This is a must-read:

A suggestion for meeting the UK Government’s renewable energy target because the adopted use of windfarms cannot meet it,

By Richard S. Courtney, Thursday 26th October 2006

Source: The [1] 2006 Annual Prestigious Lecture to
The North of England Institute of Mining and Mechanical Engineers
and
The Institute of Materials, Minerals and Mining (North East)

On 2010 06 18, Richard S. Courtney posted [2] an excellent and easy-to-understand illustration of the uselessness of windfarms to the blog of Anthony Watts, the most popular science blog in the world.  In that posting, Richard Courtney compares the reasons for constructing windfarms to the reasons for construction the Wall of China: Useless, impractical and extremely costly for meeting the ostensible purposes but very, very effective as widely-visible propaganda efforts.