Mentor Mon Ltd are progressing the Morlais demonstration zone off the coast of North Wales. The project aims to provide future developers with an offshore platform from which to utilise tidal energy generation capacity. The zone consists of a seabed area of 35 sq km to the west of Holy Island and will have a generating capacity of up to 240MW, making it one of the largest tidal stream energy sites in the world.
Our client, Stockton Drilling Ltd, were appointed by Mentor Mor to undertake the installation of five 600 metre-long, 450mm diameter horizontal directional drills (HDD) with associated HDPE ducts to provide the conduits for the future export cable landfalls. Each HDD will have an onshore entry point and extend out to sea, passing below 30-metre-high costal cliffs and the intertidal zone to an exit point located offshore.
Our geotechnical team in Scotland carried out the design of the bores, seeing us undertake a range of surveys and investigations. The scenic site is exposed to the full force of the Irish Sea, constraining the potential to undertake offshore intrusive geotechnical investigations. In order to provide information on ground conditions along the length of the drills, a trial HDD pilot bore was completed and aerial supplemented topographical survey data was captured using a LiDAR-equipped drone. We also took to the sea to carry out a series of seismic surveys, seeing our experts gather bathymetrical and sediment data.
North Wales minister Lesley Griffiths said in a recent statement: “Anglesey and north Wales as a whole are very well placed to play a key role in innovative low carbon energy generation which benefits local communities. Not only will the project be a boost to future low carbon energy production but will also generate jobs and skills in the area.”
Chris Gell, Waterman’s Technical Director in our Perth office and National Service Lead for Geotechnics, commented: “This appointment builds on an extensive portfolio of previous appointments with Stockton Drilling, including large cable landfalls for SSE in Scotland and Ireland. On this project, our team worked tirelessly to design the five profiles, maximising the use of 3D ground modelling using AutoCAD Civil 3D. This allowed us to fit the bore profiles within a very constrained corridor and all under a tight programme imposed by the need to complete the trial HDD Pilot Hole prior to the start of the protected chough bird breeding season. It is great to see the project now coming to fruition with the successful completion of the trial drill.”
The scheme is anticipated to complete in the summer of 2023.