Developing efficient, scalable energy systems with a modular approach
The sea is always in motion. Even when it appears calm and the wind is weak, it can still generate waves that travel for hundreds or even thousands of kilometres. This movement carries a vast and steady flow of energy, a renewable resource that can be converted into electricity.
Yet, despite its potential, wave energy is still a marginal player in the global energy mix. The main barrier lies in the efficiency and robustness of wave energy converters (WECs), the systems that convert wave motion into electricity. Operating in the harsh and unpredictable conditions of the open sea, these devices face a constant risk of failure, which makes it particularly challenging to guarantee long-term performance.
A New PTO designed for reliable, long-term wave energy conversion
This is the starting point for the MEGA WAVE PTO project, whose goal is to design and test a new power take-off (PTO) system. The PTO system is the core component of WECs responsible for capturing wave motion and converting mechanical energy into usable electrical power.
The project is supported by the Horizon Europe programme and is aligned with broader EU strategies such as the Green Deal and the Sustainable Blue Economy. Moreover, it is carried out by a robust European consortium. Among its partners are CETO Wave Energy Ireland Ltd., CGEN Engineering Ltd, Mocean Energy, Cheros SRL, WavEC Offshore Renewables, Scuola Superiore Sant’Anna, and the University of Edinburgh, along with institutional members like Ocean Energy Europe. The project started in May 2024 and is scheduled for completion in 2028.
By developing a new modular, fully electric PTO system, the project aims to improve overall system reliability and significantly reduce operational costs. These improvements are key enablers for the commercialisation of wave energy. But also for its effective scalability and integration into the European Union’s renewable energy strategy.
Moreover, these goals align with Europe’s broader effort to reduce its dependence on imported energy, an increasingly urgent priority in today’s uncertain geopolitical landscape.
Why wave energy is Europe’s next bet
Wind and solar are currently leading the clean energy transition. However, their output is inherently variable. It depends on sunlight and weather conditions, factors that can lead to fluctuations in supply and put pressure on power grids. Wave energy, by contrast, offers a more stable and predictable energy profile. Its natural movements persist even when the ocean appears calm.
Moreover, wave motion can be forecast with a high degree of accuracy, allowing operators to estimate in advance how much energy will be generated. This enables more efficient grid management and reduces the risk of sudden peaks or drops in supply. More over, this lower the need to activate gas plants or other fossil sources as backup during periods of low renewable output. As a result, wave energy enhances grid reliability and complements intermittent sources like solar and wind, increasing the overall resilience of the energy system.
This resilience is further reinforced by the high energy density of waves. Compared to wind or solar radiation, waves carry more energy per square metre, making them particularly well-suited for areas with limited space and high energy demand. That means space such as islands, coastal communities, and offshore installations.
In terms of global potential, the numbers are striking. According to the Intergovernmental Panel on Climate Change, wave energy could generate up to 29,500 terawatt-hours per year. That’s nearly ten times the current electricity consumption of the European Union. With more than 66,000 kilometres of coastline, Europe is in a strong position to lead in this field. Countries with high wave exposure, including Portugal, Ireland, Spain, France, the UK, and Italy, could become early adopters and drive forward energy independence.
Barriers to scaling ocean power
Despite decades of research and pilot projects, wave energy technologies have yet to achieve large-scale commercial deployment. At the core of these struggles are WECs, which, unlike wind turbines or solar panels that operate in relatively controlled environments, are constantly exposed to a harsh marine environment. They face a constant risk of failure due to corrosion, saltwater intrusion, mechanical stress, and extreme weather. Designing systems capable of withstanding these factors without compromising performance remains both technically demanding and costly.
The PTO system represents one of the most vulnerable components. In fact, the irregular and multidirectional nature of wave motion exposes it to fluctuating forces that accelerate wear and increase the risk of failure. Many prototypes perform well in laboratory settings but fail to maintain performance once deployed at sea.
Additionally, cost remains another critical issue. Building, installing, and operating WECs typically requires more resources than established renewable technologies such as wind or solar. The levelised cost of energy (LCOE) for wave power is still significantly higher, largely due to the need for frequent maintenance and specialised marine operations. In particular, the cost of operation and maintenance (O&M) can account for a disproportionate share of total expenses, limiting the viability of long-term installations and discouraging private investment.
Finally, the lack of standardisation in the sector further limits its scalability. Most WECs are engineered for specific wave conditions and locations. As a result, their applicability in different environments is limited. This hinders the development of unified design approaches that support industrial-scale manufacturing and cost reduction.
A new generation of Power Take-Off systems
These technical and economic constraints have placed wave energy in a kind of “valley of death”, a stage where innovation exists but cannot cross into mass deployment. However, this context could change significantly with the MEGA WAVE project. The project aims to address one of the main barriers holding back the sector by introducing a new generation of modular PTO systems.
Modular and standardised PTO solutions for wave energy converters
Unlike traditional PTOs, which are often tailor-made for specific devices or locations, MEGA WAVE PTO is designed as a flexible system that can be integrated into different types of WECs. This adaptability allows for easier customisation based on site-specific wave conditions. It enables designers to tailor systems more effectively to local environments. At the same time, it contributes to the broader industrial goal of standardising components in the wave energy sector. This is particularly relevant in a field where the lack of common technological benchmarks has slowed progress and increased costs.
Modular components also simplify maintenance and make it possible to upgrade or replace parts without redesigning the entire system. Each module operates independently. So if one unit fails or requires maintenance, the others can continue functioning without interrupting the overall system. This fault-tolerant design significantly increases the reliability of the converter and is particularly advantageous in offshore environments, where access for repairs can be limited and costly.
Furthermore, the PTO system is fully electric, eliminating the need for hydraulic or pneumatic components, often associated with complex architectures and higher maintenance demands. Without these elements, the system becomes mechanically simpler and more compact, which further streamlines integration into different WEC designs. In addition, electric actuation allows the PTO to respond quickly and precisely to the constantly changing motion of ocean waves. Unlike fluid-based systems, which are slower to adjust, electric components can instantly adapt to variations in wave height, speed, and direction. This real-time responsiveness ensures efficient energy conversion under variable marine conditions, maximising performance while minimising mechanical stress.
Magnetic gears and smart monitoring for high-reliability operation
Another key innovation of this PTO system is the use of magnetic gears, which operate without physical contact. By relying on magnetic coupling rather than mechanical engagement, they eliminate friction, significantly reduce wear, and improve overall system durability. When combined with permanent magnet generators, which are known for their high efficiency and reliability, the system can maintain strong performance even at low wave speeds, ensuring more consistent energy production.
Moreover, integrated condition monitoring and control systems are embedded within the PTO. In this way they continuously track the operational status of key components and collect real-time data on parameters like temperature, vibration, and mechanical load. These diagnostics enable predictive maintenance strategies. In fact, they allow operators to identify early signs of wear or malfunction before they result in system failure. This approach significantly minimises the need for costly emergency repairs or offshore interventions. These needs are particularly complex and expensive in marine environments.
The dual-phase validation
One of the most promising application areas is remote or decentralised energy systems. Many islands, offshore facilities, and coastal communities still depend on imported fossil fuels. In such settings, a stable and autonomous power source like wave energy can offer a cleaner, more reliable alternative while also creating new opportunities for local innovation and economic growth.
The technology will be validated through a dual testing phase. The first is a 1 kW prototype under controlled laboratory conditions. The second one is a 100 kW system in a real-sea environment. This approach allows for the assessment of both component-level performance and system-level integration in operational scenarios. Testing will focus on reliability, efficiency, resilience to marine conditions, and adaptability to different types of WECs.
Expected results are promising. The project aims to reduce the LCOE by 30 to 40 percent and cut O&M costs by half, while significantly improving reliability and scalability. MEGA WAVE PTO could set a new standard for the sector. It could also accelerate the commercialisation of wave energy and contribute to a more diversified and resilient renewable energy mix in Europe.
In addition, using recyclable materials in key components supports more sustainable end-of-life management and aligns the system with circular economy principles. This approach helps reduce the environmental footprint of wave energy technologies and reinforces their role in achieving the EU’s net-zero emissions targets by 2050.
References:
- Mueller, M., Vicente, M., Bastos, P., Brito e Melo, A., Burchell, J., Galbraith, M., Skarmoutsos, G., Ab Rasid, S., Britton, C., Gyftakis, K., Fontana, M., Vertechy, R., Jeffrey, H., Forehand, D., Merlin, M., Roeder, J., Zweifel, M., Brewster, P., Retzler, C., Santos Herran, M., & Chubb, L. (2025, July 17). Modular Electrical Generator Power Take-Off System for Wave – MEGA WAVE PTO. In Proceedings of the 16th European Wave and Tidal Energy Conference (Vol. 16).
- Sergakis, A., Salinas, M., Gkiolekas, N., & Gyftakis, K. N. (2025, February 27). A review of condition monitoring of permanent magnet synchronous machines: Techniques, challenges, and future directions. Energies.
Fox, J., & Merlin, M. (2025, August 31). Deliverable D2.2 – System Modelling and Power Electronics Design Assessment (Report No. D2.2, Version 1.0). In Modular Electrical Generator PTO System for Wave – MEGA WAVE PTO (Grant Agreement No. 101147321).
