Techno-Economic Optimisation for a Wave Energy Converter via Genetic Algorithm

Sergej Antonello Sirigu,Mauro Bonfanti,Giuliana Mattiazzo,Giovanni Bracco,Giulia Cervelli,Giuseppe Giorgi,Ludovico Foglietta

doi:10.3390/jmse8070482

Sergej Antonello Sirigu, Mauro Bonfanti + Show 5 more

Open Access

https://doi.org/10.3390/jmse8070482

Copy DOI

Abstract

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.

Highlights

Based on the gradual depletion of conventional fossil fuels, and most importantly, the established awareness of their destructive impact on the environment, recent years have witnessed a compelling momentum towards the energy transition and decarbonisation, shared by industry, governmental bodies and policy-makers
Considering a matrix composed of technology readiness level (TRL) and the technology performance level (TPL), deficient development pathways tend to increase TRL first, at low TPL; optimal trajectories should increase TPL first, at low TRL, and increase TRL towards commercialisation [3]
This paper proposes a comprehensive techno-economic optimisation of the PeWEC, which is a self-reacting wave energy converters (WECs) extracting energy from the oscillation of a pendulum sealed in a floating hull [28]

Summary

Introduction

Based on the gradual depletion of conventional fossil fuels, and most importantly, the established awareness of their destructive impact on the environment, recent years have witnessed a compelling momentum towards the energy transition and decarbonisation, shared by industry, governmental bodies and policy-makers. Considering a matrix composed of technology readiness level (TRL) and the technology performance level (TPL), deficient development pathways tend to increase TRL first, at low TPL; optimal trajectories should increase TPL first, at low TRL, and increase TRL towards commercialisation [3] Is it challenging to perform an accurate estimation of some performance aspects at low TRL, due to inherent limitations of small-scale devices and subsystems, techno-economic aspects should be taken into account. A representative example is the optimisation of the hydrodynamics and power absorption of an uncontrolled device, followed by a design of an optimal controller, followed by the inclusion of technical constraints and efficiency, reaching the stage of cost evaluation and reduction Such an incremental approach is justified by the complexity of the system, neglecting mutual interaction typically leads to a suboptimal solution

Objectives

Results

Conclusion