Although the wind farm’s 58 Siemens SWT-3.0-101 turbines have a combined capacity of 174MW, only 169MW is exported to the grid, co-owners SSE said.
The next largest operational Irish wind farm, is the 100MW Knockacummer site in the south west of the country, according to Windpower Intelligence, the research and data division of Windpower Monthly.
Utility SSE developed the Galway site alongside Irish forestry firm Coillte with a joint investment of more than €280 million, of which €20 million was spent on local suppliers and contractors, the two companies stated.
The power generated by the two-phase project south west of Oughterard will be provided to SSE’s retail arm, SSE Airtricity.
Galway Wind Park, Ireland's largest wind farm, by the numbers! pic.twitter.com/cTDgTVz8VG— SSE Ireland (@SSEIreland) 23 October 2017
The commissioning brings SSE’s operational portfolio in Ireland up to 28 sites with a combined capacity of 768MW, it said.
Stephen Wheeler, managing director, SSE Ireland, said: "The development of Galway Wind Park demonstrates how two industry leaders can join forces to deliver the country’s largest onshore wind farm.
"We’re extremely proud at SSE that Galway Wind Park will make the biggest single contribution of any renewable energy site towards greening our national energy supply and decarbonising power generation across the island."
Galway is one of four wind farms that Coillte, alongside its partners, has invested €400 million in over the last 18 months. This includes €160 million invested in the 36.5MW Raheenleagh and 58MW Sliabh Bawn projects.
The forestry firm last week announced it was exploring a range of partnership and joint venture models to help it develop more than 1GW of wind farms in Ireland.
Coillte chief executive Fergal Leamy said: "As the largest wind farm in Ireland it supports our commitment to mitigation of climate change and Coillte’s stated ambition to develop over 1GW of renewable energy to power a million houses annually."