Advancing Wave Resource Assessment: The Mutriku OWC Case Study – MAR+ Project

In recent years, marine renewable energies have experienced significant progress, although the pace of development has been uneven across sectors. While floating offshore wind and tidal technologies have achieved commercial readiness, wave energy is still focused on technology validation efforts with a series of pilot demonstrator projects planned for the coming years all around the globe. Closing this gap will require the development of robust, validated design methodologies that combine fully-controlled laboratory tests and field measurements in order to both reduce technological risks, andalignment with market demands. IHCantabria and BiMEP (Biscay Marine Energy Platform) have collaborated for over a decade to provide specialized scientific and technical services in the field of marine renewable energies. One of the key areas of activity has been to coordinate efforts to integrate physical / numerical laboratory approaches with open-sea field testing across multiple demonstrator scales. In the framework of this collaboration, the Mutriku Wave Power Plant (MWPP) – commissioned in 2011, operated by BIMEP and which has delivered more than 3,2GWh of electricity to the grid - has been a key focus area of research activities. Building on this foundation, IHCantabria has reached an advanced methodology for multidirectional wave characterization and full-spectrum analysis in complex port environments (Romano et al., 2023). This innovative approach enables, for the first time in the state-of-the-art, a detailed assessment of wave energy resource, both within sheltered port areas (e.g., docks and berths) and in adjacent waters outside breakwaters. This distinction between exploitable and potential wave resources is crucial for a realistic and future techno-economic assessment and feasibility of wave energy plants, such as MWPP. Leveraging these advancements, and within the framework of the MAR+ project, this novel wave resource characterization methodology has been applied to the MWPP area. This methodology includes five interconnected steps: 1) spectral wave climate characterization in offshore waters using historical data; 2) wave downscaling toward coastal zones and in front port areas; 3) high-resolution and multidirectional spectral wave within sheltered port areas and adjacent environments; 4) statistical / historical wave energy resource assessment based on IEC 62600-101 standards; and 5) forecast system design for short-term prediction of wave conditions and energy potential, forced by oceanographic and meteorological deep water predictions. Preliminary results demonstrate the effectiveness of this approach in accurately characterizing wave resource within the MWPP area, providing a robust basis for design and optimization wave energy capture systems that could play a crucial role in the decarbonization of ports and coastal areas. The methodologies presented, while particularized to Mutriku area, are potentially relocatable to offer broader applicability to analogous and similar coastal and port environments. Furthermore, they complement ongoing research, including the integration of digital twin technologies, to advance the development and deployment of wave energy systems. This study will highlight the preliminary outcomes of these methodologies, underlining their potential to shape future advancements in marine renewable energy.