[holding answer 17 September 2007]: Advice from National Grid, the GB System Operator, is that the percentage of total electrical energy that can be produced by wind generation is likely to be limited by economic rather than technical considerations and that any limit will lie beyond the Government’s current renewable targets or aspirations. This view is supported by evidence from abroad, with a number of countries having achieved, in percentage terms, the wind generation output that the UK currently aspires to.