Covering an area of about 80km², the £2bn wind farm features 160 Siemens-built turbines that will help generate low-carbon energy to power about 400,000 residential households per year.
UK Energy and Climate Change secretary Amber Rudd said: "This offshore wind project will generate enough clean electricity to power hundreds of thousands of homes and will support 100 long term, skilled engineering jobs, giving more people the financial security of a regular pay packet.
"Gwynt y Môr has a key role to play in our long-term plan to develop a secure energy mix in this country that is diverse and home grown."
Siemens, which is responsible for 12-year service and warranty contract, has also developed sub-stations for the project.
Claimed to be the world’s second largest offshore wind power plant, the Gwynt y Môr will be 60% owned by RWE Innogy while Stadtwerke München and Siemens own 30% and 10% interests respectively.
RWE Innogy CEO Hans Bünting said: "We currently expect to invest over €1bn up to 2017 in growing renewables, with wind power at the forefront of that investment.
"At the end of this year 40% of our power generation from renewables will already come from offshore power production.
"Due to this increase in offshore capacity our operating result will see double-digit growth."
