Surewave and the Horizon Europe project Natursea-PV recently held a joint technical webinar on modelling and validation methods for concrete structures used in offshore floating PV applications.

The session connected work across both projects, which share a common engineering challenge: enabling floating PV systems to operate in harsher marine environments by improving the durability and predictability of concrete-based components and by reducing uncertainty in long-term performance.

The webinar followed a modelling chain from material level to structural level. It started with machine-learning approaches to predict concrete properties from mix design data, with the aim of accelerating mix optimisation and reducing dependence on repeated lab campaigns. It then covered thermodynamic modelling of cement hydration and phase assemblage to support durability assessment in marine exposure, including the role of low water-to-binder ratios in UHPC and how chemistry influences porosity and transport properties.

A third focus was high-fidelity numerical simulation of chloride ingress in geometrically complex 3D concrete microstructures. This included explicit representation of fibres, cracks, and interfacial transition zones, and the use of simulation to explore “critical paths” that can drive faster ingress locally than what simplified, homogeneous models predict. The final part moved to structural modelling of reinforced concrete components, linking material behaviour and loading histories to structural integrity assessment and validation workflows.

Across the presentations, a consistent theme was that durability testing is slow and often difficult to generalise across mix designs and structural details. The webinar therefore emphasised predictive toolchains that combine experiments with modelling so that critical parameters can be identified, sensitivities quantified, and design choices supported with traceable assumptions.

The full webinar recording is available here:watch on YouTube.

The SUREWAVE prototype has now been installed, marking an important project milestone in demonstrating sustainable floating breakwater solutions for offshore energy applications.

Floating breakwaters are designed to protect floating photovoltaic (FPV) systems from wave loads. Conventional breakwaters typically rely on standard concrete and EPS cores, materials that can be carbon-intensive and difficult to recycle. Within SUREWAVE, partners have developed circular concrete alternatives that lower CO₂ emissions while maintaining durability and structural performance.

The prototype measures 3.40 m × 1.70 m × 1.05 m and is constructed with:

• Lightweight aggregate concrete (LWAC)
• High-performance concrete (HPC)
• Cellular lightweight concrete (CLC) for buoyancy

These materials incorporate recycled aggregates, glass waste, fly ash, ground-granulated blast-furnace slag (GGBS), and low-carbon cement. Following laboratory testing and mix optimisation, the structure has been placed at ACCIONA’s R&D maritime demonstration site in the Port of Gijón, Spain.

The prototype will undergo long-term exposure testing under real environmental conditions to assess durability, cracking behaviour, and material performance.

As part of the SUREWAVE project, we are not only developing sustainable floating breakwaters — we are also working to ensure their long-term structural safety under real offshore conditions.

One of the critical aspects of this work is understanding how cracks propagate in reinforced concrete, particularly in the steel rebars at the core of the breakwater structures. To model this, we apply Linear Elastic Fracture Mechanics, with a focus on Paris' Law for fatigue crack growth under cyclic loading.

Under repeated wave-induced loads, even small cracks can expand gradually until they compromise the reinforcement — a failure scenario that is both costly and risky. By modelling crack evolution and simulating its progression, we can design more resilient structures and reduce lifetime maintenance demands.

Our crack propagation simulations require:

• Detailed load histories from finite element models
• Accurate material properties under cyclic stress
• Realistic initial crack geometries

This approach enables us to build a Structural Health Management System capable of supporting long-term monitoring and proactive maintenance.

The SUREWAVE consortium held its 30-month summit in Madrid last month, hosted at Acciona's facilities. This was the fifth of six planned technical meetings, bringing together core project partners from Clement, Acciona, SINTEF, IFEU, Sunlit Sea, MARIN, and CEIT.

Over two days, we reviewed results from across the project: from technical design and structural simulations to social and environmental assessments. The workshops enabled detailed discussion on risk assessment, sustainability strategies, and deployment planning.

Participants also toured Acciona's concrete laboratories, where key testing for the project's floating breakwater solution has taken place. These labs are central not only to SUREWAVE but to other ongoing innovation in sustainable construction materials.

As always, meeting in person proved valuable for aligning on methods, discussing results in depth, and reinforcing collaboration across disciplines. The summit concluded with a shared dinner in central Madrid — a welcome opportunity to connect informally and experience local culture.

In the HEU-funded SUREWAVE project, we are developing sustainable concrete solutions with a reduced CO₂ footprint. Various concrete mixtures were tested in the lab for mechanical performance and durability properties, and the most optimized mix was selected for the prototype.

The prototype (see image), measuring 3.40m x 1.70m x 1.05m, was constructed using circular lightweight aggregate concrete (LWAC), high-performance concrete (HPC), and cellular concrete. These circular solutions were designed using recycled and other secondary materials or by-products such as recycled aggregates from construction and demolition, glass waste, fly ash and ground granulated blast furnace slags.

The prototype will be installed soon at ACCIONA's R&D maritime demo site in the Port of Gijón, Spain, where it will undergo long-term durability testing in real environmental conditions.

Floating breakwaters are essential for protecting lakes, rivers, and near-shore marine environments from wave and wind action. Traditionally constructed using concrete shells and Expanded Polystyrene (EPS) cores, these structures present challenges in terms of environmental impact and cost.

Through the EU-funded SUREWAVE project, we are pioneering more sustainable and circular alternatives. Our efforts focus on replacing conventional materials with low-carbon, high-performance alternatives while maintaining structural integrity and buoyancy:

Innovative Materials in Development

• Lightweight Aggregate Concrete (LWAC) and High-Performance Concrete (HPC) for durable and waterproof outer shells.
• Cellular Lightweight Concrete (AAC) to replace EPS in the core, reducing weight while maintaining buoyancy.

Key Benefits

• Lower Carbon Footprint: Incorporating recycled aggregates and green cements (e.g., GGBS, fly ash).
• Structural Reliability: Engineered for resilience in demanding marine environments.
• Circularity: Designed with lifecycle sustainability in mind.

These material innovations support the broader goal of the SUREWAVE project: enabling robust, offshore-capable Floating PV systems by integrating circular concrete breakwaters that mitigate wave loads and enhance energy yield.

We're excited to share our progress as we move towards a more sustainable and scalable future for offshore renewable energy.

As part of the SUREWAVE Project, the Ceit Research Center team has been actively collaborating with ACCIONA to test their eddy current corrosion sensor on the floating breakwater prototype. This critical technology will help monitor and assess the structural integrity of the breakwater over time, focusing on corrosion-related degradation of the reinforced rebars.

Initial Testing at ACCIONA’s Facilities

The Ceit Research Center team is currently at ACCIONA's facilities to conduct an initial scan of the breakwater structure. This scan serves as baseline data, which will be essential for future comparisons once the breakwater is exposed to real-world marine conditions at the Port of Gijón. This step is crucial in evaluating any potential corrosion that may occur due to prolonged exposure to the harsh marine environment.

Monitoring Corrosion Over Time

The final placement of the eddy current corrosion sensor is currently being determined. Once installed, the sensor will monitor a specific area of the breakwater structure in real-time, transmitting data remotely throughout the experiment. This will allow the team to continuously track the health of the structure, providing valuable insights into the long-term effects of marine exposure on the reinforced rebars.

This testing phase is a key step toward ensuring the durability and resilience of the floating breakwater, contributing to the SUREWAVE project’s broader mission to enhance the longevity and performance of floating photovoltaic systems in marine environments.

Looking Ahead

The data gathered from this sensor will play a pivotal role in improving the design and material choices for future floating solar infrastructure. Monitoring the corrosion of critical components like the reinforced rebars is essential for ensuring the long-term reliability of offshore renewable energy installations.

For more information on Ceit’s contributions to the SUREWAVE Project, stay updated on our SUREWAVE website.

As a key partner in the SUREWAVE Project, ACCIONA is leading efforts to develop sustainable, circular materials for the construction of floating breakwaters, aimed at protecting floating photovoltaic (FPV) systems from ocean waves. This Horizon Europe-funded initiative is focused on improving the efficiency and longevity of floating solar panels in marine environments by creating innovative solutions that prioritize sustainability.

Leading the Development of Circular Materials

ACCIONA's Construction Technology Center is at the forefront of the SUREWAVE Project's sustainability goals, leading the work package on the design of circular materials for the floating breakwater. The team is working on creating two types of sustainable concrete, which have been validated through the construction of a prototype to be installed at the Port of Gijón in the coming months.

The floating breakwater aims to protect floating solar panels from waves, which increases their operational availability and energy production. This is critical for the efficiency and reliability of floating solar installations at sea.

Sustainable Concrete Innovations

1. High-Performance Concrete:

• Compressive strength: 120 MPa
• Material efficiency: Requires 40% less material due to its high strength.
• Sustainability: Incorporates slag and fly ash, reducing the clinker content by 20%. Clinker is one of the most polluting components in cement production.

2. Lightweight Concrete:

• Density: Less than 1900 kg/m³
• Recycled materials: Replaces conventional lightweight aggregates with recycled glass aggregates and uses recycled construction and demolition waste (CDW).
• Cement: Utilizes a blast-furnace slag-containing cement, which reduces clinker content by 35%.

For the core of the breakwater, ACCIONA has designed a cellular concrete:

• Density: 365 kg/m³
• Sustainability: Utilizes minimal cement and incorporates recycled glass aggregates, further reducing the environmental impact.

A Prototype at the Port of Gijón

The floating breakwater prototype, developed with these innovative materials, is set to be installed at the Port of Gijón in the coming months. This installation will serve as a key milestone in the SUREWAVE Project, validating the use of circular materials in real-world marine environments and contributing to the sustainable development of the floating photovoltaic sector.

Collaboration Across Europe

The SUREWAVE Project brings together seven partners from six EU countries, all of whom are committed to developing a reliable structural solution for floating solar installations. By combining cutting-edge research and sustainable construction techniques, the project aims to contribute significantly to the future of renewable energy and sustainable construction.

To learn more about ACCIONA's role in the SUREWAVE Project, visit the full details on their website here.

Floating Photovoltaic (FPV) systems represent an innovative approach to renewable energy generation, especially in marine environments. However, these FPV infrastructures are continuously exposed to extreme wave loads throughout their operational life. Understanding the hydrodynamics of FPV systems is crucial for optimizing their design and ensuring long-term reliability. The SUREWAVE project leverages state-of-the-art tools to design these systems, but it's essential to validate these tools with experimental data to ensure accuracy.

As part of the European Union-funded SUREWAVE project, project partner MARIN (Maritime Research Institute Netherlands) conducted 1:10 scale wave basin tests to study the hydrodynamic behavior of FPV systems. The tests focused particularly on the performance of the flexible hinges that interconnect the photovoltaic panels, which are a critical component in ensuring the robustness of these systems.

Hydrodynamic Test Results

The tests, conducted in MARIN's advanced wave basin, utilized a 5 × 3 FPV matrix both with and without an external floating breakwater (FBW). These tests provided valuable insights into how FPV systems interact with wave forces in marine environments. The results offer a comprehensive look at the hydrodynamics of FPV systems, helping to inform more accurate and efficient designs.

This dataset, now publicly available, serves as an excellent resource for anyone working on FPV systems or marine technologies. Researchers, engineers, and developers can use this data to validate their hydrodynamic models and improve the accuracy of their simulations.

Access the Data and Publication

• The full dataset from MARIN's tests is available on Zenodo.
• A detailed description of the results has been published in a journal article, accessible here: Journal Publication.

Contributing to the European Commission's Renewable Energy Goals

The research conducted through the SUREWAVE project supports the European Commission's renewable energy targets, helping to advance sustainable energy solutions through better design and performance optimization of FPV systems. The data gathered from MARIN's experiments is instrumental in helping designers create more reliable and resilient FPV systems capable of withstanding the harsh conditions of marine environments.

Get Involved

We encourage the research and industrial community to utilize this dataset to further improve the hydrodynamic design of FPV systems. By contributing to model validation and enhancing simulation accuracy, you can play a part in advancing the future of renewable energy.

For more information, feel free to contact Joep van der Zanden from MARIN (Maritime Research Institute Netherlands).

As part of the SUREWAVE Project, ACCIONA plays a key role in developing sustainable solutions in the construction of floating solar farms. By utilizing innovative concrete mixes, ACCIONA aims to reduce environmental impact and promote a circular economy through the use of recycled and waste materials. These efforts are centered on two main environmental goals: maximizing the use of waste materials and reducing the carbon footprint of concrete production.

Key Environmental Objectives

1. Maximizing Waste Utilization: ACCIONA is focused on developing sustainable concrete mixes using a variety of waste materials, such as:

• Recycled aggregates from construction demolition waste.
• Lightweight aggregates made from glass waste.
• Fly ash and ground granulated blast-furnace slags.

These sustainable concrete solutions help reduce the amount of waste going to landfills while conserving natural resources that would otherwise be used in conventional concrete production.

"We are focusing on two main environmental objectives. The first one is to maximize the use of waste materials by developing sustainable concrete mixes with recycled materials and other waste materials. This will reduce the amount of waste material going to landfills and helps to conserve primary or natural materials."

2. Reducing the Carbon Footprint: ACCIONA is also committed to reducing the carbon footprint of concrete mixes by:

• Using less cement.
• Partially replacing cement with bio products like fly ash and ground granulated blast-furnace slags.

By reducing cement content in concrete, the environmental impact of concrete production is significantly minimized, contributing to the overarching goal of creating more sustainable building materials.

"The second is to reduce the carbon footprint in concrete mixes by using less cement or by partially replacing the cement with bio products like fly ash and ground granulated glass-furnace slags."

Sustainable Concrete for Pontoon-Type Breakwaters

Before addressing their specific innovations, it’s important to understand the current context of pontoon-type breakwaters used in offshore renewable energy projects. These breakwaters are traditionally manufactured using:

• A structural shell of conventional concrete.
• An inner core of expanding polystyrene, both of which have high costs and high carbon footprints.

There is a growing need for more sustainable alternatives in the manufacturing of these breakwaters. ACCIONA’s contribution to the SUREWAVE Project is addressing this need by offering environmentally friendly concrete solutions using waste materials.

"There is a research need to develop more sustainable solutions. Acciona brings to the project sustainable concrete solutions using waste materials, like recycled aggregates from construction demolition waste, lightweight aggregates from glass waste, fly ash, and ground granulated blast-furnace slags."

Towards a Greener Future

ACCIONA's innovations in concrete production for the SUREWAVE project are a critical part of the ongoing effort to make offshore floating solar installations more sustainable. These breakthroughs not only help to reduce landfill waste but also contribute to lowering the carbon footprint in the construction sector—aligning with the SUREWAVE Project’s overall mission to promote sustainability and innovation in renewable energy.

To learn more about ACCIONA’s role in the SUREWAVE project and the sustainable concrete solutions they are developing, visit www.surewave.eu.

The SUREWAVE Project, led by SINTEF, is a European-funded initiative aiming to enable floating solar farms to operate effectively in extreme open sea environments. This multinational project brings together partners from Norway, Germany, Spain, and The Netherlands, reflecting a strong collaborative effort across Europe to push the boundaries of renewable energy.

Key Innovations

The project's central innovation is the use of a large concrete barrier placed in front of the floating solar modules. This barrier protects the solar modules by dampening a portion of the wave energy that would otherwise directly impact them, allowing for more reliable and efficient energy generation in harsh marine environments.

Main Objectives

The SUREWAVE Project has two primary objectives:

• Innovative Design: Developing innovative floating solar farms that can withstand open sea environments.
• Extreme Conditions: Deploying these solar farms in challenging environments, where high waves and severe weather conditions would typically hinder solar energy generation.

Project Overview

Led by SINTEF: The project is spearheaded by SINTEF, one of Europe's largest independent research organizations.

Multinational Collaboration: Partners from Norway, Germany, Spain, and The Netherlands are working together to make this ambitious vision a reality.

Focus on Sustainability: The project is paving the way for sustainability in renewable energy innovations, contributing to a more sustainable future.

Stay Updated

The SUREWAVE team continues to work on more use cases and developments, which will be shared in future updates and videos. Stay tuned as the project explores further applications of this floating solar technology.

Learn more about the SUREWAVE project and its efforts towards sustainable energy solutions at www.surewave.eu.

On April 9th, 2024, the 3rd SUREWAVE summit took place in Rostock, bringing together the consortium partners to share and discuss cutting-edge research and developments within the project. The event highlighted promising progress in various areas, particularly focused on floating solar technology and the integration of wavebreakers, showcasing the critical advancements being made towards more resilient offshore renewable energy systems.

Key Highlights of the Summit

The summit featured detailed presentations from partners, showcasing exciting simulation and testing results, including:

• Wavebreaker Simulations in Ocean Conditions: These simulations are essential for assessing how wavebreakers can mitigate the impacts of harsh marine environments on floating solar parks. By dampening waves, the wavebreakers protect solar installations from damage, helping to increase their lifespan and operational efficiency in offshore conditions.
• Floating Solar Parks and Wavebreakers: Another key focus was the combined simulation of floating solar parks with wavebreakers. These integrated systems represent a major leap forward in offshore floating solar technology, enabling large-scale solar energy generation in open sea environments. The simulations provided critical insights into how these systems can function together to withstand extreme ocean conditions.
• Critical Point Simulations and Testing: Detailed simulations and physical tests at critical points in the floating solar and wavebreaker systems were also discussed. These simulations are crucial for identifying potential failure points and ensuring that all components can withstand high-stress conditions in the ocean, ensuring the overall durability and safety of the systems.
• Environmental Impact Analysis: A significant portion of the summit was dedicated to understanding the environmental impact of these innovations. The environmental analysis looks at how floating solar and wavebreakers interact with marine ecosystems, aiming to minimize negative impacts while maximizing renewable energy output.

Collaboration Across the Consortium

The summit was not only an opportunity to share research results but also to strengthen collaboration between the various partners. A particular highlight of the event was the participation of Clement Germany GmbH, who hosted the event and provided an insightful tour of their cement factory. Clement's role in developing innovative, circular concrete materials for the wavebreakers is key to ensuring that these structures are not only effective but also sustainable in the long term.

Looking Ahead

The SUREWAVE project is funded under the Horizon Europe program and aims to push the boundaries of offshore floating solar technology. With the combination of floating solar systems and wavebreakers, the project is creating resilient and efficient renewable energy solutions capable of withstanding the challenging conditions of open sea environments. As research continues, the next steps will involve further refinement of the designs and scaling up pilot projects to test these systems in real-world marine environments.

Stay tuned for more updates on the progress of SUREWAVE as we continue to unlock the potential of offshore floating solar technology, working towards the EU's goal of achieving climate neutrality by 2050.

Special Thanks

We extend our sincere thanks to Clement for hosting the event and for their contributions to the SUREWAVE project, as well as to all our partners for their invaluable research and collaboration.

On April 25th, 2024, the European Climate, Infrastructure and Environment Executive Agency (CINEA) hosted an insightful workshop titled "Solar PV Energy Projects Clustering Event," bringing together 15 projects focused on diverse aspects of Solar Photovoltaics (PV).

This workshop provided a platform for discussion among CINEA's Horizon 2020 and Horizon Europe-funded projects, alongside policymakers, to explore PV integration and operational aspects such as Building-Integrated PV (BIPV), Vehicle-Integrated PV (VIPV), Agro-PV, floating PV, and the performance and reliability of PV plants.

The event facilitated valuable face-to-face discussions on challenges and opportunities within the Solar PV sector, contributing to the overarching goal of achieving climate neutrality. The workshop also featured poster presentations of all participating projects and included group discussions on three key topics:

• Competitiveness
• Digitalization and operability
• Sustainability and circularity

The Surewave project, funded under the Horizon Europe program, was represented at the event. Surewave focuses on advancing floating PV technology. During the workshop, meaningful discussions took place with representatives of other floating PV projects such as NATURSEA-PV and BAMBOO, resulting in collaborative efforts to push forward offshore floating PV solutions.

This workshop was an excellent initiative by CINEA, fostering collaboration and knowledge sharing across the Solar PV sector to support the transition towards a more sustainable energy future.

The SureWave project introduces cutting-edge floating photovoltaic (PV) systems tailored for marine settings, brought to life by SINTEF with industry frontrunners.

This video unveils the resilience of our technology against marine elements, focusing on how it stands up to varying wave, wind, water depth, and flow conditions.

Through comprehensive simulations and real-world wave basin tests, we demonstrate the project's commitment to sustainability and innovation. Explore the deployment of these solar panels and the protective floating breakwater system designed for optimal performance in the demanding oceanic environment. Join us to see how SureWave is harnessing renewable energy for a greener future.

#SureWave #FloatingSolar #RenewableEnergy #MarineEngineering

The SureWave project has recently completed the development of a global system design for floating solar systems, featuring integrated wavebreakers. This design is adaptable, intended to accommodate a wide array of project sizes and specifically tailored to meet the diverse local sea conditions and size requirements at different sites, including variations in wave heights, periods, and directions.

Our methodology highlights the design's potential for customization, ensuring it can be adjusted to fit the environmental conditions and spatial needs of various locations. To illustrate this adaptability, we present configurations of 0.4 MW and 7 MW as instances of how our solutions can be modified, showcasing the design's flexibility and configurability.

This update underscores our efforts towards providing scalable and bespoke solutions in the renewable energy domain, addressing a variety of project demands across maritime settings.

Exciting developments in SUREWAVE, a project that's promising to deliver circular floating wavebreakers for floating solar.

Imagine a floating breakwater, a simple yet innovative solution, very well suited to protecting other floating structures such as floating solar installations. Through the EU-funded SUREWAVE project, project partner ACCIONA and others have driven extensive research towards an optimal wave breaker for shielding FPV installations from harsh marine conditions, offering a more resilient approach to energy production.

What sets SUREWAVE apart is the careful consideration given to concrete formulations. Lightweight Aggregate Concrete (LWAC) and High-Performance Concrete (HPC) is currently being explored, seeking an optimal composition in order to increase circularity and reduce the CO2 footprint - all while ensuring the structural reliability of the wavebreaker.

Addressing concerns about the cement industry's impact on CO2 emissions, SUREWAVE takes a practical approach by minimizing cement content. This involves the use of low-carbon cement paired with Supplementary Cementitious Materials (SCMs) like ground granulated blast-furnace slag (GGBS) and fly ash (FA). It's a step towards meeting the rising demand for sustainable solutions without overstating the case.

But the real excitement lies in SUREWAVE's commitment to a circular model. Leveraging non-primary available resources, recycled materials such as aggregate from concrete waste and lightweight aggregate from recycled glass breathe new life into concrete mix designs. It's not revolutionary; it's a pragmatic move towards environmental responsibility.

• Connector loads and resistance with the work from Sunlit Sea (NO) & Sintef (NO)
• Floating breakwater design and mooring with Clement (DE)
• Circular concrete material designed for the Floating breakwater composition thanks to Acciona (SP)