The programme was launched in March 2012. It pays EUR 0.7/kKWh for projects that are operational by 31 December 2015. But the Irish energy department has relaxed the definition of operational so that developers will be eligible for support as long as 75% of a wind farm is operational within nine months of 31 December 2017.
Rabitte was speaking at the Irish Wind Energy Association (IWEA) annual conference.
The extension removes risk for developers that are not able to connect to the grid in time to meet the original deadline. The change allows them to delay projects slightly if there are constraints in the grid system.
Rabitte emphasised the economic opportunities for Ireland to export wind energy to the UK, where meeting renewable energy targets will be "challenging".
"Ireland's overarching objective is not just to make renewable energy an increasingly significant component of our domestic electricity supply by 2020, but to make it a significant component of our export sector," he said.
The department is also seeking an extension to the earlier support scheme, Refit 1. This is awaiting state aid approval from the European Commission and a decision is expected soon, Rabitte said.