Up to 350 jobs will be created during the construction of a new biomass power station in Killala, Co Mayo.
Mayo Renewable Power is investing €180m in the plant on the site of the former Japanese chemical company, Asahi.
Some 30 full time jobs will be created once the plant is completed.
Mayo Renewable Power, with equity from US investment firm Weichert Enterprise, is to construct the 24 megawatt biomass plant.
The project is being financed by Ulster Bank, AIB and Barclays and is expected to be up and running by 2017.
When completed, it will be the largest biomass power station in the country.
The Taoiseach Enda Kenny has turned the sod at the site and speaking to Midwest Radio, he appealed to farmers to get involved in the project.