Floating into the Future: Unlocking the Potential of Offshore Wind Energy

As we wave goodbye to another colossal year at WindEurope 2025 in Copenhagen, we are reminded of the collective passion and innovation this incredible industry has to offer. This year’s theme of Scale up, Electrify, Deliver: Putting wind at the heart of Europe’s competitiveness, was even more pertinent as Europe races toward its 2030 net zero targets.

At this moment in time, leaders from across the wind industry are looking at ways to innovate and make wind power the cornerstone of European competitiveness while simultaneously bolstering energy security, delivering affordable power, and creating thousands of jobs.

In this blog, we delve into offshore wind, floating substations and more with Hitachi Energy’s Didier Mallieu, who shares his outlook on harnessing the power of wind to accelerate the energy transition.

I am Didier Mallieu. As an electrical and nuclear engineer, I've had an exciting career managing aspects of the power sector, spanning generation and transmission, working with utilities, engineering companies, and OEMs. I am also a father and grandfather deeply concerned about our planet's future. I am convinced that accelerating electrification through Renewable Energy is essential to the energy transition we urgently need for environmental, economic, and social reasons. That’s why I've dedicated this phase of my career to this sector.

In my current role as Solution Manager for Renewables at Hitachi Energy, I am helping to drive the technology roadmap for the grid integration part of the energy transition – specifically, connecting large-scale renewable farms to power grids and strengthening those grids to reliably bring clean energy to consumers.

Offshore wind is an amazing technology. It allows for the development of very large power plants harnessing stronger, more consistent winds than typically found onshore, leading to high-capacity factors – meaning more energy generated per installed megawatt. Because turbines can be larger offshore and visual impact is reduced, we can deploy gigawatt-scale projects. The estimated global technical potential of offshore wind is vast – potentially twice or more the total current global electricity consumption. If you add solar power, which has an even larger potential, we clearly have access to tremendous renewable resources coming from the sun and wind to cover the world’s future energy needs. That’s good news, because not only will we need vast amounts of clean electricity to provide a better quality of life globally, but to also power a sustainable circular economy, and reengineer transportation, industries and agriculture.

Currently, the dominant offshore wind technology uses foundations fixed directly to the seabed to support the wind turbines and electrical substations. That technology works extremely well and is cost-competitive in relatively shallow waters, typically less than around 60-80 meters deep. In mature markets, its cost per kWh is often lower than new fossil-fueled power plants and is competitive with other renewables.

However, such shallow waters represent only around 20% of the usable ocean area globally. The vast majority (around 80%) of the offshore wind resource lies in deeper waters. To unlock this potential, we need floating technology, where wind turbines and their substations are mounted on floating platforms anchored to the seabed with mooring systems.

Therefore, Floating Offshore Substations (FOSS) are needed as the central electrical hub for large-scale floating wind farms in these deeper waters. They collect the power from turbines via dynamic inter-array cables, step up the voltage, and enable efficient transmission to shore – making it technically and economically feasible to develop the majority of the world's offshore wind potential, particularly along the Atlantic and Pacific coasts, in the Mediterranean Sea, and across the Asia-Pacific region.

Originally, most electrical equipment like transformers and switchgear, as well as wind turbines, were designed for stable, onshore conditions. Floating platforms, however, are constantly moving due to waves, wind, and currents. The primary challenge is ensuring all systems, especially the critical electrical components within the FOSS, can safely withstand these motions not just in extreme conditions (a classical mechanical design challenge to cope with accelerations and tilt), but continuously over the entire 25–30-year operational lifetime (a fatigue engineering challenge).

This requires reassessing designs and rigorous validation. That’s an exciting task for engineers and scientists at companies with a long tradition of technology leadership like Hitachi Energy. We are not starting from scratch: we leverage decades of experience delivering equipment for demanding marine environments, including Oil and Gas platforms, ships, and have already supplied equipment for the world's first floating wind turbines. Proven design tools and testing procedures from both electrical and marine engineering must be applied correctly and transparently, building investor confidence in the Technical Readiness Level (TRL) of FOSS solutions and bankability.

No single, dedicated set of standards for FOSS exists yet. Instead, current projects under development rely on a combination of existing electro-mechanical standards and marine/offshore standards. Applying these correctly requires expertise.

We must also be careful not to over-standardize too early. While standardization is key for cost reduction in the long run, premature or overly prescriptive standards could stifle the innovation needed to mature the technology and optimize designs for affordability. For example, standardizing all equipment for the absolute worst-case conditions globally might be unnecessarily costly for milder sites. Furthermore, advancements in very reliable equipment, digital monitoring systems, and optimized maintenance strategies can potentially reduce the need for high levels of redundancy, driving costs down.

So, the approach is cautious progression: yes, to standardization, but only based on sufficient project experience, and in a way that still allows for further innovation and site-specific optimization.

Sure. One of the reasons why offshore wind is so promising is because it allows for large windfarms and wind turbines, what has driven costs down. Scale is the major driver for cost reduction.

The next challenge will be to bring floating technology’s costs into the range of the other renewables technology. We already checked that AC electrical equipment is quite robust against sea movements and can be reinforced when needed for floating application. Similarly, it is easy to show that floaters’ costs will decrease as the industry grows, because the mature ship industry gives us useful benchmarks. In Hitachi Energy, we cooperate intensively with leading floater designers and yards to optimize the total cost. The first projects will need significantly more engineering checks and tests, to ensure that risks taken by the pioneers are under control, but once enough experience is gained, I am convinced that costs will be OK.

Regarding high voltage dynamic cables able to withstand floating conditions, we hear from cable manufacturers that the effect is the same: for the first projects, cables will be expensive because of additional tests and engineering, but cost will go down with scale and experience.

HVDC is also a great technology to decrease costs and electrical losses and ease integration into power grids. We are currently analyzing how to adapt HVDC equipment to floating conditions to harvest even more offshore wind potential in a competitive way.

That’s a critical question that the entire renewable industry, including turbine manufacturers and electrical equipment suppliers like us, is actively addressing. The good news is that most key materials, like steel for structures and copper or aluminum for electrical components, are relatively abundant and highly recyclable.

The transition to a circular economy is absolutely vital here. In a linear model, used materials are waste. In a circular model, they become perpetual assets – a resource you invest in once and recover repeatedly, provided you have sufficient clean energy for the recycling process.

Floating wind technology can be particularly advantageous in this respect. Dismantling a floating wind farm at the end of its life is potentially simpler than for fixed-bottom structures, as the entire platform can be disconnected from its moorings and towed back to shore for controlled decommissioning and material recovery. Communicating these circularity aspects and the true lifecycle benefits to investors and policymakers is increasingly important.

Are you ready to capture and harness the power of the wind? If you’d like to discover more about offshore wind or speak to our teams about your projects, please don’t hesitate to contact us.