Offshore Windfarm Construction

In recent years the Port has developed its infrastructure to provide a base for offshore windfarm construction and offshore windfarm support services in the Irish Sea. The portfolio of the offshore wind farms constructed from Mostyn includes seven projects.

North Hoyle 2003/2004 30 turbines 10nm from Mostyn
Burbo Bank 2005 25 turbines 16nm from Mostyn
Robin Rigg 2006/2007 60 turbines 97nm from Mostyn
Rhyl Flats 2008/2009 25 turbines 20nm from Mostyn
Walney 1 2010 61 turbines 56nm from Mostyn
Walney 2 2011 61 turbines 56nm from Mostyn
Gwynt-y-Mor 2013-2014 160 turbines 20nm from Mostyn

The 160-turbine Gwynt-y-Mor project currently under construction will be one of the world’s largest offshore windfarms to date (576MW).  Installation of turbines has commenced in May 2013 and is expectd to be completed in the late summer of 2014.  Servicing of this windfarm, together with the North Hoyle and Rhyl Flats windfarms will then be undertaken from a new purpose-built O & M Base presently being built at Mostyn by RWE Npower.

More info: News

The most common wind turbine installation process which has been used at Mostyn to date involves:

  • Unloading components (towers, hubs, blades and nacelles) from Lo-Lo and Ro-Ro vessels;
  • Laying down of large components in preparation for offshore construction works;
  • Pre-assembly of the nacelles and towers ready for transportation by jack-up barge to the wind farm site.

This video shows how the construction of Walney 1 offshore windfarm was carried out from Mostyn in 2010.  

Wind turbines being shipped to the offshore windfarm construction site.To facilitate construction and O & M operations the Port has extensive (75 acres) lay-down and storage land adjacent to 310m of riverside quays with a design depth alongside of minus 9m Chart Datum. Additionally, a 180m length Ro Ro Berth with a 225 tonnes capacity Linkspan is also available. During Rounds 1 and 2 projects, cranes with lifting capacities up to 1,300 tonnes were used to discharge and reload very heavy turbine components, including foundation monopoles.  Also available is warehousing and workshop facilities for the storage of sensitive turbine parts together with final fitting of electrical and hydraulic components.

More info: Facilities & Cargo

Large jack-up vessels have an important role in offshore windfarm construction.The berths and seabed conditions at the Port have proven to be well suited for the safe berthing and loading of large jack-up vessels. Since 2004 numerous vessels of this type including ‘Excalibur’,  ‘Jumping Jack’,  ‘Lisa A‘, ‘Resolution’, ‘Goliath’,  ‘Kraken’, ‘Vagant’,  and ‘Sea Worker’ have all successfully used the Port during various windfarm construction projects.

 In addition to the 310m riverside quays, a Ro Ro berth of 180m length together with a Linkspan  of 225 tonnes capacity is available for the discharge of turbine components from Ro Ro vessels.  During recent projects, the use of this type of vessel has proven to be highly efficient and economical with the average time to discharge a vessel carrying three complete turbines being between 9 and 11 hours.

Wind turbine components being loaded ready to be taken out to the windfarm construction siteThe main benefits from Ro Ro vessels are that discharge operations are not as susceptible to wind restrictions as are Lo Lo ships.  Also, the use of an independent Ro Ro berth for discharge operations avoids operational conflict as it allows for the main construction berths to be dedicated for use by the more costly installation vessels. 

Clients we have worked with on various offshore renewable energy projects include RWE Npower, EON Renewables, Dong Energy, Siemens Wind Power A/S, Van Oord Offshore, MT Hojgaard A/S and Vestas Wind Technology.