Along with a market-competitive levelized cost of energy, a current energy converter technology strongly benefits from an extensive consideration of socioeconomic, environmental, and regulatory factors early in the design process. As part of a technology performance level assessment, a series of assessment questions and guidance are developed and presented to evaluate an early-stage current energy technology on holistic criteria considering the entire device lifecycle. The assessment represents an accumulation of industry and research experience to date and relies on regular updates to ensure alignment with industry best-practices, regulatory requirements, and up-to-date technical understanding. A cradle-to-grave (materials, manufacturing, installation and deployment, operations and maintenance, and end-of-life) assessment of capabilities and functional requirements % MA- currently calling functional requirements engineering specifications within the PBE team, not sure if we should start using "engineering specifications now and be consitent with our language considering the potential desal paper. If I'm interpretting this incorrectly pls ignore me.for tidal, river, and ocean current technologies has been completed. This work presents the evaluation questions and qualitative %(i.e., high, medium, and low)performance criteria for current energy converters deployed in tidal, ocean current, and/or river applications. Key considerations related to manufacturing and installation include supply chain robustness, manufacturability and related job creation in the end-user and/or adjacent communities, and the time-to-repayment of the embodied energy debt. During deployment and maintenance operations, the safety of the device and subsystems during disconnect or grid failure, the difficulty and frequency of offshore heavy-lift activities, the avoidance or mitigation of area-use conflicts, the sea-states and weather conditions that permit maintenance access, and the availability of contingency plans (should conditions change unexpectedly) are a portion of the considered assessment criteria. Results include the potential impact of early-stage design decisions on the socioeconomic, environmental, and regulatory performance of a technology that allows developers to increase the product value and probability of success, and minimize costly late-stage design iterations through early and broad consideration of factors affecting overall performance and acceptability.
{"title":"comprehensive assessment tool for low-TRL current energy converters","authors":"Dominic Forbush, Jonathan Colby, Nicole Mendoza","doi":"10.36688/ewtec-2023-388","DOIUrl":"https://doi.org/10.36688/ewtec-2023-388","url":null,"abstract":"Along with a market-competitive levelized cost of energy, a current energy converter technology strongly benefits from an extensive consideration of socioeconomic, environmental, and regulatory factors early in the design process. As part of a technology performance level assessment, a series of assessment questions and guidance are developed and presented to evaluate an early-stage current energy technology on holistic criteria considering the entire device lifecycle. The assessment represents an accumulation of industry and research experience to date and relies on regular updates to ensure alignment with industry best-practices, regulatory requirements, and up-to-date technical understanding. A cradle-to-grave (materials, manufacturing, installation and deployment, operations and maintenance, and end-of-life) assessment of capabilities and functional requirements % MA- currently calling functional requirements engineering specifications within the PBE team, not sure if we should start using \"engineering specifications now and be consitent with our language considering the potential desal paper. If I'm interpretting this incorrectly pls ignore me.for tidal, river, and ocean current technologies has been completed. This work presents the evaluation questions and qualitative %(i.e., high, medium, and low)performance criteria for current energy converters deployed in tidal, ocean current, and/or river applications. Key considerations related to manufacturing and installation include supply chain robustness, manufacturability and related job creation in the end-user and/or adjacent communities, and the time-to-repayment of the embodied energy debt. During deployment and maintenance operations, the safety of the device and subsystems during disconnect or grid failure, the difficulty and frequency of offshore heavy-lift activities, the avoidance or mitigation of area-use conflicts, the sea-states and weather conditions that permit maintenance access, and the availability of contingency plans (should conditions change unexpectedly) are a portion of the considered assessment criteria. Results include the potential impact of early-stage design decisions on the socioeconomic, environmental, and regulatory performance of a technology that allows developers to increase the product value and probability of success, and minimize costly late-stage design iterations through early and broad consideration of factors affecting overall performance and acceptability.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135817074","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}
Maria C. Uyarra, Iratxe Menchaca, Sarai Pouso, Laura Zubiate, Dorleta Marina, Enored Le Bourhis, Thomas Soulard, Sandrine Jamet, Niall Dunphy, Janete Gonçalves, Erica Cruz, Juan Bald
Despite the benefits of marine renewable energies (MRE) to the decarbonisation, public opposition has often been posed to MRE projects. This opposition is one of the reasons slowing down Europe´s energy transition towards clean energies. Aside from one wave energy production farm operating in Europe, other developments are still at pilot or prototype phases. In the context of European SAFEWAVE project (https://www.safewave-project.eu/), we aim to understand the causes that trigger opposition to wave energy projects and identify how communication could improve the perception and attitudes towards MRE projects. To achieve this aim, a systematic analysis of ongoing wave energy projects, scientific bibliography and social media has been carried out. Outputs of this research indicate that opposition to wave energy is rather limited and primarily posed by national and local communities, as well as NGOs. Opposition emerges after envisaging negative affection on i) economy (e.g., conflict with existing uses), ii) social aspects (e.g., local communities for which the benefits are unclear), and iii) the environment (e.g., uncertainty on environmental impacts). Despite much of the wave energy information available on the media is produced and communicated by scientists and engineers (which should be considered a reliable sources of information), most of the communicated content focus on the drivers, the technological developments and benefits. Limited information on potential impacts of wave energy projects is shared. The target audiences vary between channels; YouTube, Facebook and Google have a wider audience than Twitter, which seeks a more professional audience. A holistic communication approach, in which both expected benefits and impacts are communicated may reduce opposition and help society to become more marine energy-literate, allowing for informed decisions and responsible behaviours/attitudes. Availability of official documents, participatory approaches, and transparency are crucial for improving the perception of future wave energy projects.
{"title":"Wave energy communication and social opposition","authors":"Maria C. Uyarra, Iratxe Menchaca, Sarai Pouso, Laura Zubiate, Dorleta Marina, Enored Le Bourhis, Thomas Soulard, Sandrine Jamet, Niall Dunphy, Janete Gonçalves, Erica Cruz, Juan Bald","doi":"10.36688/ewtec-2023-436","DOIUrl":"https://doi.org/10.36688/ewtec-2023-436","url":null,"abstract":"Despite the benefits of marine renewable energies (MRE) to the decarbonisation, public opposition has often been posed to MRE projects. This opposition is one of the reasons slowing down Europe´s energy transition towards clean energies. Aside from one wave energy production farm operating in Europe, other developments are still at pilot or prototype phases. In the context of European SAFEWAVE project (https://www.safewave-project.eu/), we aim to understand the causes that trigger opposition to wave energy projects and identify how communication could improve the perception and attitudes towards MRE projects. To achieve this aim, a systematic analysis of ongoing wave energy projects, scientific bibliography and social media has been carried out. Outputs of this research indicate that opposition to wave energy is rather limited and primarily posed by national and local communities, as well as NGOs. Opposition emerges after envisaging negative affection on i) economy (e.g., conflict with existing uses), ii) social aspects (e.g., local communities for which the benefits are unclear), and iii) the environment (e.g., uncertainty on environmental impacts). Despite much of the wave energy information available on the media is produced and communicated by scientists and engineers (which should be considered a reliable sources of information), most of the communicated content focus on the drivers, the technological developments and benefits. Limited information on potential impacts of wave energy projects is shared. The target audiences vary between channels; YouTube, Facebook and Google have a wider audience than Twitter, which seeks a more professional audience. A holistic communication approach, in which both expected benefits and impacts are communicated may reduce opposition and help society to become more marine energy-literate, allowing for informed decisions and responsible behaviours/attitudes. Availability of official documents, participatory approaches, and transparency are crucial for improving the perception of future wave energy projects.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135817511","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}
A major challenge of ocean wave energy converter (WEC) development is to test in the actual ocean. In this article, how a point absorber (PA) WEC was developed and tested during the mid of November 2022 in the ocean is reported. The WEC named Sindhuja-1 was developed from concept, numerical modelling, and laboratory testing. The test site was the VOC Port in Tuticorin, India. The WEC consisted of a buoy, a spar, and a power take-off mechanism. The buoy diameter was 0.75m and the spar length was 10m. The whole design was done at IIT Madras and preliminary tests were done at the wave basin at IIT Madras. The system was transported to the site and a preliminary test was conducted at the harbour area where the water is calm and has a depth of more than 10m. The purpose of the tests was to check any leakage, buoyance, and stability. After that, a hired fishing boat dragged the system over the ocean surface to a location where 20m water dept is there. The distance from the coast was 6km, and wave heights of approximately 0.5-0.8 meters. For the sea trial design, electronic items were insulated, and a cylindrical cover was also put over the electrical components to avoid water splashes or rain. It was found that the system worked vertically, and the system produced a power of about 100W. The paper will explain the challenges faced during the planning and execution of the system.
{"title":"Open Sea Trial of a Wave-Energy Converter at Tuticorin Port – Challenges","authors":"Abdus Samad, Prashant Kumar, Suman Kumar, Devesh Singh, Saket Kapse, Sohorab Hossain, TVS Kalyan Chakarvarthi, Akshoy Ranjan Paul, Abhijit Chaudhuri, Surajit Chattopadhaya, Sunkara Sai Arun Kiran Karthik","doi":"10.36688/ewtec-2023-484","DOIUrl":"https://doi.org/10.36688/ewtec-2023-484","url":null,"abstract":"A major challenge of ocean wave energy converter (WEC) development is to test in the actual ocean. In this article, how a point absorber (PA) WEC was developed and tested during the mid of November 2022 in the ocean is reported. The WEC named Sindhuja-1 was developed from concept, numerical modelling, and laboratory testing. The test site was the VOC Port in Tuticorin, India. The WEC consisted of a buoy, a spar, and a power take-off mechanism. The buoy diameter was 0.75m and the spar length was 10m. The whole design was done at IIT Madras and preliminary tests were done at the wave basin at IIT Madras. The system was transported to the site and a preliminary test was conducted at the harbour area where the water is calm and has a depth of more than 10m. The purpose of the tests was to check any leakage, buoyance, and stability. After that, a hired fishing boat dragged the system over the ocean surface to a location where 20m water dept is there. The distance from the coast was 6km, and wave heights of approximately 0.5-0.8 meters. For the sea trial design, electronic items were insulated, and a cylindrical cover was also put over the electrical components to avoid water splashes or rain. It was found that the system worked vertically, and the system produced a power of about 100W. The paper will explain the challenges faced during the planning and execution of the system.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135817002","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}
Molly Grear, Ali Trueworthy, Aeron Roach, Hannah Mankle
As we pursue more justice and community driven renewable energy projects, more decision making is put in the hands of community leaders. Appropriate tools and resources are necessary for communities to determine what wave energy developer might fit their community needs and wave resource. While there are methods and tools for communities, researchers and wave energy developers to determine the wave resource or potential locations for wave energy development, we are lacking a tool to help communities take the next steps in pursuing wave energy.
A community driven design process was undertaken in Sitka, AK, in conjunction with evaluating the local area for wave energy resource. The community had interest in wave energy development, a decent wave resource area accessible, and existing maritime expertise that could aid in operations and maintenance. Further, as a remote island, the community viewed alternative energy development positively as a way to achieve more energy independence. Still, in this community driven process, we identified a gap that while the community may be interested in a wave energy project, there was little data on which wave energy devices would be appropriate for the community and few tools to help them choose.
This presentation will highlight questions that the participants from Sitka, AK still have after engaging in a community centered design process. We compare the requirements that the community prioritizes with the tools that researchers and developers have to evaluate those requirements, allowing assessment of whether these tools are useable and adequate for community use. We also show an analysis of a selection of current wave energy developers with some of the community focused factors and proposals for tools that may be useful in future community energy development. This research ultimately highlights what factors must be presented to a community for them to choose to pursue installation of a device.
{"title":"Choosing wave energy devices for community-led marine energy development","authors":"Molly Grear, Ali Trueworthy, Aeron Roach, Hannah Mankle","doi":"10.36688/ewtec-2023-385","DOIUrl":"https://doi.org/10.36688/ewtec-2023-385","url":null,"abstract":"As we pursue more justice and community driven renewable energy projects, more decision making is put in the hands of community leaders. Appropriate tools and resources are necessary for communities to determine what wave energy developer might fit their community needs and wave resource. While there are methods and tools for communities, researchers and wave energy developers to determine the wave resource or potential locations for wave energy development, we are lacking a tool to help communities take the next steps in pursuing wave energy.
 A community driven design process was undertaken in Sitka, AK, in conjunction with evaluating the local area for wave energy resource. The community had interest in wave energy development, a decent wave resource area accessible, and existing maritime expertise that could aid in operations and maintenance. Further, as a remote island, the community viewed alternative energy development positively as a way to achieve more energy independence. Still, in this community driven process, we identified a gap that while the community may be interested in a wave energy project, there was little data on which wave energy devices would be appropriate for the community and few tools to help them choose.
 This presentation will highlight questions that the participants from Sitka, AK still have after engaging in a community centered design process. We compare the requirements that the community prioritizes with the tools that researchers and developers have to evaluate those requirements, allowing assessment of whether these tools are useable and adequate for community use. We also show an analysis of a selection of current wave energy developers with some of the community focused factors and proposals for tools that may be useful in future community energy development. This research ultimately highlights what factors must be presented to a community for them to choose to pursue installation of a device.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135966399","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}
Göran Broström, Sam Fredriksson, Nimal Sudhan Saravana Prabahar
Tidal energy is considered to be one important future source of renewable energy. There is presently a strong development in new technology, and there is an emerging need to e.g., describe the turbulence intensity and its characteristics in a tidal stream. In this study we consider a high resolution Large Eddy Simulation (LES) in water with 80 m depth and a tidal stream with a maximum volume mean flow amplitude of 2 ms-1. the simulation is designed to describe turbulence characteristics at a developer site outside Holyhead in the Irish Sea. We find that the turbulence intensity and characteristics has clear time dependence, and that it is 100% stronger on the retarding tidal current as compared to the accelerating tidal current. We also find that it depends on the distance from the bottom. The turbulence is highly anisotropic with much longer length scales in the flow directions than perpendicular to flow direction. The simulation setup and results for mean flow quantities and turbulence measures are discussed in the presentation. Finally, results are compared with results from a ship mounted ADCP for mean flow characteristics and for turbulence quantities.
{"title":"Tidal turbulence in medium depth water, primarily a model study","authors":"Göran Broström, Sam Fredriksson, Nimal Sudhan Saravana Prabahar","doi":"10.36688/ewtec-2023-566","DOIUrl":"https://doi.org/10.36688/ewtec-2023-566","url":null,"abstract":"Tidal energy is considered to be one important future source of renewable energy. There is presently a strong development in new technology, and there is an emerging need to e.g., describe the turbulence intensity and its characteristics in a tidal stream. In this study we consider a high resolution Large Eddy Simulation (LES) in water with 80 m depth and a tidal stream with a maximum volume mean flow amplitude of 2 ms-1. the simulation is designed to describe turbulence characteristics at a developer site outside Holyhead in the Irish Sea. We find that the turbulence intensity and characteristics has clear time dependence, and that it is 100% stronger on the retarding tidal current as compared to the accelerating tidal current. We also find that it depends on the distance from the bottom. The turbulence is highly anisotropic with much longer length scales in the flow directions than perpendicular to flow direction. The simulation setup and results for mean flow quantities and turbulence measures are discussed in the presentation. Finally, results are compared with results from a ship mounted ADCP for mean flow characteristics and for turbulence quantities.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135966579","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}
An analysis of oscillating water columns (OWC) at the Mutriku Wave Power Plant to understand their efficiency in transforming ocean energy into electricity. The study aims to estimate the rate of convergence of wave energy flux to kilowatts hour of each OWC and determine whether it is more accurate to estimate for each OWC independently or as part of a system of equations. The dataset includes electricity production data from 7 turbines in the MWPP during 2019, along with ocean measurements such as significant wave height, wave period, wave energy flux, swell direction, and wind direction. All models in the paper have varying coefficients which change with the significant wave height. The methodology includes the use of generalized least squares and local polynomial kernel methodologies for coefficient estimation.
{"title":"Analysis of Mutriku's OWC performance","authors":"Isabel Casas, Jon Lekube","doi":"10.36688/ewtec-2023-138","DOIUrl":"https://doi.org/10.36688/ewtec-2023-138","url":null,"abstract":"An analysis of oscillating water columns (OWC) at the Mutriku Wave Power Plant to understand their efficiency in transforming ocean energy into electricity. The study aims to estimate the rate of convergence of wave energy flux to kilowatts hour of each OWC and determine whether it is more accurate to estimate for each OWC independently or as part of a system of equations. The dataset includes electricity production data from 7 turbines in the MWPP during 2019, along with ocean measurements such as significant wave height, wave period, wave energy flux, swell direction, and wind direction. All models in the paper have varying coefficients which change with the significant wave height. The methodology includes the use of generalized least squares and local polynomial kernel methodologies for coefficient estimation.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"128 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135011291","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}
Wave energy converters typically use various control methods to extract energy from ocean waves. The objective of the control system is to optimize the energy extraction process, taking into account the dynamics of the system and the wave conditions. The task of deriving the optimal control laws of wave energy converter arrays for regular and irregular waves using the Pontryagin minimum principle was previously investigated in the literature. The result is a combination between the singular arc and bang-bang control laws. For irregular waves, some complexity arises due to the radiation state-space representation, which requires ignoring the hydrodynamic coupling terms related to the added mass and radiation-damping coefficients; this reduces the computational complexity of the control force but adversely affects the solution's accuracy. Also, the derived control laws are specific to a particular wave condition. Recently, the optimal control of a flexible buoy wave energy converter was derived using the convolution representation for the radiation force. In this work, the optimal control laws of flexible buoy wave energy converters are modified to simulate wave energy converter arrays; then, the results are compared to those obtained by dropping the hydrodynamic radiation coupling terms. Although using a convolution representation adds computational complexity to the optimal control problem, it generates an equation that is generic to any wave condition, can be used with any wave spectrum, and provides an expression for the switching condition.
{"title":"A time domain approach for the optimal control of wave energy converter arrays","authors":"Mohamed Shabara, Ossama Abdelkhalik","doi":"10.36688/ewtec-2023-472","DOIUrl":"https://doi.org/10.36688/ewtec-2023-472","url":null,"abstract":"Wave energy converters typically use various control methods to extract energy from ocean waves. The objective of the control system is to optimize the energy extraction process, taking into account the dynamics of the system and the wave conditions. The task of deriving the optimal control laws of wave energy converter arrays for regular and irregular waves using the Pontryagin minimum principle was previously investigated in the literature. The result is a combination between the singular arc and bang-bang control laws. For irregular waves, some complexity arises due to the radiation state-space representation, which requires ignoring the hydrodynamic coupling terms related to the added mass and radiation-damping coefficients; this reduces the computational complexity of the control force but adversely affects the solution's accuracy. Also, the derived control laws are specific to a particular wave condition. Recently, the optimal control of a flexible buoy wave energy converter was derived using the convolution representation for the radiation force. In this work, the optimal control laws of flexible buoy wave energy converters are modified to simulate wave energy converter arrays; then, the results are compared to those obtained by dropping the hydrodynamic radiation coupling terms. Although using a convolution representation adds computational complexity to the optimal control problem, it generates an equation that is generic to any wave condition, can be used with any wave spectrum, and provides an expression for the switching condition.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135014156","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}
The power take-off (PTO) system is a core component in WECs as it plays a critical role in power production. In numerical models the PTO systems are commonly represented and simplified through a combination of linear stiffness and damping terms in the equations of motion. These parameters are influential to the dynamic response and thus affect the power performance of WECs. In the preliminary design and optimization of WECs, proper tuning of the PTO damping and stiffness could reflect better the potential of the concept. In practice, the PTO damping and stiffness are tuned to maximize the absorbed power by achieving the desired velocity amplitude or phase of the velocity with respect to the excitation force. However, recent literature has indicated that the selection of PTO parameters for maximum mechanical power absorption is not necessarily optimal for the maximum production of electrical power when the conversion efficiency of the electrical machine is included. To obtain these parameters which maximize the delivered electrical power, wave-to-wire models are widely used. Nevertheless, wave-to-wire models are predominately established by using time-domain models which can be associated with large computational efforts from the perspective of early-stage design and concept evaluation. To tackle this challenge, a spectral-domain-based wave-to-wire model is proposed to cover both hydrodynamic and electrical responses. In this paper, a spherical heaving point absorber integrated with a linear permanent-magnet generator is used as reference. The relevant nonlinear effects are incorporated by statistical linearization using spectral-domain modelling. In particular, the nonlinear effects considered in this work include the viscous drag force, the electrical current saturation and the partial overlap between the translator and stator components of the linear generator. The model results are then verified against a nonlinear time-domain-based wave-to-wire model. Subsequently, the proposed model is applied to identify the PTO parameters for maximizing the electrical power in various wave states. The computational efficiency and accuracy of the proposed spectral-domain model are compared with the time-domain model, with regard to the identification of the proper PTO damping and stiffness. Based on the results, the advantage of using the spectral-domain-based wave-to-wire modeling in PTO tuning is demonstrated.
{"title":"Spectral-Domain Modelling of Wave Energy Converters as an Efficient Tool for Adjustment of PTO Model Parameters","authors":"Jian Tan, Antonio Jarquin Laguna","doi":"10.36688/ewtec-2023-278","DOIUrl":"https://doi.org/10.36688/ewtec-2023-278","url":null,"abstract":"The power take-off (PTO) system is a core component in WECs as it plays a critical role in power production. In numerical models the PTO systems are commonly represented and simplified through a combination of linear stiffness and damping terms in the equations of motion. These parameters are influential to the dynamic response and thus affect the power performance of WECs. In the preliminary design and optimization of WECs, proper tuning of the PTO damping and stiffness could reflect better the potential of the concept. In practice, the PTO damping and stiffness are tuned to maximize the absorbed power by achieving the desired velocity amplitude or phase of the velocity with respect to the excitation force. However, recent literature has indicated that the selection of PTO parameters for maximum mechanical power absorption is not necessarily optimal for the maximum production of electrical power when the conversion efficiency of the electrical machine is included. To obtain these parameters which maximize the delivered electrical power, wave-to-wire models are widely used. Nevertheless, wave-to-wire models are predominately established by using time-domain models which can be associated with large computational efforts from the perspective of early-stage design and concept evaluation. To tackle this challenge, a spectral-domain-based wave-to-wire model is proposed to cover both hydrodynamic and electrical responses. In this paper, a spherical heaving point absorber integrated with a linear permanent-magnet generator is used as reference. The relevant nonlinear effects are incorporated by statistical linearization using spectral-domain modelling. In particular, the nonlinear effects considered in this work include the viscous drag force, the electrical current saturation and the partial overlap between the translator and stator components of the linear generator. The model results are then verified against a nonlinear time-domain-based wave-to-wire model. Subsequently, the proposed model is applied to identify the PTO parameters for maximizing the electrical power in various wave states. The computational efficiency and accuracy of the proposed spectral-domain model are compared with the time-domain model, with regard to the identification of the proper PTO damping and stiffness. Based on the results, the advantage of using the spectral-domain-based wave-to-wire modeling in PTO tuning is demonstrated.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135061002","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}
Rónán Gallagher, Carwyn Frost, Pál Schmitt, Charles Young
This paper presents a three-dimensional numerical study employing an actuator line model to investigate the effect of turbine solidity on the performance of a Transverse Axis Crossflow Turbine (TACTs). Transverse Axis Crossflow Turbines have a low rectangular form and are ideally suited to relatively shallow tidal and riverine sites due to their ability to handle bi-directional flow intake. Lift based TACTs are not well understood due to their complex hydrodynamics when the downstream sweep passes through the wake produced by the turbine shaft and the upstream sweep. The blade loading, hydrodynamics and ultimately power produced during the downstream sweep depends on the number of blades and turbine solidity. This numerical study is carried out using OpenFOAM and replicates planned fieldwork where the power and in-service blade loading will be monitored as a function of turbine solidity. Turbine solidity is a dimensionless parameter that measures the proportion of blade area to the projected turbine frontal area. Turbines achieve peak performance at an optimum solidity and tip speed ratio. Solidity can be varied by changing the number of blades or changing the turbine radius. An increase in solidity causes the peak performance to reduce and shift to a lower tip speed ratio albeit with a greater torque.
This paper also explores the effect that maintaining turbine solidity has on turbine performance over a range of typical inflow velocities. Turbine solidity is held constant by varying both the number of blades and turbine diameter. Iso-solidity has been investigated for horizontal axis wind turbines but little is known about the effect of maintaining turbine solidity on TACT performance.
{"title":"A Numerical study on the effect of solidity on the performance of Transverse Axis Crossflow Tidal Turbines","authors":"Rónán Gallagher, Carwyn Frost, Pál Schmitt, Charles Young","doi":"10.36688/ewtec-2023-273","DOIUrl":"https://doi.org/10.36688/ewtec-2023-273","url":null,"abstract":"This paper presents a three-dimensional numerical study employing an actuator line model to investigate the effect of turbine solidity on the performance of a Transverse Axis Crossflow Turbine (TACTs). Transverse Axis Crossflow Turbines have a low rectangular form and are ideally suited to relatively shallow tidal and riverine sites due to their ability to handle bi-directional flow intake. Lift based TACTs are not well understood due to their complex hydrodynamics when the downstream sweep passes through the wake produced by the turbine shaft and the upstream sweep. The blade loading, hydrodynamics and ultimately power produced during the downstream sweep depends on the number of blades and turbine solidity. This numerical study is carried out using OpenFOAM and replicates planned fieldwork where the power and in-service blade loading will be monitored as a function of turbine solidity. Turbine solidity is a dimensionless parameter that measures the proportion of blade area to the projected turbine frontal area. Turbines achieve peak performance at an optimum solidity and tip speed ratio. Solidity can be varied by changing the number of blades or changing the turbine radius. An increase in solidity causes the peak performance to reduce and shift to a lower tip speed ratio albeit with a greater torque.
 This paper also explores the effect that maintaining turbine solidity has on turbine performance over a range of typical inflow velocities. Turbine solidity is held constant by varying both the number of blades and turbine diameter. Iso-solidity has been investigated for horizontal axis wind turbines but little is known about the effect of maintaining turbine solidity on TACT performance.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135151262","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}
Bruno Paduano, Edoardo Pasta, Nicolas Faedo, Giuliana Mattiazzo
This study focuses on addressing the challenge of integrating the tangled mathematical model of the mooring system into an effective control synthesis. The presented synthesis framework utilises the impedance-matching technique to achieve the desired controller performance by adapting the control parameters to align with the dynamic characteristics of the moored wave energy device. By leveraging this technique, the simulation framework provides a means to effectively incorporate the intricate mooring dynamics into the control synthesis process. Furthermore, this paper aims to delve into the concept of defining a representative control action by examining the input-exciting force of the feedback-controlled system. Through a straightforward case study, the authors demonstrate the significant impact of the mooring on the system dynamics and underscore the applicability of the proposed simulation framework. Moreover, the paper verifies the importance of considering the controlled system’s exciting input when addressing control synthesis, particularly in panchromatic conditions.
{"title":"Control synthesis via Impedance-Matching in panchromatic conditions: a generalised framework for moored systems","authors":"Bruno Paduano, Edoardo Pasta, Nicolas Faedo, Giuliana Mattiazzo","doi":"10.36688/ewtec-2023-344","DOIUrl":"https://doi.org/10.36688/ewtec-2023-344","url":null,"abstract":"This study focuses on addressing the challenge of integrating the tangled mathematical model of the mooring system into an effective control synthesis. The presented synthesis framework utilises the impedance-matching technique to achieve the desired controller performance by adapting the control parameters to align with the dynamic characteristics of the moored wave energy device. By leveraging this technique, the simulation framework provides a means to effectively incorporate the intricate mooring dynamics into the control synthesis process. Furthermore, this paper aims to delve into the concept of defining a representative control action by examining the input-exciting force of the feedback-controlled system. Through a straightforward case study, the authors demonstrate the significant impact of the mooring on the system dynamics and underscore the applicability of the proposed simulation framework. Moreover, the paper verifies the importance of considering the controlled system’s exciting input when addressing control synthesis, particularly in panchromatic conditions.","PeriodicalId":201789,"journal":{"name":"Proceedings of the European Wave and Tidal Energy Conference","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135825569","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：