Geological Considerations for

Offshore Windfarm Development

A. Wheeler1, M. McGrath1, M. Coughlan1,3,

B. Dorschel1,2

1ERI & School of Biological Earth & Environmental Sciences 2Alfred Wegener, Institute, Bremenhaven, Germany

3Department of Marine Engineering Geology, MARUM, University of Bremen, Germany

Ireland’s offshore renewable energy potential

Wind

Mean wind speed at 50 m

Ireland’s offshore renewable energy potential

Wave

Annual average wave height

Ireland’s offshore renewable energy potential

Tidal Energy

Geological controls of renewable energy infrastructure

To build wind farms you need foundation solutions

To build tidal energy farms you need to understand energy regimes and sediment dynamics

Geological controls of renewable energy infrastructure

Understanding sediment dynamics in the Irish Sea – partnership with Gaelectric Developments Ltd

Understanding sediment dynamics in the Irish Sea – partnership with Gaelectric Developments Ltd

Understanding sediment dynamics in the Irish Sea – partnership with Gaelectric Developments Ltd

Recent projects and developments

CeSQuORE - Celtic Sea Sedimentary Processes, Quaternary Stratigraphy & Offshore Renewable Energy Development

ISSITEG - Appraisal of the Irish Sea Seabed Imaging for Tidal Energy Generation

MARUM partnership – North Sea windfarm developments

CeSQuORE

0 10 20 30 40KPa

0

40

80

120

160

200

Dep

th (

cm)

C ore_001

ISSITEG

ISSITEG

Defining signatures for benthic currents > 2m s-1

ISSITEG

ISSITEG

North Sea – MARUM partnership

Area 1

Area 2

Area 1

•East-west valley•Intersecting southern valley•Eastern meander system

Calcareous silty clay

Shell rich organic mud with clay and peat clay

Clays,silts and sands, some stiff

Clays,silts and sands, some stiff

Core 1 Core 2 Core 3

Site 1 Site 2 Site 3

What’s the big idea

To site wind farms we need to understand the sub-seabed constraints

Depth to bedrock and stratigraphies

Hydrodynamics and scour potential

Sub-seabed geotechnical properties

What’s the big idea

To determine sub-seabed properties

Drill and collect physical samples

Do in-situ measures e.g. CPT

What’s the big idea

What is driving the systems that produce these stratigraphies?

Process and palaeoenvironmental succession that determines the physical properties

Sediment physical properties –> geotechnics is easy

-> predict and interpolate geotechnics

We want to put the Geology back in Engineering Geology