The Floating Offshore Wind Market and Technology Review gathered data from 18 floating design concepts being developed. It found potential to bring down the levelised cost of energy to £85-£95/MWh, at a capital expenditure of £2.4 million/MW. Current capex of prototypes is £5.2 million/MW. Semi-submersible platforms, with simple installations, can achieve the lowest potential cost, slightly less than spar-buoy and tension-leg platform designs.
The biggest cost savings through technological development is expected to come from the platform (16%), the turbine (12%) and balance of plant (9%). But the critical areas for technological development are in reducing the size and weight of the platform, followed by improving installation procedures and portside operations and maintenance, the report found.
The Scottish government commissioned the review because developing near-shore floating wind projects may be a cheaper option in the future than far-shore fixed foundations sites for Scotland. The report set out to provide a comprehensive assessment of the technology and to encourage further development.
If the UK is to reach 20-55GW in offshore wind installations by 2050, in a drive to increase renewables in the UK energy mix and cut carbon emissions, it will need to consider sites either deeper than 40 metres or further from shore than 30 kilometres, the report said. Scotland has many deep water nearshore sites well suited for wind energy development. With high winds and the potential to use existing facilities from the oil and gas sector, such as ports and supply chain providers, there are also opportunities for Scotland to take a lead in commercialising floating foundations, it said.
The report was launched at at RenewableUK’s Global Offshore Wind 2015 event in London this week. Fergus Ewing, the Scottish energy minister, confirmed the Scottish government’s commitment to a successful and sustainable offshore renewables sector: "This report will help as we look to reduce costs of floating wind technology and increase the opportunity for Scotland to take the lead in commercialising this technology."
To date, there is one Scottish commercial offshore wind project, the 180MW Robin Rigg site to the south-west of the country, and a pipeline of 5GW of consented projects, all with fixed foundations.
The report is available for download at http://www.carbontrust.com/media/670664/floating-offshore-wind-market-technology-review.pdf