energy in regions of limited surface wave energy resources. \u0000These results could potentially pave the way for longer-time scale characterization of internal waves and the development of devices to harness this energy resource (thereby powering the Blue Economy), while augmenting the portfolio of marine renewable energy resources. Further, the dominance of internal wave energy resources during summer seasons when the water column is stratified can augment the surface wave energy resource that can be diminished during the summer season.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131417642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}