Patent ID: 8915714

Claim:
A partial pitch wind turbine blade of at least 35 meters length, the blade comprising: an inner blade section; an outer blade section coupled to said inner blade section at a pitch junction, said outer blade section operable to pitch relative to said inner blade section, wherein said inner blade section comprises a first blade profile for a stall-controlled aerodynamic blade with a first aerodynamic profile having a first maximum lift coefficient (CLmax1) and a first cord (Ch1) at the end facing said pitch junction and wherein said outer blade section comprises a second blade profile for a pitch-controlled aerodynamic blade with a second aerodynamic profile having a second maximum lift coefficient (CLmax2) and a second cord (Ch2) at the end facing said pitch junction, and wherein said blade comprises a discontinuity between said first and second blade profiles between said pitch junction, which discontinuity is such that [(CLmax1)×(Ch1)] is at least 20% greater than [(CLmax2)×(Ch2)].