Ok, doing a project at the moment and this is one of the issues I have to overcome; The information I have researched is as follows: If this is the case then a 88m diameter rotor should generate 2400kW? But the below diagram from the same page shows a 80m diameter rotor generates 2500kW! http://www.windpower.org/res/rotorsk.gif [Broken] When I put this data into a graph I end up with a curve rather than a straight uniformed line? http://img221.imageshack.us/img221/1328/powergraphmi7.jpg [Broken] Can anyone help me understand what I am doing wrong and guide me through what I am meant to be doing? I'm not doing physics or maths I am doing Arch & Construction Management. Many thanks!