Work has already started on clearing the site at the Alexandra Dock, and the construction of buildings for the blade manufacturing and wind turbine assembly facilities is due to begin in the summer, and production of the first blades is scheduled for winter 2016.
"The development will ... help to drive down the costs of offshore wind. It marks the beginning of a new industry based here and exporting worldwide," Davey said.
Siemens committed to building the £310 million (€405 million) SWT-6.0-154 blade manufacturing plant last March, three years after it was first announced.
The company expects to employ 1,000 people at the site, which will have the capacity to produce 600 blades a year for the UK's offshore market. Siemens said 550 people will work in the manufacturing facilities, while a further 450 will be employed in the logistics and servicing centre.
The first project that will use the facilities will be 402MW Dudgeon, off the Norfolk coast, it was announced at the groundbreaking ceremony. Siemens will use the factory and quayside for part of the installation of the 6MW turbines.
Siemens was the first turbine manufacturer to commit to building a large-scale production facility in the UK to supply the country's offshore sector.
Since then, MHI Vestas has announced plans to lease Vestas' production facilities on the Isle of Wight to produce blades for the V164 8MW turbine.
Other offshore manufacturers, such as Gamesa/Areva and Alstom, are still looking at the market.