Floating offshore wind has the potential to deliver cost effective, secure and safe low carbon energy for the UK from the mid 2020s
The report highlights the offshore wind resource available around the UK in water depths of between 50 to 100 metres, and the need to utilise these resources closer to shore and closer to where the electricity is required, in turn providing secure and cost competitive renewable energy.
The Articulated Wind Column (AWC) is a deep water wind foundation designed specifically to do just that, and here at MEES, over the last several years, we have been specifically focussing on developing the AWC foundation for this purpose, successfully creating a foundation that provides both a technical and economical solution.
Accessing Deeper Water
The UK has many high-energy offshore wind sites within 70 to 100km of the shoreline, but which sit at water depths in the range of 50-100m, beyond the depth at which existing foundation technologies are commercially viable. Cost competitive foundation technology suitable for these deeper waters would enable the UK to make the most of the favourable (but currently unexploitable) wind energy resources around our coastline.
To deliver an improving and competitive LCoE, Offshore Wind needs
1. Access to good quality wind resource
2. To be close enough to shore and power users so that transmission costs (capital and losses) to users are minimised and operations and maintenance costs reduced
3. Reduced capital costs by ongoing innovation and improvements
To achieve this the UK needs a range of foundation types to cover water depths up to 100m. The UK’s position on the continental shelf means that, apart from a few spots, there is very little water deeper than 100m sufficiently close to shore for offshore wind exploitation. Fixed foundations (which will include gravity base and jackets as well as monopiles) will be the prime solution in water depths less than 30m, with floating foundations providing the lowest cost solution in water depths over ~50m. Between 30m and 50m a mix of floating and fixed bottom solutions is likely, depending on site conditions. With a range of technologies covering both fixed bottom and floating foundations, the UK will be well equipped to harvest offshore wind with the best LCoE potential.
If the UK is to capitalise on its offshore wind resource then it will be important to open up more of the marine estate for potential offshore wind farms. Constraints from other stakeholders, as well as site conditions, are likely to limit the shallower water sites that are suitable for fixed foundations. Offshore wind turbines are increasing in size, with turbines in excess of 10MW (and blade diameters over 200m) being developed for deployment in the 2020s. Floating technology offers a credible path to economically exploit these larger turbines, as well as a 3-7% reduction in the LCoE for smaller turbines. Floating foundations are still some way from large scale deployment. Given the decision making horizons associated with new wind farms, technology that is demonstrated by 2020 has the potential to be deployed at farm scale no earlier than 2025. The offshore wind industry is currently focused on delivering the ‘Round 3’ sites. These will be delivered without floating technology. At this stage there is little, if any, market pull for floating solutions and technology push will be needed until deeper water sites are provided; possibly in later Crown Estate licensing rounds. Policy needs to encourage the development of floating technology suitable for UK waters if it is to be available from the mid 2020s.