First Minister Alex Salmond, left, favours growth of wind power. Getty Images

The Treasury does not agree with the level of subsidies being offered but has been forced partially to back down because of the political imperative of keeping the coalition together. The secretary of state Ed Davey, a Liberal Democrat, believes in setting medium-term targets on emissions but has been forced to back down and to accept a time-limited policy, which will be reviewed again after the next election. The result is that no one believes the policy being published this week is the right answer, or that it will endure beyond 2015. Read more