Although sea and ocean waves have been widely acknowledged to have the potential of providing sustainable and renewable energy, the emergence of a self-sufficient and mature industry is still lacking. An essential condition for reaching economic viability is to minimise the cost of electricity, as opposed to simply maximising the converted energy at the early design stages. One of the tools empowering developers to follow such a virtuous design pathway is the techno-economic optimisation. The purpose of this paper is to perform a holistic optimisation of the PeWEC (pendulum wave energy converter), which is a pitching platform converting energy from the oscillation of a pendulum contained in a sealed hull. Optimised parameters comprise shape; dimensions; mass properties and ballast; power take-off control torque and constraints; number and characteristics of the pendulum; and other subcomponents. Cost functions are included and the objective function is the ratio between the delivered power and the capital expenditure. Due to its ability to effectively deal with a large multi-dimensional design space, a genetic algorithm is implemented, with a specific modification to handle unfeasible design candidate and improve convergence. Results show that the device minimising the cost of energy and the one maximising the capture width ratio are substantially different, so the economically-oriented metric should be preferred.

The energy innovation scenario sees hybrid wind-wave platforms as a promising technology for reducing the variability of the power output and for the minimization of the cost of offshore marine renewable installations. This article presents a model that describes the installation of a 5 MW wind turbine on a floating platform designed by Fincantieri and equipped with gyroscopic stabilization. The use of gyros allows for the delivery of platform stabilization by damping the wave and wind induced motion on the floater and at the same time producing extra power. Shetland Island was chosen as the reference site because of its particularly harsh weather. Final results show that the total production of power in moderate and medium climate conditions is considerable thanks to the installation of the gyro, together with a significant stabilization of the platform in terms of pitching angle and nacelle acceleration.

The paper thoroughly examines the operational efficiency of two prototypical Wave Energy Converters – specifically, a flap and a point absorber. The analysis draws upon data gleaned from both the SWAN numerical model and the ECMWF ERA5 database. The research centers on the scrutiny and comparison of these two data sources, with a focal point on Pantelleria island as a case study. Additionally, the investigation delves into the productivity discrepancies of the wave energy converters by utilizing corresponding historical datasets. Through a meticulous comparison of sea state occurrences derived from SWAN and ERA5, the study uncovers disparities and discerns variations in the productivity estimates of the two Wave Energy Converters. This comparative assessment seeks to evaluate the appropriateness and efficacy of each data source in faithfully portraying the environmental conditions conducive to wave energy conversion. Moreover, the study posits broader applicability to the Blue Economy. The outcomes of this analysis contribute significantly to advancing comprehension regarding the interplay between data sources, sea state events, and the productivity of wave energy converters, all geared towards the overarching objective of minimizing uncertainties in design.