Support Structures for Offshore Wind Turbines
Article published on Wednesday, 05 June 2013
Offshore support structures and foundations for offshore
wind turbines are proposed and delivered using a range of solutions. The
advantages and disadvantages of each design concept are difficult to assess
in a comparative and fair way. The support structure designer has to consider
a host of issues in order to provide an appropriate solution. These factors
are led by both the project and the external environment and include but
not limited to:
• Depth of the water column • Mass needing support •
Turning and bending forces on the structure • Location specific issues
such as wind, wave, tidal and current considerations • Seabed geology
and soils • Scour and sediment movement • Environmental impact • Construction
requirements • Installation requirements • CAPEX • OPEX • Decommissioning
In the sections on support structures and foundations,
the following definitions have been used:
Support structure: This comprises of the foundation
and its method of fixing to the seabed.
Foundation: The foundation of a support structure
for a wind turbine is the structural and/or geotechnical component, from
the transition piece or tower down to the seabed.
Tower: The tower is a structural component, which
forms part of the support structure for a wind turbine, usually extending
from just above the water level to the nacelle of the wind turbine and
is often, but not always, joined to the foundation by a transition piece.
The support structures for large offshore wind farm developments
fall into two main categories; floating and grounded designs. Both types
can be further differentiated by their layout, method of installation,
structural configuration, and the selection of their construction materials.
According to the structural configuration, the support
structures can be sub-categorised into six basic types:
• Monopile Structures • Tripod Structures • Lattice
Structures • Gravity Structures • Tripile Foundation • Floating Structures
For this, support structure designs may be utilised combining
the features of the categorised structures.
Offshore Wind Turbines sub-structures - kindly provided