Dogger Bank: profiling a true titan of wind power

14 November 2017 (Last Updated July 29th, 2020 22:01)

Ownership arrangements for the four Dogger Bank offshore wind projects, the biggest ever, have been agreed and can now move on to the financing stage and then construction. But just how much power will these colossal wind projects bring to the UK?

Dogger Bank: profiling a true titan of wind power
Dogger Bank will be the world’s largest offshore will project when fully developed, providing the UK with 4.8GW of clean, renewable power for decades. Credit: Courtesy of Forewind

In 2008, the Crown Estate identified nine offshore zones ideal for the development of windfarms. The largest of these was on Dogger Bank, a sandbank anchored between the UK and Denmark. The bank sits between 125km to 290km off the east coast of Yorkshire, and is raised higher than the seabed around it at depths of between 18m and 63m below sea level, in what was once Doggerland; a stretch of land that once connected the UK to Scandinavia.

The Crown Estate sought to develop this area to ensure energy security for the UK, with the nine blocks expected to generate a quarter of the UK’s total energy needs by 2020. The Forewind Consortium was established as a result of the licensing of these zones, made up of four energy companies, RWE (now innogy), SSE, Statkraft and Statoil, which in 2010 was announced as the development partner for the Dogger Bank.

“In 2015, Forewind successfully completed its objectives and obtained planning permission for four separate 1.2GW offshore wind projects,” says a spokesperson for innogy. “These are: Dogger Bank Creyke Beck A which covers 515km2 and is 131km from shore at its closest point; Dogger Bank Creyke Beck B, the largest of the Dogger Bank projects in an area with a size of 599km2  and, like Dogger Bank Creyke Beck A, it is also 131km from shore at its closest point; Dogger Bank Teesside A, has a size of 560km2 and closest point from shore at 196km; and Dogger Bank Teesside B, is 593km2 in size and is 165km from shore at its closest point.”

Statkaft sold its shares in the consortium in March of this year and in August, the ownership agreements for the blocks were agreed as SSE and Statoil each owning 50% of Creyke Beck A, B and Teesside A. Meanwhile, innogy would own 100% of the Teesside B block.

With the preliminary agreements finally in place, how will a windfarm of this scale and importance be realised?

The largest ever wind farms

Dogger Bank will be the world’s largest offshore will project when fully developed, providing the UK with 4.8GW of clean, renewable power for decades. This equates to around 5% of the predicted demand for power in the UK and will be transported via underground, high-voltage cables.

Each block will have a capacity of 1.2GW, or four terawatt hours (TWh) per year from up to 200 turbines. The exact size of the turbines is yet to be decided and will likely vary from block to block depending on the best fit for the terrain. They will all be fixed to the seabed and arranged around a central, high-voltage direct current converter platform.

Innogy, along with Statoil and SSE, is keen to keep the project moving and begin construction as soon as possible. “The ability to progress the project within the required timescales will very much depend upon when the next CfD auction takes place,” says the spokesperson. “For many reasons, it is important that government make these dates available as soon as possible.”

For a project of this size, obtaining all the necessary permissions will undoubtedly take several years. “Any timescales for the project, which we plan to rename at some point, will therefore depend on any future CfD,” the spokesperson continues. “However, we would hope to be in a position where we are able to have a Financial Investment Decision secured by 2020 with a view to commencing construction in 2022.”

As global demand for energy grows year on year, and renewable technologies continue to push reliance on green power, energy sources must be increased. In September, it was announced that offshore wind power is now cheaper than nuclear and natural gas in the UK, news celebrated by many.

“Today’s results are further proof that innovation in the offshore wind industry will bring economic growth for the UK on an industrial scale,” said Hugh McNeal, chief executive of RenewableUK at the time. “The UK needs to establish new trading opportunities as we leave the European Union, and the UK’s offshore wind sector is a world leader in a global renewable energy market currently worth $290bn a year.”

The Dogger Bank project will be an important asset for British power, with each of the four windfarms reducing CO2 emissions by almost two million tonnes per annum. At double the size of any windfarm constructed to date, each farm will be able to power a million homes.

The experience to face challenges

The ownership agreement was a big step for the Dogger Bank project and following it, Forewind will officially shut down, having delivered its objective. SSE, Statoil and innogy must now move forward with the projects, tackling challenges along the way.

“There are always challenges when building a large infrastructure project out at sea; however, we are very fortunate to have such an experienced team supporting the development,” says innogy’s spokesperson. “The location of the windfarm is favourable too, with fairly shallow water and an existing grid connection point in Teesside.”

All three are experienced companies that have worked within the windpower sector for years. Statoil’s first commercial offshore windfarm became operational in 2011, positioned off the coast of Norfolk, Sheringham Shoal, consists of 88 turbines and powers approximately 200,000 UK homes. The farm marked the beginning of the companies move away from oil and towards the renewables sector. Dogger Bank will be the sixth offshore wind project the SSE will embark on, alongside over 50 onshore windfarms.

Innogy has now been working in the offshore wind sector for over a decade, over which time a lot has changed. This experience will be essential for a project of the scale of Dogger Bank. “The journey started around fourteen years ago when we developed and built the UK’s first commercial-scale offshore windfarm, North Hoyle, at 60MW,” explains innogy SE director of investment and asset management for offshore wind Richard Sandford. “At that point, we as an industry were really just taking the first tentative steps into offshore wind. For example, we were using adapted fishing boats to support offshore construction. Fourteen years doesn’t seem that long ago, but in industry terms, particularly in terms of technological and cost reduction advancements, it is a lifetime.

“Since that period, the industry has been using bigger turbines with bigger foundations, creating larger capacity windfarms,” continues Sandford. “We have gone through a positive learning curve around supply chain, leading to more collaboration as companies become more capable and experienced; design is more reliable and technology has adapted to meet the industry’s requirements; and installation is often quicker for both for foundations and turbines.”

The offshore wind industry continues to grow larger by the year and with it the turbines and farms. Dogger Bank will be an important source of clean power for the UK, but there will undoubtedly be challenges along the way.