• Energy Research

Abstract CECO is a recently proposed Wave Energy Converter (WEC), which harnesses both the kinetic and potential energy of waves. Currently, CECO is at the third level of technology readiness (TRL3). In this context, maximising the wave energy absorption under a wide range of wave conditions is crucial for the future development of the device. Therefore, this work aims to explore in detail the main parameters (operating water depth and wave conditions) that influence CECO's performance in terms of Captured Energy ( C E ) and Captured Energy Efficiency ( C E E f f ). For this purpose, a panel-based model, which was calibrated from previous physical model tests was used to construct the CECO matrices of absorbed wave power at different operating water depths. The wave conditions of the Atlantic coast of the Iberian Peninsula (2005–2014), which were modelled using SWAN, were used as case study. Overall, CECO offers promising results for C E and C E E f f , reaching values up to 600 M W h and 45%, respectively. In addition, it was found that CECO's power absorption reaches its maximum for values of peak wave periods ( T p ) ranging from 10 to 13 s and the fact that the operating water depth does not impact significantly the performance of the device.

Abstract CECO is a recently proposed Wave Energy Converter (WEC), which harnesses both the kinetic and potential energy of waves. Currently, CECO is at the third level of technology readiness (TRL3). In this context, maximising the wave energy absorption under a wide range of wave conditions is crucial for the future development of the device. Therefore, this work aims to explore in detail the main parameters (operating water depth and wave conditions) that influence CECO's performance in terms of Captured Energy ( C E ) and Captured Energy Efficiency ( C E E f f ). For this purpose, a panel-based model, which was calibrated from previous physical model tests was used to construct the CECO matrices of absorbed wave power at different operating water depths. The wave conditions of the Atlantic coast of the Iberian Peninsula (2005–2014), which were modelled using SWAN, were used as case study. Overall, CECO offers promising results for C E and C E E f f , reaching values up to 600 M W h and 45%, respectively. In addition, it was found that CECO's power absorption reaches its maximum for values of peak wave periods ( T p ) ranging from 10 to 13 s and the fact that the operating water depth does not impact significantly the performance of the device.

This work was supported by the PORTOS project co-financed by the Interreg Atlantic Area Programme through the European Regional Development Fund [grant number EAPA_784/2018]. During this work, R. Claus was also supported by the “Programa Severo Ochoa de Ayudas para la investigaciónn y docencia”, a research fellowship programme financed by the Government of the Principality of Asturias (Spain) [grant number AYUD0029T01 Becas Severo-Ochoa AYUD0029T01

This work was supported by the PORTOS project co-financed by the Interreg Atlantic Area Programme through the European Regional Development Fund [grant number EAPA_784/2018]. During this work, R. Claus was also supported by the “Programa Severo Ochoa de Ayudas para la investigaciónn y docencia”, a research fellowship programme financed by the Government of the Principality of Asturias (Spain) [grant number AYUD0029T01 Becas Severo-Ochoa AYUD0029T01

CECO is a novel Wave Energy Converter (WEC) concept, which has shown promising results in previous studies. The present work focuses on assessing the performance of CECO for a 11-year horizon in relation to the characteristics of the wave climate (intra and inter-annual seasonal variations) by means of two performance indicators defined ad hoc: Captured Energy (CE) and Captured Energy Efficiency (CEEff). For this purpose, the CECO matrix of absorbed wave power was constructed for an operating water depth of 30 m using the panel-based model ANSYS®-AQWA™. The Atlantic coast of the Iberian Peninsula, which presents a highly seasonal and energetic wave climate, was used as case study. Overall, it was found that CECO is able to capture large amounts of wave energy, especially for milder wave conditions, with values of CEEff exceeding 40%. However, for harsher wave conditions the results of CEEff decrease considerably ranging from 10% to 20%, which may result from the current design of CECO. In this context, the results obtained offer some valuable insight into the future evolution of CECO with the purpose of addressing the limitations of the current design and to optimise its performance according to the wave conditions for specific locations.

CECO is a novel Wave Energy Converter (WEC) concept, which has shown promising results in previous studies. The present work focuses on assessing the performance of CECO for a 11-year horizon in relation to the characteristics of the wave climate (intra and inter-annual seasonal variations) by means of two performance indicators defined ad hoc: Captured Energy (CE) and Captured Energy Efficiency (CEEff). For this purpose, the CECO matrix of absorbed wave power was constructed for an operating water depth of 30 m using the panel-based model ANSYS®-AQWA™. The Atlantic coast of the Iberian Peninsula, which presents a highly seasonal and energetic wave climate, was used as case study. Overall, it was found that CECO is able to capture large amounts of wave energy, especially for milder wave conditions, with values of CEEff exceeding 40%. However, for harsher wave conditions the results of CEEff decrease considerably ranging from 10% to 20%, which may result from the current design of CECO. In this context, the results obtained offer some valuable insight into the future evolution of CECO with the purpose of addressing the limitations of the current design and to optimise its performance according to the wave conditions for specific locations.

To mitigate the effects of wind variability on power output, hybrid systems that combine offshore wind with other renewables are a promising option. In this work we explore the potential of combining offshore wind and solar power through a case study in Asturias (Spain)—a region where floating solutions are the only option for marine renewables due to the lack of shallow water areas, which renders bottom-fixed wind turbines inviable. Offshore wind and solar power resources and production are assessed based on high-resolution data and the technical specifications of commercial wind turbines and solar photovoltaic (PV) panels. Relative to a typical offshore wind farm, a combined offshore wind–solar farm is found to increase the capacity and the energy production per unit surface area by factors of ten and seven, respectively. In this manner, the utilization of the marine space is optimized. Moreover, the power output is significantly smoother. To quantify this benefit, a novel Power Smoothing (PS) index is introduced in this work. The PS index achieved by combining floating offshore wind and solar PV is found to be of up to 63%. Beyond the interest of hybrid systems in the case study, the advantages of combining floating wind and solar PV are extensible to other regions where marine renewable energies are being considered.

To mitigate the effects of wind variability on power output, hybrid systems that combine offshore wind with other renewables are a promising option. In this work we explore the potential of combining offshore wind and solar power through a case study in Asturias (Spain)—a region where floating solutions are the only option for marine renewables due to the lack of shallow water areas, which renders bottom-fixed wind turbines inviable. Offshore wind and solar power resources and production are assessed based on high-resolution data and the technical specifications of commercial wind turbines and solar photovoltaic (PV) panels. Relative to a typical offshore wind farm, a combined offshore wind–solar farm is found to increase the capacity and the energy production per unit surface area by factors of ten and seven, respectively. In this manner, the utilization of the marine space is optimized. Moreover, the power output is significantly smoother. To quantify this benefit, a novel Power Smoothing (PS) index is introduced in this work. The PS index achieved by combining floating offshore wind and solar PV is found to be of up to 63%. Beyond the interest of hybrid systems in the case study, the advantages of combining floating wind and solar PV are extensible to other regions where marine renewable energies are being considered.