A Sea Change in Energy Thinking

Offshore wind farms could be a key part of the energy solution as the world works towards a low-carbon future. But challenges of cost, technology, collaboration, and institutional support must be overcome for them to be an effective and viable long-term option.

A Sea Change in Energy Thinking

By Patricia Seoane da Silva, Lux Research


Rapid technological developments in recent years have brought about a sea change in green energy thinking and generated a rising tide of global interest in offshore wind farms.


Last year alone, China installed around 17 gigawatts (GW) of offshore wind capacity – more than the combined total built by every other country in the world over the past five years. China now has around 26GW of offshore wind capacity – almost half the worldwide total of 54GW.


Hong Kong is meanwhile looking to get in on the act as it works towards a target of achieving carbon neutrality by 2050, in part through the development of zero-carbon and renewable energy, including wind energy. 


The city’s biggest energy provider, CLP, is carrying out a feasibility study into an offshore wind farm in the south-eastern waters of Hong Kong. Early findings indicate improvements in turbine technology and costs make offshore wind farms an increasingly viable medium-term option.


To find out more about the potential for offshore wind farms in Hong Kong, watch this video.



In Europe, Japan, South Korea, and Taiwan, there has been a strong push to increase offshore wind capacity – but the technological potential continues to be limited by the elevated capital costs involved.


The key to achieving the cost reductions necessary involve economies of scale, collaborative innovation, and institutional support. 


Foundations for growth

Foundations represent around 29% of the capital costs of offshore wind farms, according to a report from the U.S. Department of Energy’s National Renewable Energy Laboratory. This means that their mass production would significantly reduce costs.


Assuming cost decreases by 15% for every doubling of production volume, the capital costs for floating wind could decline by nearly 40% if the number of installations increased by an order of magnitude. 


Common topologies of offshore wind turbine foundations include semi-submersible, tension leg platform, and spar-buoy.
Common topologies of offshore wind turbine foundations include semi-submersible, tension leg platform, and spar-buoy.

As well as seeking economies of scale, the industry will also need to narrow down the wide range of designs and configurations that exist today. The dominant foundation topologies today are semi-submersible, tension leg platform (TLP), and spar-buoy.


Semi-submersible foundations have taken the lead in the market thanks to their simpler installation and maintenance, where the entire structure is mounted onshore and towed to site without expensive heavy-lift operations.


A tension leg platform is conceptually similar to semi-submersibles except that the foundation is anchored to the seabed with tensioned mooring lines that results in high horizontal stability, but this also makes installation and maintenance more complex.


A spar-buoy foundation made popular by Equinor is suitable for mass production thanks to its hull geometry, but it requires on-site assembly which calls for significant offshore environment expertise.


While the three foundation topologies currently dominate the floating wind landscape, other novel designs with potentially lower cost per watt ratios – such as mini-turbine platforms – are being experimented with.


While conceptually advantageous, these designs are unlikely to succeed due to their mechanical complexity, and the industry is expected to lean towards semi-submersible foundations and, to a lesser extent, spar-buoy foundations.


Innovative partnerships

Offshore wind technology is far from mature, and environments further offshore need to be better understood for the technology to turn today’s interest into practical commercial deployment.


The industry must gain better understanding of wind and wave interactions, as the natural frequency of offshore wind turbines is significantly higher than that of bottom-fixed turbines – more than 100 seconds, as opposed to less than three seconds.


This difference makes offshore wind turbines more prone to heavy oscillations, which calls for renewed design rules to mitigate the increased effect of structural fatigue.


In addition, available wind resources at waters deeper than 60 metres need to be accurately assessed to optimise power production and develop offshore wind farm design procedures.


Collaboration is critical, and the industry is beginning to see industry leaders like Equinor partnering with Masdar and ORE Catapult to share offshore wind data.


Similar formal and informal partnerships need to be replicated. Collaboration between developers, energy companies, and governments are essential for the industry to grow.


Institutional support

In the final analysis, offshore wind remains a relatively expensive form of power generation, and financial support is needed to secure its long-term adoption.


Combined with the decarbonisation efforts of countries which may otherwise lack the land resources for conventional wind farms, top-down government initiatives remain a pivotal third factor for offshore wind development. 


China, for instance, has set targets for its combined wind and solar power capacity to increase to 1,200GW by 2030 and for renewable energy to account for over half of total installed power generation capacity by 2025.


Among the measures outlined by the National Energy Administration, the country will promote offshore wind clusters with 10GW-level bases in its eastern coastal areas, including the Shandong Peninsula, the Yangtze River Delta, southern Fujian, eastern Guangdong, and the Beibu Gulf. 


China’s 18,000 km of coastline has more than 3 million square kms of area suitable for wind power development.


The 2050 offshore wind capacity target set by the European Union (EU) is another good example of this challenge. The EU is continuing to investigate various forms of financing for offshore wind projects to promote the deployment and eventual achievement of this goal. 


Countries, including those in the EU, are promoting and investing in offshore wind development.
Countries, including those in the EU, are promoting and investing in offshore wind development.

Research and development support must also continue, as well as participation from key infrastructure players to enable offshore wind turbine assembly and installation. A successful example of this is the port of Rotterdam, where an expansion of offshore wind power generation facilities is being progressively implemented.


Institutional support is the key to unlocking existing infrastructure and bringing together key stakeholders to establish an effective long-term offshore wind supply chain.