T2-3 | Ocean-based renewable energy such as offshore wind, solar, wave, thermal and tidal energy

T2-3

Ocean-based renewable energy such as offshore wind, solar, wave, thermal and tidal energy

Orals

| Tue, 03 Jun, 14:00–15:30 (CEST)|Room 5

Posters on site

Posters virtual

Further information on the theme is available at: https://one-ocean-science-2025.org/programme/themes.html#T2

Orals: Tue, 3 Jun, 14:00–15:30 | Room 5

Chairperson: Deborah Greaves

14:00–14:10

OOS2025-1021

Pathways to achieving sustainability – a vision for offshore renewable energy in 2030, 2040, 2050

Ewa Spiesz, Deborah Greaves, Henrique de Paula, Jose Rodrigo Rojas, Rebecca Williams, Freya Croft, Eric Mwangi Njoroge, Shenghui Li, Ana Brito e Melo, and Andrea Copping

The development of offshore renewables is globally recognised as an essential part of the solution to address the climate crisis. In the development of these new technologies, we retain the responsibility and best practices for assessing potential environmental and socio-economic effects, mitigating unacceptable changes, and being prepared to reverse course if we find that irreparable damage is being done. The positive vision for offshore renewables development presented in this abstract was developed partly based on UN DOALOS regional workshops outcomes and will be a part of the upcoming UN World Ocean Assessment III, chapter on offshore renewables. It presents the best practices and tools needed to realise this vision by 2030, 2040, and 2050.

Achieving this vision requires a set of best practices and tools, as well as filling gaps in our knowledge of offshore renewables. A plan for applying the tools and addressing the gaps globally is presented that includes an implementation schedule.

The positive offshore renewable energy vision must encompass multiple sectors and cross-sectoral activities related to the ocean in a sustainable manner, including environmental sustainability, economic growth, social inclusion and equity, contributing to a sustainable blue economy in 2050. Increasing coordination and cooperation among diverse marine sectors will maximise the sustainable use of the oceans. A large-scale roll-out of sustainable offshore technologies worldwide will require promoting offshore renewable energy technologies in developing countries, including concessional and preferential terms, mutual understanding, and fair equity sharing.

The vision predicts the surface of the oceans occupied by offshore renewable energy to increase 10-fold in 2050 as compared to 2024, while technology advancements will allow the energy yield to increase 40-fold by moving further away from shore. Multiple sources of ORE (offshore wind, offshore floating solar, ocean thermal energy conversion, tidal stream, wave energy) will be developed and will need to share offshore space with other industries, such as aquaculture, hydrogen production, and critical mineral recovery, to optimise ocean space use. Nature-inclusive and environmentally friendly designs will help to avoid and minimise environmental impacts, increase biodiversity, resulting in climate change mitigation and alleviation of the biodiversity crisis.

The vision requires that most governments will adopt renewable energy goals, including offshore renewable energy and the rapid scale-up of ocean energy technologies beyond offshore bottom-fixed wind, including offshore floating wind, wave, tidal, offshore floating solar and OTEC (as well as combinations of these), with the ambition of 4 terawatts of ocean energy installed worldwide by 2050, contributing significantly to limiting global warming to 1.5°C.

How to cite: Spiesz, E., Greaves, D., de Paula, H., Rodrigo Rojas, J., Williams, R., Croft, F., Mwangi Njoroge, E., Li, S., Brito e Melo, A., and Copping, A.: Pathways to achieving sustainability – a vision for offshore renewable energy in 2030, 2040, 2050, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1021, https://doi.org/10.5194/oos2025-1021, 2025.

14:10–14:20

OOS2025-448

Combining offshore solar and wind: Maximising energy, minimising space

Brigitte Vlaswinkel, Paula Kellett, Ian Hutchison, Pedro Almeida Vinagre, Melina Nalmpanti, Johanna J. Heymans, Xabier Remirez, Maria Apolonia, Miguel Amado, Paula Bastos, Luana Clementino, and Inês Machado

The ocean is becoming crucial for the sustainable development of our blue economy, including our offshore renewable energy and sustainable food sectors. However, maritime space is finite, and hosting these industries in combination with managing other uses of the sea is becoming more challenging. Multi-use of marine space offers an opportunity to optimise the limited space and minimise potential conflicts of use.

The EU-funded project BAMBOO (Build scAled Modular Bamboo-inspired Offshore sOlar systems), running through 2024-2027, aims to develop a blueprint for large-scale (>1km²) offshore solar systems that fit in the space between offshore wind turbines within utility scale offshore wind developments. This groundbreaking approach offers several benefits beyond co-locating blue economy activities. Energy production per unit of sea space could increase up to fivefold in offshore renewable energy development areas, including those located in the North Sea. This is enhanced by the complementary seasonal patterns of solar and wind energy in Europe, with more wind in autumn/winter and more sunlight in spring/summer. Additionally, co-location of these activities enables efficient integration and shared use of electrical infrastructure, known as 'cable pooling.' This maximises infrastructure capacity and offsets revenue losses from curtailment, significantly boosting energy generation from the shared marine space.

The project’s ambition is to tackle the challenges and barriers for the implementation of such sustainable, large-scale offshore solar systems and to provide a standard industry format for the rollout of offshore solar projects worldwide.

This presentation introduces the concept and benefits of combined offshore solar and wind developments, presents the ambitions of the BAMBOO project, and outlines the technical, environmental and other scientific challenges it is addressing. It highlights the importance of smart marine spatial planning and multi-use required to facilitate the sustainable development of the global blue economy. It also shares initial results from the project around the methodologies BAMBOO is developing for assessing and managing the potential environmental and life cycle impacts of large scale offshore solar developments.

How to cite: Vlaswinkel, B., Kellett, P., Hutchison, I., Almeida Vinagre, P., Nalmpanti, M., Heymans, J. J., Remirez, X., Apolonia, M., Amado, M., Bastos, P., Clementino, L., and Machado, I.: Combining offshore solar and wind: Maximising energy, minimising space, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-448, https://doi.org/10.5194/oos2025-448, 2025.

14:20–14:30

OOS2025-339

Wind-wave hybrid energy system: An innovative marine energy technology for sustainable development

Tianyuan Wang, Deborah Greaves, Martyn Hann, and Hongda Shi

Offshore wind energy and wave energy are of great interest due to their huge reserves and potential for providing reliable sources of renewable power. As a primary means of decarbonization, offshore floating wind turbines (FOWTs) are advancing towards larger structural sizes to extract more energy, and wave energy converters (WECs) are seeking economies of scale by increasing the number of installations. However, this trend means that more seabed area will be taken up by the development of these devices into large array commercial projects. Considering the strong space-time correlation between wind and wave resources, the combination of FOWT and WEC, i.e., the wind-wave hybrid energy system, would be a beneficial way to optimize the seabed area required for energy extraction, while minimizing the impact on the marine environment.

The main advantages of integrating FOWT and WEC are as follows: (i) The wind turbine and WEC array share the floating platform foundation, mooring system and electrical equipment, significantly reducing the construction costs; (ii) The WEC array mounted on the platform could not only convert the wave loads acting on the platform into power outputs, but enhance the platform stability via control strategies to further improve the overall energy extraction efficiency; (iii) The synergistic harvesting of wind and wave energy offsets the intermittent nature of a single energy source and decreases the hours of zero production compared with a stand-alone FOWT.

For such a complex multi-physics, multi-body system, the key challenge is its survivability in extreme sea conditions, where the platform stability is highly dependent on the collaborative control of the WECs. To this end, this study focuses mainly on the control strategy of the WEC array, as well as its contribution to the system stability and overall power performance. The analysis object is a typical FOWT-WEC hybrid system, consisting of an IEA-15-MW reference wind turbine (RWT), a UMaine-VolturnUS-S semi-submersible platform, and three toroidal, heaving-type WECs installed on the side columns of the platform. Based on an aero-hydro-elastic-servo-mooring coupling numerical framework, multiple WEC-based survival strategies are proposed to enhance the wind and wave resistance of the integrated system. Moreover, a multi-objective, multi-parameter optimization model is introduced to identify the optimal system configuration using global-local-combination intelligent algorithms. This study discusses in detail the key technologies for enhancing the survivability of wind-wave hybrid systems, and the findings are of great significance in achieving net-zero goals.

How to cite: Wang, T., Greaves, D., Hann, M., and Shi, H.: Wind-wave hybrid energy system: An innovative marine energy technology for sustainable development, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-339, https://doi.org/10.5194/oos2025-339, 2025.

14:30–14:40

OOS2025-372

ECOP

Offshore Wind Energy & Shorebird Migratory Connectivity in the Gulf of Mexico

Jonathan Choi, Allie Anderson, Candace Stenzel, Pat Halpin, and Autumn-Lynn Harrison

The US is accelerating offshore wind energy development to achieve its climate goals, including in the Gulf of Mexico. Though the US is considering impacts to whales, seabirds, turtles, and bats during development and deployment, it has spent comparatively less effort considering the impact on shorebirds. Concurrently, American shorebirds are in severe decline, with population reductions of over 35% since 1970. Thus, the rapid decarbonization of the US energy supply through offshore wind poses potential collision and displacement risk for a group of species of conservation concern. Tracking data, like those curated by the Smithsonian Migratory Bird Center’s Shorebird Science and Conservation Collective, can provide critical insight to address this complex conservation issue. The Shorebird Collective is a partnership of more than 70 scientists who have contributed tracking data collected from over 3,330 individual shorebirds of 36 species to inform on-the-ground conservation. This data could be used to prioritize conservation efforts including the purchasing of habitat or securing water access in critical stopover sites and to help managers identify the impacts of conservation action at different points along the flyway. This presentation presents initial results from a subset of the Collective’s dataset to show how shorebird migration connects US offshore wind lease areas to other ecosystems spread across the Americas. In conducting this analysis, we hope to not only inform wind energy siting considerations in the Gulf, but too also provide initial insight into potential mitigation measures, whereby negative impacts to shorebirds could be “offset” by habitat restoration elsewhere along the migratory corridor. In so doing, the Shorebird Collective serves a vital bridging function between scientists and conservation stakeholders by organizing and applying knowledge from shorebird science to address urgent conservation questions.

How to cite: Choi, J., Anderson, A., Stenzel, C., Halpin, P., and Harrison, A.-L.: Offshore Wind Energy & Shorebird Migratory Connectivity in the Gulf of Mexico, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-372, https://doi.org/10.5194/oos2025-372, 2025.

14:40–14:50

OOS2025-643

ECOP

An ecosystem model for assessing potential impacts of offshore windfarm on Eastern English Channel ecosystem

Yansong Huang, Raphaël Girardin, Frida Lasram, Georges Safi, Ricardo Oliveros Ramos, Antoine Quennevat, and Ghassen Halouani

The development of offshore windfarms (OWF) is crucial for the energy transition to achieve decarbonisation targets. However, the ecological effects of this expansion remain largely unexplored. This study use the OSMOSE model to investigate the potential impacts of OWF in the Eastern English Channel (EEC) ecosystem. The primary objective is to 1) improve the assessment of OWF effects on ecosystems by integrating multiple pressures within a single modelling framework, and 2) analyse ecosystem responses under various OWF deployment and fishing restriction scenarios.

The OSMOSE model is a multispecies, individual-based model that relies on opportunistic predation. It was calibrated to reproduce observed trends of biomass, catch, and catch at length in the study area from 2002-2022. The model's emergent properties (e.g., growth, food web structure) were validated to ensure ecological realism.

A factorial plan of simulations, incorporating OWF deployment and fishing restriction scenarios, provides ecosystem projections up to 2050. The OWF deployment scenarios include: 1) cost minimization, 2) exclusion from regulatory environmental protection zones, 3) long distance from the coast, and 4) a balanced scenario that combines elements from the previous three. The fishing restriction scenarios include: 1) no fishing closure, 2) closure for trawlers, and 3) closure for all fishing fleets. To represent potential OWF impacts, the simulations considered fishing restrictions during the operational phase and the following factors during the construction phase: fishing access restrictions, underwater noise, and sediment resuspension. Biomass, yield, and size-dependent indicators were analysed in a spatially and temporally explicit manner to provide insights into the OWF impact on different aspects of the EEC ecosystem.

At the scale of the entire study area, we observed a slight influence of OWF on total biomass and total catch. However, size-based indicators showed an increasing trend under certain scenarios, suggesting a potential reserve effect. At the individual OWF scale, the response of these indicators varied across different areas. This study highlights the importance of considering both the specific deployment sites and fishing regulations in cumulative impact assessments of OWF.

How to cite: Huang, Y., Girardin, R., Lasram, F., Safi, G., Oliveros Ramos, R., Quennevat, A., and Halouani, G.: An ecosystem model for assessing potential impacts of offshore windfarm on Eastern English Channel ecosystem, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-643, https://doi.org/10.5194/oos2025-643, 2025.

14:50–15:00

OOS2025-1531

Advancing Offshore Wind: Enhancing Ocean-Based Renewable Energy through Sustainable Practices and Biodiversity Conservation & Restoration

Claire Weller, Laura Iborra, and Ben Williams

Over the past two decades, RWE has developed, constructed, and operated offshore wind projects totaling 3.3 GW across 19 sites in Europe, with approximately 20 GW under development worldwide. This experience has shaped a comprehensive approach to the responsible development of ocean-based renewable energy, supporting climate mitigation via the production of green energy rooted in four key sustainability principles, namely positive biodiversity contribution, circular economy, climate resilience, and local benefits.

Within the biodiversity pillar, RWE has undertaken several initiatives to protect marine ecosystems. Examples include the installation of an artificial nesting tower for Kittiwakes at Gateshead (UK) in the context of the Dogger Bank South offshore wind project, to support a critical nesting colony, and the use of innovative vibro-piling techniques at Kaskasi (Germany) to reduce noise impacts on harbor porpoises. Through projects like our Reef Cubes project in the Baltic Sea, RWE collaborates with academic partners to create artificial habitats, thereby promoting marine biodiversity. These initiatives demonstrate RWE’s ambition to have a net positive biodiversity impact by 2030.

The circular economy pillar drives projects aimed at reducing waste and reusing materials. RWE’s BladeReUse initiative transforms decommissioned blades into durable noise barriers, while the company has pioneered the installation of recyclable turbine blades at Kaskasi (Germany) and plans to extend this approach to offshore wind farms at Sofia (UK) and Thor (Denmark), closing material loops and reducing landfill waste. These initiatives reflect RWE’s commitment to achieving full circularity by 2050.

RWE’s climate change strategy involves reducing emissions in alignment with 1.5°C targets. The GreenerTower initiative at the Thor project utilizes “greener steel” with reduced CO₂ emissions, contributing to RWE’s goal of climate neutrality by 2040. Additionally, dual-fuel service vessels powered by methanol and batteries, deployed in North Sea operations, reduce CO₂ emissions by up to 10,000 tons annually, advancing low-carbon marine operations.

The local benefits pillar emphasizes RWE’s commitment to supporting coastal communities. At the Whitby lobster hatchery, funded by RWE through the Sofia wind farm, RWE collaborates with local fisheries to maintain healthy fish and shellfish populations, support the local fishing industry, and raise awareness of marine protection. RWE has also developed a reskilling program with the Baltic II wind farm for volunteer fishermen, enabling them to validate competencies needed to work in the offshore wind industry. RWE’s projects foster strong community relationships, ensuring long-term positive impacts.

RWE’s approach adheres to the mitigation hierarchy—avoid, reduce, restore, and compensate—and aligns with international frameworks such as the UN SDGs and the Offshore Coalition for Energy and Nature (OCEaN). This presentation will present RWE’s sustainability journey. As climate impacts on oceans intensify, RWE’s adaptive management and cross-sector collaboration model offers a blueprint for scaling nature-positive solutions that are resilient, equitable, and inclusive.

Through this presentation, we aim to share lessons learned, best practices, and future ambitions, contributing to the collective knowledge necessary to expand sustainable offshore wind energy as part of the global response to ocean conservation and climate resilience.

Keywords: offshore wind, biodiversity, circular economy, climate resilience, local benefits, sustainable development

How to cite: Weller, C., Iborra, L., and Williams, B.: Advancing Offshore Wind: Enhancing Ocean-Based Renewable Energy through Sustainable Practices and Biodiversity Conservation & Restoration, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1531, https://doi.org/10.5194/oos2025-1531, 2025.

15:00–15:10

OOS2025-1166

Reconciling offshore wind energy and biodiversity governance: Lessons from the North Sea region

Maaike Knol-Kauffman, Ben Boteler, Cristian Passarello, Nikolaos Giannopoulos, and Froukje Platjouw

The North Sea region is pivotal in achieving the EUs ambitious renewable energy targets, with offshore wind energy (OWE) playing a crucial role in the transition to sustainable energy. However, the expansion of OWE presents significant challenges to marine biodiversity, highlighting the need to reconcile OWE development with biodiversity conservation in support of progress towards the European Green Deal.

Despite various directives and regulations at the EU and domestic level, there are notable incoherences in offshore renewable energy and biodiversity governance. For instance, the Renewable Energy Directive (RED III) purports to accelerate permitting processes but lacks alignment with the Marine Strategy Framework Directive (MSFD) and introduces important exceptions to the existing nature conservation rules within the EU, potentially compromising the level of protection of marine biodiversity. Similarly, the Maritime Spatial Planning Directive (MSPD), praised by the EU as offering the remedy to both the spatial challenges and biodiversity challenges created by the proliferation of OWE, has been criticized for prioritizing OWE expansion over nature conservation. At the same time, the recent Nature Restoration Regulation’s impact on aligning OWE growth with biodiversity goals remains uncertain, because it expressly prioritizes the long-term climate benefits of OWE’s expansion over the foreseeable short-term damage to nature.

In the CrossGov project, we conducted case studies on offshore wind governance in Germany, the Netherlands and Norway. Based on the application of CrossGov’s policy coherence evaluation framework in these contexts, we present insights about the gaps and opportunities for better conservation, protection, and restoration of biodiversity within OWE governance. While focusing on the North Sea Region, these insights can provide valuable guidance for other regions within Europe and beyond struggling to overcome challenges related to incoherences between offshore energy and biodiversity policies. These lessons are essential for developing pathways toward more holistic and balanced ocean governance.

How to cite: Knol-Kauffman, M., Boteler, B., Passarello, C., Giannopoulos, N., and Platjouw, F.: Reconciling offshore wind energy and biodiversity governance: Lessons from the North Sea region, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1166, https://doi.org/10.5194/oos2025-1166, 2025.

15:10–15:30

Discussion

Posters on site | Poster area "La Baleine"

Display time: Tue, 3 Jun, 17:00–Thu, 5 Jun, 20:00

P105

OOS2025-17

Environmental Benefits of Flexible Wave Energy Converters: A Novel Investigation of Airbag-Based Device

Qing Lu, Deborah Greaves, Siming Zheng, Martyn Hann, Hongda Shi, and Xun Meng

The increasing demand for renewable energy, driven by the urgent need to mitigate climate change and achieve net-zero emissions, has highlighted ocean energy as one of the most sustainable and promising resources. Wave energy converters (WECs) are pivotal technologies for harnessing marine wave power, providing substantial environmental benefits by reducing dependence on environmentally harmful, non-renewable energy sources such as fossil fuels. Efficient wave energy utilization holds significant potential to contribute to a cleaner, more sustainable energy future. To minimize ecological disruptions while preserving marine biodiversity, various innovative WEC concepts have been proposed. Among them, flexible wave energy converters (FlexWECs) attract great attention due to their lightweight deformable structures and reduced construction costs, significantly resulting in a lower environmental impact than traditional rigid-body WECs. Furthermore, the flexible design of FlexWECs enables adaptation to diverse environmental scenarios, enhancing energy extraction efficiency.

In contrast to rigid-body WECs, FlexWECs are characterized by their rubber-like, deformable structures, allowing broadband power absorption and simpler WEC designs. Recent trends in device development have focused on FlexWECs, where primary energy-absorbing components, power take-off (PTO) systems, and other subcomponents are constructed flexibly. Over 20 FlexWEC devices have been developed to date, most of which are still in the concept or laboratory test stages, indicating substantial potential for further development and research. Among these, deformable airbag-based converters and flexible membrane systems stand out for their adaptability and energy absorption capability. Leveraging flexible materials that can deform in response to varying wave conditions, these devices are capable of effectively capturing wave energy across a broad range of frequencies.

As a key contributor to wave energy research and the development of FlexWECs, the University of Plymouth has made significant strides in promoting more adaptable, resilient, and environmentally sustainable wave energy solutions. This study focuses on a deformable airbag-based FlexWEC, engineered to optimize wave energy capture by adjusting its form in response to ocean conditions. Using high-fidelity computational fluid dynamics (CFD) simulations, the research explores the airbag’s dynamic behaviour under wave interaction, primarily analyzing multi-physics fluid-structure interactions (FSI) within a multiphase setting. The study examines essential relationships between structural deformation, hydrodynamic response, and energy capture efficiency, aiming to illuminate the underlying interaction mechanisms between wave energy devices and waves. Building on these insights, this research provides valuable perspective on the development of novel FlexWECs that harness renewable marine energy while minimizing environmental impact, achieving a balance between sustainable ocean resource utilization and the preservation of marine ecosystems.

Keywords: Renewable marine energy; Environmental benefits; Preservation of marine ecosystems; Flexible wave energy converters; Fluid-structure interactions

How to cite: Lu, Q., Greaves, D., Zheng, S., Hann, M., Shi, H., and Meng, X.: Environmental Benefits of Flexible Wave Energy Converters: A Novel Investigation of Airbag-Based Device, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-17, https://doi.org/10.5194/oos2025-17, 2025.

P106

OOS2025-355

The Influence of Mid-Atlantic Bight Seasonal Oceanographic Variability on Commercial Species Dynamics

(withdrawn)

Samantha Alaimo, Bill Bright, Jeff Brust, Colleen Brust, Jeff Kaelin, Daphne Munroe, Travis Miles, Grace Saba, and Josh Kohut

P108

OOS2025-650

ECOP

Assessing Blue Growth in the UK North Sea: expert modelling of how offshore wind development affects a complex social-ecological system

Will Burton, Gavin Bridge, and Tom Webb

This paper considers the UK North Sea as a complex social-ecological system whose component parts interact in dynamic, non-linear and multi-scalar ways to produce unexpected emergent phenomena. Effects of the continued and projected expansion of the offshore wind industry within this system are not well understood, yet potentially challenge existing forms of marine governance. We report on a project that used Fuzzy Cognitive Maps to pool knowledge from focus groups and interviews with Marine Experts; and that assessed, weighted and combined perceived relationships between different entities of the UK North Sea System into an aggregated map. We show how the map can be used as a semi-quantitative model, predicting potential emergent effects for the expansion of offshore wind. We further show how the most complex relationships can be interrogated further via a social-ecological action situations framework drawn from work on complex social-ecological systems. The paper shows how a whole-system perspective can help illuminate the realities of Blue Growth in ocean systems; revealing the viability of matching continued marine development with environmental protection and social justice commitments.

How to cite: Burton, W., Bridge, G., and Webb, T.: Assessing Blue Growth in the UK North Sea: expert modelling of how offshore wind development affects a complex social-ecological system , One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-650, https://doi.org/10.5194/oos2025-650, 2025.

P109

OOS2025-671

ECOP

Wave atlas of French Polynesia - Application on modelling wave energy facilities development in Islands and the related consequences on CO2 emission reductions.

Hélène Chabbert, Corinne Dubois, Marie Peniguel, Axel Roy, and Victoire Laurent

A new wave energy atlas database for French Polynesia

A wave reanalysis was carried out over the whole French Polynesian ZEE, using Météo-France's MFWAM model at 0.05° resolution, derived from the WAM model with a spatial resolution of 5 km, a three-hourly step, and a temporal depth of 30 years. These results have been published on the ODATIS open data platform.

Compared with existing reanalysis, the islands are better modelled, and it leads to better estimates of wave conditions and propagation.

It has been applied to wave energy evaluation over the whole French Polynesia.

Learnings, opportunities and limits of this new wave energy atlas data base

This has been used as the basis for evaluating and prospecting wave energy sites for the development of several energy facilities in order to select the best spots.

Our work deals with the learnings, opportunities and limits of using these datasets to calculate the estimated production of a wave energy facility and the CO2 emission reductions that the sites concerned can target.

An example for all islands

Why and how can the same types of methodology be deployed on other islands?

How to cite: Chabbert, H., Dubois, C., Peniguel, M., Roy, A., and Laurent, V.: Wave atlas of French Polynesia - Application on modelling wave energy facilities development in Islands and the related consequences on CO2 emission reductions., One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-671, https://doi.org/10.5194/oos2025-671, 2025.

P110

OOS2025-789

Decarbonizing Islands : Challenges and opportunities

Corinne Dubois, Bruno Lemort, Noemie Bahin, and Mauna Reveil

Islands play a crucial role in the global energy transition and the decarbonization of power generation. On one side, they are particularly vulnerable to the impacts of climate change, and on the other side, they offer a privileged setting for the development of innovative solutions.

Surrounded by oceans, islands have access to a sustainable energy resource: wave energy. Harnessing this vast natural wealth is an obvious solution to meet the growing energy needs while reducing CO2 emissions. In these regions, where the current cost of energy can reach €900 per MWh compared to €112/MWh in mainland France, and where dependence on fossil fuels remains very high, marine energy presents a high-impact opportunity. INot only it helps avoid significant amounts of CO2 emissions, but the projects are also already competitive in these contexts.

However, the challenge lies in the scale of the projects, which remain small because of the consumption and because of islands’ logistical available infrastructures. To ensure their success, it is essential to multiply these initiatives across multiple sites and adopt a global vision for the industry. Many experiences showed that pilots farms do not work well for remote islands.

Islands, as true biodiversity sanctuaries, pose a major challenge in the development of marine energy: minimizing local environmental impacts. This requires close collaboration with local populations and marine authorities to select strategic locations where the impact on ecosystems is minimized. The long-term benefits, especially in terms of carbon emissions reduction, are overwhelmingly positive compared to the possible local impacts to survey.

Additionally, submerged infrastructures, such as wave energy converters, can create artificial reefs, thus contributing to the preservation of biodiversity and local marine resources. The challenge is to balance these impacts, ensuring that each project becomes a genuine asset to the island environment.

Wave energy offers several advantages. It provides stable electricity production with very low emissions, estimated at around 36 gCO2e/kWh. Furthermore, its installation requires little land, which is a valuable asset in island territories where space is limited. This technology holds great promise for delivering autonomous energy to remote island populations.

In addition, wave energy integrates effectively with other local renewable energy sources. It complements systems such as SWAC (seawater air conditioning), hydropower for stabilizing production rhythms, as well as wind or photovoltaic energy. This synergy strengthens the stability of the electrical grid while minimizing energy storage needs.

Thus, islands are an essential starting point for promoting a sustainable energy model. By harnessing ocean energy, we can, not only decarbonize these territories at a competitive cost compared to the current mix, but also already demonstrate the viability of this sector for medium size WECs .

How to cite: Dubois, C., Lemort, B., Bahin, N., and Reveil, M.: Decarbonizing Islands : Challenges and opportunities, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-789, https://doi.org/10.5194/oos2025-789, 2025.

P111

OOS2025-837

Techno-economic analysis of the Sea Water Air Conditioning technology under real operating conditions as a sustainable space cooling solution on a global scale

Franck Lucas, Kanhan Sanjivy, Perceval Raybaud, Richard Bailey, and Neil Davies

The deep water of seas and oceans is an important resource that remains currently poorly known and underutilized. Thermal energy production is one possible use, but there are many others. The use of deep water for space cooling is a particularly promising application because air conditioning of buildings is expected to become a significantly more energy-intensive sector in the coming years due to economic growth, population expansion, and the intensifying effects of climate change. While conventional air conditioning systems, predominantly relying on vapor compression cycles, have attained technological maturity, their energy efficiency is expected to cease significant growth. Meanwhile, passive cooling solutions such as natural ventilation and electric-powered fans may prove insufficient in maintaining indoor comfort in hot and humid climates. Addressing these challenges necessitates the pursuit of more efficient cooling solutions, especially to ensure indoor comfort during extreme heatwaves. Deep Sea Water Air Conditioning (SWAC) technology emerges as a promising alternative to both conventional and passive cooling methods, as recent measurements showcase its remarkable performance. By drawing seawater from great depths (over 900m), SWAC systems directly cool buildings without the need for supplementary backup systems, ensuring precise indoor temperature regulation. This article provides a comprehensive performance analysis of two SWAC installations deployed in French Polynesia across various building types. One installation has been serving a hotel since 2011, while the other was commissioned to supply a hospital in 2022. These installations are fully instrumented, enabling precise determination of energy performance metrics and operating parameters, which influence performance. Moreover, the great originality of this study is that one of the two buildings operated for more than 10 years with a conventional air conditioning (chillers) before transitioning to SWAC. The measurements carried out on this building before and after connection to the SWAC make it possible to clearly establish experimentally the gains offered by this technology. To complete the energy performance characterization, this article proposes an economic evaluation based on actual operating costs, highlighting the advantages and potential drawbacks of SWAC as a replacement for conventional air conditioning systems. At the end, this article presents the worldwide potential for SWAC application, identifying all regions where the technology can be utilized.

How to cite: Lucas, F., Sanjivy, K., Raybaud, P., Bailey, R., and Davies, N.: Techno-economic analysis of the Sea Water Air Conditioning technology under real operating conditions as a sustainable space cooling solution on a global scale, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-837, https://doi.org/10.5194/oos2025-837, 2025.

P112

OOS2025-951

Monitoring Offshore Wind Turbines - A science-environment-society observatory

Olivier Labussière, Alain Nadaï, Adeline Bas, and Catherine Boemare

In 2022, the first wind turbines were installed off the French coast, with more to follow.

The EOLENMER project, funded by the French Energy Agency (Ademe), aims at understanding the interaction between wind farms, the marine environment and the surrounding territories, which are currently sources of tension at certain sites. The project seeks to establish an interdisciplinary research framework, similar to an observatory, to monitor the installation and development of the first offshore wind farms and analyze their bio-socio-spatial impacts.

This project brings together more than fifty researchers, geographically dispersed and affiliated with various French research organizations (CNRS, France Energies Marines, IFREMER, IRD, Universities). It covers four maritime regions and will monitor six sites: in the English Channel (Fécamp, Courseulles, Saint-Brieuc), in the North and south Atlantic (Groix-Belle-Ile, Saint-Nazaire), and in the Mediterranean (Leucate, and more broadly, the strategic planning of floating wind turbines).

It consists of three modules:

i/ A Territorial Diagnosis: This work package consists of a baseline assessment of selected sites, analyzing the challenges of offshore wind energy and the local stakeholders' dynamics.

ii/ Thematic Monitoring: This work package relies on current scientific approaches in various fields in order to analyze and monitor the relationship between wind farms and the marine, terrestrial, and local environments (e.g., employment, tourism, fishing, land value, landscape), ideally on an annual basis.

iii/ Open, Interdisciplinary, and Participatory Monitoring: More experimental in its approach, this work package explores, with non-academic actors from local communities or relevant industries (e.g., science shops, art-science collaborations), debated dimensions of the relationships between wind farms and their environment.

The overall objective of the project is to identify and follow the issues raised by the development of offshore wind turbines (diagnosis), to measure and monitor the evolution of these issues (thematic monitoring), and to open up and problematize the methods through which issues are assessed, when these have become controversial (open monitoring). The work will result in annual reports, scientific publications, and presentations at scientific conferences. It will also experiment with new forms of writing and dissemination, in collaboration with non-academic stakeholders, to make its findings accessible to a wider public.

Our presentation will detail this project and introduce first results.

How to cite: Labussière, O., Nadaï, A., Bas, A., and Boemare, C.: Monitoring Offshore Wind Turbines - A science-environment-society observatory, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-951, https://doi.org/10.5194/oos2025-951, 2025.

Posters virtual | online

Display time: Tue, 3 Jun, 17:00–Thu, 5 Jun, 20:00

vP21

OOS2025-627

ECOP

Enhancing Blue Economy Through Multi-Use Offshore Wind Farms: Hydrodynamic Impacts and Opportunities for Sustainable Resource Use

Seyed Taleb Hosseini, Johannes Pein, Joanna Staneva, Joseph Zhang, and Emil Stanev

The European Green Deal's goal of transforming the EU into a modern, resource-efficient and competitive economy depends on the establishment of a sustainable blue economy. This study pursues a multi-use resource strategy to promote the Blue Economy under the EU Green Deal, with a particular focus on the potential of multi-use offshore wind energy and low trophic level aquaculture. The multi-use of offshore wind farms (OWFs) for the dual purpose of energy and food production exemplifies the benefits of multi-use of marine space, such as promoting restoration and regeneration, nutrient and carbon sequestration or improving water quality. This study is a fundamental step in our efforts to simulate realistic hydrodynamic conditions at the Meerwind-OWF site (German Bight, North Sea).

We investigate the interactions between OWF monopiles and wind-driven waves, with a focus on how these structures influence local and regional hydrodynamics. The model captures detailed transitions from broad ocean boundaries down to near foundation scales, providing insights into flow modification and changes in wave patterns around the OWF. To this end, a high-resolution 3D modelling framework (coupled circulation-wave-sediment-biogeochemistry) based on unstructured grids is employed, allowing an effective transition in resolution from ~2 km at open marine boundaries to ~2 m near foundations. Our analysis reveals a reduction in mean current velocities near the structures and changes in wave heights, which affect the potential energy distribution of the surrounding water column. The monthly potential energy anomaly increases outside the OWF, affecting an area well beyond the farm boundaries, while decreasing within the farm boundaries. The monopiles reduce the monthly significant wave height (Hs) within the OWF and beyond. The prevailing westerly waves affect the tidal asymmetry, particularly on the eastern side of the piles. This results in an asymmetry in the intensity of turbulent wakes on either side of the piles, in both monthly and tidal timescales. These changes can significantly affect sediment transport, nutrient dynamics, and habitat conditions around the OWF.

Building on these findings, we have developed a series of what-if scenarios to assess the potential of combining OWFs with aquaculture facilities. The scenarios explore different configurations within and around OWFs and assess their impact on ocean dynamics, nutrient cycling and ecosystem health. By varying factors such as climate change, the spatial arrangement of monopiles or operational strategies, the scenarios provide critical insights into optimising multi-use strategies. For instance, co-locating low trophic level aquaculture in OWF can enhance nutrient uptake and improve local water quality, while also contributing to carbon sequestration and supporting biodiversity. This approach is consistent with the principles of sustainable blue growth, which emphasises the importance of maximising economic benefits while mitigating environmental impacts. By integrating advanced modelling techniques and scenario-based analysis, the study provides a robust framework for assessing the trade-offs and synergies of multi-use ocean space. Our findings contribute to a broader understanding of how multi-use offshore platforms can be used to support the transition to a sustainable blue economy. This can be useful for policy makers, industry stakeholders and coastal managers.

How to cite: Hosseini, S. T., Pein, J., Staneva, J., Zhang, J., and Stanev, E.: Enhancing Blue Economy Through Multi-Use Offshore Wind Farms: Hydrodynamic Impacts and Opportunities for Sustainable Resource Use, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-627, https://doi.org/10.5194/oos2025-627, 2025.

vP22

OOS2025-585

ECOP

Unfolding and exploring uncertainties for possible and desired futures offshore through co-created scenarios for the development of offshore wind farms

Laura Gusatu

The last decades of research have produced increasing evidence on the multi-level impacts of the current and future large scale OWF infrastructure planned in the North Sea basin, as an attempt to lower GHG emissions and reduce the dependence on fossil fuels. Most scientific knowledge produced is focused on various ecological effects on the marine habitats, with a smaller body of literature also drawing attention to socio-economic effects on various marine space users (in particular fisheries).

However, while scientific knowlede on potential risks and synergies advances, there are still high uncertainties with regards to the potential and desired futures of the North Sea, often used as argument for political inaction. Such uncertainties are due to unknown effects from global, regional, and local factors, that range from climate change’s impacts on the marine environment, consequences of geo-political events, economic and technological trends, consumer patterns shifts and much more.

This study aims at unfolding those uncertainties and exploring desired, potential and possible alternatives for the development of offshore activities in the North Sea basin, in the context of a nature, energy and food transition.

The potential scenario narratives are first considering potential cause-effect chains derived from the influence of global factors, through the lens of selected IPCC SSP scenarios, integrating scientific evidence (projections, modeling results of RCP scenarios) into a coherent scenario storyline. Second, the desired and possible narratives are derived from the local socio-ecological context, through mapping stakeholder expectations, perspectives and desires, in a number of workshops and interviews with local stakeholders. Third, each scenario narrative further informs a spatial representation of the distribution of offshore activities, using GIS data from open source repositories as well as data from related modeling efforts (e.g. species distribution). Results are used to qualify and quantify trade-offs between various alternatives, emphasizing gains and looses when certain policy and management options are considered.

An inclusive and transparent analysis of potential trade-offs between alternative space allocation options in the marine space will assist the strategic decision-making process for balancing offshore wind with other interests, within the boundaries of the North Sea ecosystem.

How to cite: Gusatu, L.: Unfolding and exploring uncertainties for possible and desired futures offshore through co-created scenarios for the development of offshore wind farms, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-585, https://doi.org/10.5194/oos2025-585, 2025.