The last two steel monopiles left Birkenhead, north England on 9 August for installation at the 160 offshore wind turbine site, located eight miles off the north Wales coast.
RWE npower renewables’ Gwynt y Môr project director, Toby Edmonds, said: "All 160 wind turbines require a bespoke foundation. Each one has been fabricated to fit the seabed conditions and water depth at every location.
"While foundation installation activity will continue into next year, offshore piling is likely to become much less frequent. The majority of the foundation works associated with the fitting of transition pieces do not require piling."
In recent weeks the longest monopile, measuring 64 metres and the heaviest at 708 tonnes, have been installed.
50 wind turbines are in place and all four export cables laid between the beach at Pensarn, near Abergele and the two offshore substations.
Gwynt y Môr will use Siemens 3.6MW turbines and generators and be capable of generating energy for 400,000 homes – around a third of homes in Wales.
Gwynt y Môr is a €2billion offshore wind farm jointly financed by RWE Innogy; Stadtwerke München GmbH, Munich’s municipal utilities company; and Siemens.