Floating wind 'to hit $145/MWh'

Floating turbines could drive down the cost of offshore wind power to below £85/MWh ($145/MWh) by the mid-2020s, according to new calculations by US tension-leg platform (TLP) designer Glosten.

A new engineering design study, carried out for the UK's Energy Technologies Institute (ETI), suggests the company's PelaStar TLP – a five-armed-hull concept moored by synthetic fibre tendons in water depths of between 55-1,200 metres – could deliver "further reductions as the technology matures".

"We completed a substantial amount of engineering, design and model testing, as well as project execution planning and installation engineering, and are pleased to find the results have validated our earlier work," says Glosten project manager William Hurley.

The PelaStar, optimised to operate in wind speeds of 10 metres per second, is cued up to be fitted with a 6MW Alstom Haliade 150 turbine for trials at the deep-water Wave Hub demonstrator facility off Cornwall, in southwest England.

"[The study] shows a highly promising opportunistic path for the industry to achieve, and exceed, cost targets for the end of the decade and beyond to make it a commercially attractive option," adds Hurley. "We are ready for a full-scale 6MW demonstration project."

The WaveHub demonstrator could be online as early as 2016, but ETI offshore renewable programme manager Andrew Scott cautions more development work is needed before final sign-off.

“We see WaveHub as the best demonstration site for this type of technology in the UK – given its environment and capability," Scott tells Recharge.

"There is a lot of development work required to enter a demonstration project of this detail, as well as ensuring the business case is robust. Until that has completed, nothing is agreed.”

Estimates suggest that the UK's offshore wind resource – which represents over a third of Europe's total potential – could power Britain's nearly three times over.

"This project has already validated our earlier research into offshore wind, which showed that that access to high wind areas which are reasonably close to shore will result in very competitive energy costs," says Scott.

"By 2030, offshore wind could be delivering energy at costs similar to the lowest cost forms of low-carbon generation."

The UK Department of Energy and Climate Change's current 2020 target for offshore wind is a levelised cost of energy of £100/MWh. Turbines currently installed off Britain are producing at around £130/MWh