Evolution not revolution: Q&A with Chris Willow, head of floating wind development at RWE

The Global Wind Energy Council (GWEC) has projected that floating wind will rise to six per cent of total offshore wind capacity in 2030 and approximately 15 percent of the global offshore wind market in the long term.

International electricity generation company RWE has been at the forefront of floating wind development. It has unveiled three high-profile demonstration projects to provide insights into the challenges and opportunities of different structure types, materials, mooring systems and installation methodologies. Additionally, it has been active in securing several offshore leases, most recently procuring an area with a capacity to develop up to 1.6 GW of floating offshore wind off the California coastline.

Inspiratia insights

• Unlike seabed fixed installations, there won't be a one size fits all design that will dominate the industry, and different regions will have different drivers.

• Using dynamic cabling rather than static to connect turbines to the substations is the biggest challenge in achieving the requisite transmission infrastructure for floating wind.
  
  
• Floating wind will see a more rapid proliferation globally than fixed seabed, with several large-scale players already investing in the market.
  
  
• Regulators will need to tweak policy as floating wind will not be able to compete on a like-for-like basis with seabed fixed capacity, so it is essential that in different markets, it is treated separately from the seabed fixed sector.
  
  
• 2023 offers significant opportunities for the floating wind sector, with several auctions coming up where floating wind will be on the agenda.

What opportunities does floating wind offer compared to fixed bed offshore and onshore wind?

The obvious benefit of floating wind is that it unlocks new areas by enabling offshore wind deployment in areas that would not be possible using seabed fixed.

The seabed fixed industry has grown up in the basin of the North Sea, the Baltic Sea and the Irish Sea, where you have a combination of high wind speeds, relatively shallow waters and close proximity to large load centres.

The benefit of floating wind is that we can now deploy offshore wind further out to sea in greater water depths. Floating wind does require the same combination of factors to be effective but unlocks the opportunity for more extensive development of large-scale renewable energy across more extensive areas and jurisdictions.

One of the major challenges of commercial-scale floating wind is the upscaling of the supply chain. How will RWE engage with the supply chain to ensure that it can support a commercial-scale industry?

The key point for me is that floating wind is an evolution of seabed fixed, not a revolutionary new technology. This is especially important when talking about the supply chain. Floating wind will indeed be on a much larger scale than today, and if we were to build up a supply chain from scratch, it would be a huge undertaking. But we are piggybacking on the progress the seabed fixed market has made over its development, especially in the last ten years.

For example, with turbines, there has been massive supply chain development for the seabed-fixed market, meaning the capacity to build large-scale turbines is already present. This will significantly reduce the transitionary period for floating wind, fitting comfortably into the market. There will be some software changes, but fundamentally, it will be the same turbines used in seabed fixed installations.

The construction of the foundations is the space which will require the development of new manufacturing capacity. Still, it won't represent a wholesale change. Many of the same players which fabricate seabed fixed foundations will be able to adapt to offer floating concepts as well.

That doesn't minimise the technical challenges in constructing these foundations. However, it is a huge difference from where we were in 2010, so it is more about understanding the differences between seabed fixed and floating and working through them systematically.

The experience RWE has in deploying a gigawatt-sized seabed-fixed offshore project in the North Sea will be central in delivering a future gigawatt-scale floating wind project. RWE plans to proactively and extensively engage with the supply chain to gain a better understanding of what is needed to build up a robust business case for investment and growth. RWE has already conducted detailed supply chain engagement to understand specialist skills, identify capability gaps and explore opportunities for closer collaboration.

RWE is participating in three high-profile floating demonstration projects, all with different turbine sizes and structural designs. What is the rationale behind these differing demonstration projects, and what does RWE hope to demonstrate?

What is interesting about floating wind compared with seabed fixed, which has consolidated into two designs, is that we have 100 or more different designs available on the market, with each bringing different features to the market and other kinds of benefits and challenges.

We are conscious that we must fully understand all the drivers that will make the most successful floating wind concept over the next 10-20 years. We also understand that choosing the right concept is a complex process, based not only on technical performance but manufacturability and the impact of the structure on other sea users in the mooring layout and assembly process.

Subsequently, RWE believes that there won't be a one size fits all design that will dominate the industry, and different regions will have different drivers.

This is why we have taken a diversified approach to our demonstration projects. For example, the TetraSpar demonstrator is a steel tubular structure in the North Sea, and the DemoSATH is a concrete barge structure in the Atlantic.

We can consider which is optimal for successful, safe, and cost-effective deployment by analysing these projects. So, we're using these experiences and communicating with other designers and institutes to build a more holistic approach to understand and predict where the future will be. Crucially, the learning that we get from these projects will help drive down costs and minimise risk for our commercial-scale projects in the future.

How critical is collaboration in the upscaling of the sector? Is RWE seeking any collaborative agreements?

Collaboration can take different forms. The floating wind sector will immediately be a global market. For a company like ours with a historical focus on Europe but a growing global focus, we will need to find partners in different markets who can give us insights into particular markets and understand how policies differentiate and what stakeholders require.

We have collaborative agreements on seabed fixed and floating projects in Japan and Taiwan. Those partners provide the insight we couldn't obtain on our own. Additionally, as we are a large-scale seabed fixed developer, we're talking to the major players in the supply chain to get a good understanding of the main concerns in floating development ahead of time, understanding their challenges and collaborating on how to solve them.

RWE is actively collaborating with other developers in joint industry projects, such as the Carbon Trust (CT), the Offshore Renewable Energy Catapult's Floating Wind Centre of Excellence (OREC FOW CoE) and France Energies Marine (FEM) to address shared issues and to overcome industry-level barriers. In addition, we have floating wind-related partnerships with companies in France, Japan, Korea, Norway and the UK.

Does the transmission infrastructure exist to support a large-scale floating wind industry? 

For floating offshore wind farms, you must use dynamic cables rather than static ones to connect your turbines to your substation. Dynamic cables are not a new technology, but they have yet to be deployed at a large scale for offshore wind, so there is a need to build practical experience.

However, going back to the idea of evolution, not revolution, the transmission system for a floating wind farm will look and feel pretty similar to a seabed fixed project. We will use the same substation equipment and have a large export cable from the substation to the shore. Additionally, the onshore substation and plugging into the onshore grid will be identical.

The primary benefit of floating wind is that it will allow a market like the UK, which currently has a high concentration of offshore capacity in certain areas, to plug in offshore wind generation in different parts of the market, such as the Celtic Sea or Scotland.

Therefore, floating wind's geographic diversity will support the system from being skewed towards a specific region, reinforcing the grid, and avoiding the high peaks and troughs of generation.

Of the 57.1MW of floating wind installed in 2021, 48MW was in the UK. Will the UK remain the hotbed for floating installations? Outside of the UK, which jurisdictions do you see having the biggest potential growth?

The UK's offshore wind sector has been a real success story, and it has built up the skills, knowledge and supply chain which translates into the floating sector. The challenge is that the market is proliferating globally, and other countries have similar ambitions. In the next couple of years, we will see several French pilots come online, with France taking the industrial opportunity of floating wind very seriously. Korea has also shown genuine interest, with significant activity in the sector off the coast of the city of Ulsan. Additionally, the US is likely to be a significant player. Japan also has great potential, and due to its deep waters, it will require much of its offshore capacity to be floating installations. Finally, Norway has a lot of potential as it has a highly developed supply chain and port infrastructure from its development of oil and gas rigs. Its government hopes to use this expertise in the renewable sector to create a North Sea super grid.

Therefore, the UK will not be as clearly ahead in floating as it is in the seabed fixed market. However, this is a positive as the technology it pioneered through this early stage will be delivered worldwide, providing opportunities for companies to export those skills to other markets.

How is current regulation affecting floating wind projects? Does there need to be a better framework?

The policy regimes established for seabed fixed will be able to incorporate floating very quickly, removing the trial-and-error process as we advance. In addition, mechanisms such as the contracts for difference schemes in markets like the UK will be central in providing investors' confidence while also giving consumers good value driving cost reduction.

In the short term, floating wind will not be able to compete on a like-for-like basis to seabed fixed capacity, so it is important that in different markets, it is treated separately from seabed fixed so that it can compete to secure current contracts, grow in scale and reduce its cost.

Floating wind will require some tweaks in policy, with some markets wanting to see greater local involvement, but fundamentally the policy regime for seabed fixed is going to be suitable for floating.

This is a real advantage in that it gives developers working in developed markets confidence that the policy regime is already there. It also means that markets looking to set up a floating wind industry can look to the best practice of those established markets and import it into their own.

What upcoming deals do you have on the table that you are most excited about?

Firstly, winning in California was significant, securing an area with a capacity to develop up to 1.6 GW of floating offshore wind.

It's a validation of a lot of the work we've done in RWE to establish ourselves as a market-leading player. The site we secured has a water depth of more than 700 metres, so there are some big challenges to resolve, but we have the in-house technical capability and insight to do this.

Looking towards 2023, we have several auctions coming up, namely the Brittany South auction, the French Mediterranean I and II auctions, the Utsira Nord auction in Norway and the Celtic Sea seabed lease in the UK.

Therefore, these are the processes that our project teams are actively working on, and they are gearing up to be as competitive as possible in the coming year.