Monopile-mounted wave energy converter for a hybrid wind-wave system

• Published in: Energy conversion and management 2019-11, Vol.199, p.111971, Article 111971
• Main Authors: Perez-Collazo, C., Pemberton, R., Greaves, D., Iglesias, G.
• Format: Article
• Language: English
• Subjects: Converters; Damping; Exploitation; Hybrid systems; Hybrid wind-wave; Incident waves; Marine energy; Marine resources; Offshore drilling rigs; Offshore energy sources; Offshore operations; Orifices; OWC; Physical modelling; Projects; Renewable energy; Scale models; Substructures; Turbines; Water circulation; Water column; Water depth; Wave energy; Wave energy, Offshore Wind; Wave power; Wind power; Wind turbines; Wind waves
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2019.111971

•A hybrid wind-wave energy converter for monopile substructures is developed.•A thorough experimental campaign is carried out using a 1:40 model.•The interaction of the hybrid energy converter with the wave field is characterised.•The influence of turbine damping and wave conditions on performance is assessed. Multipurpose platforms are innovative solutions to combine the sustainable exploitation of multiple marine resources. Among them, hybrid wind-wave systems stand out due to the multiple synergies between these two forms of marine renewable energy. The objective of this work is to develop a hybrid system for monopile substructures, which are currently the prevailing type of substructure for offshore wind turbines, and more specifically to focus on the wave energy converter sub-system, which consists in an oscillating water column. For this purpose, an in-depth experimental campaign was carried out using a 1:40 scale model of the wave energy converter sub-system and the monopile substructure, considering regular and irregular waves. Based on the experimental results the performance of the device and its interaction with the wave field were characterised – a fundamental step to fully understand the benefits and limitations of this hybrid wind-wave system, which sets the basis for its future development. Regarding the performance, the best efficiency was obtained with the turbine damping corresponding to a 0.5% orifice size, and two resonance peaks were identified (T = 9 and 6 s). As for the interaction of the hybrid system with the wave field, between 5% and 66% of the incident wave power is reflected and between 3% and 45%, transmitted. The wave period was found to be the parameter that most influenced wave run-up on the substructure. This characterisation of the behaviour of the hybrid system shows that it is indeed a promising option for further development.