The site is located at St Asaph business park, north Wales. Balfour Beatty will be responsible for constructing the associated buildings and the installation of low-voltage equipment and cables. It will also assist with the installation of the high voltage machinery.
Construction is due begin this month, with completion expected in summer 2016.
The 256MW Burbo Bank extension project in the Irish Sea was approved by the UK government in September. It is the first commercial project to use the MHI-Vestas V164 8MW turbine.
Last month, Dong contracted VolkerInfra to install the onshore cables for the project connecting the point where its export cable reaches land near Rhyl, north Wales, to the new onshore substation.