Davey was joined by Siemens executives, local MPs and councillors and other industry figures as construction officially started at the site.
The construction of buildings for the blade manufacturing and wind turbine assembly facilities is due to begin this summer. Production of blades for its SWT-6.0-154 turbine is set to begin by the end of 2016.
Davey said, "It marks the beginning of a new industry based here and exporting worldwide."
Siemens expects to employ 1,000 people at the site, which will have the capacity to produce 600 blades a year for the UK and European offshore markets.
The first project that will use the facilities will be Statoil and Statkraft's 402MW Dudgeon, off the Norfolk coast, it was announced at the ceremony. Siemens will use the factory and quayside for part of the installation of the 6MW turbines.