Patent ID: 8500408

Claim:
A wind turbine blade comprising: an external aerodynamic surface having a longitudinally-extending spanwise axis, a chordwise axis transverse to the spanwise axis, and a thickness axis transverse to both the chordwise and spanwise axes; and a plurality of longitudinally-extending spars, wherein at least one of the spars includes: a longitudinally extending first spar portion having a plurality of laminated first layers, wherein individual first layers terminate at different longitudinal locations to form a first end portion having a plurality of first projections and first recesses, with individual first projections alternating with individual first recesses along the thickness axis, and wherein at least two of the first recesses have different depths; a longitudinally extending second spar portion having a plurality of laminated second layers, wherein individual second layers terminate at different longitudinal locations to form a plurality of second projections and second recesses, with individual second projections alternating with individual second recesses along the thickness axis, and wherein at least two of the second recesses have different depths; and wherein individual second projections are received in corresponding first recesses, and individual first projections are received in corresponding second recesses, to join the first spar portion to the second spar portion.