From the technical challenges of connecting with the onshore grid to the consequences of Brexit, the U.K. will have to negotiate numerous obstacles to achieve its highest hopes for developing offshore wind’s contribution to the national electricity supply.

Until recently, the U.K. generated more electricity from offshore wind than anyone else. Although it has been overtaken by China, the U.K. remains at the forefront of exploiting this fast-growing source of energy. However, with an ever-more congested onshore grid, supply chains under pressure, and an increasingly competitive global scene, there are several major issues that industry needs to consider as it enters the next phase of developing infrastructure.

1. As demand increases, what will offshore-to-onshore connection look like?

More than 20 years after the first offshore wind farm was installed in the U.K., many of the connection points to the onshore grid are becoming saturated. What shape will the offshore part of the network take? National Grid ESO has identified within its Holistic Network Design how a more coordinated approach between onshore and offshore network design will benefit consumers and other interested parties.

This is just one option put forward in a competitive pan-European marketplace. The industry needs to consider whether a densely interconnected, meshed DC grid, often suggested as a panacea for congestion at connection points but still largely untested, is optimal for an island nation like the U.K.

A meshed “supergrid” network in the North Sea using offshore wind farms as nodes has been discussed for around 15 years. Although on paper a DC mesh has seemed like a great idea, for many technical and commercial reasons it has not yet taken off.

Is the period between now and 2030 the time when a meshed concept gains momentum throughout Europe, or is the necessary commitment so large that the network will continue to be built one long radial piece at a time? Should an element of central planning return to the European electricity network?

2. How can we improve offshore to onshore grid integration?

Whereas the U.S. is starting with a blank sheet of paper, there are already 25 years of water under the bridge for the European network in terms of international links and integrating offshore wind power. This has created a complicated, multilayered network that can’t be entirely untangled without significant changes to the network configuration and the ensuing public and political concerns. No single technology offers a perfect solution, so which of our technical tools — such as DC transmission networks, energy storage and load control with deferment — do we deploy and where?

With so many assets well into or approaching the end of their design lives, we need to explore whether system elements can be repurposed or if they must be replaced. It seems unlikely that future networks will be based on a revolutionary technology, so are we faced with sporadic evolution? Can we focus such an evolutionary approach and pick winners faster?

3. How will offshore transmission projects be financed?

There have been a few shifts between public and private finance for the offshore wind sector in the U.K. The industry went through an initial period of government-supported funding, followed by a period of private consortium funding. Now we are back to reduced public support for offshore renewables through price control and support mechanisms.

On the one hand, the costs of offshore wind are being driven down with the technology learning curve, as the increasing size of turbines and ambitious scope of projects have led to reduced installation costs and economies of scale. The expectation is that other supply chain costs will continue to decline as experience grows, albeit at a slower rate, and as the latest techniques, vessels and equipment are incorporated.

In contrast, one of the challenges in executing the new British Energy Security Strategy is the scale of investment required to continue to reduce or even stabilise prices, with the low-hanging fruit of technology development already taken. The Department for Business, Energy & Industrial Strategy (BEIS) recognises the need for private investment and the requirement for the current Contracts for Difference process to be changed to manage the significant change in the volume of renewable power being generated.

Political and social agendas are pushing the renewables market to become cost competitive, bringing in large economies of scale and requiring deep pockets to drive development. The picture is therefore murky, particularly as governments might waver on carbon reduction commitments amid recent events.

Can we expect some investment certainty for particular energy strategies on a 20- or 30-year time scale to enable the push to decarbonise?

4. Is it time to ramp up floating wind generation in deeper water?

As the shallower parts of the continental shelf become saturated with fixed-bottom turbines, the industry must consider developing much greater penetration of floating wind generation in deeper water. If this transition is made, it will be important to learn lessons from the U.S. on how to make this a success, because the U.S. deep-water sector is about to receive a large amount of investment. This will likely result in the U.S. advancing along the technology learning curve at a faster pace than the EU. Is this a repeating pattern in which the U.K. and EU perform the hard miles of research and development but then underfund deployment to capitalise on savings through ambition and scale?

The U.K. and Europe should pay attention to what is happening across the Atlantic to learn from the inevitable mistakes that will be made and the solutions that result. The ScotWind programme, which will lease areas of the seabed around Scotland and create up to 25 GW of new generating capacity, will be built over the next decade and is likely to be the largest floating wind project in Europe. For the U.K. to stay ahead of the curve, the industry needs to start thinking about how hard to push scale-up where the U.K. has weaker pull-through, so that the U.K. matures geographically relevant technologies.

5. What effect does the global resource shortage have on U.K. development?

Will there be enough resources to meet the global demand for floating wind energy generation? Countries such as Japan and China have massive demand for new energy sources and vast amounts of deep coastal waters. The moment the technology becomes available, they will want to replicate it. This could cause a global resource problem, in terms of the parts and raw materials as well as the people and technical knowledge. Other locations such as the U.S., where the energy price is higher per delivered megawatt per hour, can afford to invest more in offshore wind projects, whereas the cost/price balance in the U.K. is lower.

In addition, there is the issue of brain drain and staffing. At present, the leading players in this area are from the U.K. and Europe, but they are being pulled to offices in the U.S. and the Far East. The industry needs to consider how it can work to meet aspirations elsewhere without adversely impacting aspirations in the U.K.

All parts of the U.K. and EU supply chain will come under even greater stress. Which nations will break first and who will stay the course?

6. After Brexit, what does the U.K.-EU trading relationship look like for energy?

Exactly how the U.K. leaving the European Union will affect the offshore wind sector remains to be seen. Domestic policies, trade deals, and U.K. relationships with European partners will affect everything from regulations to raw materials. The full impact from international volatility, which has had particularly strong effects on energy supply, also remains to be seen. This final question is not for technologists or engineers, but rather for economists and politicians. It will be key to the future of the industry.


The extraordinary potential of offshore wind generation hinges on establishing effective, sustainable supply chains. A collaborative approach is vital.

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David Slee is a program manager specialising in the installation and protection of marine cables, pipelines and structures at Burns & McDonnell. He has more than 30 years of experience in the implementation and connection of renewable and nonconventional energy to the grid.