Offshore wind floating system demonstration project

Paul Boughton
The Energy Technologies Institute (ETI) is investigating whether it could use Wave Hub, the world’s largest wave energy test site, to accommodate floating offshore wind turbines as part of a demonstration project valued at over £25 million.

Plans for the offshore wind floating system demonstration project, which would open up new areas off the coast of the UK and help bring generation costs down, were announced by the ETI in October 2011.

The project will see the design, construction and installation of a floating system demonstrator by 2016 at a site with high wind speeds up to about 10 metres per second in water between 60 and 100 metres deep.

It will be operated for at least two years to show it can generate high levels of electricity, be maintained without using specially designed vessels and to verify the predicted technical and economic performance.
Wave Hub consists of a gird-connected ‘socket’ on the seabed approximately 10 nautical miles off the north coast of Cornwall in South West England.
Designed to test arrays of wave energy devices in eight square kilometres of sea, it has been commissioned by the ETI to complete a study to investigate whether the waters around Wave Hub would be suitable for testing floating wind turbines as part of the project.

It is estimated that the UK has over a third of Europe’s potential offshore wind resource – enough to power the country nearly three times over. Tapping into this economically, particularly in deeper waters off the west coast of the UK, will require significant technology developments and floating wind could be a solution.

Wave Hub has four berths in total. Two of these have already been reserved by wave device developers Ocean Energy Limited of Ireland and Ocean Power Technologies, based in the US and UK. Two berths remain, each measuring one kilometre by two kilometres.

Dr David Clarke, ETI Chief Executive said: “The ETI is seeking potential sites to host the demonstration project and we will be working with Wave Hub to see if it could be suitable for hosting the offshore wind floating platform. This is a challenging project and will need local marine engineering skills and support facilities as well as the right water and wind conditions.

“The concept for the floating platforms is to be able to access near-to-shore, high wind speed sites off the west coast of the UK which would bring down the cost of generating electricity so the Wave Hub site offers some interesting possibilities.”
Claire Gibson, Wave Hub General Manager, said: “We have commissioned a study to investigate whether the Wave Hub site is suitable for testing floating wind turbines in response to the approach made by ETI. This study will establish whether the site has the necessary characteristics and if a single wind turbine demonstrator project is deliverable at Wave Hub.
“We have a particular advantage in that the offshore grid infrastructure and onshore substation are already in place, and we also have a team that has experience of managing the design, consent and installation of offshore energy projects. We clearly need to consult with a wide range of groups and other sea users about this opportunity and this forms an important part of the study.”

The feasibility study is being funded by the ETI and carried out by Halcrow.  It is expected to be completed before the summer.

The ETI’s Request for Proposals for companies interested in taking part in the demonstration project closed on 27 January with a high level of interest from organisations in the UK, Europe and beyond.
The selection process has now started and it is expected that the contract will be awarded early next year.

A study commissioned by the South West RDA (Regional Development Agency) and published in 2010 calculated there are sufficient marine energy resources for commercial use within 50km of the South West coast to deliver 9.2 Giga Watts (GW) of electricity, equivalent to the annual needs of 20 per cent of UK households, or 5 per cent of the UK’s electricity needs by 2030.

Of this, 2.5GW could come from deep-water floating windfarms, 1.2GW from wave energy, 1.1GW from tidal stream, and 4.4GW from offshore wind, much of it from two existing offshore windfarms planned in the Bristol Channel and off the Dorset coast.

The UK government recently announcement that South West England is the UK’s first Marine Energy Park. This embraces the opportunity of generating offshore wind in addition to wave and tidal energy.

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