Demo sites pave the way for offshore wind's future

The UK is among the front runners in developing offshore turbine test facilities. Several demonstration projects are under construction or planned at sites around the country

Two Siemens 6MW turbines were installed for offshore testing at Gunfleet Sands in early 2013
Offshore turbine technology has come a long way since 1991, when 11 450kW Bonus Energy turbines were installed at Denmark’s Vindeby development. More than 20 years later, offshore wind has become a firmly established feature of European electricity generation.

But taking the industry to the next level — large-scale projects deploying significantly larger turbines, further from shore, and doing so cost-competitively — is now the focus for many. Proving the technical and economic viability of "next-generation" turbines is crucial to the industry’s development, and it is here that demonstration sites will play a central role.

The UK is at the forefront of their development, with a number of sites under construction or planned. Among the largest is a project by the National Renewable Energy Centre (Narec) off Blyth, Northumberland. The proposed £400 million (€500 million) project — Narec’s largest to date — would be of up to 100MW capacity. It would feature up to 15 turbines, arranged in three arrays. Each array would
be no bigger than 33.3MW, so combinations of four 7MW turbines, five 6MW turbines or six 5MW units would all be feasible.

The goal is to provide a testing ground for next-generation turbines in a near-shore, deep-water environment. The facility would reflect the conditions found at more distant North Sea sites. At Dogger Bank, for example, 125 kilometres off the Yorkshire coast, water depths of 18-63 metres are to be found. The depths just 12 kilometres off Blyth are 35-58 metres.

The Blyth demo site would require all the infrastructure of a Round 3 project and closely resemble one, albeit on a smaller scale. It would allow foundation and turbine combinations to be tested in a deep-water, grid-connected, low-cost environment. These new testing facilities would sit alongside established onshore testing and logistics facilities. With an application submitted to the Marine Management Organisation in March 2012, the consenting process remains on track. Narec hopes to receive the green light this summer and bring the project online by 2015.

Scotland at the forefront
Further up the east coast, the European Offshore Wind Deployment Centre (EOWDC) in Aberdeen Bay is also making progress. Aberdeen Offshore Wind Farm Ltd — a joint venture between Swedish power company Vattenfall and Aberdeen Renewable Energy Group (AREG) — filed an application for the project in August 2011. An addendum was submitted in July 2012 and the Scottish government gave its consent in March 2013 for the development of a project of up to 100MW.

Iain Todd, project spokesman for EOWDC, considers the Scottish government’s approval extremely positive news for both Scotland and the UK’s offshore wind industry. He says it will help "position Scotland, the UK and Europe at the global vanguard of the sector". The plans call for the installation of 11 turbines, 2.0-4.5 kilometres offshore, providing a facility for turbine manufacturers to test their technologies in an offshore environment. Work to address the consent conditions is due to commence shortly, in liaison with Marine Scotland and statutory advisers. Offshore construction could start in 2015.

Scotland’s west coast is also set to host offshore turbine test facilities. Clydeport’s Hunterston site in North Ayrshire is the focus of a 24MW demo project, under development by utility SSE and Scottish Enterprise. An extension of SSE’s Centre of Engineering Excellence for Renewable Energy, it will host the development and testing of up to three turbine prototypes over a five-year period. Scottish Enterprise is actively backing the test centre’s delivery and is investing £4.3 million from the National Renewables Infrastructure Fund.

Hunterston is an onshore site that offers a number of advantages for testing offshore turbines. The site’s wind resource replicates offshore conditions and it is already grid-connected. And testing offshore turbines onshore will provide 24-hour access for modifications and repairs, an important consideration for early series prototypes.

SSE submitted a planning application and environmental statement for the project to North Ayrshire Council in September 2011. Five months later, planning consent was granted. With site-enabling works completed, site mobilisation began in February 2013. Construction work started in early March.

The foundations will be installed over the coming months and the first turbine components are scheduled for delivery in August. The first two turbines should be installed by September and the site should be operational by October 2013.

Hunterston will feature three turbines: one from Siemens, one from Mitsubishi and a third from another supplier. The third will be installed on the berth to be operated by Scottish Enterprise. It will be leased to a manufacturer with firm plans to invest in the Scottish offshore wind supply chain. In March, Scottish Enterprise invited expressions of interest from potential tenants.

Big turbines
A single-turbine demo project is also nearing fruition on Scotland’s east coast. South Korean firm Samsung Heavy Industries announced in January that it would base its UK offshore wind activities at the Fife Renewables Innovation Centre in Methil. A 19-strong team will be based there to develop the 7MW demo project.

The project will see the installation and testing of Samsung’s 7MW offshore turbine over the next five years. Work started on the onshore meteorological mast in November, and the jacket foundation is due for delivery shortly. Subject to Scottish government approval, turbine installation would follow.

Recent months have also seen the 12MW Gunfleet Sands 3 project take shape. Located in the Thames estuary, beside the Gunfleet Sands 1 & 2 offshore wind farm, it is Dong Energy’s first UK demo site and will host the first offshore tests of Siemens’ new 6MW turbines. Installation of a pair of SWT-6.0-120 units was completed in January — the first time the turbines have been installed at an offshore location.

In March, Siemens received approval from GL Renewables Certification for offshore testing to start. Commissioning at Gunfleet Sands 3 was completed in April and Dong will shortly begin a programme of tests to verify the turbines’ performance, reliability and functionality.
With ambitious offshore wind targets in the years ahead, but limited sector-specific industrial development so far, the UK has the opportunity to prove through its demonstration sites that it is serious about the sector’s future.