Energy firm Energia has created 200 new jobs as part of a €3bn investment in renewable energy.
The investment programme will also create some 3,000 to 5,000 construction jobs.
The announcement comes as it opened its new headquarters at Blanchardstown in Dublin.
The 200 jobs will be filled over the next five years at the company's new Dublin offices.
Energia Group currently employs 800 people across the island of Ireland.
The investment will be implemented across a range of major renewable energy projects including onshore and offshore wind farms, solar power, hydrogen fuel generation, bio-energy facilities and the smart grid.
Energia said the investment is in line with the government commitment to increase the amount of electricity generated from renewable sources from 30% to 70% by 2030.
Taoiseach Leo Varadkar said reducing greenhouse gas emissions means making “big changes” at government, business, community and individual level.
He added: “I commend Energia Group for announcing this investment in a range of renewable energy projects, from wind farms to bio-energy, which will help us to reduce greenhouse gas emissions, give us cleaner air and reduce the need for expensive fossil fuel imports.”
Richard Bruton, Minister for Communications, Climate Action and the Environment, said: “Decarbonising our electricity supply is crucial to all the changes we are making as we make the transition away from fossil fuels.
“The move to electric vehicles, for example, will only be effective if the electricity being used has been generated from renewable sources.”
Energia Group CEO Ian Thom said: “This is a proud day for Energia Group and an important milestone as we celebrate 20 years serving in the deregulated energy markets across the island of Ireland.
“To date we have invested over €1bn in the Irish energy market, driving developments to meet the needs of a high performance economy and society, north and south.
“Our decision to invest in renewable technology and energy infrastructure in the coming years is a clear signal of our intent to build on our continuous commitment to Irish communities, the economy and the sustainability of Ireland’s energy supply while contributing decisively to decarbonisation and the protection of our domestic and global environment.”
Established in 1999, Energia Group has offices in Dublin, Galway, Cork and Belfast.