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Going off the deep end in 2010

2010 looks like being the year when offshore wind power takes off globally in a major way. Europe is currently the global leader – during 2008, 366 MW of new offshore wind capacity was installed, bringing the cumulative total in EU waters to 1471 MW. And the UK is for once at the front of the pack- having overtaken Denmark last year with over 600 MW installed. Longer term, the European Wind Energy Association says cumulative offshore wind capacity in Europe may reach 40 GW by 2020 and 150 GW in 2030.

So far, the largest project planned is the 1 GW London Array in the Thames estuary, with work expected to start early next year, and completion of the first 630 MW part scheduled for 2012. But shortly details will emerge of the nine winners in the UK’s ‘Round Three’ offshore wind project competition, which could see wind farms of up to 5 or even 10GW being established off the east coast.

Initially, in the first phase of offshore wind deployment, on-land wind turbine designs were in effect ‘marinized’ for offshore use, and located relatively near to shore. But now new design concepts are emerging specifically for the challenging offshore environment. They are larger: several 10 MW offshore turbines are currently under development, including Clipper wind’s Britannia, and the novel vertical-axis ‘Nova’. And they involve new ways of installing them further out to sea: seven radical new designs for offshore wind turbine foundations have been identified by the Carbon Trust, in a global competition involving over 100 candidates from engineering companies around the world. Selected designs include floating turbines anchored to the seabed, and spider-like tripod structures, along with more conventional monopiles – steel tubes driven into the sea-bed.

The overall aim of the Carbon Trust programme is to accelerate the construction of offshore wind farms by reducing construction costs and overcoming key engineering challenges of going further out to sea, in deep water up to 100 miles out, in depths of up to 60 metres, or maybe more. Up to three final winners will have their designs built and installed in large-scale demonstration projects in 2010–2012 with funding from a consortium led by the Carbon Trust.

The new wind turbine designs

The NOVA is perhaps the most dramatic new turbine design. It is a giant 120-metre tall 10 MW, V-shaped vertical-axis turbine, funded as part of the Energy Technology Institute’s £20 m wind support programme. The NOVA consortium includes groups from Cranfield, Sheffield and Strathclyde Universities. Prof. Frergal Brennan from Cranfield told Cleantech (Vol. 4 Issue 4) that ‘offshore vertical-axis wind turbines offer the potential for a break through in offshore wind energy availability and reduced life cycle costs due to their design characteristics of few moving parts and the sitting of the generator at the base level potentially allowing large-scale direct drive. Their relatively low centre of gravity and overturning movements make the turbines highly suitable for offshore installation’.

Meanwhile, VertAx Wind Ltd is working with SeRoc, Giffords and others on their own 10 MW H-shaped vertical axis offshore turbine. VertAx say it will be ready for operation in about 5 years. But Clipper wind’s more conventional propeller type 10MW Britannia should be ready by 2011.

Perhaps the most novel design is the ETI-supported Blue H ‘Deepwater’ turbine project, which is focused on the design and feasibility of a 5 MW floating offshore wind turbine, for use in up to 300m of water. A steel prototype is being tested in the Mediterranean, but the ETI funded project will focus on concrete construction to cut costs. The development consortium is led by Blue H Technologies of the Netherlands with BAE Systems, the Centre for Environment, Fisheries and Aquaculture, EDF Energy, Romax and SLP Energy.

According to a study by the Carbon Trust, the UK will need to build at least 29 GW of offshore wind by 2020. The UK Energy Research Centre says that ‘Whilst this represents a challenge similar in scale to developing North Sea oil and gas, it is seen as technically feasible’. But UKERC is currently looking at the economic prospects. It notes that ‘during 2000 to 2004, offshore wind power costs were relatively stable with typical CapEx ranging from c. £1 m to £1.5 m/MW. But, in the last 5 years costs have risen dramatically, doubling from approx £1.6 m to £3.2 m/MW. The main drivers for this are supply chain constraints for components (e.g. wind turbine generators) and services (e.g. installation), and to a lesser extent, fluctuations in the Euro/Sterling exchange rates and commodity prices’.

Looking forward, it says recent estimates of the short to medium term cost outlook are that, in the absence of extreme movements in macro economic conditions and/or the onshore wind power market, offshore wind CapEx is not expected to alter dramatically over the next five years. In fact, it says, the industry consensus is for a slight rise in the next two years, followed by a slight fall out to 2014/2015.
See: www.ukerc.ac.uk/support/tiki-index.php?page=Offshore+Wind+Costs.

The UK is of course not alone in developing offshore wind. In addition to projects in Denmark, the Netherlands, Norway, Sweden, Belgium, France, Germany, and elsewhere in Europe, in 2009 China installed its first 3-MW 90 metre diameter ‘Sinovel’ offshore wind turbine, the first unit of a 100 MW Shanghai Donghai Bridge demonstration project. In parallel there are said to be some 37 offshore wind projects under development in the USA.

Although costs are higher offshore, load factors are also higher, and, potential impacts on sea mammals aside, there are fewer environmental impact issues to contend with than with on-land location. Moreover, as wind projects are sited further and further out to sea, there will be fewer conflicts with in-shore/coastal fishing and navigation interests. With the North Sea possibly able to offer 200 GW or more of generation capacity ultimately, and large resources also existing elsewhere in the world, offshore wind seems to have a bright future.

For a roundup see: http://www.renewableenergyworld.com/rea/news/article/2009/12/optimism-in-offshore-wind-a-market-buzzing-with-activity?cmpid=WNL-Friday-December11-2009

Posted by Dave Elliott on January 2, 2010 8:59 PM | Permalink