Scottish floating wind projects could be brought to market at a cost of £85 per megawatt hour (MWh, €94.24/MWh or US$105.68) by 2027, according to analysis by the DeepWind supply chain cluster
But analysis by advisory firm Aegir Insights suggests the first commercial floating wind projects in Scottish waters could actually be delivered at a very much lower cost – a stunningly low £60/MWh (€66.48/US$74.6), in the same timeframe – thanks to the use of attractive sites, upscaling benefits and technology maturation. “Industrialisation will be the differentiator,” said Aegir Insights.
Speaking during a 25 June 2020 virtual conference, ‘How is Scotland preparing for the large-scale development of floating wind projects?’ organised by Scottish Enterprise, DeepWind cluster manager at Highlands and Island Enterprise Paul O’Brien said, compared to the first pre-commercial floating wind projects in Scotland – which have a levelised cost of energy (LCOE) of £200/MWh – commercial-scale projects could be brought on line at £85/MHh by 2027.
DeepWind’s analysis also suggests Scottish floating wind could be cost-competitive with bottom-fixed offshore wind projects in Scottish waters by 2031.
Mr O’Brien highlighted that the recently launched ScotWind leasing round includes five sites at which the water depth was such that floating wind was the only suitable solution. He also identified significant developer interest in those sites, and that proposed changes to the UK’s contracts for difference (CfD) regime would support floating wind, removing it from direct competition with bottom-fixed projects.
Mr O’Brien said DeepWind had also identified cost reduction drivers between pre-commercial projects and commercial-scale projects that would help to drive down the cost of Scottish floating wind. These primarily take the form of cost reduction in substructure design and construction and in the cost of installing floating projects, including mooring systems.
Aegir Insights’ analysis indicates that an even more dramatic cost reduction path could be possible. The big question, it said, is how far floating cost levels can come down with increasing project scale, better sites, and technology maturity.
Aegir Insights founder and managing director Scott Urquhart, who started work in the offshore wind sector in 2011 with Ørsted, told OWJ that the scale of potential commercial floating wind projects in Scottish waters – which Mr O’Brien put at up to 500 MW – and the larger scale of upcoming projects in Norway such as Hywind Tampen, would enable the industry to reduce costs significantly.
“We also need to bear in mind that 75% of the kit for bottom-fixed and floating wind projects is essentially the same,” said Mr Urquhart, noting that bottom-fixed projects in Scottish waters in the same timeframe would likely come in the mid-£40/MWh range.
“Scale will be a big part of the cost reduction that can be achieved,” Mr Urquhart said. “By the time large-scale floating wind projects are being built, very much more cost-effective ways to fabricate and install floating wind will have been found.”
He compared the approach used in Norway to build the Hywind Scotland substructures – with three different facilities involved and structures having to be towed between sites – with what he said would be a much more efficient, leaner process for large-scale floating wind projects in Scotland in the mid-2020s.
Aegir Insights looked at the cost out potential for an early commercial scale floating project in four steps. The first was a demonstration technology baseline in which a floater project cost model was made for the Hywind concept, which is calibrated to public announcements on Hywind project and contracts. Technology was assessed for both Hywind Scotland (2017 delivery) and Hywind Tampen (2022 delivery), both based on 8-MW wind turbines.
The second step analysed site conditions. A competitive ScotWind reference site was selected, having an average water depth of ~80 m and mean wind speed of 10.2 m/s at 100 m.
The third step was permitting and assessment. The ScotWind leases will have construction completion in 2027 at the earliest – the same timeframe used by the DeepWind cluster in its analysis – driven by permit lead time to qualify for CfD auction participation.
On the fourth step, technology maturity and scale, Aegir Insights said its scale effects were derived from an assumption of a 500-MW commercial project size, plus balance of plant savings from the use of much larger, 15 MW+ turbines than those used in Hywind.
Further cost-out was assumed towards 2027 for Hywind and other floating foundation concepts, including tonnage savings, assembly industrialisation, mooring design, and installation durations.
“The main cost differentiation between floating concepts will be ability to do industrialised assembly on a first commercial project, considering the immature supply chain and potentially large quayside areas needed,” Aegir Insights concluded.
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