Geological Considerations for Offshore Windfarm Development A.Wheeler 1, M. McGrath 1, M. Coughlan 1,3, B. Dorschel 1,2 1 ERI & School of Biological Earth & Environmental Sciences 2 Alfred Wegener, Institute, Bremenhaven, Germany 3 Department 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

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

ISSITEG

Defining signatures for benthic currents > 2m s -1 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 Core 1Core 2Core 3

Site 1Site 2Site 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