Carbon Trust Calls for Onshore Assembly of Offshore Wind Turbines Study (UK)

 The Carbon Trust is currently working on a major new Technology Accelerator initiative focused on reducing the cost of energy (£/MWh) from offshore wind by more than 10 %.

The Offshore Wind Accelerator (OWA) is funding large-scale research, development and demonstration (RD&D) projects to unlock technological barriers to advance the industry, and thereby accelerate its development so that significant carbon emissions reductions are achieved. Projects have been selected based on their potential impact on the cost of offshore wind farms and on their ability to deliver operational improvements in the short to medium term. This initiative has been structured as a funding collaboration between the Carbon Trust and a number of international energy companies active in offshore wind farm development.

The OWA Foundations Technical Working Group has identified the potential for onshore wind turbine assembly to deliver significant cost benefit to the design of future offshore wind farms. State of the art installation of wind turbines offshore is to install the foundations in one campaign before towers; nacelles and blades are installed in a second campaign. In the meantime export cables and infield cables are installed and pulled into the foundations to facilitate early hook-up and energizing once the turbines are in place.

Presently, state-of-the-art installation of offshore wind turbines requires an initial pre-installation of the foundations followed by a second installation of the towers, nacelles and blades. In the meantime, export cable sand infield cables are installed and pulled into the foundations to facilitate early hook-up and energizing once the turbines are in place.

There are concepts studied today where the wind turbine components (tower, nacelle, blades) are assembled onshore into complete units. Installation is then performed by either.

— single-lift installation: assembling the wind turbine components onshore and lifting the complete wind turbine onto its pre-installed foundation, or,

— integrated installation: assembling the wind turbine components and foundation onshore and then transporting and installing the unit as an integrated system (e.g., SPT Offshore or GBF).

The scale and distance offshore of many Round 3 projects indicates that the most economically and technically feasible solution for installation may be onshore assembly of offshore wind turbines.

The objectives of this study are to:

— assess the costs, benefits and risks of assembling wind turbine components onshore and transporting pre-assembled structures offshore; assessment should compare self-lift and integrated installation to traditional installation,

— identify risk mitigation measures which may be achievable for Round 3 (e.g., discussions with turbine manufacturers regarding allowable nacelle accelerations, insurers, etc.),

— understand implications of early and interrupted energizing,

— suggest ways to address commercial issues, guarantees and responsibility.

The contractor will provide architectural services, engineering services and integrated engineering services, urban planning and landscape engineering services, related scientific and technical consulting services, technical testing and analysis services.

[mappress]

Offshore WIND staff, December 22, 2011