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Oscillatory wave energy converters of the sloped type may allow absorbing power from ocean waves efficiently if a valid optimal design is used. In earlier studies, the optimized geometry for the CECO device was defined by implementing a simplified frequency-domain model. In this paper, that geometry is evaluated against the former one by taking into consideration a more realistic modelling approach and assessment scenario. The two geometries were benchmarked through a time-domain model, which allows taking into account realistic sea states and the use of end-stops to limit the amplitude of CECO motions. It was concluded that the optimized geometry allows extra energy production for most of the irregular sea states evaluated (45% more annual energy production). Performance indices were also used to compare the two geometries and it was concluded that the optimized geometry was particularly advantageous for the more energetic sea states. Overall, this study clearly shows that the choice of the generator rated power and end-stops span length are key aspects in determining realistically the annual energy production of sloped-motion wave energy converters.

Oscillatory wave energy converters of the sloped type may allow absorbing power from ocean waves efficiently if a valid optimal design is used. In earlier studies, the optimized geometry for the CECO device was defined by implementing a simplified frequency-domain model. In this paper, that geometry is evaluated against the former one by taking into consideration a more realistic modelling approach and assessment scenario. The two geometries were benchmarked through a time-domain model, which allows taking into account realistic sea states and the use of end-stops to limit the amplitude of CECO motions. It was concluded that the optimized geometry allows extra energy production for most of the irregular sea states evaluated (45% more annual energy production). Performance indices were also used to compare the two geometries and it was concluded that the optimized geometry was particularly advantageous for the more energetic sea states. Overall, this study clearly shows that the choice of the generator rated power and end-stops span length are key aspects in determining realistically the annual energy production of sloped-motion wave energy converters.

This work reviews the advances in the development of CECO, a wave energy converter (WEC) of the floating oscillating bodies subgroup that has its motions and power take-off system (PTO) restricted to an inclined direction. For this purpose, the review is conducted on the basis of the Technology Readiness Levels (TRLs), the most frequently used metric to assess the maturity of a technology. The main conclusions and milestones of each stage are also presented along with an introduction to the ongoing works and a general picture of future research lines.

This work reviews the advances in the development of CECO, a wave energy converter (WEC) of the floating oscillating bodies subgroup that has its motions and power take-off system (PTO) restricted to an inclined direction. For this purpose, the review is conducted on the basis of the Technology Readiness Levels (TRLs), the most frequently used metric to assess the maturity of a technology. The main conclusions and milestones of each stage are also presented along with an introduction to the ongoing works and a general picture of future research lines.

CECO is a wave energy converter (WEC) of the oscillating body type equipped with an inclined PTO system and being developed at the Faculty of Engineering of the University of Porto. In the last years, several research studies have been performed to assess and to improve the performance of this WEC, using both physical model tests and numerical simulations. The main objective of this paper is reviewing the most significant findings of past research works, so as to provide a detailed overview about the present status of knowledge, but also presenting recent outcomes on the development of CECO and the next research steps. It discusses the influence of the PTO slope angle and damping on the efficiency of CECO harvesting wave energy and describes its energy conversion stages. Furthermore, the intra-annual variability of the wave resource (i.e., on a monthly basis) is considered in the analysis of the influence of the PTO inclination and local water depth at the deployment site on CECO captured energy and captured energy efficiency, along the North Atlantic coast of the Iberian Peninsula. The results have shown significant differences between the summer and winter months and also highlighted the fact that the initial geometry of this WEC is more suitable for the less energetic wave climates, characteristic of the southern locations of the case study area and of shallow waters. The conclusions obtained supported the design of an enhanced version of CECO, prepared for the more energetic stretches of the study area, which presents a hydrodynamic efficiency of more than twice the original one, for the target wave conditions.

CECO is a wave energy converter (WEC) of the oscillating body type equipped with an inclined PTO system and being developed at the Faculty of Engineering of the University of Porto. In the last years, several research studies have been performed to assess and to improve the performance of this WEC, using both physical model tests and numerical simulations. The main objective of this paper is reviewing the most significant findings of past research works, so as to provide a detailed overview about the present status of knowledge, but also presenting recent outcomes on the development of CECO and the next research steps. It discusses the influence of the PTO slope angle and damping on the efficiency of CECO harvesting wave energy and describes its energy conversion stages. Furthermore, the intra-annual variability of the wave resource (i.e., on a monthly basis) is considered in the analysis of the influence of the PTO inclination and local water depth at the deployment site on CECO captured energy and captured energy efficiency, along the North Atlantic coast of the Iberian Peninsula. The results have shown significant differences between the summer and winter months and also highlighted the fact that the initial geometry of this WEC is more suitable for the less energetic wave climates, characteristic of the southern locations of the case study area and of shallow waters. The conclusions obtained supported the design of an enhanced version of CECO, prepared for the more energetic stretches of the study area, which presents a hydrodynamic efficiency of more than twice the original one, for the target wave conditions.