Efficient wind turbine blades, wind turbine blade structures, and associated systems and methods of manufacture, assembly and use

A wind turbine blade, comprising:

• an external aerodynamic surface having a longitudinally-extending spanwise axis, a chordwise axis extending transverse to the spanwise axis, and a thickness axis extending transverse to both the chordwise and spanwise axes;
• and
• a plurality of longitudinally-extending spars providing internal support for the aerodynamic surface, wherein at least one of the spars has inner and outer surfaces that are generally flat and wherein the local external aerodynamic surface is curved, further wherein the at least one spar includes a laminate of precured composite material, the laminate of precured composite material including:
• a plurality of precured, pultruded composite layers, wherein each of the pultruded composite layers overlaps with the others in the at least one spar at at least one longitudinal location, and wherein individual precured, pultruded composite layers have a chordwise extent and a thickness extent less than the chordwise extent;
• and
• a plurality of adhesive layers interposed between adjacent precured, pultruded composite layers.