The foundations research area focuses on cost reduction for wind turbine substructures, from fabrication through to decommissioning. Foundations account for approximately 16% of the CAPEX of an offshore wind farm and therefore are a key target for cost reduction within offshore wind. The work to date in the Offshore Wind Accelerator (OWA) has included the launching of a foundations innovation competition which has resulted in several of these winning designs being installed offshore.
More recently, studies have focused on a more detailed approach to research looking at optimising different processes in foundation installation as well as trials to refine design methodologies and investigate new ways of installing foundations.
A number of the projects in the foundations research area are large demonstration projects that have been part of the OWA’s demonstration projects. Projects to date have examined new design methods for monopiles (PISA), and improvements to jacket manufacturing (JaCo).
Suction Installed Caisson Foundations for Offshore Wind: Design Guidelines
The Carbon Trust has published in 2019 the Suction Installed Caisson Foundation Design Guidelines, to provide clarity and guidance to the industry on the design of suction caissons foundations for offshore wind. The document brings together the latest understanding and research to provide an overview of the critical factors to consider for these foundations and to give practical support to engineers in order to manage the design process efficiently and cost-effectively.
Foundations innovation competition
In 2011 the OWA launched the foundations innovation competition to help support innovative foundation designs. The four winners (from 104 entries) of this competition were:
- GBF - float-and-sink gravity base structure
- Keystone Engineering - inward guided batter structure (IGBS) jacket foundation installed with a met mast in the Hornsea Round 3 Zone (press release)
- SPT Offshore - suction bucket jacket foundation used as the foundation for a single turbine demonstration as part of the Bokrum Riffgrund offshore wind farm project
- Universal Foundation - suction bucket foundation installed with two met masts in the Dogger Bank Round 3 Zone (press release)
Underwater Inspection Methods
The Foundations research area has also widened its focus to look at operational issues such as the inspection of existing structures. An OWA study looked at Underwater Inspection Methods; the challenges faced in the industry so far, especially those that are new and unique to offshore wind. As a result of this study, it was identified that there were a number of technology gaps and therefore the OWA launched a competition in July 2017 to identify new technologies that could inspect specific defects in steel substructures.