The 23.5% figure in the Wikipedia article comes from the same REF 'report'. Note that anti-wind spin by the REF propagandists came up on ET before (see here, here and here); and a 'report' by another anti-wind belief tank based on basically the same data for the UK also came up (see here).

Utility firm reports alarming drop in renewable power output > National News > News | Click Green

It said this finding is consistent with data from Ireland and Northern Ireland which showed output in 2010 was approximately 23.5%, as compared to 31% in the previous year, and the average figure of 32.3% for the years 2002 to 2009.

I haven't been able to double-check the 23.5% figure itself yet, but it is suspect: say, if they divided annual generation with year-end capacity, that would be a big underestimate due to the significant capacity added last year.

_{*Lunatic*, n.
One whose delusions are out of fashion.}