UK pushes floating wind farms in drive to meet climate targets

In waters 15km south-east of Aberdeen, renewable energy companies are preparing to celebrate yet another landmark in the drive to end Britain’s reliance on fossil fuels.

Five wind turbines, each taller than the Gherkin building in the City of London, fixed to 3,000-tonne buoyant platforms have been towed to the UK North Sea from Rotterdam where they will form part of the Kincardine array, the world’s biggest “floating” offshore wind farm.

Wind farm developers have dabbled since the 2000s with floating technology to overcome the limitations of conventional offshore turbines. These are mounted on structures fixed to the seabed and are difficult to install beyond depths of 60m, which makes them unsuitable for waters further from shore where wind speeds are higher.

Floating projects, which are anchored to the seabed by mooring lines, are rapidly moving from the fringes to the mainstream as countries turn to the technology to help meet challenging climate targets.

Britain was the first country to install a floating offshore wind farm off the coast of Peterhead, Scotland in 2017. But existing floating projects are modest in size. The Kincardine array has an electricity generation capacity of 50MW compared to 3.6GW for the world’s largest conventional offshore wind farm.

Now the bigger wind developers are stepping up a gear with plans to build more schemes on a larger scale.

Denmark’s Orsted, Germany’s RWE, Norway’s Equinor along with the UK’s ScottishPower and Royal Dutch Shell are just some of companies on a long list of bidders vying to build floating schemes in an auction of seabed rights for about 10GW of offshore wind projects in Scottish waters. The bidding round closed in mid-July with the winners expected to be announced in early 2022.

The UK is separately examining an auction exclusively for floating wind in the Celtic Sea, the area of the Atlantic Ocean west of the Bristol Channel and the approaches to the English Channel and south of the Republic of Ireland.

Developers expect the costs of floating projects to fall rapidly as more projects are deployed. In 2018 floating wind costs were estimated at more than €200 per megawatt hour, nearly double the cost of nuclear power in the UK.

The Offshore Renewable Energy Catapult, a UK technology and research centre, is hopeful developers will be able to build “subsidy free” floating projects at prices below forecast wholesale electricity costs in auctions as early as 2029. Conventional offshore wind developers reached this inflection point in a UK government auction in 2019.

UK prime minister Boris Johnson, who is hosting the UN’s COP 26 climate summit later this year, has set a 1GW floating target out of a total 40GW offshore wind goal by 2030. He has underlined the importance of accessing the “windiest parts of our seas” as part of the UK’s goal to cut carbon emissions to net zero by 2050. 

Other countries including France, Norway, Spain, the US and Japan are pursuing the technology, which experts said would particularly appeal to countries with limited access to shallow waters, or where the geology of the seabed makes it impossible to install conventional “fixed-bottom” turbines.

WindEurope, an industry body, predicts one-third of all offshore wind turbines installed in Europe by 2050 could be floating.

Countries pursuing floating wind are interested in it “not just as an opportunity to deliver net zero targets. It has a real potential to be a driver of economic growth as well,” said Ralph Torr, a programme manager at the Offshore Renewable Energy Catapult.

Much like the UK supply chain has lost out to foreign companies in the construction of conventional wind offshore farms — despite Britain having more than anywhere else in the world — there are concerns the mistakes will be repeated for floating technology. Manufacturing work for the Kincardine project was carried out in Spain and Portugal and the turbines and foundations assembled in Rotterdam.

Competition with other markets was already high as they all tried to gain a “first-mover advantage”, said Torr, who warned the UK government’s 1GW floating wind target by 2030 was not “going to unlock huge investment in the supply chain or infrastructure because it’s [just] a handful of projects”.

The Offshore Renewable Energy Catapult and developers are urging the government to commit to a second target in 2040 for floating wind, which they believe would provide confidence to industry to invest in the necessary facilities in Britain.

“Because floating [wind] becomes economic in the 2030s, it’d be much better to understand what the longer term pipeline is,” said Tom Glover, UK country chair at RWE. He added that in the Scottish seabed rights auction, developers had to “provide a commitment and an ambition for Scottish content”, which should benefit the local supply chain.

Wind developers are conscious that UK suppliers need time to gear up. Christoph Harwood, director of policy and strategy at Simply Blue Energy, which is developing a 96MW floating scheme off the coast of Pembroke in Wales, said projects that were larger than the earliest floating schemes but were not yet at a full commercial scale would be important in that process.

“If the UK supply chain is to benefit from floating wind, don’t rush into 1GW projects, take some stepping stones towards them,” he said.

Tim Cornelius, chief executive of the Global Energy Group, which carries out offshore wind assembly work at the Port of Nigg on the Cromarty Firth in north-east Scotland, said the size of floating wind turbines offered opportunities to UK suppliers. 

The floating turbines are much bigger than their conventional offshore counterparts so need to be built closer to their point of installation, which precludes using the lowest cost manufacturers in China and the Middle East.

The floating turbines require “an astonishing amount” of deepwater quayside space at ports, Cornelius explained. His company is looking at creating an artificial island for quaysides in the Cromarty Firth in Scotland, which he says would require a “material investment but is entirely justifiable as long as developers are prepared to commit”.

But he warned that “as it currently stands, the [UK] supply chain isn’t in a position to be able to support the aspirations of the [floating offshore wind] industry”.